Creation date: 28/01/2003
Source of this page: http://yves.maguer.free.fr/WiFi/page_wifi_yves.html
With translation to any language is possible young stag
Year English translation one 22/03/2008
To go directly to synopsis.
I make studies of radio links (mesh possible) or of covers WiFi or WiMax.to Voir my CV.
My rural partner: Numevia
My town partner (hotspots): Coffeespot
Me consulter: (to remove _POURIEL of the email).
If one day, you succeeded in reading all this page (cheer!), capitalize your effort, and read then only them differences!
HTMLDiff (google is my friend, “keygen” also)(I want to pay 1 euro by utility, not more).
My page seems to be censured in China.
it is by here with a proposal of réseau
with a grid.
Description of the problem to be solved, resulting from the true life, I quote:
I live in a small hamlet (place says Mouillecrotte) which depends on the commune of BRESTOT in the Eure.
I also live to 9 km of the DSLAM of which I depend and with 80dB I am not eligible with the ADSL.
I live to 11 km of an antennaWIMAXet I thus made make on site a test of eligibility with the WIMAX (currently deployed in the Eure by Altitude TELECOM for “to cover” white areas of the ADSL)… which is revealed negative (I live in skirt of forest and am not thus not in visu direct with this antenna WIMAX).
In short I live where high banc is not available!
Please help me!
Here “Gruyere of
high banc” ADSL
(for Loiret) and I place in lower part the establishment of WiMax byMedialys
Interesting, not? WiFi, it, go there or people want it.
for the happy holders of licensesWiMaxà
areas: Aquitaine, Alsace,
Bourgogne, Brittany, Corsica, Poitou-Charentes
I invite you to stipulate obligation with the owner of the license, with to authorize its customers to resell their access, according to a price defined by them, the customers.
Ben, au case or WiMax would disappoint, one can play the chart (!) complementarity (include/understand WiMax+WiFi).
Why I say that? Because a pylone WiMax is sold 90.000 euros. I speak just about installation, not of refunding recurring of the licenses, which will fix, in the long term, it price of the subscription for the final customer.
The known as areas will be able to take part, admittedly, but how long?
«Nous suffered from a deficit of the suppliers ADSL who did not cover sufficient our rural areas, they was satisfied with the big cities. The Wi-Fi/WiMAX couple really was essential like the technical solution best adapted », explain Dominique Randon.
Prudence is of setting:
“Them misant WiMax operators on the rural areas of the markets developed will expose themselves to low registers difficulties as services DSL will take a lead in these territories. “
Will FT “encircle” the WiMAX pylons?
that would fall to water. But
to allow not
to follow the doctrinaire approach"
All goes very well, madâÂâme Marchioness….it was in 2002!!!!
parcelling out of the licences does not allow one
to reach a sufficient critical mass to be profitable."
Le WiMax functions well (3Km of range downtown) with 2.5GHz ...... forgiveness, but I glousse!!! (that resembles too much of WiFi, Mort Of Laughing).
“Even if it is
initially used for
the installation of
principal market of Wimax is the cities", a
estimated Jean-Paul Rivière (Altitude Telecom). Indeed, Jean-Paul: “A
to start from this pivotal year , incomes
will cease growing bigger, to reach 23 billion dollars in 2013".
Lastly, they are only
L' intervention des local government agencies in telecommunications. Report of work of the Committee of the Networks of Public Initiative. March 15, 2007.
WiFi against WiMAX according to Intel
that there is (still) qui
croient in WiMAX as rural solution!! They will have
2013, if Altitude Telecom poses
3500 WiMax stations
Tiens! one tells me ici (minute 52) qu' one needs 10.000 stations to cover France….I can in to conclude that Altitude Telecom will not solve digital divide with WiMax???
En Ukraine: "  shows the viability of the use of BreezeMAX 3500 in the service road ofzones urban very populated"
En Germany, Les purchasing [of licenses WiMAX] engaged to ensurecouverture of 25 _ of the communesde their zones from here with2011
I put myself a question about mobile WiMAX (802.16e); how not vider quickly la batteriede the mobile device (considering the power of emission necessary)?
La radio coverage is better of 20 _ into 2,5 GHz than into 3,5 GHzInclude/understand 20 _ better in WiFi than in WiMAX, for France.Couvrir of the zones of not very dense habitat in Mobile WiMAX with 3,5 GHz will be thusplutôt expensive.
Pessimistic vision of Pierre Beaufils [Greenwich Consulting] on l' future of WiMax
“When well even the flow of the 3G would not be enough, simplest remain to connect itself to a Wi-Fi network whose access is in general free or integrated into the mobile offers of the operators. Moreover, Wimax still involve big problems as regards consumption electric, which reduces the autonomy of a portable. A problem that does not know the 3G which proposes a better management of the battery. “
assessment of an experimentation in rural area (Country of the Valleys
of Saintonge) in January 2006.
If WiMax does not go, there will be always WiFi:
France puts itself at the “mesh”.
“What one less knows about Wi-Fi, [...], it is that it allows point-to-point connections in line of sight bordering les10 kilometers thanks to the antennas with profit " (source Pierre-Antoine Baubion) (I confirm, I did it. With 100mW (in the air), 10Km is the high limit.). The configuration which I have used was: An access point (AP) normal with the emission and a large antenna with la reception.
This means that it becomes possible to collect a AP well beyond its coverage area for portable PC or PDA.
They is the Parisian ones which will be content, grace with400 hotspots installed from here the end of June 2007!
The world records are of 200Km with 300mW in the cable (=25dBm) (it is not thus pas 3 times more than 100mW in the air, but much more), which fact a power in the air (WORSE) of 48Watts!! in France us naps limited to….100mW, i.e. 480 time less. (source
Le record passes to382Km(18/05/2007) with large antennas:
And with304Km in 5GHz (802.11a) ., between Sardinia and Italy.
Voici des vidéos ofFrance3on WiFi installations for to serve “isolated” villages.
To bring Internet to those
which do not have the ADSL:
The large ones networks…
A company (Alsatis)
to equip in WiFi.
Nomotech équipe la Normandy in WiFi, by using fiberoptic and beams herziens.
Un mariage fibre and WiFi (rather than WiMax) in the Rhone.
And of small networks…
Rural WiFi is in evolution, here solutions which function:
A Viviers-lès-LavaurFrançois Laperruque used one mesh network withOLSR(comparable withOSPF) and freifunksite in Germanbinaires
A Saint CerninSylvain Lacaze used the infrastructure mode withWDS
A Vaours Didier Lebrun diffuse Internet in WiFi, via the satellite since 2003. Didier uses 4 ADSL bonds today, since it coupled its network with that duplateau Cordais, as one can see it on this splendid chart, in time reality.
In Villeneuve-Tolosanne, Marc Quinton with used OLSR and soundpropre firmware here a vue satellite with the bonds
A VerdonPatrice Valade cross the valley of the Dordogne to bring it high-flow (in WDS) in a zone “whiter than white”.
Au Mayet of Montagne, Dominique proposes the subscription with20 euros/monthLa chart of cover of its network.
A Tamniès, Richard Bonnaffoux, propagates his networkde relay out of relay
A Plougonven, Marc replaced his satellite connection by oneligne Symmetrical France Telecom with flow guarantees. (SDSL, 2Mb/s).
A let us Trébons on the fatty one, Jean and Robertont makes their network which serves 25 hearths (07/2006).
With Catllar and Los Masos, l' association WiFi Conflenttraverse the valley of the Small fireclay cup to deliver Internet free, with a mesh network composed of “Locusworld “house”.
A Saint Bresson, a chart of the network, provided byPascal from Montpellier(Quand the townsmen give the hand to the rural ones
Mode WDS is used to make pass the bytes of network of a point WiFi access to another.
One can thus relay the WiFi network on the long ones distances and to benefit from the WiFi network at each point access.
Voici un access point the commercial, which allows this function WDS. (80euros, 06/2006)
The difference with a repeater, is that the repeater allows to relay that only one apparatus WiFi (only one channel, the distant MAC address is repeated).
La list RAN (Rural Area Network) gathers this kind of initiatives.
One has sympathetic meetings:Rencontre of spring RAN 27 and May 28, 2006 with TAMNIES
To put faces on names, voici a photograph of group
Among the last meetings, there was:Rencontres wifi 23 and September 24, 2006 in the Verdon
The last meeting was it
samedi March 31 and Sunday April 1, 2007 with the Printemps Wi-Fi 2007in Auvergne
Here < C 0 > Report de these enriching and sympathetic nerves days.
Creation S.O.L:LE TRADE UNION LOCAUX OPERATORS
solutions [CPL, WiFi, WiMAX, 3G (GSM), satellite] by
Solutions carried out by professionals:
Du WiFi with a grid in Gordes in Luberon.
A Borce and Etsaut, they use a mixture of CPL (30MHz max) and WiFi to prolong a satellite solution.
Le CPL " outdoor " (of the meter towards EDF) and “indoor” (of the comptor towards the catches sectorest in the course of normalisation (10/2005).
However the CPL could scramble the band AM as that seems to be the case with the U.S. (vidéo of 18Mo, in English).
On parle de EDFbox and edfbox.fr
Typically, on a zone or there are 350 NRA (connection ADSL), it is necessary to equip 10.000 transformers EDF (à 3000 euro each one), for distribuer CPLaux same subscribers. Moreover, it is necessary to place one repeater CPL at the end of a few hundreds of meters to preserve a flow raised. In addition, it would seem that the steps administrative are long;1 an, before the implementation (03/2007).
If France Telecom (FT) wants to makecernage (to install not-profitable high-flow to kill competition) on each network, they will have to spend of the thousands euros for each more quoted WiFi network high… pffff….: -)
“France telecom wants to make of Wi-Fi on the commune of 300 inhabitants orj' have deployed my transmitters!!!! “known as Dominique.
When I see that FT establishes concurrent solutions (in WiFi) precisely there or of the microphone-operators (see list RAN) try to survive, whereas there is place with side to désservir those which do not have an access Internet high banc, I am only fairly astonished by the absence of FT in Wimax on the metropolis. The ARCEP me surprised ace!.ouiap, does it of it is FT who is not interested in this market… officially… for to make good figure.
Saint Cernin and Viviers are already encircled. FT even encircles maintaining communesavant que the material is operational. Example: Wifi-quercy-south. Ca wants to say that you only have very little money to spend to make you encircle (to declare one association aiming at installing of WiFi mutualized) (more you you make known, more you will be encircled quickly). Super not? :-)
During this time, FT puts WiFi more rentable in the cities. They are not only… “Visiblement, Sprint intends to aim at the market of the nomadism".
FT sold a contract withcertains departments so that the distributors of their communes are equipped in high-flow before 2006.
It is the charter of the departmentsisolants innovating.
One is there; made the assessment.
But what some did not include/understand, it is that it acts to only equipceux which to peuventavoir the ADSL, therefore is excluded, the private individuals (or companies) who are too far from distributor !! (environ 8 _ of the population) Then in the statistics, guess how one counts? and well on count the communes equipped, and of ceux blow which is too moved away from the distributor, pass tooubliettes
At the end of 2007, it will remain 620 000 Net surfers on the edge of the motorway of information (99_ covered population)
Me would have been lied? according to this source (HDRR) who relates to 11 areas there would be 800 thousand people concerned (in 2006!), which would make 1.600.000 people for France (22 areas).
The deficiency relates to also
(Very Small companies) “un millionne is evenpas connectedà
Internet " (12/2007).
Still a detail concerningdébit WiFi in shift:
If you wait until new materials (bringing more of flow) appear to equip you, I think that you mislead a little, here why:
There are 2 types of connections
The first are done at short
raised. But because of
these flows are less. Evolutions
current tend to erase this handicap (see MIMO,
number of antennas). "Les débits
realitiesoscillent between 40 and 50 Mbit/s
inside the buildings and
they exceed briskly100
Mbit/s in space
The seconds will thus not benefit from technologies aiming with to mitigate the effect of the echoes.
In addition, it seems rather difficult to me to install 3 (or 7) antennas, there or there is one of them today.
The current flows obtained in shift, are likely to return le current material perennial than that of the cities.
In conclusion, it is maintenant qu' it is necessary to invest on installations of countryside.
Quand le débit cities (FTTB or FTTH) will be larger, it will be enough to change - not antennas - but the boitiers (connected to the antennas) to convey the flows futures. The cost of the evolution will be thus minor.
Le FTTA (100Mb/s in 42GHz) is an abuse language, its range (3Km) is very reduced by report/ratio in WiFi.
Objectives and strategy
I seek to know if one can make
of authentification which is not centralized; if you have
brief replies,vous can
to write to me
(to remove _POURIEL email).
the bonds which leave this page
Or are my readers:
Testez your débit in the 2 directions
Le blog of WiFi
That is it what it is WiFi?
Why one speaks about it now?
Why gradually legal in France?
WiFi for what to make?
Which are the competitors of WiFi (2.4GHz/11Mbit/s)?
Swelled, Is MHz, Mb/s it what?
Which is the bond between flow in bit/s and bytes transferred?
Which are the various standards of WiFi?
what has to take that which goes most quickly?
Why y' has 2 antennas on the AP?
Yes, but all that they is assumptions?
How to take the control of its material via Ethernet (RJ45 or WiFi) since a PC?
With what is used for to take the control of its material?
How to know if a WiFi connection will go, without material?
How to implement the software “Radio operator Mobile”?
Y does it have ancestors of WiFi in France?
Which is the price of the material to date?
How a link long distance is established?
How one takes omnidirectional a step expensive?
That is what can scramble us and which scrambles one?
How to do without the electric cable until the AP?
Then what to make? 4 solutions
Which solution to choose?
what a hub (repeater),
a switch, a bridge (bridge),
How to choose between fixed or re-used address IP?
Who buy IP addresses?
Addresses MAC, addresses IP re-used, how that goes?
Not of waiter DHCP on a bit?
The address Can IP, it be unspecified?
It is what a mask of sub-network (“subnet mask”)?
How to identify the computer which is connected to Internet?
To have is an address IP, that enough?
Les Can AP go on the roofs without problem?
is waves they bad for health?
How to detect the radio waves?
How to put a mini-NCV in a satellite toshiba?
How to add a connector on D-LINK DWL-650+?
With WiFi is what I would be pirated?
How to improve a WiFi connection?
One can to make a bad antenna “ricoré”?
It there T it has reflectors on the antennas grids SD27?
Why my compass does not work well?
But the lightning?
My antennas are well granted?
Le Does WiFi, that grow bigger well?
How to find itself there in connectors?
How to choose the cables?
End of a myth on WiFi, them walls, them doors and windows?
Who will gain, the pair coppered (the wire of the telephone) or the radio?
Which is the form of radiation of an antenna?
How to circumvent an obstacle?
Pourquoi this page? to synthesize and solidify information data by forums, the press, the Web, my courses, my experiments, it good direction.
That is what it is WiFi?
WiFi is means of communication by radio waves enters computers (in the broad sense). From a software point of view, it is the equivalent of a LAN (network) of company.
The protocol used is pressed on Ethernet and allows to make to pass protocol IP (Internet Protocol).
Why one in speaks now?
Because that becomes gradually
legal in France. It
was necessary initially that Jospin authorizes the radio communications
encrypted (with 40 bits with
the time) above the public domain.
It was then necessary to
ARCEP) on the authorized power, for not
to obstruct the Army
Frenchwoman (the ministry for
defense), former owner
And then in the USA and in the other countries of Europe, it is already legal, and the sales progress.
Why gradually legal in France?
Because this technology can concurrencer
Telecom France, at the time or this one would occur (sentence
ART defends France Telecom: “One gives satisfaction with France Telecom immediately with detriment of the subscribers and one push back with later the decisions in favour of competition "selon Jacques Veyrat
The limit in power relates to the sortie antennes, what is still très restrictive for point-to-point bonds (by opposition to bonds makes with an antenna omnidirectional). By definition the point-to-point bonds cannot to scramble that very little world since the waves are focused towards the other point. Legislation U.S. (or Canadian) holds some count, it is more tolerant for the bonds not at point.
ART wishes to study themliaisons point-to-point (thus supérieures with 100mW) on a case-by-case basis:
“The operator who wishes to deploy connections not with not, withportées noncompatible with the limitations of powerindiquées in the tables, must to solicit with this effect near the Authorityune autorisationd' use of frequencies "
It should be noted that liaisons point-to-point WiFi, with less 100mW of PIRE, can be made on6 with 8Km, contrary with the assertions of the ART, which envisaged 1Km. Voir comment ici .
On the other hand, if you modifiez the antenne (to put one of them more powerful) of your WiFi material, without modifying (to program) power of the apparatus (to lower it),votre installation becomes illegal. Ne do not count on the scruples or competences of salesmen of material, for you to prevent some.
In March 2005, and to my knowledge (which is limited), itminimum of programmable power is of approximately 0dBm. For information, 0dBm corresponds to1mWThe dBm can be negative, not Watts.
The limitations of power are
Watt with 0.1 Watt (according to the channels) exit antenna
for the 2.4
GHz in France.
In Canada, these limitations are of 4 Watts, in Germany of 500mWatts.Les English (Ofcom), evoke the possibility of authorizing10W, it who nuierait doubtless in Wimax!!! Me, my opinion, it is that it is Paris which fixes the powers and which they is the rural ones who suffer from it….who spoke about delocalizations???
