DFS - Wireless Log - What does "Time elapsed" mean?

[Lexicon44]

Hi,

I'm running Merlin 3004.388.7 on an RT-AX88U Pro. Under System Log --> Wirless Log, I see "DFS State: In-Service Monitoring (ISM)" and "Channel cleared for radar: 104/80". I'm wondering what "Time elapsed" means.

I saw others post screenshots where their time elapsed is measured in hours. Mine rarely makes it beyond 15 minutes, and often resets after a few seconds.

Does this mean that radar was detected? If so, I would expect the channel to switch, but it doesn't and I never notice any interruption to my WiFi connection.

Or is this the time since the last scan for radar, in which case why doesn't it happen with a regular cadence, and why would others have it happens after multiple hours.

 

[ColinTaylor]

Is your bandwidth set to 20/40/80/160?

The elapsed time is reset every time the chanspec (channel/bandwidth) changes. So with the bandwidth set as above, and with no 160MHz capable devices connected the chanspec will be 104/80. As soon as a 160MHz capable device connects it will change to 104/160. When that device disconnects it will change back to 104/80.

Also, if you have the channel set to Auto and have lots of nearby access points using all the channels that might also cause the router to move to a "better" channel.

 

[Lexicon44]

In that case, the plot thickens.

My control channel is set to auto with DFS channels included. The channel does change on occasion, but I would say maybe once per week? It definitely doesn't correspond to the time elapsed timer resetting.

My bandwidth is set to 20/40/80 MHz with 160 MHz disabled.

If I watch the Wireless Log page, the elapsed time parameter changes and resets. None of the other parameters change, including channel and bandwidth. Weird?

 

[jetpack42]

This used to happen to me when I used the auto channel option. In my case, I had the router set to "Auto" channel with DFS channel selection enabled and I did not use 160 MHz, like in your case. I found that the timer resetting had no actual effect on my router's wireless performance and I always assumed it was either a bug with the wireless drivers, or it had something to do with the router's automatic channel selection (despite my router never changing channels from the channel it initially selected).

When I started to manually select the channel (100/80), the time elapsed counter stopped resetting. The only time I ever saw it reset after that was when it detected radar once and moved to a non-DFS channel.