OsmoBTS doesn't generate measurement indications in absence of uplink bursts
If there are no uplink bursts received (but timestamp indications sent) from OsmoTRX, osmo-bts-trx doesn't appear to generate RSL MEAS REP messages at every SACCH multiframe (103 frames), as expected. Odd.
The entire measurement computation + reporting process is driven by
lchan_meas_check_compute(), which is only called from the l1sap whenever a PRIM_INFO_MEAS is reported up. In absence of bursts/blocks, this primitive is not reported and subsequently no measurement reports are generated.
What we should do instead is track the frame number and whenever the SACCH multiframe ends, we should trigger a RSL MEAS REP. the missing uplink bursts all have to count as erroneous, i.e. 100% bit errors.
The entire dualism of PH_DATA.ind / PH_TCH.ind containg (unsued) measurement data, but then having a separate PRIM_INFO_MEAS is odd to begin with. The measurements should always accompany the PH-DATA.ind / PH-TCH.ind and PRIM_INFO_MEAS should be abandoned.