Our English friends se
pose questions (robotized translation):
Thank you Dominique for
In short, not of additional power in 2.4GHz because interferences, to pass to 4W radiated in 5.8GHz and limitation in the cable when Europe requires it.
The 5GHz (802.11a) is to dateinterditen France for one external use,mais that could change.
Ben yes, that changed (02/2006), to see thempuissances authorized in fonction of frequencies.
Then I put myself the question: why the ARCEP authorizes the 5GHz with 1Watt or WiMax with 20Watts and WiFi with 0.1Watt?
I am not the only one to ask me this question:
" the needs for frequencies increase. If us let us continue to distribute them in an ineffective way,purement administrative and on a base nationale, the industry of the télécoms will not take its take-off. One needs an approach which is inspired more operation of the market ", souligne with the daily newspaper Vivian Reding(police chief of the Commission European as regards télécoms)
I would even say “local market”, ViVian, in thinking in Wifistes rural!
of SagaTel for the ARCEP (2006)
Good, then let us positivons!!:
With 1W in 5GHz, which range do we have?
...11Km, by report/ratio in WiFi 2.4GHz under the same conditions (8.55Kmnous let us have gained….3Km!!
How that is it done? (if little?) Ben yes, with the increase in frequency, the loss in the air passed from -124dB with -134dB.
We lost 10dB because of the frequency and gained 10dB with the power.
With antennas well in height (half fresnel=0,12m of release) one would have 24Km
Under these conditions (dégagement of 23m), WiFi 2.4GHz would carry to17Km
sometimes I do not resist
emulously of you
to make divide what makes me die laughter (MDR), like
this labsus inpharse
phrases concerning WiFi5 (802.11a, 5GHz):
“The Wimax material will be intended foropératueurstélécoms professional ". thank you Dominique.
One speaks to me here
of WiFi with
flow of 150Gb/s, super!
But which is its range by
By considering that the sight is direct (Fresnel with 0dB) one arrives at…500meters!! thus unsuited to rural WiFi.
To use mon utilitaireil is necessary to recoverle run-time enginqui made 20méga.
If you seek “WiFi” on the site of ART (ARCEP), you find with the 05/08/2004, 47 articles, no the synthèse up to date.
Message personal for
the Prime Minister
Would be necessary to limit the power of WiFi (100mW) at exit of cable of antenna rather than at exit of the antenna (WORSE).
Ca would enable us to use légalement des unidirectionnelles antennas
Sinon, la France of in bottom flow, eh quite elle will remain in bottom
In my opinion, it is better that work is done in the Creuse one (nearshore) rather than in China or inInde (offshore oil rig).
And now, that bears a name: homeshoring(telecommuting in residence)(less transport, less oil taxes… zut!).
I did not find in “small Larousse” of definition equivalent Radiated Isotropic Power (WORSE).
Then you known as “y' with the ADSL”, except that:
communications director of France
for the Limousin, insists on profitability
installations (DSLAM): “We should reach 80 to 100 customers
to hope to deaden over three years, the equipment
of a telephone centre
in ADSL. “ Knowing
that in rural area 8 _ subscribers
only are likely to take out a high subscription
calculations are quickly made:pas of connection for
communes of less than 2.000 inhabitantsIt is
moreover the threshold that the operator fixed itself
public. They were
32.079 with the last census " (on 36.000 communes in
A colleague did not understand that with 250 signatures, FT does not install a DSLAM. It is necessary to consider100 signatures in a ray of 3Km(as the crow flies, which corresponds to 5Km of wire telephone) so that the DSLAM of FT is profitable.
My remark with me, it is that one should not take des figures on the practices of yesterday, to predict the use technologies of tomorrow.
I point out les European texts:
Texts of the European commission
- The recommendation of the European commission from March 20, 2003 inviting the Member States withfaciliter the utilisationdes hertzian lans (R-LAN, also called w-LAN andWi-Fi) for accéder at the public services
I do not invite you to read
them, because they are
to be read by those which write them, only.
normal (like me), it is incomprehensible. Idem for the Constitition
Wimax(me I wait
to see the price of Wimax: 125
precisely, ART wants
to nauseate them
peasants (and telecommuters) because themlicenses
will be sold with the biddings (as for the UMTS)
the cities will be profitable).
Tiens, ils opinions changed! :-)
Ô you, living deep France, you does not expect with it that the operators of WiMax start with to equip the zones lesmoins profitable in premier(you saw what it is passed for the ADSL, not?). "99 _ of the population " it is the objective, deep France it is the 1 _ remaining. After all, that only makes 600.000 voters… with less than the townsmen appreciate the holidays with the countryside?
Les forgotten amount with nearly 4 million individuals
Let us note that on the 70 projetsde communities referred by Arcep, that proposed bydépartement the English Channel is le seulà to have filled the reduction objective of the digital divide.
“But even with Wimax,il will remain to reabsorb a residue of zone white " according to Jean-Daniel Poisson with TDF.
is the true alternative to the last kilometer"...Ha!!!
It is for that they start
by equipping them
godforsaken holes (8000
inhabitants) kind .......Genève,
ouarf, mdr, forgiveness… it is not
funny. Finally, one can
prolong me by of WiFi…
"bénéficier of a service access to Wireless Internet in the large ones metropolitan cities, CQFD.
"85_ places of access [Internet] come from a local initiative"
For the moment, only Altitude Telecom (Iliad/Free) has a license, and can sell " Pre-WiMax " at a reasonable price. Especially if one consider that one can cancel soundabonnement France Telecom with 15euros/mois. Le total grouping attracts world!
If ART is obstinated to sell themlicenses WiMax with the biddings, without remettre in question that d'Altitude Telecom, this one will be in situation of monopoly, and will thus be able, in the long term to increase its tariffs. With less that Altitude Telecom be interested only in the companies…
D'autre part, si too little of licenses are vendues, it will risk se to produce an agreement between WiMax operators (with 2 or 3, that should not be too hard…il remain only Maxtel, Bolloré Télécom, HDRRet the license main road of Free), like that at summer the case for the operators GSM (see price of the SMS and the intervention of the government).
Hold, what I said to you: “Doit one to expect a concentration of the WiMax offer?"
“Last March [03/2007], the operator [Free] did not speak more than of one “experimentation" for 2007 [en white area
Freeentend to propose the nomadism (high banc without wiredans cities
It is odd, one had learned to me with a course of economy that if one was less than 5 competitors,on could to agree to cancel the effect of competition(With 10_ of fine on the sales turnover, that is worth perhaps the blow of to continue like that?).
Ca makes too a long time that we pay l' tax telecom:
2003-1997= 6ans. 6ans * 3 euros * 12 months = 216 euros
C'est à us them users, who should be returned this money, not in the State.
216 euros * 15 million users = 3240 million euros. The fine will sera of 534 million euros.
Profit of the operators: 3240 - 534 = 2706 million euros. Not beautiful life for them??
Merci qui?? thank you the ARCEP.
(Calculation is false because there was not 15 million users in 1997, but good… on another side, you saw lowering the price of telecom frankly mobile of 2003 with today??? me, not)(operators continuele racket on the international oneLe benefit for the operators flirte thus with the 500_!Le roaming has the NOZZLE in water!
Citizen, is you ready to vote
a tax with
monopôle, which would consist
to pay with
the State for each company, X_ of the turnover
market divided by the square of
companies of this market? The
goal being of
intolerable economically a monopôle, all in
to live the start-up.
There is more than 20 operators ADSL (in 2005). That is to say them owners who will sell of WiMax are animals (I doubt it) that is to say ART preach not for many users citizens. I do not have dreamed, it is well the government which indicated it chair ART?
Why the operators would not get along for not to go up biddings? Because it takes them time for to know.
Thus mutualisation of the pylons or points high, for GSM was not possible (economy of 20_). Damage, it is the user who pays.
WiFi, that feels good! especially since
that themlicenses is free,
finally for the small operators! (05/2007)
Heu….unless one should not pay?? (Exemple of calculation for the operators of radio local loop)
Yearly rental of provision: R = A * (DF/F) * (DS/S)
S = 550.000 Km² , F = 2450 MHz, DF = 13 * 20 MHz = 260 , DF/F = 0.1, has = 31709395,59
with DS = 1Km² for example, that madeR= 5,76 euros
Yearly rental of management: R = 533.572 € * (DS/S)
R = 0,97 euro
I cannot read the site of the ARCEP, que
this texte means (20/02/2006)? qui
With my Freebox WiFi close to the window, I am an operator?
And then there is the problem
To choose a FAI in ADSL according to the number of customers who it quittent (churn).
WiFi for what to make?
1) for one mobile access Internet
with the travail,
it is less expensive than of
to cable and
to maintain wire and catches in the walls. Ca does not make
to work a person to declare a computer on one
catch (that is called mixing) each time
that one changes
catch. One passes from a
part to another (or one
limit to one
other) without losing connection Internet (that is called it
Les travailleurs nomads or mobiles are 15 _ more rentables that the others.
one can profit
terrace without trainer a wire. As
soon as one has more one
one avoids cables between those. The
WiFi is propagated through the doors and them
follows the corridors and the stair-wells. WiFi is propagated
also by reflexion on the houses of opposite.
No the computer in the living room!. that the TV. Yes but source of media (Internet) is the modem and the computer, it is necessary then to send information (music/films) towards TV. To avoid wire in the corridor, there is WiFi. Here why the FAI propose 2 boitiers: a WiFi modem + a boitier “decoder” (WiFi towards TV/chaine Hi-fi). Boitiers of video offset are incompatible with WiFi (even frequency).
in the bus
in Paris in progress), in
with a satellite connection (arrêt
operation in 2006) or ratherpour
a380 AIRBUS) (AIRBUS continues in GSM) (reprise
service with $10 per flight)(mais
with security issues for BOEING,
since the WiFi access is related to the system plane), in the
voiture (Ca is called “war
driving” when one seeks just
to find WiFi terminals), inmétrole train, withla FAC
A test took place on the TGV Paris/Bordeaux in November 2003.
The availability is planned for 09/2007dans 52 trains TGVAvailable to the 12/2007 sur line TGV Is
Aux stations d'essence des autoroutes (A10). Chez Carrefour (A62).
With the terrace of one café, in public places very attended (they are called “hotspot”) such as lesgares, aéroportslist with the 09/2006), the restaurants rapides, in the camping
in the hôtels
it is free (“service
B&B is true
success! We receive
users explaining us that they do not go any more but to
B&B because WiFi is free there! “dit
Alexander Casassovici, President de WaveStorm),
Dans les cuisines restaurants, for gérer customer orders.
in the rue.
Yes, then I say “in
the street” but it is for
to make “well”.
Hein? Ben yes, customers of the thing-BOXES (ADSL+WiFi modem) are not formed to place their thing-BOX of such kind that it diffuses in the street (so still it is the intention of these customers) (yes, there are money or service to be gained).
If such is your case, will know that placer is needed your thing-BOX behind a window for that it diffuses in the street.
This message also concerns and especially the users of FON, which risk être disappointed by the range of their Fonéra (Fon-BOX).
But FON received the message and proposes an antenna patch to fix on a pane, by means ofventouses
Une description of the fontenna, version to be stuck.
The fontenna (antenna FON) increases the range of will fonéra. Demonstration of fabcool
and with the fontenna:
Despite everything, onewardriving
during 1:30, with an antenna of 7dBi on the roof of the car, gives
4000 access points (04/2007). Here
(thank you Stephan):
I consider it regrettable that there does not exist site to index and to factorize this kind of initiatives!!
Ca would be used for better telephoning in WiFi or with surfer free more easily…
free for 8 million habitants (in Mexico City).
On 50.000 hotspots (WiFi access) there are 6 of them _ which are free (at the beginning of 2005). But ça could to change, because the operators seek with to approach final customer. Eh yes, that which reads a publicity pays! (statistically). Imagine that Google puts publicities in the pages of acceuil of its hotspots (one calls that a captive gate).Ca there is, it is fait. Rrrhhaa, the FAI do not have there thought ..... it is bundle!! ouf! :-)
As for the GSM, the
multiplicity of the hotspots
Big Brother in company
“Bill”, “Linus” or
?? The projet
Mobile FONd' Internet starts in Spain…
Avec tomizone, they have competitors (sourcecarte
of the persons in charge of Ozonne and FON, on
LCI in February 2006.
2) pour to equip the campaigns
That it is for the telephones
portables or for the access
Internet high banc, policies (mêmes
Europeans) does not envisage to force
or public to cover 100 _ territory. N
the other hand, l'
authorize WiFi to extend the bonds high
isolated communes. A
typical solution is
to install one
relatively expensive satellite connection, which ispartagée
with 15 userspar WiFi to deaden the unit on
a few years.
Another solution is of relayer with of Wimax and/or of WiFi, the fiberoptics which pass on the motorways or les access ADSL (NRA) of the close villages. There exists possibilities ofaggregation band-widthde several suppliers access Internet (FAI). But it is possible to make the same thing “manually” for less expensive, while declaring plusieures footbridges (worms of the different FAI) on one even network. The objective is more reliability, than the profit of flow.
le report/ratio at the National Assembly
un bon exemple by Didier Lebrun (attention at the prices, they drop)
activesont developed RAN (Rural
Area Network), they are reachable sur
The idea is to bring high banc until thatched cottages, by any means (WiFi long distance (several kilometers) to prolong existing accesses Internet: satellite, ADSL, CPL, fibre, etc…).
3) pour to pay moins
An access unlimited to the quarter of the price of market.
For 4 users with WiFi
material, if it there
in ONE has which
have a connection towards Internet,il
to divide with the autres and to be made rembourser
of what it pays. For the
3 others, they ne pay that 1/4 of
prix of a connection Internet. (This is normally
one needs a license operator telecom,
N the other hand, if the 4 users use en even time Internet for télécharger, each one will have only 1/4 of the flow.
Telegraphic connections (if it of a) take there precedence over WiFi connections. This can be prevented in putting a software who distributes the flows in way homogeneous (seeQOS, Quality Of Service, NetLimiter (Windows), wondershaper (Linux)(explications
The remote loading (of large files) uses connection Internet has 100_, therefore in this case the flow is divided.
But in the other cases: - consultation of pages Internet, - remote loading only one among the 4 users, one will not feel difference compared to a solution without division.
Software exists to program the hours to which one prefer to download (in the night for example).
Into WiFi, the flow of the AP
is divided by
users connected above.
In WiMax also, ADSL too. The number of users by sold flow, is called ittaux of application
In ADSL, a nice operator will sell the flow maximum, to divide itself between 20 users, less nice, will sell it with 30 users.
The access Internet in France, costs 5 computers
30euros the access
ADSL (ou 35 euros the ADSL nu), in one
year that made 360euros. Today for this price,
there is one
normal computer. If one changes computer every 5 years,
fact that access Internet costs 5 computers. Le
price of the access
is onefactor determining for the users.
companiesextrait of this article (08/2005):
Tariff means noted for a flow of 1 Mbits/s per month
A- Paris, great zones of businesses, equipped with deblocking with xSDL or BLR:610euros HT/mois
B- Communes of the first 10 urban areas in province:660euros HT /mois
C- Common peripherals of the 10 first urban areas métropolitainres and zones not dégroupées but with BLR:710euros HT /mois
D- Other dégroupées zones of the territory:800euros HT /mois
E- Territories having a single offer ADSL, generally via France Telecom:930euros HT/month
F- Other territories without cover xDSL: 2.000 euros HT /mois.
I point out that there is only a seul owner of the pair coppered, onesociété deprived: France Telecom…
With the voice on WiFi (VoWi-Fi), prolongation of the téléphonie on Internet (ToIP)
Linksys and PhoneSystems.net announce a solution of VoIP. Panorama VoIP in March 2006
PDA GSM/GPRS and WiFi with Skype in March 2005.
Le development ofVoIP fact fear with the mobile operators,(perte incomes on the roaming)… especially if one can to program its own telephone.
“The telephones Dual-mode [GSM and WiFi]sont already manufactured by Motorola Nokia, Fujitsu, HP and NEC."
Voir aussi Milkfish (solution SIP).
Attention with listeningspirates on SIP with “SIPtap”.
Mariage WiMAX and MIMO for telephony. One speaks about “smart beamformingpour to imitate the MIMO of WiFi.
sociétésdont employees needs have forinternal mobility deploy the voice on Wi-Fi with small scales
"50 _ mobile calls passed through the employees of companies are carried out at the office, although less expensive fixed telephones are at their disposal"
Project FON will use to telephone thanks topartenariats with operators GSM. (good fear adviser?) :-)
Voici une carte geographical de la FON/Neuf cover.
Another with Ozone, Meteor Networks, Fon or the restaurants Mc Donald' s
And with Boingo.
Ca always did me frankly to laugh, drawn radio ranges with the compass (Ozone/Paris)…
"Ce network does not belong to anybody, “ explained Rafi Haladjian during the launching of the start-up Ozonne
If it were true, nobody would have sold it with Last nine cegetel!!!
To kill competition, the secrecy to bleed the consumer.
La Freebox V5 left, and the WiFi telephone which goes with also… (on can put besides full with things inside.Linux core 2.6
the CTIA mettent
in place a programmepour to test the range of
(In French,program ne se translated not always by software
François and all those of his WiFi network cantéléphoner for 1centime of euro the minute, towards fixed telephones in France, but without passing by subscriptions Internet (offers triple play: freebox, 9box, livebox, etc.)(~30 euros) and subscription FT (14 euros).
