tree 80b46ca4327c0902778eb3fd62e4c751af866f98
parent f47f68a9d8e4421398e2369e4b18de8c52a9d396
author Jacob Erlbeck <jerlbeck@sysmocom.de> 1433412752 +0200
committer Jacob Erlbeck <jerlbeck@sysmocom.de> 1433749209 +0200

tbf: Add adaptive DL CS adjustment

To cope with transmission failures due to bad radio conditions, a
different coding scheme with more redundance can be used.

This commit adds an implemenation that is based on the Ack/Nack
ratio per PACKET DOWNLINK ACK/NACK message received from the MS.

Basically the CS level is decreased, if the block error rate goes
above cs_adj_upper_limit (default 33%), and it is increased, if the
rate drops below cs_adj_lower_limit (default 10%). Only blocks that
have been encoded with the current CS are taken into account.

Note that this approach doesn't measure the MS->BTS conditions and
that the measurement values reported by the MS are not taken into
account.

Ticket: #1739
Sponsored-by: On-Waves ehf