2017-01-25

OpenWRT Backfire on WRT54GL signal strenght

Because I wanted my home router to use at least decently supported software that provides complete out-of-the-box support for native IPv6, I recently got around upgrading my WRT54GL's firmware from White Russian to Backfire, which is the most recent OpenWRT release that fits the hardware's limited amount of flash memory.

One issue remains unanswered:

In GNOME shell's top panel and WiFi menu, the signal strength remains at 2 out of 4 bars. Given how the router sits only a few meters behind me, I would have expected much better signal strength than that.

Would anyone happen to know how to improve on these results? Thanks!

3 kommenttia:

-dsr- kirjoitti...

The firmware change won't improve that.

The options are:

1. change the channel to the one with the least interference

2. remove obstructions in the signal path between antennae

3. increase effective transmission power by using a directional antenna instead of an omnidirectional antenna

4. increase transmission power

Martin-Éric kirjoitti...

The channel is one that isn't used by anyone else in the building, as verified with the 'sudo iwlist wlan0 scanning | grep Channel: | cut --delimiter : --field 2 | sort -g' command line.

Transmission power is at the maximum setting allowed by Luci.

Please note that I wasn't expecting a firmware change to improve throughput. I'm merely surprised to find that the performance is so poor to begin with. The access points from my neighbours all seem to offer maximum signal strength according to GNOME shell's WiFi network selection applet.

Unknown kirjoitti...

So, a few things: First of all, Wi-Fi is tricky. WRT54GL is a very old router, and you should probably get something newer, _especially_ if you care about speed.

It's hard to say exactly what the “two bars” mean. It could mean signal strength, it could mean noise floor, it could mean SNR, it could mean something entirely different and random. iwconfig will give you more raw numbers, but note that even those are just a single sample, and these things can vary on the millisecond-level. (In particular, the “current speed” measurement is sort of worthless, since it varies by the packet.) But do note that 2.4 GHz channels are _overlapping_. If you are on channel 5 and your neighbor is on 6, these will have considerable interference.

The simplest solution is to move to the 5 GHz band, where you have 16–20 20 MHz channels that are nonoverlapping (modern standards combine these into wider channels for much higher speeds, all the way up to 160 MHz). But WRT54GL can't do this, because, well, it's a product that's fifteen years old and technology improved a lot since that.