Transform an old cellphone into footbridge towardsVoIP with Skype and IPdrum (and benefit from the prices “SkypeOut” on your calls of portable, in the coverage area of the old man portable).
One can call that onemobile WiFi, who added to the offer “triples play”, fact one offer… “quadruple play".
Triple play it is telephony,
to have the TV drops, if one uses the MPEG-4 instead of
Inventel allows téléphoner with Internet, without computer,et with one very good quality of sound.
And to say that there are some who telephone 6 hours for $29, withskype in the avions [English]! (source
For the train, one would need catches sector in the oars (to monopolize the catch “razor” in the toilets, as I have it made in the TGV, it is not well!)
Ca is likely to be socially interesting, if one can use resources provided by private individuals (WiFi terminals) for to telephone…
(until or the altruism will go?)(that points out time or one to me went in the neighbor who had the telephone, for télépnoner. One he gave money or one proposed some at least: -) courtesy? …)
There are then preoccupations with a posting, an outline of solution with “craiefiti
I am not the only one to think thus,to voir Ozone
the festival ofUMA
The UMA has the aim of promoting the roaming enters networks of mobile telephony and WiFi network servants or access points public with the wireless networkings. The roaming, that please say that one passes from one network to the otherdans the same one communication.
While waiting for the UMA you can combiner advantages of mobile (GSM) and skype while calling your proper number (skypeIN) which will be redirected towards your corresponding (skypeOUT).
Here a firstmise
in work, at Nortel Networks
Another at LG, a téléphone Dual-mode 3G/WiFi.
testschez Free and Last nines
(June 2006). Détails
Favours for France Telecom which envisages to make UMA, with its “LivePhone” (= " Unik”?).
The question that I am posed, it is: Which will be the maitrise of the user on changement of tarif in the course of conversation?
C' is well what I craignais….(06/2006)
Compete with between the PocketOne of Internet Club (become Neuf Cegetel) and Twin?
prix VoIP calls (since a machin_BOX) from France
VoIP functions better if all packages IP borrow it even way, a solution withMPLS
A company, or a small rural
network (in WiFi)
can use oneservor
Asterisk to connect telephones
traditional (analogical, FAX) oubien of the téléphones
The product presented is only
a connection series (RS232), but this field
with the management of a house (maison
(power station of alarm (already in “without
electric doors, video monitoring (them
already exist), simulation of
presence, energy management,
projets more ambitieuxconsistent to connect plusieures technologies of transmission. Personally, that itches me since to discuss a long time on the telephone with my corresponding by listening to it on hatred Hi-fi, with a microphone in the middle of the part ;-)
For faire remote monitoring.
Certain software on mobile
devices allows prendre
contact with the people connected on the same access point.
Me, I await the version which will make it possible to do without the point access to connect itself with its close relations (with the clean direction) (I speak about the close relations; -) I.e. in ad hoc mode. One could then to point its apparatus towards a person and while apputant on one button, to exchange coordinates…
Which are the competitors of WiFi (2.4GHz/11Mbit/s)?
WiFi to the standard 802.11g
WiFi to the standard802.11 pre-N fact 2.4GHz/450Mbits/s
The values of flow are theoretical, in practice that made less (count half).
The terminals relay of WiFi are the AP, their price is accessible with the private individual.
Bluetooth (12Mbit/s)(range 10m) (2.4GHz) (protocol L2CAP, not native IP),
Wavelan (to 800 MHz) (disparu
HomeRF (2 Mbit/s) (disparu
ZigBee (250 Kbps) (2.4GHz) objective low consumption and small range (à to come)
Like telephone GSM, technologies following require terminals relay on pylones (expensive), thereforepas of GRATUITES connectionspoint-to-point en between private individuals
Hiperlan2 (5 GHz) (à to come) (I do not know the price terminals relay),
UMTS (384Kbit/s) (à to come) en test with Toulouse102 euros (10 hours) or 15 euros of the heure (3 operators thus not of competition) (voici of what to have an idea of the tariffs)(la Visio with 20euros/heure)
UMTS R5 (1Mbit/s) (à to come) (you have 100 billion euros to be refunded, finally if you use!!) pauvres operators (suite
Flash OFDM (10 times the UMTS) (à to come)
will Ultra Wide-band (UWB/WUSB) (400 Mbit/s) (à to come) (range 10m) be likely to replace Bluetooth
Wimax (à to come), it is like WiFi, but with Watts, of the pylons and the licenses moreover, public price and technological effervescence in less. But that seems to change with l'utilisation technologies OFDM+MIMO
WiBroà to come) (for June 2006) (30Mbps) (2,3Ghz) (Wireless Broadband, standard 802.16e) it is of Wimax for South Korean.
If you move with 250km/h (or less), it there will have in 2006 (still not seen in 2007) leMBWA
BluWan (40,5-43,5 GHz) (12Gbits/stheoric)
to come) (3Mbit/s)La
standard envisages to reach 14 Mbit/s,
with a bond going up going up to 320 kbit/s
802.16mà to come, not before 2009) (1Gbit/s into fixed and 100Mbit/s in mobile) with MIMO.
Le LTELong Term Evolutionà to come) in 2009/2010 should make 100Mb/s. Oui, it makes already 173Mb/s in 2008.
One day, of the radio connections with 2Gbps (56GHz) withle Gi-Fi(spectral effectiveness of 0.035 (28Hz by bit))?
Versions owners (compatible with 11Mbit/s with other manufacturers) allow of WiFi 802.11b 22 or 44Mbit/s.
Idem with the 802.11g with 54Mbit/s, there exist versions owners faster: 108Mbit/s and125Mbit/sBut I believed to understand that certain technologies used channel 6 “to dribble” on those of with side…
Une comparison of the costs in energy electric emphasizes that WiFi is 25 times less greedy than WiMAX, which, is to him 2 times less than the 3G WCDMA.
Swelled, MHz, Mb/s it is what?
is the unit of the hertz.
Ca measures a frequency,
i.e. the number
in one second.
Electricity, in France, is delivered with 50Hz.
b/s, bps, bit/s: mean all the same thing: bits a second. Ca measures one flow numerical informations (or data processing) exchanged. A flow measure a quantity for a given time.
bit: it is the unit of computers, that is worth 1 or 0. .
B/s: attention, there is a trap! It is about byte (English word) a second. byte means byte. A byte is a whole of 8 bits.
bps: attention, still a trap. Ca can be bauds a second.
baud (or bd Ca becomes complicated. The computer knows that the bits which are worth 0 or 1, therefore a bit has 2 states possible (perhaps a day onewill codera 5 bitsdonc 32 possible states). Connections between computers can to handle tricks which have 4 states possible. Thus one trick can transport 2 bits.
The number of states is called the valence. The valence of a bit is worth 2. The valence of the trick of my example is worth 4.
And bauds then? The bauds are the tricks of my example.
To convert bauds into bits it is necessary to know how much bits are coded in a baud for the connection in question.
How one makes? Ben for example if one varies frequency (like the frequency modulation, the FM of the radio), one can decide that a variation of +1 code state 1 of the bit and that “not of variation " codes state 0 of the bit. In this case the valence equal 2.
But if one adds the two bits to code them in only one variation, one could have:
“not of variation” if the two bits are to 0,
variation of +1 so only bit 1 is to 1,
variation of +2 so only bit 2 is to 1,
variation of +3 if the two bits are to 1.
K, (k): Ca please say kilo, thus 1000 (if one speaks about Hz).
M: that please say méga, therefore 1000 times one kilo (if one speaks about Hz).
G: that please say giga, therefore 1000 times a méga (if one speaks about Hz).
if one speaks about Hz?
Ben yes, for the data processing specialists who measure bits, 1 kilo 1024 are worth (2^10). It is insane not? But like one is mistaken that of 2_, one lets make confusion.
Thus in my example one can code 2 bits during one time of the frequency (one period corresponds to one Hz).
The way of coding the bits makes it possible today to place until 256 states (= 8 bits) per period (0.125Hz by bit). But these systems are more sensitive to the disturbances and by consequentle flow reality goes down again in conditions of ground (practical flow different from theoretical output).
This is true so much so that one prefer to change system of coding when the connection is bad. It is what explains various possible flows of WiFi according to outdistance.
When a WiFi material tries to change system of coding, not badly of bits are lost. It is thus preferable to select (manually) flow right in lower part.
The spectral effectiveness
flow (in b/s) by the carrier frequency
WiFi) and by the number of cells. A
cell is one
WiFi, there is as much as connected users.
WiFi 802.11b has a maximum spectral effectiveness of: 5.500 000 (b/s)/2.450.000 000 (Hz)/1 = 0.00224
Ca wants to say that one transmits 445 times the same bit (445Hz by bit). It is much, and it is improvable perhaps with802.11n(theoretical output 320 Mb/s for 2.4 or 5 GHz)(7.6 Hz by bit)
The spectral effectiveness gives an idea of “output” system of coding.
All this is true only in the condition of comparing system codings which have samebande passante (BP).
Kézako? (that is what it is?): It is the diameter (of) pipe (X) used in parallèlle multiplied by (ur) the number. The band busy is then the equivalent of the sum of the sections of the pipes used. There you understand that more I have pipes in parallèlle, more the aggregate rate will be high.
A pipe is a channel. A canal has une width of bande (difference between frequency more high of the channel and the lowest frequency) which corresponds with the section of my pipe.
For information, the 802.11b has 3 (or 4, to see low) disjoined channels (on 13 available in France), whereas the 802.11a have 8 disjoined channels.
One cannot thus compare spectral effectiveness,que for the same BP. l' effectiveness should not be compared spectral of fiberoptic, who has “I do not know how much width of channel” time the number channels (160), with the spectral effectiveness of WiFi 802.11g who have ONLY 13 channels with 20MHz by channel…
To compare one would need a measurement which divides the effectiveness spectral by BP.
When one arrives at a spectral effectiveness near to 1, it will be necessary to worry about the antennas used. Indeed, les antennas with whorls (the omnidirectional ones) superimpose them adjacent waves (periods of the signal, the Hz, for one even bit). The antennas which have one dipole, will not have this problem (example; the family of the SD27).
Which is the bond between flow in bit/s and bytes transferred?
One takes as assumption that
system of transmission
is not reliable. Thus
one sends a whole of bits (a byte, or one
package of bytes) and one checks that they are well
that one applies before the emission a calculation which gives one
and one sends also the key. With
the reception, one
key, it must be equal to
the received key. If the
summer abimés during transport
(different keys), one in
inform the shipper and one them
checking and the abimés bits occupy one
part of the flow,
what explains the difference between the flow
theoretical and flow
The more the bits are abimés, the more the flow decreases.
There exist protocols which do not check the good one reception bytes: UDP (which has the same role as TCP).
One can check a byte with a bit additional, that apelle the bit of parity.
One can check a package of bytes with bytes additional, that apelle CRC or check sum.
Count 10 at least _ flow for
control bits (for
a protocol worthy of this name),
what makes un byte for 10 roughly speaking bits
Which are the various standards of WiFi?
The 802.11 is
nomalisé by the IEEE.
Le a, le b and nconcernent it electronics, the others are layers rather software.
|type||comment||carrier frequency (MHz)||theoretical output (Mbits/s)||range with antenna (S)omnidirectionnelle (S) (meters)||range with antenna (S)unidirectionnelle (S) (meters)||treatment of the signal||No. of channels|
|802.11a||good for the city||5700||54||50||ofdm||12|
|802.11b||most widespread. good for the countryside||2400||11||100||8.000 (legally, if not more)||dsss||13|
|802.11c||functions “bridge”. becomes 11d|
|802.11d||limitations France and Japan||13|
|802.11e||quality of service (ping and flow minimal)|
|802.11f||roaming (change of access point without disconnection)|
|802.11g||B version “city”||2400||54||100 without obstacles
||8.000 (legally, if not more)||ofdm|
|802.11h||management of power against mutual jamming||5700||ofdm|
|802.11i||safety, replacement ofWEPThe WPA is not retained (with TKIP).
Le WPA2 is retenu, based on an encoding AES.
|802.11j||as (legislation has it different)||4900|
|802.11k||routing according to the quality of service,geolocalisation|
|802.11ma||Amelioration definitionsau level of the physical layers (PHY) and access to the media (MAC)|
|802.11n||pas before 2006 (use of technology MIMO).||2400 or 5700||320, 600
|higher than the 802.11g
||??? depends on the number of antennas (3
|802.11p||Wireless Access in Vehicular Environments (WAVE). roaming fast|
|802.11r||roaming rapid directed continuous flows, streaming kind video, VoIP etc…|
with a grid ;-)
assessment in March 2006
|802.11t||Wireless Performance Prediction (WPP) methods of test, QoS.|
|802.11u||harmonise the communicationentre WiFi and networks external (telephony)|
|802.11v||gestion networksWiFi: monitoring, configuration and update (centralized)|
|802.1x||authentification on waiter|
Comments on the table:
range: with an one-way antenna (only one direction, 5° approximately) or omnidirectional (on 360°)
the number of channels depends on the laws on each country. Japan is passed from 3 to 14, others 8 or more. France passed from 3 to 13, but by keeping a WORSE limitation, i.e. one can legally use only the antennas omnidirectional of origin if one does not separate the emission from reception.
More there are channels less one has chances to be scrambled mutually in the same geographical area.
Parmis the 13 channels available in France, it would be possible to use 4 of them disjoints (which does not interfere between them; channels 1,4,8 and 11), if one takes into account filtering. (Passe-bande (in pi) constituted of 3 components before the exit antenna?)
The usual disjoined channels are: 1,6 and 11.
The more one is scrambled, the more the flow drops (automatically).
Treatment OFDM is more suited than DSSS to to eliminate it mutual jamming.
With the WiMAX, other standards arrive.
source wireless-fr.org/b002_norme80211a Marc Olanie
source hsc.fr … securisation_802.11b.pdf
Y' has what has to take that which goes most quickly?
The increase in the carrier
frequency has 4 effects
1) the course of the radio waves approaches a line (like the light). Disadvantage: one does not circumvent any more obstacles. Diffraction becomes weaker. Diffraction it is when the object which receives the wave becomes small transmitter.
2) the waves reflected on walls are more strong. (phenomenon of echo: advantageous inside buildings, becomes scrambling if one receives the principal wave and sound echo.
3) it authorizes a flow (in méga bits by seconds (Mb/s)) higher.
4) the way traversed by the waves in the air, for same received power, is lower. Diffraction in the air, rain, snow.
It is for that which I say that of WiFi with one high frequency is better for the city or the interior of the batiments, then that WiFi with more low frequency is better for countryside.
I do not know what it is of
walls. A priori, I would
say that with the increase in
the waves cross better (x-rays to do radios of
human body). More the
matter contains water or
more it stops the waves. One
needs holes larger than
wavelength for letting well pass the waves.
The wavelength is calculated as follows: lambda = speed of light /frequency.
Example: 12cm = 300.000 km/2450 MHz.
Théorie source radio and calculations , la theory of the antennas summarized a little (in English)
I simulated comparisons
(large a mercy
in Bent Roger
and its software “Radio
144 MHz (frequencies of the radio operator amateurs),2400 MHz5700 MHz
Why y' has 2 antennas on the AP?
Everyone agrees to say that electronics selected the antenna which receives best, but…
A AP is an Access Not (Access
electronic boitier able to receive packages of bits
of a shipper has and to send them to one
recipient B, then
that has is not in connection with B. One calls that the mode
in opposition to the “ad hoc” mode which does not
to make relay.
The antennas in question are omnidirectional.
That is to say the problem which consists in making an antenna who does not collect that a transmitter, at a given place, with an aim of being it less scrambled by the others.
The principle is “to work” these differences to reveal only the wave which comes from a direction data (our transmitter).
That is to say a part or there
are a musical bottom, and two
in the corners.
I place a microphone (A) close to that which speaks, and one other microphone (B) with the mileu of the part. By electronics, I calculate the signal resulting from has less B. This signal gives me le speech of has without the musical bottom. It is like that one fact one-way microphones. Finally almost.
As the sound is propagated with 300m/s, it is necessary that I delay (for to superimpose) the signal of the microphone has before withdrawing to him the signal B. For 1m between has and B, I must delay has of 1/300 S, equalize 3.3 milli second (3.3ms).
With our two antennas it is
the same thing, except that
waves move with 300.000Km/s. I
it is that it
10cm => 0.33 10th-9s = 0.33 nano second =>3GHz
Antennas with 8 branches existent, but not yet for WiFi (though). It d'antennes acts adaptatives (intelligent). In this case one does one species oftriangulation (by treatment of the signal) between the antennas and the point distantpour to filter the signals which are intended to him. Antennas must be isolated of a half wavelength (6cm for WiFi) (dephasing of 180°), this relates to only the omnidirectional aerials to make them equivalent to an antenna one-way at one moment T (see ZoneFlex from Ruckus Wireless). It would seem that the UMTS will not benefit from this system, already operational in other countries (Asian).
One from of thus deduced, that in urban environment (there or there is many echoes), modes “right antenna only” (or left), give less good performances that the mode diversity.
