For several weeks now my Android phone has been losing it's WiFi signal momentarily, typically at about 3 minute intervals (about 3 minutes, 1.5 seconds) and occasionally at some longer interval that always seems to be a multiple of just over 3 minutes. This causes an interruption of several seconds while the WiFi connection is re-established and typically fails any kind of download/streaming that is happening, makes web sites "unreachable" and generally makes the phone unusable as a data device due to the frequency. The signal remains down for about a second, but the phone takes a few more seconds to reconnect to the router.
This happens regardless of proximity to the router, which shows a very strong signal - usually -40 to -30 dBm or better in the same room, nowhere in the house less than -70 dBm. It also happens regardless of whether the phone is plugged in or on battery.
Some specific things I've tried that had no effect:
- Changing channels (I've tried 1, 4, 8 and 9).
- Turning off the router's guest access.
- Turning off the 5.0 GHz band.
- Setting the router to Wireless N only (though that did prevent my laptop from connecting, which only supports G).
- Changing the phone's wireless advanced settings sleep policy to Never.
- Setting the battery mode to Performance mode.
Monitoring the signal on my phone with WiFi analyzer, shows all WiFi signals on all channels drop to nothing when the WiFi connection is lost (there are two other networks on different channels which are strong enough to be relevant, with about 6 others constantly fading in and out). WiFi analyzer shows 3 separate signals for my router, the main 2.4 GHz, the guest 2.4 GHz and the 5.0 GHz.
Using WiFi Analyzer on my wife's phone side-by-side shows no change in signal when my phone drops, nor does her phone drop.
Monitoring the signal using our laptop, side-by-side likewise shows no signal loss and likewise the laptop does not lose it's WiFi connection.
But, at work, the phone seems to not exhibit the same behavior, or, if it does, it's very occasional. Monitoring it all day at work I only saw the signal drop 3 or 4 times. The signal strength of the various networks there is comparatively weak.
AT&T were super helpful: "Sorry, we can't help you with WiFi problems. You could try doing a factory reset on your phone".
The router is relatively new, but has been working fine with this phone since last Dec.
Phone : Motorola Atrix MB860, System version 4.5.141.MB860.ATT.en.US, Android 2.3.6, Build Number 4.5.141. Router : Belkin N750 DB (F9K1103 v1 (01C)). Router Firmware: 1.00.46 (2011/10/28 6:37:11). Security : WPA/WPA2-Personal (PSK)