Feature #2724: Improve default timers
RF channel teradown timers (T3109) way too large
- sends a
RR CHANnel RELeaseto the MS via the LAPDm link (RLL on Abis)
- deactivates the SACCH locally on the BSS side
- waits for 20s, and only then issues a
RF CHANnel RELeaseon RSL which deactivates the channel
This means that a MS that is not responding to the
RR CHAN REL (because it is out of range, was switched off, is broken, has lost radio signal) causes us to use the scarce radio channel for 20s more than needed.
According to 3GP TS 44.018 Section 3.4.13, this is timer T3109 (between RR CHAN REL and RF CHAN REL). It is set to 19 seconds in our default, which is ridiculously long.
There's also T3111 which should be started when the main signalling link is disconnected.