The treatment of the echo on
similar, put at
leaves that the wave is shifted much in
since it course of the larger distances. Thus one
of way of 15 meters corresponds to one
difference in time of
50 NS (20MHz).
One can also exploit the
to determine the distance to the AP, and thuslutter against the hacking
Products with 7 antennes is in project at Netgear, with the “BeamFlex technologyThe competitors Linksys (Cisco) and US Robotics await standardization 802.11n. Belkin proposes (March 2006) materialincompatible with the future standard 802.11n
should use MIMOEspecially
that there exist puces
dedicated to the MIMO (11/2007).
If technology is mixedMIMO
and non-MIMO, one gains nevertheless in
flow, but not as much
that with all the apparatuses in MIMO.
source wifi-vitry.net/article Marc Olanie
Yes, but all that they is assumptions?
not since j' have
Initially it is necessary to move away the thingummies wifi parce sufficiently whether they “sprinkle” or “radiate” with a little everywhere (I checked with paper aluminum to make mask), all is not armoured inside. I suspect them to sprinkle (also) by the cable of food (considering that the part transmitting is right with dimensions of food part, finally on my USR2249).
My AP continued to function whereas I had disconnected 2 antennas, the guy. I moved away them (one on the 2nd floor, the other with the DRC), once separated from 2 times 25cm of concrete, that calmed. I gave the antennas to carry out the tests
Then, “it” is said to me that the selected diversity mode better antenna?? Thus if I in suprime one, then that I gives and that I remove the other, (by keeping all environment identical (position, orientation, polarization, natural person in the beam of waves, etc.)) then mode diversity must function at least as well as one of the modes only one antenna?
Ben they is FALSE, it walks more badly, ya not photoWhether it is the right-hand side or the left which I connect only.
Moreover you can test yourselves! (be methodical, rigorous and patient)(one draws the conclusions only on what is répétable).
Attention, the diversity mode
is a mode of training, it
fact of the tests. I
thus made an average slipping on 8
measurements (several tens of seconds), and I concluded when
measurement is stabilized. Contrary
the modes only one
are stable as of the first measurements.
Ca seems logical, since it has many treatments (described above) to many measures, to make in mode diversity.
The diversity mode seems very “intelligent” since if I put an one-way antenna (on the right exit) in more of the 2 basic omnidirectional aerials, it is left there very well! Ca please say that it does not suppose the spacing enters les antennas like constant, but which it has an algorithm more complicated. By analogy with the microphones, it is a little like if the one-way one collected the signal of that which speaks (A) and the 2 omnidiectionnelles ones collected the background noise (B).
But the manufacturers, they say ...... Manufacturers protect their secrecies of fabriquation.
Moreover the tendency is to be protected moreover in more. At the beginning, the materials could be programmed (example of those which contain PRISM II) whereas my USR2249 (more recent) who contains a ACX100, is protected. The kit of development is communicated only to the partners of Texas Instruments. These partners engage (by contract) with not to diffuse the kit. unixiens write pilots, thank you with them!
But good, the last chips are credits, and allow “to treat” also network GSM. When it is known that certain solutions of payment (“protected”;)) ) on Internet, are based on codes communicated by GSM, you see what I want to say…
And then when a manufacturer (Agere) arrives atrésultats (technic MIMO: 162Mbps in 5GHz) , it releases a little knowledge.
to take the control of its material via Ethernet (RJ45 or
since a PC?
charts PCMCIA with a chip
[PrismII based cards: limited functionality]
Ambicom WL1100 PC
Dell TrueMobile 1150 Series
D-Link DWL-650, DRC-650, DCF-650W
LA4111 Spectrum24 Wireless LAN
Urgent Linksys WPC11 Wireless
Efficient SpeedStream SS1021
source pcmcia-cs.sourceforge.net/début 2003.
To choose its material, herelist
compatible with NetStumbler,
a tool for scanner/to seek access points.
(Linksys/Cisco) turns under Linux (y' in has which very
and thus can for this reason,être
charged with what one wants inside. For example SveaSoft or OpenWRT.
their emboite the pas,
but with only one antenna: - (
Here are others:
Sveasoft (17 euros), DD-WRT ProjecHyperWRTWifi-box projectOpenWRT (for the pro of Linux).
source des URL above.
5 of WRT54G, did not make it possible to change the software
it is possible, without modification of the material.
The customer is right always, thus, Linksys/Cisco having included/understood what made the success of the WRT54G, it leavesWRT54GL (L like Free?)
With the case or the WRT54G a rare food product, the RAN devriendrait group, and more particularly François Laperruque, propose one alternative (for the moment in 802.11a with 5GHz); the chart “WRAP " and its software (voyage Linux) and the charts WiFi (miniPCI) which go inside.
And as the RAN group is very active, Marc Dilasser, it Breton, gives usune description of the Buffalo WHR G54S which is an alternative to WRT54G.
Boxqui has in more one modem ADSL and the voice on IP
It is a
“box” multi-operators, if you want.
The problem it is thatl' antenna is not detachable!! aïe! damage, not good for the RAN.
166 euros/unit oupss!
For a portable PC, best is to
have a connector
external on the chart PCMCIA, exemple
what is used for to take the control of its material?
It would seem that the electronics of the AP or the WiFi charts that is to say the same one. On the other hand the prices differ, and them functions too!
In short, there are two types of material: the 802.11a and the 802.11b.
The 802.11c types, D, E, F, G, H, I, 1x, are only software who can be placed in microcomputers dedicated to these tasks (microcontroleurs are said) and consequently locked up in a boitier.
Another solution consists in programming it material since your computer (the PC). When the logiciciels are available AND that the material allows this programming, one can to choose the functions which one wants to make with WiFi.
- to adjust the power of the emission part (to minimize les interferences) [; -) with FT&ART],
- to post the force (dBm) signal received (that avoid being equipped of a portable PC with pcmcia and netstumbler),
- to connect WiFi to the LAN (network filiare) (with a catch (RJ45) and a cable which joined the charts network of others computers),
- repeater (to be used just as relay to connect 2 others wifists),
- router (to choose towards whom to send a package received which ne is not intended to me),
- waiter of IP addresses (to allocate these addresses dynamically (DHCP)),
- waiter of authentification.
The problem is that if one
to move away the antenna from the PC,
to put it on the roof for example, the power sent
received by the material WiFi will be
lost in the cable (one
“pigtail calls”). And on does not put the PC
on the roof
How to know if a WiFi connection will go, without material?
For outside, the software
“Radio operator Mobile” allows
- emitted power,
- losses due to the cables and connectors with the emission,
- profit of the sending antenna (plain or omni directional),
- losses due to the relief (and other characteristics) of ground,
- losses due to the distance in the air,
- profit of the reception antenna (linked or omni directional),
- losses due to the cables and connectors to reception,
- the threshold of sensitivity of the receiver.
Alas, I did not find information on the buildings and the trees (information “sensitive” for soldiers). Thus an impossible connection according to this simulation, will be really impossible. On the other hand a possible connection ne will be really that if there is no obstruction by buildings or trees. In this case, only the tests will be able to answer with the question. If one sees (with the eyes) the distant point, it is inevitably not the best case, but ya the strong ones chances so that it goes.
Here what can produce the software “Radio operator Mobile”:
The green bonds authorize a flow of 11Mb/s theoretical (or 54Mb/s), the yellow bonds authorize 1Mb/s.
For the interior of a building, the Wiplan software of atSygmum(the company do not exist any more), allowed to simulate the cover of each AP:
But this software is not
available any more because it belongs
to the INSA of Lyon, as Guillaume explains it to me Of
Rock, a programmer of Wiplan
On the other hand, other software exists:
- "SITE PLANNER " of wireless valleynetorange.comairwave.com) with The USA which has just been bought (2006) by Motorola,
- "WINPROP " of Awe-communications in Germany. Example of result:
There are some which treats
the wave propagation into 3
to implement the software “Radio operator Mobile”?
Le logiciel "Radio Mobile " use data of altitude to simulate connections radio.
A partir de maporamaet of one postal address, you will find the coordinates in degrees/minutes/seconds, to locate a WiFi station in the software.
You will find the data of altitude for your need ongeoengine.nima.mil
I used the formatdted0avec the precision “Military Specification”:
Desired Product Level = DTED
level 0 (30 arc second)
Navigate using = Starting Center Not
Starting Center Not, to seize the coordinates
to click “roam DMS” => new page, to go in bottom, to correct the coordinates to have multiples of degrees,
to click “raster to export” => new page, to click on the file ZIP, which makes 80Ko by zone of 1 degree square.
To decompress by keeping the repertories.
ancestors of WiFi in France?
Yes, of the networks radio operator amateurs already in place (144MHz for 9.6Kb/s), we give the example: f1te.org/numerique
framework of excavations in the Russian basement
100m of depth, the Russian scientists found
vestiges of copper wire which went back to approximately 1000 years. Les
Russians concluded from it that their ancestors laid out
already it there
is 1000 years old of a network of copper wire.
The Americans, to make good measure, have also proceeded with excavations in their basement until one depth of 2000m. They found glass fibre remainders there.
It proved that they were approximately 2000 years old.
The Americans concluded from it that their ancestors laid out already 2000 years ago of a glass fibre network numerical. And that, 1000 years before the Russians!
One week later, in Belgium one published it official statement according to: Following excavations in the Belgian basement until a depth of 5000m, the Belgian scientists do not have anything found whole.
They concluded from it that the Former Belgians laid out already it there is 5000 years old of a Wifi network. “: -)
the price of the material to date?
there are many sites!
a link long distance is established?
On remplace the antenna of origine by - is an antenna the commercial (SD27 24dBi, with 65euros), - is an antenna manufactured oneself (limps of ricorée 11dBi) (antenne strainerOne can also put a keyUSB in one limps of ricoré, but on ne does not know the profit
Des clés USB (which makes 15dBm instead of 17dBm for the AP) exists with external connector, to connect an antenna at fort there profit:
If you have chance, your key USB contains perhaps one connector U.FL (inside), Comme that one:
and here with a pigtail U.FL (towards RP-SMA undoubtedly) connected above:
This connector seems to be a MS156, rather than one U.FL (need for a point of adhesive).
Attention with the mechanical brittleness of assembly!!
The WiFi material of origin is delivered with one (of) antenna omnidirectional (right stem which “radiates” all around it, with 360 degrees), to respect them laws on power output in an unspecified direction.
By replacing this antenna by one-way (which only in only one direction) one emits increases (one concentrates) power since the wave is not sent any more on 360°, but on 18° (approximately) only, therefore 20 times more.
The P.I.R.E is the radiated isotropic power equivalent. It is the maximum of what is measured around (360°) of one antenna. Thus for the same power sent by the cable (pigtail), an one-way antenna will have WORSE 20 times higher with omnidirectional. Precisely dBimesurent this faculty to pass the waves in air.
Hold, for example here are some photographs of my antenna ricoré, connected to my AP (a USR 2249):
and when I would like to put 3 ricorées (to make a network with a grid), I would use onecouplor 3 voies, oubien I would manufacture it myself (considering price of $60).
One uses a coupler to have a adaptation
of impedance (50 ohms) and not too many losses.
After being itself occupied antennas, it is necessary (to try) to regulate certain parameters related to the travel time (longer) waves, to obtain good flows
For the moment (09/2006) it is not possible that by changing it firmware (software) of the WRT54G and en carrying out UNIX orders
(thank you Didier).
If one does not fear the illegality, one can also put one WiFi amplifier on each side of the connection.
one takes omnidirectional a step expensive?
avec du gros cable hyper frequency bidouillé.
With a little more work, on
can make 10dBi with 7 whorls, oubien a 14dBi
(9 whorls) at a cost of almost 10euros (without
madeleine and the end of chocolate; -)).
what can scramble us and which scrambles one?
The apparatuses which are on the same frequency or at frequencies harmonics. A harmonic is a multiple frequency of one another frequency (of which the division of largest by more small an entirety gives).
with 2.4GHz, there is (I always do not have checked these information):
the microwawe ovens (I have checked),
the missiles crotales or radars of the Army Frenchwoman,
transmitters (or cameras) for to off-set it video (television),
certains radars automobilesqui, in WiFi, close to the road,theirs envoient information with the police officers hidden further.
The tool to observe if the
frequency is free
be called one
analyzer of spectrum, but it costs an arm and a leg! By
against there exist equivalents not expensive (150 euros when
09/2006), to seeWi-SpyOne
external of Wi-Spy
A beautiful morning the network of Sylvain did not function any more, afterwards investigations, it determined that sound network was scrambled.
Stephan, Sylvain and myself let us have decided to seek it culprit, with a WiSpy key which was made directional thanks to one limps of ricoré. Here thing: Then we checked directivity by putting a AP on channel 2 with one “beacon interval " of 1ms (at bottom thus):
Variation of the width (of the intensity in fact) of gross column on the left must with the fact that I turned the antenna in another direction that of a. On channels 8 with 11, one a normal use of WiFi (beacon interval of 100ms) sees.
Then we left to
fish… and we found one
beautiful LINE: -) a frequency with 2434MHz which
bell-tower of the church:
After a psychological pressure exerted by Sylvain on owner of the hovel, it is proven that our jammer consisted of a camera with video offset, which is not perhaps not approved in France, if it comes the USA (200mW).
The apparatus génait also a WiFi printer at another neighbor.
As an information, my “wavemeter” does not have anything found, since the power was not enough raised for him, then that this same power scrambles WiFi which works with of low powers (- 60dBm).
A solution (temporary?)
to change channel on
the network of Sylvain. If
the parasitor persists, it will remain
if it exceeds the French standards (with
to see with the ANF, 1500euros
of fine). If it is not
the case it does not remain any more which has to pass in
802.11a oubien to put fine netting to make obstacle. La
bandage 2.4GHz is free with all that implies!!
To have an idea of the
of use of the waves
radio, look byexemple
How to do without the electric cable until the AP?
has to use unutilised wire of a cable
RJ45) to bring the food to a. Wire
dated) correspond to a use for
telephony (ISDN). If
you directly connect the AP to the PC it is necessary to use a cable
crossed (also called “modem cable”) which connects:
connections “tranceive” of with dimensions has with the “receive one” with dimensions B,
connections “receive” of with dimensions has with the “tranceive one” with dimensions B.
It is thus judicious to use the twisted pair (7-8) for to bring the food. “Returns of measurement” (judicious) can be used with terminals 4 and 5, for to check that the tension with the good value at the boundaries of a.
Caution!!! I was made have, when I have cabled that, that did not go. The indicator “power” ignited but the AP did not function (the indicator dated does not ignite).
Explanation: my Ethernet
cable made 25m (one has right
When I put the food of an
end (with dimensions PC), other
(with dimensions AP) I lost 1.2volt. Like the food
(in load), there remain nothing any more but 4.7 - 1.2 = 3.5v, and
Alors what to make? 4 solutions
1 - to put the computer in the attic, with one cable Ethernet of 5m: Ben let us see!!! it is owl as solution (them owls live in the attics, not me).
2 - to use the 2nd twisted pair to put it in parallel with the first, as that I would lose 1.2/2 = 0.6v, therefore the AP will be fed into 4.7 - 0.6 = 4.1v, I do not have tested, that perhaps go (for 25m).
3 - to change the food for another which deliver 4.7 (or 5) + 1.2 = 5.9 (or 6.2) volts. Like the consumed current do not vary, it is not the sorrow to seek to control tension with 4.7v with the 2nd twisted pair.
4 - to use the POE only at one minimal distance. If the goal is not to put a 220v under the rain, the useful part of POE can be summarized at distance AP/attic. In this case length POE is equal to: length of mast + 1m (to go to the shelter of the rain). For a mast of 4m, made Ca (25/(4+1))= 5 time less voltage drop, i.e. 1.2/5 = 0.24volt. There,c' is sure that it goes, since there remain 4.7 - 0.24 = 4.46volts. To 4.2v it goes, to 3.8v it goes more.
One can notice that there remain 25 - 5 = 20m of pair twisted who can be used to bring the 220v until the food (it is more aesthetic to have 1 wire which traine, rather than 2 (according to my wife). The risk is to bring parasites (50Hz) on wire of data, but like the current is weak there is chances that it goes.
Calculation of the current on the 220v: puissance= 5volts * 0.8 amps = 4watts. A bad food should have (with the conk) one output of 0.7, therefore power absorptive on the 220v will be of 4/0.7 = 5.7watts. For 220v, that made a current of: 5.7w/ 220v = 26mA (milli Ampères) which does not induce parasites on wire of data.
10/100Base-T and the cablage
Which solution to choose?
It is you which see!! Personally, I chose the numéro
4 (minimal distance = 5m); elle
terminal voltage of the AP is (in load) of 4.2v. For
parasites, y' does not have any, according to my measurements which are
duration of the “ping”. I have values on average with3msThe players in network will appreciate!!
The “ping” is an order which I type on line, i.e. - in a window “terminal” for the unixiens, - in a window DOS for the windosiens. Syntax is:
with X to give address IP of the material wifi distant.
The order ping is used to know if a machine is present on Internet network.
Caution: the firewall
(avoid-fires) can stop
orders “ping” (ICMP echo)
For the continuation, @ wants to say address.
C' is what a hub (repeater), a switch, a bridge (bridge), a router?
All this equipment provides the function “modem cable " or cables cross.
the hub connects all
the bridge filters the @ip according to @ mac,
the switch is a bridge which moreover separates the types from networks materials (concept of bit),
the router separates the fields d'@ IP. The router must to be configured to function.
