We currently have 2 Cisco 1030 APs set up in a bridge connection (root to non-root). However, the signal strength constantly varies between -53dBm and -80 dBm (SNR also drops during this timeframe). We have checked the area with a frequency scanner and there is no noise that should interfere with the WLAN link. I have tried finding Cisco documents that specify how a radio link between 2 AP should behave (will the signal differ with increase/decrease in load?), but as far as I can see there is no documentation discussing this. We have another bridge pair a couple of meters beside this first pair, here the signal strength remains pretty constant around -53dBm, sometimes it jumps up to -80 dBm for a very short time (not at the same time as the other pair of bridges). The two bridge pairs are running on non-overlapping channels (1 and 6).
The other WLAN bridge installations that we have are also quite stable in signal strength.
Has anyone experienced something similar, or know what could be causing this?