Uplink DTX support
This was never tested and we should check the status + fix it with OsmoBTS.
Uplink DTX is important to reduce possible uplink interference, but even more so to conserve battery power of the mobile station.
#6 Updated by laforge about 3 years ago
- parsing of the DTX related RSL/OML bits/IEs (DTX is under control from the BSC, and it can chose to activate/deactivate it dynamically, AFAIR)
- activation of the logical channel towards the MS with DTX enabled or disabled (if BTS needs to do something here; might also be the case that all messages are fully provided by the BSC)
- ensure that the processing of uplink measurements (signal quality / BER) into RSL uplink measurement reports is handled correctly
- ensure that LAPDm is working correctly. LAPDm should not be notified that bad frames have been received during periods where DTXu has muted some bursts/blocks. If we did that, it would look like a much higher actual error rate than we have.
- ensure that signalling in both direction works as expected, for both SAPI0 on FACCH as well as SAPI3 (SMS) on SACCH
- ensure that voice handling on the traffic channels works as expected, particularly in terms of the RTP integration for both HR and FR
- AMR e.g. will transmit SID frames and change the transmission interval of RTP frames
It might make sense to compare our behavior with that of an ip.access nanoBTS in order to have protocol-level compatibility.
#13 Updated by msuraev about 3 years ago
- % Done changed from 0 to 20
- parsing of the DTX related RSL/OML bits/IEs..
- ensure that the processing of uplink measurements..
- activation of the logical channel towards the MS with DTX enabled or disabled..
- change the transmission interval of RTP frames
#16 Updated by msuraev about 3 years ago
- % Done changed from 20 to 80
The patches are pushed to gerrit/users/max/dtx-test branch and are ready for review/testing. Note support is implemented for sysmoBTS (updated firmware required for AMR tests) and LC15 BTS models. AMR-HR support is incomplete which might result in audible disturbances while testing.