The MAC addresses it is of Ethernet, IP addresses it is of the Internet.
The MAC address is closely related to serial number of the material Ethernet network. I point out that WiFi is initially of Ethernet. For certain materials, it is possible of to change l'@MAC, therefore mistrust on safety based on filtering @MAC!!
L' addresses IP (xx.xx.xx.xx) can be fixed or re-used (y' does not have any enough for everyone on Internet). L'@ IP is coded on 4 bytes, that made 2^ (4*8) = 4.294.967 296 (4 billion) addresses possible, but that is not enough.
How to choose between fixed or re-used address IP?
If you bought one @ fixes, it
is single with
against those which one not bought fixed d'@ IP, and which in
choose one randomly, can take of them one which has
bought by someone else, and can, one day, to enter in
conflict with this one. Of
or interest to ask one of them
For example, the supplier of access Internet (FAI) gives some one different to each time one connects oneself with a modem 56K, or connection ADSL crosses every 24:00 to force reallocation of one @ IP.
Who buy IP addresses?
The FAI, the companies, that avoid to them to have time of calculation and of the flow network dedicated to part of re-use.
Addresses MAC, addresses IP re-used, how that goes?
The MAC address is coded on 6
fact 48bits. 2^48 =
281.474.976 710.656 (280 thousand billion) possible addresses.
This makes it possible to
allot a single number to each
One indicates by “brin " the whole of computers which are electrically connected (with a cable modem (2 ordi) or a hub (several ordi)) by Ethernet.
When one puts this material
in the computer,
this one goes
to charge with finding one @ IP corresponding to the @MAC (
opposite correspondence (stored in a table) is made
protocol ARP). For that,
it will ask all them
same bit, by a request which speaks
with everyone (broadcast
in English). The
computer with which one programmed
will answer (in broadcast) the computer which has
fact the request,
by a value d'@IP. This fonction
be called DHCP
When a material wants to speak with a @IP, it will use count ARP to find l'@MAC, and to send information to him.
The computer which answers provides the function waiter DHCP, the ordi who request is customer DHCP.
Attention, if there are several computers which answer, it is fastest which gives l'@IP!!
The normal configuration is: Only one waiter DHCP by bit, or at all.
Not of waiter DHCP on a bit?
Function DHCP is
hierarchical. Ca please
that one can
to propagate this request (on different bits)
(it is said that
the protocol is “routable”) until finding one
The equipment which sees 2 bits must have 2 @MAC? bingo! it is one switch or a router.
Today the AP can make customer
DHCP and waiter DHCP,
or to have a fixed @IP. The
AP sees 2 bits, the telegraphic network
the catch RJ45) and the wireless networking (WiFi).
I observed that with the DHCP,
WiFi, which was
solved when I passed in IP
statics (@IP allotted manually). This
solution is not
certainly not the good one. My
material: WRT54G and DWL520G,
with a USR2249 out of repeater.
provided an explanation which plait me well:
disconnection every 10 minutes: it is
with the fact that the PC
is in “automatic” address IP, in other words the PC goes to ask an address IP
with waiter DHCP of the modem.
This waiter “lends to him” an address IP for a lease of 10 minutes.
Beyond that, the PC must Re-ask a new address IP.
To do that ports 67 should be left & 68 open in UDP (that is regulated in
your firewall) because if not the PC cannot require/receive sound addresses IP
and thus it cannot be connected any more to Internet => disconnection.
Under Win98, duration of the
post yourself with
The address Can IP, it be unspecified?
It @ held there:
127.0.0.1 (“localhost”, which wants to say “myself”)
10.0.0.1 with 10.255.255.254
172.16.0.1 with 172.31.255.254
192.168.0.1 with 192.168.255.254
who are interpreted by materials network to ensure function particular. For example, by convention, one give 192.168.0.254 for one @ IP of a router.
@ the IP are selected in ranges of values, which are programmed in waiter DHCP.
@ the IP are sold by an organization (internic). To make economies, those which achété @ IP make use of it for to be identified on Internet, and, “mask” one sub-network behind these @ IP. Thus the sub-network can accèder with Internet. Ca is called the NAT. I would speak again about it.
Yes, but I did not buy d'@IP
me! , then?
Ben the supplier of access to Internet (FAI), him, bought @ IP.
It is what a mask of sub-network (“subnet mask”)?
It is something which
expresses the size of under
which is the range of its @ IP. Bytes
(or bits) of the mask
who are to 0, correspond to @ possible of under
bytes (or bits) to 1 correspond to what is not
not under network
(outside, Internet). The
1 is on the left, them
0 on the right
Example: the 255.255.255.0 mask, expresses that under network can possèder 254 computers (the 0 and the 255 are reserved, thus 256-2=254)
There exists another notation
of the mask, added
with @ the IP: ww.xx.yy.zz/NHere, NR means the number of bits with 1.
For the 255.255.255.0 mask, NR is worth 24.
One applies the mask to l'@ destination, for to determine towards or to send the packages of bits.
The interest of the mask is to identify if one @ IP of destination is under network or not. If the destination is in under network (even bit), one sends it directly with the ordi recipient, if not one sends the request towards the ordi which is connected with Internet (footbridge).
How to identify the computer which is connected to Internet?
One affects one to him @ IP reserved which is made for that, this ordi is called footbridge or “gateway”. For example 192.168.0.1.
To have one addresses IP, that is enough?
Not, to post this page, you
did not type d'@
that functions), but “HTTP: //yves.maguer ......”,
there is thus a correspondence which is made. This function
be called DNS, it is ensured by a waiter DNS. Le
DHCP can also configure the values of DNS.
If a machine is present
the order ping (said “pinguer”) by its @IP but
not by its name, then there is a problem of DNS.
There are more qualified
Explications with captures of screen (Windows 2000).
Les routers between FAI are localised in Paris. This increases the ping in province and limit unnecessarily it flow with Paris and especially the flow province-province.
Les Can AP go on the roofs without problem?
NOT, the AP are conceived to
used in interior (with
this day). There are 2
to solve: the bad weather (rain,
wind) and the temperature. With
the temperature, my
AP, a USR2249,
broke down, there was in the history: “AP card
After placehaving placed it in front of a ventilator, it east went back to to function. I thus realizedune turn of refroidissementplacée on the roof, for he. Ca it also protect from the rain. I do not have fear for cold, because it consumes 4W and that is enough with to protect from cold when it functions.
The short period of omnidirectional aerial which exceeds large tube, is enough to sprinkle all the house (2 stages).
With this installation, the heat wave does not have it géné!
Good, and then I have a second
apprehensive, which goes badly even to 30°.
While launching navigator Internet to go to config. of the AP, in the mitre “status”, it sometimes posted there
Wireless MAC: 00-00-00-00-00-00
And there, it does not make any more connection with another material wifi. (the luminous witness of the medium does not flicker of way variable).
Solution: (do not laugh), you disconnect it to you put with the regrigerator during half an hour, you replug and it remarche until one cuts to him the 220v.
The AP WRT54Gsemblent wet
cold being sensitive. Locked
in a box seals of electrician (example:
Legrand 920 62, 220 X 170 X 86 cm, approximately 20
with at side or below the AP, one
heating, regulating system
of temperature (between 10 and 20°C) (thermo plunger
of aquarium in
driving position with a diode in series on
220V (1N4003 with 1N4007), lamp of terrarium with one
heating cord with thermostat), it seems to me that
to go. Attention
external cables (especially
do not have to move under the influence of the wind.
According to the thermo isolation of the box, I think that a heating from 10 controlled Watt with 10°C would be enough. The AP heat already of 4 Watts constantly.
If not, certain AP conceived to function in outsidecommencent to appear at DLink. D' others ici.
Les waves they is bad for health?
OUI, it is clear! On the other hand it should be known that it vient some du cosmos since the ground (and the human one) exist.
Thus all is question of quantity. Quantity received (power) isinversement proportional to the square of the distance (surface of a sphere according to the ray: S=4*PI*r²). With equal surface, the more one is near, the more one collects waves.
I applied following
Power of the source/(4 * pi * distance * distance). For
powers considered following:
relay television: 1000Watts,
transmitters FM: 1000Watts,
relais GSM: 100Watts
telephone GSM: 2Watts,
microwawe oven (power which escapes): 0,2Watt
WiFi apparatus: 0,1Watt,
if you want to test values.
Before criticizing WiFi, suivez these recommandationsconcernant the cellphones.
For me the essential one is: To always use the pedestrian kit delivered with your telephone.
Thus, you will pass under the red bar of the graph above.
I regret time or the cellphones had a connector for external antenna…
For the weekend of Easter,
to be tried with an egg and 2 cellphones.
As je do not know if it is a blague, if you made the experiment (far from a transmitter (power maximum of the telephone) and with a background music to force the emission), tell me…!
With the case or it would be true, one can understand that our brain “cooked” not when one telephones, thanks to the blood which control its temperature.
Followingl' business of the 40 employees out of 100 of town hall who have a headachedepuis that there are WiFi terminals in the public libraries of Paris, I indicated inrougela limit corresponding todégats irremediableproduits by the waves (zone delimited by one chain yellow and black, to prevent the access physicsderrière antennas GSM (with less 50cm)).
Then, why the cellphone with 1cm, is not not declared dangerous, whereas it is above bars red?
Because it does not sprinkle all the human body, like does it relay GSM with 50cm.
On the other hand, it was confirmed (seen on France2, 20h00) that it had effects on parotid gland, placed behind the ear which is used to telephone. Indeed, one sees that for the other ear (other side of the brain, with 17cm) the radiation is relatively weak (below the red bar).
"Le brain, the parotid gland and the auditive nerve are, indeed, among fabrics the most exposed to the radio frequencies during the use of a cellphone."
"Pour what is brain tumours nothing is still proven however it is noted that: at people reached of tumour with brain, among those which have a portable,la tumour is more often located 2,5 times on the side of the ear which was used. " CQFD.
Does psychiatrist cause??
My freebox is posed on my cathode screen, since years, therefore with 80cm of my head, and I am well, thank you.
Is necessary it to apply the precaution principle BEFORE having made a study placébo?? B2Lanoë sliced; it is not.
For me, it is YES, considering the existing studies before the facts and the massive use of the wifi. (good, for 40 people one can make an exception, that made pleasure and that costs anything (political principle?))
I met 2 employees of town hall which one says to me to have a headache, all 2, at the end of 10mmnderrière of the antennas, and I have believed them, without problem. Circumstances: on a tower water, truffé of antennasGSM, with panels and a chaine (yellow and black) which indicates limit (50cm) with whose the waves cause dégats irremediable.
Then the 40 employees of Paris are, in my eyes, of ..... large communicating. Let us await (12/2007) the result of the study nevertheless.
It is interest of the operators of GSM (which are intended on their respective market shares) to maintain confusion between harmful effects of telephones GSM and effects of WiFi. Do not play their game!!
Still quite good which makes me well laugh: the installation of brouilleurs GSMdans hospitals.
Then one prohibits the portables in the hospitals for to preserve the use of the medical device (and perhaps patients, know). For that one places one apparatus which emits more extremely (principle of jamming). CQFD.
You have a headache with the cinema??
Consequently, I do not
this study which would like to reassure us. Because
that this one measured with 1cm (distance
radiation of each one of our telephones
of independence? (Of
the testers of
have problems of memory (memory
in the short run; or I have
parked my car?)).
Téléchargez the passage TV of Richard Forget at Laurent Ruquier (“It black file of the portable ", that made 32méga, but that the blow is worth!! that makes me think of the share media which disputed the warming ( half) whereas no scientific study it disputed. (See “Une truth which disturbs", Al Gore).
When adorable Virginia asks Richard Forget if it WiFi it is similar, it answers “yes”. I him rétorquerais that one is not stuck the access point to the brain… (see table comparative above).
Harmfulness comes especiallydes telephones themselves, less of the antennas which are on roofs.
The proof, this study which shows thatça break them bits of DNA.
the WiMax terminals make 20
Watts of WORSE,
the transmitters FM make 1000 Watts,
relays GSM make 100 Watts (and there are people with whom one has nothing asked -étude in Marseilles, qui live just opposite
Les relais GSM become relays UMTSsans respect of procedures.
the satellites make 1000 Watts (but they are loins, with 36000km),
telephones GSM make 1 to 2 Watts (et one them stick to cerveau) (use the auricles or the textos). More it telephone is far from relay GSM (en campagne) more it emits extremely ( power is adjusted).
the wifi makes 0,1 Watt,
my microwawe oven (with same frequency) disturbs my connections wifi in the house, therefore the furnace “sprinkles” also the house, in spite of its shielding. Old man or nine, it is similar. Therefore I have him affected a power (0,2Watt for the escapes) higher than WiFi.
I do not have information on the téléphones without wireque one place systematically with the ear. However, consider that the terminal (bases) with which they dialogue, is close (10m). Thus the need for puissance to join the terminal (bases) is faible (compared to the telephone GSM, for which the terminal (relay GSM) is with 100m or 1Km or more).
So that a WiFi connection functions, it is enough that received power is of -60dBm, i.e. 0.000001 MW (1E-09 on the graph), or thousandths of micro Watt.
The ARCEP with ordered a study
in Supelec onpuissance
of WiFi; result WiFi isbien
authorized powers (decree n° 2002-775
from May 3, 2002).Voici
the study (12/2006).
A cellphone under continuous operation posed on eggs out of incubator, produces 6 times more death at chicks (considering on TV).
This stronger sensitivity for the organizations in the course of development (our children),semble to be confirmed here.
A chicken stockbreeder, saw his mortality to increase suddenly with the appearance of an antenna GSM with proximity of sound breeding.
It is notoire
people who work in the medium of the hyperfréquences,
are often FILLES
Influence on the eyes of the waves emitted by cellphones:
- The cornea exposed during a time prolonged with this radiation presents macroscopic damage affecting quality of the vision. The damage increases with accumulation exposures and reached a culminating point at the end of some days (192 cycles of exposure). As of suspension of the exposure, the damage tends to regress.
- On the microscopic level, other types of damage are noted. Small bubbles are created on the surface of the cornea. They are directly related to the beam microwaves and are not the consequence of heat generated in the cornea. However, contrary to those caused by the increase in heat, these damage is irreversible.
In any case, as long as one will not have, in France, ofinformations exhaustive on healthdes individuals, one will not be able to extrapolate what occurs for 62 million people in some month or years, with consequences more serious for thousands of people 40 years afterwards. See asbestos (100 000 died to come), radioactivity, etc…
Un beginning of statistics with Cmap.
Unless the statistiques ones do not come from the individuseux-mêmes? ( http://electrosensibles-victimes.be/
Une tenant who known as to suffer from electro-over-sensitiveness bound to the antenna-relays, in justice its financial backer attacks
And the role of the frequency? Ben, more one bring closer to the frequency of resonance of water (70 _ of our body) more one heats our body. This is typic WiFi telephones.
Dilemma, one is today with50V/mpour mobile phones. According to Denis Zmirou, (ex scientific director of the AFSSE) with0.6V/mon could more to have modern communications (include/understand with a flow bytes of disont (that engages only me)… 1méga bits by second). comparatif of the powers of the cellphones (11/2007).
I benefit from it to recall that the réseaux ones with a grid use less power (to voir Femtocell) that “dorsal” structures, since one does not state that with closest (more easy to join).
And I give a layer from there: antennes directionnelles, precisely, sprinkle only that towards which they point. Thus each one is not pas sprinkled by its own material, but by that of the other. I exaggerate a little because there are lobes parasites, but in the principle it is that!
Une proposition of loi (several parties) is in hand (09/2005).
There is WiFi
in the hospitals...
How to detect the radio waves?
For 20 eurosje
am to me
bought a multimeter
who makes measurement of capacity. On
gauge PF (pico Farad),
placing a wire of 3cm on an entry, I
I have say “I
detect”, I do not have say”je
Here the field intensity measuring device (or field-meter, or wavemeter) that I manufactured (thank you F1SXO to have provided me the diode1N21C
The value read is of 100mV to a few centimetres antenna omni of my USR2249 or my WRT54G (with a “beacon interval " of 1ms).
A un meter, at equal distance from the 2 antennas (the maximum), it remain10mV
Last weekend (12/2007), I was invited at a personen ville, to detect the background radiation.
I found (with this same apparatus) points with 15 or30mV on the balcon, and of the values of 3mV in all the apartment
At home, and people whom I know, there is, inside the dwelling, 0mV, zero milli volt, in normal conditions.
to put the mini-NCV of D-LINK DWL520+ in a toshiba
The same open one:
One tears off (or one déssoude) the cable side mini-NCV. Under PC, one finds 2 wire (white and black) with connectors. These wire make will 800microns diameter, and they are the coaxial ones which go on a connector U.FL:
The white wire is cut and one welds it in the place of that which one removed. Heuu… it is not with carried everyone, parkinsonian, to abstain from!! (I acknowledge being with limit of what I can make in the field) I point out that it is necessary to weld it shielding (with the mass, one of the 4 holes in square) and the heart of coaxial (with the central hole).
Here what that gives:
One will take care to fix the black wire (with adhesive tape) to avoid risks. This white wire is connected to an antenna inserted in the chassis of the PC. It gives very good performances, better than a pcmcia.
