What is the minimum carrier to interference ratio on WIFI netwotk?

Question

We check almost 200 canopy (AP module - model 5700AP Motorolla) and 20% of it is not working on the site. What should subscriber should do in order to have stable connection? Is power level, signal strenght of antenna, and directivity has something to do with interference?

Answer 1

Well, signal to noise is the most likely issue. If the ratio is low like 10-20% then most likely you will have some packet loss. In most cases you want to see better than 30% s/n If you see 40-50 you will have a very solid connection.

All of the items you mention have a bearing on that level as does environmental factors. There are several steps involved to assure good connectivity.

1. Check to see how many other access points can be seen on the channel you picked.

2. Check to see if you are using the best channel for lowest noise.

3. Assure antennas are all in the same orientation (vert/horiz)

4. Assure as little as possible is blocking line of site! If long distances are involved use a terrain map and see where you need to place the access points so that all clients are within "view".

If you are using directional antennas are they directed in the correct orientation. Is the access point on a vertical or horizontally polarized antenna (there is a 30db difference between the two) make sure the CPE is the same orientation.

If necessary get a spectrum analyzer and look to see what the interference may be across the band. It could be as simple as a noisy microwave oven (many leak at 2.4gig) or even a cordless phone system.

Good luck