Re: trx output power config in bts

osmotrx tx-attenuation (oml|<0-50>) So why do we need these «max_power_red 20» and «osmotrx tx-attenuation»

AFAIU, 'osmotrx tx-attenuation' in osmo-bts.cfg allows you to override the attenuation value sent by the BSC. It should be set to 'oml' by default, meaning that the BSC controls attenuation (via A-bis/OML).

P.S. This mailing list is more about the mobile side of the GSM stack, not core network. Please use openbsc@lists.osmocom.org for questions about radio/core network side next time.

With best regards, Vadim Yanitskiy.