I very did not
include/understand but there are charts which have
connectors U.FL, all is then simpler!
to add a connector on D-LINK DWL-650+?
D-LINK DWL-650+ seen of top and lower part:
The chart opens while cutting the plastic with the cutter, on the edges. Then, 2 metal stems on sides slide slightly and the 2 hulls release.
I placed connector (female SMA at to weld) (more running is the female RP-SMA) with horse on the circuit printed, in manner to use the plan of mass to connect the mass and to ensure la mechanical rigidity of the connector. I have connected the central stud connector (on other side of the circuit printed) with the hole which is in the middle of the formed antenna of 2 spirals.
To weld the mass, it is necessary to scrape green varnish on 1cm square so that all the length of the 2 studs of the connector, is welded (better mechanical resistance). Here it detail side welding of the central stud, I used a leg of component like wire:
The same principle wasappliqué
on a DWL-G650, except that they welded
directly the cable
on the chart.
Others put petites omnidirectional directly on the chart
Me I would advise rather, for
mechanics, to do that:
by putting a wire for the red feature, by welding the connector at the blue points and while crossing, possibly, with the feature purple.
With WiFi is what I would be pirated?
"Le only case where you can break
pre-divided, is if it belongs to a dictionary or if it is relatively
if you want to haveun
unbreakable wireless networking at the house,
the use ofWPA/WPA2
and a password of 63
including/understanding special symbolesest
I consider that a key which needsdix ans(with the computers of today, out of grid) to be broken, isincassable
You can calculate yourself here the time necessary: http://lastbit.com/pswcalc.asp
are 6 billion on
pourcents has a computer on Internet, among these, 1 out of 10
thousand is malicious pirate which want you evil. This made
that there are a few tens of attacks per day on your
computer if it is always connected to Internet.
You put of WiFi in your computer, to date, you go to find some other computers on WiFi. Ben me I you say that there are few chances that your “neighbor” is one unpleasant, malicious pirate. Thus to connect itself to Internet is much more dangerous than to make a WiFi network.
And risks it for the attacker is not the same one, if it is to 10 minutes with foot, that if it is at 10 hours of plane.
information, if you have one
divided under Windows, you give the means to
the attacker (given)
to erase your hard drive, via Internet. A fire wall (firewall)
is a protection. You can
put the fire wall for you
I use “tiny personal firewall 2.0.13”.
In addition, if you use antennas unidirectionnelles, will piratedevra is to betrès near you (because of the parasitic radiation around your antenna), is to be in the beam of the waves (which will be with plusieures tens of meters height and which fact some meters of ray), is to betrès close to the point distant.
D' another side,
those which are interested in
new technologies are of a curious spirit. And with it
those which could make a connection wifi with you, have one
) allow to voir
directly with the screen, the images which
pass on a bond
WiFi (if it is not protected). Other
There exist CD
bootables (Knoopix/Unix) which contiennent
tools for testervous-même
secutity of your network.
A total solution atImmunity(08/2006)
The pirates (or
apprentice-pirates) attack the maillon
more faibled' one system. Today
it is it
for technical reason, but by ignorance
utilisateurs, because majority of the points
does not have or little protection).
There exist also failles WiFi in MAC (Apple)… not? … if, if… (correction Extreme Airport
Le pilote Linux MadWiFi is vulnerable to the attacks (04/2007)
The filtrage of
MAC addresses does not protect you, since
that one can simulate (one “spoofer says”) any
addresses MAC with certain materials. And like in addition,
the address MAC of your AP (and those of the computers which
connect above) is diffused by the AP, the pirate lays out
all elements to be made pass for one
Le WEP is not worth any more large chose today, because it is enough the quelques ones minutes of listening (secondesau 08/2006) to break a key of 128bits, with one flow of data sufficient. Tools of attack (wardriving) name kismet, airsnort, aircrack weplab, wepattack, and some combine a rough attack and an attack by dictionary. Voici a list of logiciels.
"au not to deserve the nickname sometimes ofWeak Encryption Protocol
Certain people believe
themselves in the shelter
not diffusing (broadcast) the name of their network (the SSID).
a weak protection, since it is enough to attaque by
dictionary on SSID to find it.
In the same way, the fact of not diffusing the SSID,ne mask not your network of the pirates. The pirate sees that you emit, and he sees that you hide your SSID. (provocation?)
attaques the passives
do nothing but listen to your AP, it thus does not have therestrictement none
trace your side, of these attacks.
I personally capté
a APnormal (without modification of the antennas)
placed on one
By definition, these attacks do not do anything on your machine, they aim only tocapturer your data.
Les attaques activeobligent le pirate to be emitted (for example for to make allot one @ IP according to its @ MAC). Thus, DHCP can help the pirate.
These attacks can corrupt your data or your system, but they are detectable.
I know people, whose pleasure
is to go to see in
repertories shared (by Windows) of
Net surfers (thus even
without WiFi) which does not put any protection.
And then a key of 8 bits (a
breaks into 255
tests (attacks rough), therefore if you put a password too much
short, it will be always fragile.
In the same way, if you choose a word of passes made up current words, an attack “by dictionary” will findfacilement this word of passe, some is your mechanism of encryption.
Against this, use characters generated by chance.La difficulty is to memorize them!!
KeysRSA of 1024 bits should be used until 2010et keys RSA of 2048 bits until 2030, to preserve a good protection.
To my knowledge, encoding (in
2008) is based on the fact that if
I multiple 2 great prime numbers P and Q which give NR, it am
very difficult to find them, if only NR is known.
Let me be delirious a little.: I calculate a value N=P*Q (P and Q two prime numbers of at least 150 digits)
If a key (NR) is that which I calculated, I know P and Q instantaneously (the time of a research in an ordered continuation).
Probability that an unspecified key, is that that I calculated is weak, but it exists.
Now, with a large machine (or several distributed) and a large base of data, I calculate des billion values NR and I memorize P and Q.
Probability that I find a key instantaneously (research in my data base on criterion length or figures of left of NR) increases…
Especially if it is known that one should not use P or Q with less 150 digits under penalty of brittleness with methods traditional…
My database will be consultable on line for one moderate … hein summons?? that made fear? not, I am delirious!! (05/2007)
Microsoft found a solution for to memorize the large keys: (WCN) key USB. It is why ZyXel propose material with a catch USB.
(at the beginning of 2007) itWPS,
for simplifier the setting in
encoding in Wi-Fi
For that which can touch the material physically, seizure of a simple code PINE or even support on a button.
For that which has access only by the waves, gross key of the WPA2.
Another solution, with the test (03/2007),avec SIM chart, at SFR with Defense.
I quote (in 2003):
All in all, per hour of today, a wireless networking in 802.11b presents only little of safety and little to be easily pirated, this is why networks without wire are still a danger to the companies. Of course, it is possible to add a safety higher around with in particular the use of VPN/Ipsec, of the standard 802.1x, Firewall, but well little companies are aware of the dangers that they take by installing this kind of material and do not take thus not these precautions.
Fortunately a “substitute” of the WEP is being studied, it acts of the WPA (WiFi Protected Access). Its operation is based on one system of exchange of keys dynamic, renewed every 10 KB of data, this process is called TKIP¨ (Temporal Key Integrity Protocol). According to the manufacturers, it will be possible of upgrader Firmware of your material 802.11b to integrate the WPA. This new process should improve appreciably the safety of the wireless networkings, only flat, the algorithm used remains unchanged.
to see 802.11ipour
evolution of the WPA.
Various apparatuses supportants le WPA2
Une mise up to date of the WPA2 for Windows XP (the patch: KB893357
protection in WiFi, good. L'Alliance
Wi-Fi makes compulsory the WPA2
A la grand' mass of the pirates and hackers, (22nd European Hacker Conference at the end of 2005 with Berlin, 22C3, Chaos Communication Congress) 3845 attacks did not come with boils of the WiFi network ofAruba, and that during 4 hours. A first!!Idem in mesh.
= 802.11i = protocol CCMP + authentification 802.1x (or key
divided) + coding AES
WPA = protocol TKIP + authentification 802.1x (or divided key) + coding RC4
WEP = protocol WEP + optional authentification + coding RC4
It would seem that protocols
(WPA/WPA2) not using not
of divided key
difficult to break
Voici ma source of information, and translation French automatic.
But, it would come you to the idea from you to connect to Internet without fire wall or antivirus?? not (I hope for it).
You know that today a “contaminated” computer by a virus, spyware, (and other tricks in “.ware ") can diffuse (without WiFi) with its author what you have typed with keyboard, for example? (the worm is in apple)(les banks react).
Thus for WiFi, as Internet, meilleure safety is that which you mettez in place yourselvesWiFiRadis
Do not offer to the pirates WiFi, the protected part (LAN)(by fire wall) of Internet.
I thus share the point of view of ozone, which crypt not sound network WiFi in the big cities. However, their access Internet is constituted of a dorsal which does not seem accessible to private individual (5GHz). See attack “man-in-the-middle”, le pirate is made pass for equipment which normally you connect to Internet.
To avoid that, CISCO, put in its AP and theirs customers of functions of monitoring (WLSE) who listen to and defer the arrival again WiFi material in the coverage area of those. This function of listening also allows to locate (with a minimum of apparatuses equipped) the materials non-WiFi, with an aim of removing them interferences.
Thanks to a centralized administration, one can then adjust powers and to affect the channels to optimize radio coverage.
Attention with the traps, when you surfez with your PC WiFi portable in the street, of badly intentioneds people install “hotspots hooliganspoints pirate accesses) which immitent them truths, but which enables them to collect your data confidential of connection.
Thus do not give your Bleue card number for you to connect to a hotspot, buy a chart rather prepaid.
To hide its data,il there the VPN hascroissance of 23 _ ventes in 2004) (idem in 2006
Le point of sight of the Befti (Brigade of investigations into the frauds with information technologies)(05/2006)
the VPN, la solution for the safety of WiFi?
it is what
a page of entreprise on WiFi.
a réseau semi-public, conveyed by Internet; completely hermetic Internet has
for IPSec on OS W9x and NT4
Trapezoid wants to centralize the management of the access points.
me, if safety is not with go,
it is the door
WiFi (WCS) . And now (01/2008) that bears a name, it
Failles and patchs at Wintel (Windows+Intel) on the wireless telegraphy. (charts PRO/Wireless 2100, 2200BG, 2915ABG and 3945ABG) and their software of administration PROsetSee the software Bad_Seed
safety gives reason to the purists,
(UNIX), which does not use
pilots whose only binary ones are available, is not
concerned with this kind of fault.
you want trier
users of your WiFi terminal, bad, it is enough for you to
their donner means
to join to you
You can do it while giving as nom on your WiFi terminal(field SSID) , your email
Thus, any user of your terminal which will not have sought with you to join, will be equipped with bad intentions.
It is necessary for you to activate the option which consists in diffusing this name (broadcast SSID = yes).
The frequency to which is diffused this name (beacon interval) is programmable (of 1ms at one minute, in general).
A too low value will collapse your flow.
A too high value will return to you statistically less visible occasional users, while being visible by your neighbor, who is to him longer with the listening of your terminal.
Under these conditions vous can observer, with AirSnare (downloadable here) (which uses if necessary Ethereal) les users who connect themselves to your access point (some that is to say their OS (Operating System)),et their to send messages (if you and they, use Windows NT, 2000 and XP (order “Net send”)), oubien to prevent the guards, vigils, by email automatically.
To go further, vous can locate the pirate (by triangulation) . You must be equipped with an antenna directional and to collect it since 2 geographical points. With each point, you raise the azimuth ofla WiFi connection of the pirate and coordonées GPS of your position. By chart geographical or by software, you deduce the coordinates from them GPS of the pirate. The 2 points should not be in the same axis that it pirate, ideally the 2 azimuths are perpendicular.
If the pirate uses an one-way antenna, it you will be necessary to approach you him until you find one azimuth from which the angle is suffisament different compared to first. Indeed, a directional antenna always emits one little around, one calls it that of the parasitic lobes. If it is in a building, you can change the polarization of the antenna, to locate the stage more easily.
The more directional your antenna is, the more the localization is easy.
A manufacturer (Intel) exploited the travel time of the radio wave fordéterminer the distance to one or more AP.
In the case of an only AP, one can thus thus use the distance with the AP to prohibit the access to a.
In the case of several fixed AP, one can inform each AP on its own physical coordinates (coordinates GPS).
When a mobile computer is connected to the AP, it will be able to deduce its physical coordinates by triangulation. According to la precision of the system, it becomes possible then for the system of security management, not to authorizeconnexion of mobile, that for certain geographical areas data.
Un article on the safety of WiMAX (01/2007)
How to improve a WiFi connection?
WiFi bond is a bond bidirectionnel (by
opposition for example, with a radio operator bond between one
TV and your TV).
One thus needs that the link between you and the other are made, ET, the connection in the other direction too.
Here a diagram of a connection in only one direction:
The units in MW and dBm are absolute, them units in dB and dBi is relative. One can add uneunity indBm, with plusieures units in dBi or dB together.
An antenna has strictementles
same properties inémission
that in réception.
Only one measurement
characterizes amplification with
the emission (profit)
as with the reception (profit or
“sensitivity” according to
some) it is about measurement of the dB or dBi (profit in dBi =
profit in dB + the 2.15) (salesmen pushed us with
the highest unit; -)
What I call a “large antenna” has a profit raised, a “small antenna” has a weak profit.
The legality of the installation is measured in “AIR”, on the public highway.
In this diagram,1est the transmitter,2le receiving. The profits are green, the losses oranges.
PUI1: power (in MW or dBm) of
the material WiFi (AP
chart NCV, PCMCIA ~30 with 200mW, key USB, boitier
AMP1: power of a possible amplifier (dB),
CON1, CON2: losses (in dB) in the connectors of each side,
CAB1, CAB2: losses (in dB) in the cables of each side,
ANT1, ANT2: profits (in dBi or dB) of the antennas,
AIR: they is the losses (in dB) in the air or the obstacles,
SEU2: threshold (in dBm) of the receiving material, varies according to quality (disont -94dBm for a flow of 1Mb/s for material running),
MAR1>2: it is the margin of remaining power. If it is positive, the connection goes in the direction 1 towards 2
There, one made half of the
that the Wifi bond
function, it that connection 2 towards 1 walk too.
One realizes that there is a part common to the 2 connections. It acts of: CON1, CON2, CAB1, CAB2, ANT1, ANT2, AIR.
Ca please say that while acting on these elements one acts onDEUX radio connections (1 towards 2 and 2 towards 1).
Ca please as say, as while acting on elements PUI1, PUI2, AMP1, AMP2, SEU1, SEU2, one acts that on half of problem.
In the same way, the use of
allows to remove the losses in CAB2.
Operation is the same one as that of préamplis for TV or the satellite, one raises the signal there or it is it more extremely, therefore close to the antenna.
The difference (and the price) between a préampli WiFi and those caused, is that the préampli WiFi mustcommuter very quickly for to let pass the signal vers the antennequand the receiver becomes transmitting.
When the receiver becomes transmitting, losses in CAB2 (which become CAB1) can be compensated in increasing power of transmitter PUI2.
To decide use of a préampli, compare its price with the price difference of the cable (good or less good) for length which you envisage to use.
In short, if you want to put one cable very long, put a préampli. You will be able, then, to allow you to use a cable of ordinary quality, i.e. with more dB with the meter, thus less expensive.
Attention with the abuses
call amplificateur, an amplifier of
These apparatuses make
One makes twice
more distance with 3 apparatuses (that of the medium makes relay (DWL-G710)
that with two. It is all.
Many of other AP have already this function for a long time…
In short, the assessment is:
XX = PUI1 + AMP1 + SEU2,
YY = PUI2 + AMP2 + SEU1,
ZZ = minimum of XX and YY,
Total MARGIN = ZZ + CON1 + CON2 + CAB1 + CAB2 + ANT1 + ANT2 + AIR
According to the value of “total margin”, there will be a flow of 1Mb/s, 2Mb/s, 5Mb/s, etc…
It is this minimum which does
not seem to be
assimilated by the WiMax operators,comme
Stephan, without tweezers; -)
Now that you very included/understood, I muddle you!
Joker!!! For the materials which have 2
If one has access to the low layers of software which controls the hardware, one can use an exit for the transmission and the other for the reception. And there, you known as “why make me”?
And there I answer you to try to respect the law (current). Explanation:
If I emit slightly (ANT1)
(limit of 100mW), but
that I have
a large reception antenna (ANT2), I would collect better
that with (small) the antennas of origin (ANT1 and ANT2).
Thus on each side of the bond, if I have an antenna small for the emission (the antenna of origin) and large for the reception, I could further carry that with the antennas (small) of origin, while respecting the law: -)
Of course, one will carry
less far than if there is one
large in emission and large in reception.
But I have when
even made10km (see page
antennas of origin of my AP usr2249.
The disadvantage, it is that costs 2 large antennas with the place of one, to make the same range.
Sylvain implemented this solution on 6Km http://www.wifiquercy.net/
materials on which one
can program the power of exit:
This idea (of_SebFLebrun) is so good that I have swell not to have found it.
To respect the law and to use only one antenna in emission and in reception, it is enough to program a power of emission weak.
Example: my material has a
power (PUI1) of
the antenna of origin (3dBi) I emit with 17 + 3 = 20dBi (=100mW
I put there an antenna SD27 of 24dBi instead of the antenna of origin from 3 dBi.
