Hi, i’m from Brasil and have a question to be discussed.
Equip : 2 SR2 400mw UBIQUITI Cards
Max lenght i want is 3km(little city, over 5.000 hab)
Conf.
1 = SR2 + 25 dbi antenna grid
2 = SR2 + 8dbi hyperlink omni HG2409U
What is better?
Put the two cards to work on :
1 - Same SSID and CHANNEL
2 - Same SSID, Diferrent CHANNEL
3 - Different SSID, Same CHANNEL
4 - Different SSID and CHANNEL
Please help me on this Guys.
Att
Rafael
I would say the same ssid as you can then configure the system for fail over if on ap dies. I have seen some post in the archives regarding one issue in this type of set up and that is if the signals from the cpe’s are close (and they will be because of the 2 omni’s) there is an issue with the customer equipemnt shifting between the 2 ap’s. You’ll have to search the archives, or some one else my chime in as I don’t recall the details
Erik
Thxs for reply eric, but isn’t 2 omnis in my case, are 1 omni and 1 grid.
Ill try later the same SSID, but with the same channel???
Sorry, I miss understood your post. You will need to be on the same channel and each unit will need the same ssid inorder for the 2 units to talk.
hmmm, i think was my fault…
These 2 cards are in the same board, 1 Mikrotik MARE400 with 2 SR2 ubiquiti 400Mw Cards. He’s will be transmiting to the rest of city, comun clients( grid antenna, pci card), and i have these 2 equipments, 1 omni 8dbi and one Antenna grid 25dbi.
My question are basic if i let 2 SSID’s with 2 channels different, will be better, but can create more Noise on network, or i let 2 SSID’s with same name and equal channels will be better for Signal and Noise?
oh, thank you for the replies.
Share knowledges are always good 
(srry my poor english)
Hi Rafael
i’m Brazil, too, and have a same scenario
what is your conclusion ?
Thanks
André
Rafael, temos uma situação parecida por aqui. 2 cartões cm9 e 2 painéis setoriais. Qual a melhor configuração que você encontrou ?
Definitely go with separate channels. Using the same channel will cause throughput problems with multiple clients talking at the same time. If they’re close together then you want the channels farther apart. Go with 1 and 11.
Hi str_br.
Man in the case of setorials, i think is a good idea you use same SSID and channel, cause the signals will be in different directions and will be easyer to configure. But in my opinion, it will better you choose 2 SSID’s and 2 channels difference( like SSID 1 in channel 3, and SSID 2 channel 5 or 1), with these method the signals for the clients you will have no TX problems, but in your case with setorials you may have no trouble with same SSID’s and channels without trouble.
Bom str, tudo bem?
No meu caso, eu tenho 1 Omni 360, e uma antena normal grade de 24dbi, eu fiz as configuraçoes em canais e ssid’s diferentes. Nao tive nenhum problema, e olha que no pico de horario tem 20 clientes pendurados em cada cartao, e ainda assim o ping dos clientes ficam e 2ms a 10 ms.
Ao colocar no mesmo canal e ssid, quando ficam bastante clientes, voce pode comecar a ter problemas com os clientes tanto como lentidao(ping alto e perda de pacotes) como baixa transmissao( quando tem poucos clientes o cara fica com 11mbs ai quando tem bastante ele cai pra 2 ou 1 mbs)
Acho que voce nao vai ter problemas com setoriais, pois elas geram e pegam menos interferencia, já a omni e a 24dbi de grade geram e pegam muita interferencia, por isso nao ficou bom, tive varios problemas de clientes que ficavam na antena de grade com sinal otimo e ping baixo, ai as placas trocavam pra omni sozinho e ficava com o mesmo sinal mas lento e ping alto e perdendo pacotes. Já no seu caso isso nao vai acontecer pois voce vai setorizar os clientes. O duro vai ser quando tiver muito cliente pendurado, ai pode ser que fique ruim.
Eu pessoalmente sempre irei recomendar canais e ssid’s diferentes.
assim nao tive dor de cabeça, já com mesmo canal tive muitos problemas.
Alias nao sei o tanto de clientes que voce possui, mas notei que o modo 11b e melhor que o 11g em questao de recepcao de sinal pelo cliente.
Eu uso os cartoes da Atheros SR2, o CM9 eu nao conheco.
Mas se nao for muito ruim pra voce, deixe em canais diferentes com SSID’s diferentes, o duro e que voce vai ter de ir nos clientes e configurar diferente de acordo com a sua necessidade.
Use tambem preambulo longo, no cartao e no cliente, me ajudou MUITO, alem do modo 802.11b, pois o G estava dando alguns problemas.
Espero ter ajudado.
qualquer coisa é só perguntar.
att
Rafael Bortoluzzi
hai friends,
when, i have 2 or 3 APs on tower maybe i will put wds link with same ssid and band, and will registration client every direction.. any suggestion...come, please...!. i need your advice... 
i think easy for maintenance..........
all ap must be support wds.
Man for me, with 4 acces points in the same tower, all of them have Different SSID’s and channels.
I think it’s the better way, cause i’m having no trouble with that config. And same ssid’s and channel i experimented various problems, from high ping/packet loss to tx lowering from 11mb to 1,2 mbps.
But i didn’t work in WDS mode, and don’t know how these mode works.
In MY CASE(4 aps in tower, 1 is mikrotik 2 atheros SR2, 2 Senao CB3plus), the better way are that explained, but if you experience the WDS, but not be sucessfull, try the other method changing de SSID’s and channels and go in the clients, see the ping. If the ping was low(my case 2ms,3ms to 10ms), will be ok for the client.
Tips that happened me, ACK timeout 91 or 105, Long Preamble(in client too) and MTU 1412.
Regards
Rafael Bortoluzzi
Also remember that if you can use different polarity sectors (say 2 horizontal and 2 vertical) you can get up to 20dB seperation between signals. This might not be practical in some applications, although its easy to switch client cpe’s from vertical to horizontal and back.
Hi Rafael and All
Our experience probe different ssid and different channels is the best setup, in 2 access points.
Point A , 2 sector pannel , 2 senao mp2511 cards and different ssid’s and channels, working fine for us, with 40+ clients each.
Point B, 3 sector pannel, 3 senao mp2511 card and different ssid’s and channels, working fine too. 50+ clients in one sector.
thanks
André
Rafael (eunafita)
aqui não usamos modo “g” , sempre “b”. Nossa experiência mostrou que “g” para ambientes outdoor não funciona. E se você compartilhar entre clientes b e g, os “b” vão fazer o ap funcionar na velocidade mais baixa.
I would not use the same channel on two radios in the same box or on the same tower. You could do it (but not in the box case/box)if you are using sectors with ch1 Horizontal, ch6 Horizontal, ch11 Horizontal and then reuse one of the channels in Vertical in the other direction with about 40 feet of vertical separation. And thin I still think it’s a bad idea.
As for the ssid I would use different IDs so you don’t have people connecting to the wrong antenna. I think it’s easier to have different ssid’s
If your using the grid for back haul then why not make the ssid different?
It is amazing how many differing opinions on this topic. I’ve recently had an Indian tribe come into my town and setup a muni wifi and they are using 24 sites on storm sirens in the town. They are using Mikrotiks with 4 2.4 90 deg sectors on each pole. They are running WDS with everything on Channel 1. They haven’t gone production yet, but will be very soon. Now as I understand it, would same channel sectors (particularly those that are adjacent to one another) complete interfere with each other? Is there something about WDS would alleviate self interference?