osmo-bts: GSMTAP DL (tx) messages use hardcoded signal level 0
It would be great to encode the expected tx power for that message. So basically somehow get the current "tx power" (I think there's no API for that, it needs to check for the current value from power_params in tx_power.c in the ramping code).
If possible, also apply the extra per lchan attenuation (bs_power_red).
related code: function to_gsmtap() in osmo-bts.git l1sap.c