To return to 20dBm, I must remove the surplus of puisance of the antenna (24 - 3 = 21) with my power of emission 17dBm.
Thus I must emit to 17 - 21 = -4dBm = 0.4mW.
Here some examples of range
theoretical for 2 antennas
One can to make a bad antenna “ricoré”?
Yes, of course! It is very easy, it is enough to consult certain Internet sites (Paris-Without-Wire for example) to find bad councils which will allow to manufacture the bad ones “ricoré”: - (
good ricoré makes11dBi.
To measure the dBi, one compares (with netstumbler for example) measurements with those carried out on an antenna trade, whose profit is known. In Toulouse one compared in a SD15 (13dBi). See also it video "l' antenna ricoré for the null ones" ;-)
Ok, let us see rather how to
ricoré, Lg/4 = 44mm and Lo/4 = 31 Misters.
A to leave of these diagramsil is necessary to interpret outdistance “Lo/4” (31mm) as being defined betweenbout antenne and:
- is itbord (in bottom) de the boite (if the connector does not exceed) (see photograph of my ricoré in the paragraphComment a link long distance is established?
- is itblindage metal of connector (if the connector exceeds inside limps) (photo below).
The 31mm correspond to the central part of the driver (the heart)qui is not surrounded by metal, and which, by consequent, lets escape the radio waves. It is the partie radiant
The dimension of 31mm is critical, it must be realized with +-0.5mm.
This east coast related to the selected channel. 31mm correspond to channel of the medium.
This coast also makes it possible to adjust the impedance of the antenna. The impedance must make 50 ohm so that the antenna propagates all the energy sent by the WiFi material (of which impedance of exit makes also 50 ohm, it is standardized).
Regardez l'explication in small “the Antennas - lines of transmission”, “the ROS”. (This site is a bible for me!).
For the same reason, you must usecâble 50 ohm (the green cables make 75 ohm).
The impedance of the cables is determined by 1) the report/ratio enters - the diameter external of the cable exchange, and - the diameter interior of the cable which surrounds it (shielding, braid), and 2) it coefficient of swiftness of material insulator.
“Lg” is directly related to D, it diameter of limp.Pour one ricoré, D = 100mm and Lg = 175mm.
Also note that the distance “Lg/4” (44mm) is defined compared to the bottom (à interior) limps.
One can also cross limps it
to respect the distance
“3/4 Lg” (131mm) but it is less serious.
“It” was also said to me that 1dB was gained if one removed (with one open-limps) the small interior disc with dimensions lid.
There is no problem to leave the lid, it do not heat if one even puts it at the microwaves ( frequency with 2.4GHz).
One can check the coasts (31mm and 44mm) with fabulous instrument below, which I named it " gabaricoré "
The “caroparty” consists in meeting around beers, music and limp of “caro” or “ricoré” for to manufacture antennas.
Thus not of “caroparty” without “gabaricoré”!!
Il has there T it reflectors onantennes grids SD27?
Certain antennas grids (SD27)
are delivered without
3dB then is lost. This
one has as dimensions 105 X 77mm.
This sheet contains 2 foldings. There are thus 3 parts of 105 X 27, 105 X 23,105 X 27. The angle made 30° approximately.
Once folded the coast of 77mm becomes 65mm.
There are slits of 4mm broad to thread the ends of figure of the SD27 envisaged for this purpose.
Holes with 13mm and 76mm of the edge are at the end of the slits, for to make pass the plastic ends before threading them in slits.
An end of zinc goutière, cut with scissors, bored with the drilling machine, folded with a board, kitchen table and one screw clamp.
And here is the trick:
my compass does not work
The needle of the compass is aligned with the magnetic field terrestrial. Thus in full nature ya not of problem.
We use the compass beside one mast of antenna, one antenna. Those are out of metal and they deviate them magnetic fields and distort the indication of the compass.
problem, there is a method:
I place myself at least a meter of the mast (and of any metal part) between the point that I aim and the mast of antenna.
I point the required angle and I locate at the horizon what is in the corresponding angle.
I arrange my compass and I place myself behind mast. I turn my antenna in direction of the visual reference mark with the horizon.
If you do not believe me, you check: you places behind the mast with 1 measure, you aim at the visual reference mark and you approach the mast. With 10cm of the mast, the indication of the angle moved of 10°. Perhaps that that does not make it if one aim at north, I checked for an angle of 45°.
What, the lightning? It is already fallen on your antenna TV? Not, Ben on mine either ..... good day! ;-)
Easy to say when one lives downtown.
The lightning makes more dégats in the countryside that in city, perhaps because of the cables which are more exposed, or perhaps parce that there are more lightning conductors downtown than in shift… I do not know.
There exists lightning protector (or surge protectors) for WiFi which semblent to be effective in the absence of impact direct (when the lightning falls on the WiFi antenna).
I quote Didier Lebrun:
“Has Vaour, I observed that the addition of lightning protectors fact of losing about 1 dB in summer. In winter, I remove them lightning protectors, because I noticed that they block completely the signal when it freezes and accentuate the losses per time cold and wet. “
the computer to avoid them
overpressures on the sector. Ca
it is the radical solution, but
the onduleurs seem
to be effective against which had overpressures
with the lightning.
In shift one disconnects also the wire of telephone.
I await experience feedbacks
continu (like the SD27 (0.7 ohm)),
compared to the antennas in circuit
opened continu (ricoré and
the omnidirectional ones (infinite continuous impedance)).
My subjacent idea is thatles antennas in short-circuit continu has more chances of protéger the WiFi material, since the power due to the lightning can be on directly in mass.
Following the meeting (very
28/07/2006, it was to me
confirmed that antennas “short-circuit”
the WiFi apparatuses which are behind (in
general of the WRT54).
The day consisted with, in one the first time, to repair WRT54, by removing the component (the diversity switch) which has roasted by the lightning or the loads electrostatic (ESD).
In the second time, one protected WRT54 while placing one coil (22 nanoHenry) on the exit. The coil causes of court-circuiter low frequency currents and thus with fortiori, loads electrostatic which could accumulate.
Les manipulations sont delicate, but accessible to the people meticulous persons.
To this occasion I placed onecourt-circuit
omnidirectionnelle (of chez
IRISAGRI), so that it is protected
Since I had brought my TOSmètre, it was easy to check conservation of the impédence with 2.4GHz!
Here thus the result
Of course, we confirmed that its performances initial were preserved, by a comparative measurement in dBm (netstumbler).
Here interior of the head of
thank you Julien for
Yes, I know that appears strange it short-circuit… there is even that prevents from sleeping; -)
, Make you with the idea go that the signal high frequency propagate on the surface of the drivers…
Il is enough to look at the lightning venir to make its provisions!
My antennas are well granted?
measuring (software WLANexpert,
thank you “black Milan”) the provided
by the exit of the material wifi, one can deduce
the Rate of Waves
Stationary (TOS or ROS (Report/ratio of Standing waves) or VSWR).
This relates to only the materials which measure this current. Les materials containing PRISM2 allow it (usr 2450)
Another implementation of WLANexpert
to measure the ROS, it is of
to make a tosmeter WiFi (ROS-meter wifi, tosmetre
J'ai carried out this one (thank you Erwin), the BAT62-03W is available at Radiospares.
From the PCB, I printed and stuck on copper. I have then marked with a screw and a hammer points remarkable (corners). Then I took off it paper, it me remained the marks then on copper. I crossed to cutter to remove copper.
I welded components CMS (Component Assembled on the Surface):
You will notice the 100 Ohm (marked 101,10 with 1 zero multiplicateur=100) welded in parallel for to make 50 Ohm. One all that in one puts limps, and here:
My wrt54g emits according to a variable power.
A first solution consists in putting it parameter “SSID broadcast " with ONE, and the parameter “beacon interval " to 1 (ms) (minimum).
A second solution consists with to transfer a large file to force the emission to the maximum.
I validated the operation of the tosmeter, in placing in front ricoré iron plate, then by removing it: that influences indeed on the ROS (normal, one re-examines the waves with the shipper) (value of 16 master key with 30mV and value of 400 master key with 900mV). The court circuit on the exit gives a maximum value of 1.7volt then that under normal functioning one with 400mV (with my ricoré).
It now remains to me to calibrate it with - is antennas of trade, - is references standard ROS in 50 Ohm.
Thank you in Laurent Mennecart (the purist of HF) to have me provides standards 50 Ohm Radiall.
Initially I twisted the wire which go to voltmeter (that avoids to distort measurements when one puts the hand on wire).
With the standard, the value must make 0mV, it was not the case. With 2 resistances 100 Ohm CMS in parallel (welded in a standard connector NR), I had something well near to 0. Morality? the CMS in parallel do not make 50 Ohm with 2.4GHz!!
J'ai donc essayé to have 0mVavec the standard.
that, I welded
a leg of component
on a point medium (the branch of reference)
to which I welded
a disc. I then folded
back the disc to bring it closer
of a plan of mass. Super,
I approached the 0mV, but
to reach. I arrived at13mV minimum
- the reference gives 13mV,
- a SD27 gives 40mV,
- my ricoré 50mV gives,
- my 50 Ohm CMS give 60mV,
- adapters of the type NR towards BNC with nothing with the end give 100mV,
- same adapters with a stopper 50 Ohm of network éthernet coaxial, 60 give mV,
- an open circuit gives 220mV,
- a short-circuit gives 240mV,
well-known of (old man?) administrators network do not make
Ohm with 2.4GHz!! (see
Also think that in diversity mode, if an antenna (that which one measure) walk badly, the apparatus will make use of the other (finally it is what I noted while disconnecting second).
I can thus assemble the values of the ROS according to the tension read with the millivoltmeter:
Good, then one should not panic, considering the percentages of losses of power correspondents to the values of ROS:
4 _ lost for ROS= 1,5,
10 _ lost for ROS= 2,
25 _ lost for ROS= 3,
50 _ lost for ROS=6.
Un ROS of 1,5est limit that fix themselves, in general, them manufacturers of antennas. (VSWR <1.5 for all the channels)
By principle (bridge of Wien, I believe) only 1 quarter of power of entry, passed to exit (loss of 6dB).
Le Does WiFi, that grow bigger well?
Ben that depends, the anarchistic wifi grows bigger badly (with the OJ of Athens, “Il is then necessary to transmit the image to the newspapers… ", they drew from the cables in the night for to circumvent the saturation of the waves).
it to extend the cover of the network
each arrival of a new user. It is what one
offaire in Toulouse, but with
a mixture of fixed stations and stations mobile.
to beconfirmées by this articlede
Jim Thompson, followingce debate.
Then I put myself the
question of the bond between
jumps and the number of connected nodes. As I do not have
the formula to calculate it, I started with
hand, for a network
with a grid with3
bonds by nodeCa
makes a standard structure “nest
of bee ". I colored with
3 colors, on the basis of
point central, black:
Attention, put aside the unrealistic case or the ground is dish, that there is no obstacle and or the nodes are distributed geometrically,ce drawing is not one geographical representation, but one schémades bonds, similar toceux that I dessinaispour Toulouse, when one was not not many.
According to the number of
jumps, the number of nodes
as follows: (série1)
0, 3, 9, 18, 30, etc..
Sometimes one falls down on a point already colored. The number of already colored points evolves/moves as follows: (série2)
0,0,0,3,3,6,6,9,9,12,12,15,…, after I have decree!
Good, then I found that the difference enters values of série1, increased as follows: (série3)
3,6,9,12,15,18, etc…, it is nevertheless more sympathetic nerve! , there are +3 between each!
I thus coded a program which enabled me to continue (I am large lazy), here is the result:
I coded (red curve) X with the square (X ** 2) just to compare.
The white curve (of the number of connected nodes) evolve/move more quickly that the square.
It corresponds (with a margin of few things) withy = 1.51 * x**2
Following an email of Jean-Jacques Gaudoz, the exact formula is: there = 3/2x² + 3/2x isy = 1.5* X * (X + 1)
Which become les then limits of a mesh network of it type?
The number of jumps, will determine the travel time of one not with the other of the network (lasted of “ping”).
If it is considered that the WiFi networks which distribute one geostationary connection of satellite, have a ping with Internet of 500ms minimum, and that for the play, or the voice on line, it is a limit, then I will take the same value, 500ms.
Ca will change when constellations of 48 satellites are launched in low orbit with 400Km of altitude (instead of 36.000Km), but one is not there yet…
In addition, the AP (of today) bring a delay of disont… 5ms by node.
Before calculating, it should be seen that to join “with dimensions” network with the other, the double should be traversed, number of jumps necessary to go from the medium (black spot) until one “with dimensions”.
Thus 500ms divided by 5ms makes 100. One divides by 2 for to go from one end to another of the network, which makes 50 jumps.
One sees (!) on the curve that for 50 jumps, one can connect 3825 nodes
It is of course onelimite haute, since a structure was taken of network almost ideal and a maximum ping.
Obviously, it would be ridiculous to give a connection Internet single at the central point, because:
- the first three bonds would be saturated,
- the flows available by user too would be weak.
On the other hand, to distribute Internet in several points of it network seem to me to be a good project.
In addition, one could connect the central points (black spot) by a “dorsal” (makes a second network of it (with a grid?)) to constitute a network of networks with a grid. The dorsal then inevitably would consist of bonds more long (goégraphiquement) that those of the basic mesh network.
Bonds geographically longer, can to be obtained, for example, by the connections towards Internet (footbridges). It is the solution adopted by “Linux PC Services " (LPS). One can then choose the way more short (of many jumps) between the mesh network only, or, the mesh network/footbridge Internet 1/ footbridge Internet 2/the mesh network. LPS did it choice to pass systematically by Internet if the way in mesh network fact more than 4 jumps. I call this solution of “pseudo-mesh”, since one does not pass by the network mesh in ALL the cases, to join 2 elements of the network mesh.
LPS uses AODV which “innonde” its entourage; it is thus logical to seek to leave the network with a grid (by footbridges) as soon as possible, not to saturate it.
M@dBox of LPS is equipped (04/2005) with antennas omnidirectional, which slows down its use with countryside.
I do not know the detail ofsolution of Luceor which it, uses OLSR.
Thomas, in Pomeys, provides us the duration of " ping " in real-time, on its network.
How to find itself there in connectors?
Voici a correspondanceentre the WiFi material (your router (AP) or chart NCV or PCMCIA) and its connector of antenna.
To indicate a connector there is in first ittype
type N, SMA type, TNC type, type F, MCX type, MMCX type, UHF typetype BNC (not of threading but 2 pins), et it there in has others (photo exit of http://www.wimo.de ):.
Some are connectors (to be welded) dedicated to the test of end of chaine, example, it Hirose ms 156. It is not conceived to be handled more than 100 times.
contains a contact which
cut the bond
towards the antenna, when it is connected.
It does not have machine element allowing to maintain connection, in short, it is not a true connector.
To indicate a connector there is then the sex:
If threading is interior, it is one male(M), if not it is a female (F)
Yes, I know, it is odd!
Then, it is necessary to
determine if it is “normal” or
for “reverse polarity” in English)
Pour un male, if the center of the connector is une pointe, it is a normal
Pour un femelle, if the center of connector is un trou, it is a normal
Pour un male, if the center of the connector is un trou, it one is inversé
Pour un femelle, if the center of connector is une pointe, it one is inversé
To complicate, when it is normal, rien is not said
Then, there are connectors which are assembled at the end of one cable (à to cable), others which fix on a sheet (à to weld, chassis), others which are welded onto printed circuit (à to weld onto circuit printed).
For the same connector with to cable, there can be several possible diameters of cables, it then is giventype of cable compatible.
Certain connectors have a pas of vis opposite of the time direction (Reverse ThreadedRT
Here, to indicate a
connector, it is necessary
to know all it
who is in red.
Some examples follow:
male type NR (to be cabled)
type NR female (to be welded)
male type BNC (to be cabled)
female type BNC (adapter)
male type RP-TNC
female type RP-TNC
female type TNC (adapter)
male type RP-SMA (to be cabled)
female type RP-SMA
How to choose the cables?
A pigtail it is a cable with a
For the cables, the RG58 is recommended for 400MHzmaxi(thus not good for WiFi), the RG142 (until 15GHz) has summer retained by itfabricant pigtails
What counts, it is the number of dB per meter of cable, with 2400MHz.
When I see all these pigtails proposed without it being indicated their loss in dB at the WiFi frequency, that irritates me….
Example the RG58= 1dB/m, LMR400=0.2dB/m.
Here some équivalencesde
diameters of cables:
diameter 10mm: RG8/213 ‚ WBC400 ‚LMR400 ‚ Altelicon CA-400, Belden 9913,7810
diameter 6mm:RG58/141/142 ‚ Hyperlink CA195RW ‚WBC195 ‚LMR195 ‚Belden 8240/8219
diameter?: WBC200 ‚LMR200, Altelicon CA-200, Belden 7807
diameter 2.6mm:RG316/174/188 ‚ WBC100 ‚LMR100A, Belden 7805
A table of correspondence between connector and cables compatible.
End of a myth on WiFi, them walls, them doors and windows?
here, at home I have a AP
WiFi antenna of origin on the roof (2 antennas in diversity mode,
one is coupled with one-way).
I have one
house with a stage. The
ceilings of the DRC and the first are
composed of concrete 25cm (massive).
