Hi.
I'm troubleshooting peculiar use case with packet access and osmo-bts-trx. There are 2 options for ME to acknowledge reception of control packet to PCU according to 3GPP TS 44.060 ยง 11.2.2:
1) Packet Control Acknowledgement message
2) 4 identical access bursts
The latter can be both 8-bit RACH and 11-bit RACH (not supported by osmo-bts-trx yet). The choice of response format is defined by OpenBSC in SI: 1) is default, 2) can be activated with "gprs control-ack-type-rach" option.
The problem is that I don't understand how 2) will be handled by OsmoTRX? Shall I expect 4 consecutive RACH messages via rx_rach_fn() in scheduler_trx.c in osmo-bts-trx? Shall it be some other message/function? Will it be ignored/dropped altogether by OsmoTRX?
Hi Max,
On Thu, Jun 8, 2017 at 1:49 AM, Max msuraev@sysmocom.de wrote:
The problem is that I don't understand how 2) will be handled by OsmoTRX? Shall I expect 4 consecutive RACH messages via rx_rach_fn() in scheduler_trx.c in osmo-bts-trx? Shall it be some other message/function? Will it be ignored/dropped altogether by OsmoTRX?
I'm not sure about osmo-bts-trx handling, but osmo-trx itself will unconditionally report any RACH bursts detected according to the active channel combination. Those are the only two conditions - that the channel combination indicates to perform RACH detection and that the RACH burst is detected.
-TT
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Max -
Tom Tsou