Wifi and 3G interference

RouterOS Wireless Networking
1

I’m putting together a RB411U with a Sprint U720 minipci-e modem and a R2n wifi card. The client adapter is 802.11G, about 4 feet away. With the Sprint modem operating I am seeing packet loss on the wifi. About 2% loss even with no traffic. Ping times are mostly 1-5ms with the occasional 100+ms.

I’ve tried a bunch of settings on the R2n card to no avail. They are back to almost default now. The three antennas (2 for wifi, 1 for Sprint) are on the rear of the unit. Moving the Sprint antenna has little effect. I even put the Sprint minipci-e card back into the USB holder and plugged in in the front. Still creates packet loss.

Any ideas on how to resolve this packet loss?

2

How do you know the sprint card has anything to do with your problem?

3

Yeah, I should have mentioned this. With the Sprint card completely removed I did not see any dropped packets.

I have upped the hw-retries to 15 and this has helped somewhat. I have tried an R52n card, and a 802.11G Atheros card. Those drop packets as well.

4

This is goung to sound stupid… but…

Move the laptop away from the router a bit…

I have seen that woth 802.11N that bing too close can shut communication completely off !!

I have a Toshiba laptop that I have to keep about 5 to10 feet away, then it works GREAT…

5

Ok, I tried that… Still drops packets, thanks for the idea though.

6

I have experienced this as well although with a separate 3g router too close to the wlan. I think it’s like if you hear on the tv or radio the sound interfierance if a mobile phone is close. I can only imagine the transmitter is too powerful in those to be that close even though they operate on a different frequency. I suspect you will have to have two separate routerboards possibly in metal cases some distance apart?