With the DRC, I equipped my AP (as a customer mode) with one antenna one-way (one ricoré). I sought by or passed waves.
towards the AP of the roof (with
through the ceilings, in straight line), I have a bad signal.
While directing ricoré towards the door of the corridor, I have a good signal, idem towards the windows.
When natural persons put themselves in encadrure of carry, the signal is less good.
do not cross the murs (or ceilings). WiFi follows the
doors, the corridors, them
stair-wells, is reflected on the houses
of with side, them
trees in summer. See “Affaiblissement (attenuation) relative of
WiFi according to the nature of the obstacles (materials)".
The sitechronomicro we gives values:
|Material||Level of attenuation|
|Not smoked thick pane||1-2 dB|
|Plating/carries out of wood||2-3 dB|
|Plaster partition||3-5 dB|
|Box of office||3-5 dB|
|Partition in verre6 dB||6-8 dB|
|Water (bottle/fountain/aquarium)||6-8 dB|
|Brick wall||8 dB|
|Ceramics tiles||6-10 dB|
|Stored paper||10 dB|
|Armor-plated glass||10-15 dB|
|Concrete wall||10-15 dB|
|Metal mirrors/preparings||Total reflexion|
exists software for simuler the radio coverage in interior.
Des logiciels permettent to simulate cover of each AP:
Les anti-WiFi paintings against the hacking, are thus inefficaces, as long as one stopped not the waves which pass by windows.
This can be made thanks to the coatings thermics (transparencies!) who are used for better isolating the panes against les losses of heat.
to generalize, it is enough to imagine
house under the following conditions:
It grows dark, the AP is a source of light, there is bouillard, and the thick walls are mirroirs, the doors (not metal) are out of glass.
The problem to receive the AP is the following: “Is what you see the light? “; -)
The analogy with light is also valid to compare an antenna omni and an one-way antenna. You have a bulb of headlight of car (antenna omni), when you place it in the headlight of the car (antenna plain), the light carries much further.
another thing, as long as I there
am, as much
the mode “diversity”
is not used for
for a bond long distance (>1Km), as much itaméliore
frankly the range in interior.
to compare materials, check well that these
allow the mode “diversity”. It is necessary notament that
these materials have2 antennasA fortiori,
exclude the materials which have only one antenna:
AP, boitiers USB, charts NCV.
Apart from this criterion, I did not note difference of performances notable enters the current materials (except perhaps the threshold of reception).
If you choose AP, you can put one of them in infrastructure and it (or them) other (S) as a customer mode.
All the charts PCMCIA which I opened had 2 antennas. I do not know if all exploited the mode diversity, but that would be nevertheless astonishing that they do not exploit the 2 antennas!
The large manufacturers who propose to off-set them antennas, boitiers sell who contain the 2 antennas with to off-set, to use the diversity mode.
principle diversity applies
the receiving device at one moment T. Thus for
that your bond
either effective, it is necessary that each apparatus or
equipped with 2
antennas. See the chapter “Comment
to improve a WiFi connection?"
And why not 3 antennas for each apparatus, as on WRT54GX, for to further increase the flow and/or the range?
point of view is
confirmed by this:
"We recommend thesis first MIMO-based products to residential users. There is significantly better throughput and arrange performance than conventional products in every box we tested. MIMO-based has better approach than adding third-party, high-profit antennas but activates repeaters - it' S less complex and, even with the higher prices, usually less expensive. “
I translate; one gains more
if there are more antennas, that if one
puts antennas at strong profit, or
repeaters. It is less
expensive and less complicated to implement.
Thus while waiting, start with 2 antennas of each side of bond:)
To still improve the profit
to transform an omnidirectional aerial into antenna one-way (directive).
Arnaud (Alf92) nous propose to make it oneself. one speaks then “of antenna chocapic”….after the “antennas ricoré ", one can say that WiFi is morning; -)
Problem, I think that one cannot assemble 2 reflectors on the AP which have 2 (or 3) antennas, because of the obstruction mechanics reflectors…
Who will gain, the pair coppered (the wire of the telephone) or the radio?
+ OFDM = 1Gb/s with 5GHz (the ADSL does not have which has
La montée in flow of the networks radio operator Wi-Fi continues (07/2005)
Radio techologies make it possible to increase the flow further (03/2007):
"WHDI on the tape of the 5 Ghz emits, and can transmit to 3 Gbps while using the band-width of the 40 MHz "
What misses with this information, it is the number of channels (of 40MHz) used.
With my first course of electricity, one learned to me that the current always circulate in a loop (wire outward journey and wire return).
In addition, a loop constitutes a coil, and 2 wire coast at coast, constitute a capacity.
The capacity (condenser) is enemy increase of frequency and the increase in frequency allows the increase in flow.
“The problems which our customers encounter Freebox are dependent with too long or too short lines, or disturbed, even parasitized by a condenser placed at the time in telephone socket by the operator history”,indic Michael Boukobza, managing director of Free
If you find a condenser (a capacity) in one of your catches telephones mural, remove it!
It is the black “animal” on the photograph:
Thus I am not astonished only the solutionsfilaires high bancne is proposed that hasde less in less privilégiés(vérifiez) (the telegraphic flow “56Kb/s” is accessible to ALL la French population), whereas themsolutions radiopour an equivalent flow, see themportée to increase.
The fiberoptic untilchaqueabonné is very expensive:
tens of billion euros"
Count yourselves, with2 euros per meter and per annum., et up to 12 euros with hiring…
Especially that FT would like to adapt the monopole fibre (option PON) , for ramasser under as with the good old man temps (at the time of the monopoly of telephone) (c' is similar in Germany
To buy 1Km of coppered pair, to buy posts, to rent one excavator oubien to put antennas on its roof?
(copper is expensive (07/2006)… value of overhead lines the SNCF too!).
And noise of the power picks to make the trenches in cities? And them stoppers of circulation because of work?
(le WiFi, it is L'ecology! ;-)
well on the distances
courtes (less 100m),
"En matter of 10GE, wiring copper in twisted pair on a distance from 100 meters, as for the lower flows of Ethernet, goes quickly to become reality. This type of deployment will be officially validated with ratification of the standard IEEE 802.3an (10GBase-T), envisaged for the semione. It will have to exploit a wiring of category 7 (standard not ratified, but which made its appearance in the offers des cable-laying ships), which makes it possible to reach a frequency of transmission from 600 MHz and requires four pairs of copper, it who force to replace the traditional RJ-45 by a new type of connector ",source.
The 10GE corresponds to 10Gbits/s, on Ethernet.
In this case, a coppered pair is equivalent with a WiFi channel. 4 pairs with 600MHz are equivalent to 2.4GHz, but on 100m only.
One sees well on the curves
below that the améliorationsapportées
with the ADSL are done onles
flows and NOT on
WiFi allows moreover long distances…
See: ADSL : eligibility with more than 5000 meters of a NRA
Which is the form of the radiation of an antenna?
One calls that a
“owner of antenna” or diagram of
omnidirectionnelles antennas (tube), in driving position, send the waves with the same power all around them, on the horizontal level passing by the antenna (perpendiculaire (cross-country race-whodunnit) with the axis of the antenna (made up of one or more dipoles end to end).
Here what that gives if youregardez the antenna over (cross-country race-whodunnit):
It is what is shown by the yellow curve. To compare them the shapes of antennas, one places the point corresponding to the maximum profit on the circle most external of the squaring, with 0 degrees.
For a unidirectionnelle antenna, les other points (for each angle) are thus more close to center, and draw a geographical curve for which one receives maximum power.
The profit of the antenna is the maximum power.
Example of an Yagi aerial (like that of the TV herzienne (rake)):
Si one place, not perpendicular to the dipole, but dans the same plan (Co-whodunnit, rise) (one is placed at side of the antenna), there exists another diagram of radiation (of 0° (in high) with 180° (in bottom)).
Example of a omni 10dB (even plane, Co-whodunnit):
You see that if you place the antenna in height too much, you will not collect the signal below, for this antenna. Others antennas “sprinkle” also below, but with the detriment profit.
Example of the antenna roasts SD15 (even plane that the dipole, Co-whodunnit):
Diagram of cette antenna patch (9dBi) in copolar:
and in crosspolar:
Example of the antenna roasts SD27 (even plane that the dipole, Co-whodunnit):
Although the antennas presented have different values of profit, the squaring of the diagram is the same one (only the scale changes), what makes it possible to compare only the forms (they are standardized curves).
Example of the SD27 in cross-country race-whodunnit (plan perpendiculaire au dipole):
I turned the maximum point of 90°, so that that resembles it that it would be seen whether one were with dimensions of the antenna, on the level of ground.
It is seen that the beam opposite the antenna is broader in the perpendicular plan (cross-country race-whodunnit) that in the same plan (Co-whodunnit).
One can thus conclude, that for the SD27, the beam opposite the antenna forms a rectangle. Imagine a stick of freeze (Eskimo), you almost cut it to the end, that made a section of form rectangular.
If you turn the antenna to make so that the dipole is vertical (like a omni), then the covered zone will be one rectangle flat.
In this case the azimuth (angle compared to north) will be easy to regulate, whereas the slope (high/low) of the antenna, is more delicate to regulate.
Contrary, if the dipole is horizontal, the adjustment of the azimuth will be more delicate to regulate. On the other hand you will profit more of the reflexions on the ground. Especially if this one has the shape of an half-ellipse (see zone of Fresnel) (for example enters sides of a valley).
These 2 ways of diffusing the waves (that is called “polarization”, vertical or horizontal) must be considered according to context: to pass between buildings, to use them reflexions of ground, etc.
Il ne faut pas to mix both types of polarisation, if not you will have very bad results.
Apparatuses can program polarization dynamically (PowerStation2 Ubiquity
To be complete, it is necessary to speak about the antennas propellers (helicoid) whose dipole is not a right wire but a whorl.
In this case the diagrams Co-whodunnit and cross-country race-whodunnit are identical.
In addition, the direction in which one winds the whorl, makes that it an antenna wound in the same direction is necessary in face, under sorrow not to receive large thing.
Polarization hélicoïdale is incompatible with vertical or horizontal polarizations.
When one does not have the diagrams of radiation of antennas, one finds like characteristic, the opening. It is the angle around the maximum point power, for which the antenna emits half of its power (loss of 3 dB).
To show these owners fromces photos, I created one program which posts the palette. One selects la colorcorrespondant with the curve, and then the program generates the points inun fichier (*.ant) readable by “radio mobile ".
How to circumvent an obstacle?
More the obstacle is close to one of the two points of the connection, more it obstructs the connection, but nothing prevents to put it WiFi relay in the medium.
Un relais credit can be fed into solar, and to undergo 15 days of misty time, like says it Dominique Guardiola Falco de Quinode (in Auvergne).
Le relais actif fact more than to circumvent an obstacle, it double the range.
Dominique used 1 AP, in repeater, to decrease consumption electric compared to a solution with 2 a.
Mekari proposes une solution all in onesource. It is planned for the sun of California? or it is awaited climate warming?
In addition, I would be curious to know the maximum duration (for France, for example) of the absence of sun AND ofvent, for to determine the autonomy ofcombinaison solar wind, while using a battery 100Ah.
In the absence of power supply (sector,éolien, solar) (a AP consumes 5Watts), there exists the principle of the antenne passivate WiFiI validated his principle on ground. It acts of 2 antennas (of which one at least is directing) which is connected by a cable.
Here the principle which I checked (who must to also go for WiMax, or ofGSM 900MHz and GSM 1800MHz
Each antenna being directed towards each one of points to be joined:
Source des photographs
One sees here a relay made with limp “pringles” but any other antenna is appropriate.
On the level of the assessment of the connection, nothing is changed, if not that with place to have a great zone of Fresnel, one has 2 small, end with end.
There are people who wonder how that can go, without energy source, here my answer:
I went to a living room radio operator amateurs, I have listened to the radio in a helmet, with a station with crystal, without no source of electricity.
The volume of the sound is low, certainly.
From or the energy comes which produces the sound in helmet? ..... of the emetor.
Thus the antenna converts the radio waves into electricity, this one is thus the source to re-emit on second antenna.
On the other hand thanks to this installation, you have all them chances to have 2 well cleared zones of Fresnel, instead of one only evil released. A zone of Fresnel well released (value gives notorious)6dB of plus that a connection on the ground on a flat ground (in close-cropped-mound).
To include/understand, it is necessary to know what is a zone of Fresnel. It is the useful part of the air which transmits the radio signal.
It with the form of a “grain rice
In this example, the useful part is decreased by the ground (with left), it is the tear line. You come from to include/understand why the antennas are often on pylones: -)
And here a natural good example of pylone:
According toSylvain, le wind does not obstruct the connection.
Attention, the resin leaves badly to the machine to wash…
Here now another bond which corresponds to a distance shorter:
It is what I call a bond “in close-cropped-mound”. Ce bond will go hardly better that above, whereas la distance is of half smaller.
These profiles were obtained with “radio operator mobile”.
Toute partie of the ground which tangent the grain of riz (zone of Fresnel) améliore propagation. Thus to put the antennas highest possible the best propagation does not give. ;-) Of another side, one becomes depend on the vegetation and of constructions…
Thus our passive relay WiFi must enable us to increase surface grains of rice, therefore to increase the margin in dB, therefore to increase the flow.
It is better two goods small grains of rice, that large bad. (saying of the day: -))
But if the straight line uniting the antennas (one calls it line of sight, or English LOS) is blocked,tout is not lost
The zone of Fresnel (between the top of the obstacle and the part higher grain of rice) (here in green) makes it possible to pass the waves, but with more losses than if the line of sight were released.
To obtain best the résulat, it is necessary to aim, with each antenna, above the obstacle.
The height to be aimed depends on the distance enters antennas, but it would seem that a height should be aimed at corresponding to ray of the ellipse of Fresnel. For example, for a distance enters antennas of 3Km, that made 10m with the top of the obstacle.
Par contre, la zone of Fresnel being a éllipse, if 2 points of the connection are close (here out of chestnut) the connection will not go, since the grain of rice is completely blocked.
It is a large banana better, that a small sausage. (second saying of the day: -))
If you feel the heart of an inventor, you can take as a starting point this idea ofdirigeable of telecommunications to make a small WiFi relay…
Below my page is in work…
AP (Access Not) (Access point)
OFDM (orthogonal frequency division multiplexing)
GAF (Automatic Management of the Frequencies)
PBCC (code of protection per redundancy)
FHSS (Frequency Hopping Spread Spectrum).
DSSS (Direct Sequence Spread Spectrum)
WEP (Wired Are equivalent Privacy).
MAC (Media Access Control)
DHCP (Dynamic Host Protocol Configuration)
WPA (WiFi Protected Access)
TKIP (Temporal Key Integrity Protocol)
FAI (Supplier of Access Internet)
BSS (BASIC Service Set)
ESS (Extended Service Set)
CSMA (Judicious Carrier Multiple Access)
CRC32 (Cyclical Redundancy Check on 32 bits)
MIC (Integrity Message Codes)
EAP (Extensible Protocol Authentification)
RADIUS (Remote Authentification Dial-In Using Service)
TLS (Transport To bush-hammer Security)
LEAP (Extensible Light Protocol Authentification)
WECA (Wireless Ethernet Compatibility Alliance)
DOS (denial of service)
AES (Advanced Encryption Standard)
UMA (Mobile Unlicensed Access)
HSDPA (High Speed Downlink Packet Access)
WISP (Wireless Internet Service Provider)
Pulsers (Pervasive Ultra-wideband Low Spectral Energy Radio operator System)
Agora(Access Guaranteed and Optimized for Areas and Installation territories)
QOS (Quality Of Service)
TBF (Token Bucket Filter)
MPU (Minimun Packet Links)
MTU (Maximum Transfer Links)
SFQ (Stochastic Fairness Queueing)
MIB (MailInBlack) (authentification of email): -)
RAN (Rural Area Network)
WDS (Wireless System distribution) or Wireless Domain Server) at Cisco
OSPF (Open Shortest Path First)
OAPI (Open Access Not Initiative)
ARP (Address Resolution Protocol)
WPS (Wi-Fi Positioning System)
WPS (Wi-Fi Protected Setup)
TOA (Time Of Arrival)
PLT (Precision Technology Hiring)
WCN (Windows Connect Now)
SOFDMA (Orthogonal Scalable Frequency Division Multiple Access)
WAPI (Wireless Authentication and Privacy Infrastructure)
WLSE (Wireless LAN Solution Engine) (CISCO name)
SIP (Session Protocol Initiation) replacing of H323
FTTA (Fiber Through The Air)
GIX (Total Internet eXchange) or Node of exchange Internet between operators
To increase the range of FreeBox:
I publish these photographs
(the “modest one” and
to be used as support with improvements of these
In the round of bottom, it is
necessary to cut the vertical track (or
to remove the resistance which is under the heart of
Thus, it would not be necessary to cut the tracks towards “ANT1” and “ANT2” (round in top).
pies” of the medium, it is for
mass (on the left it was a test).
Good, then my note:
- there is no more that only one antenna instead of 2, therefore one loses the diversity mode,
- me, I would have rather added connectors (RP-SMA to be welded) on the level of “ANT1” and “ANT2” for reasons of mechanical robustness (and use of the mode diversity),
- then I would have tested with and without cut of the tracks on “ANT1” and “ANT2”.
LiveBox Sagem version: