diff options
| author | Neels Hofmeyr <neels@hofmeyr.de> | 2018-09-11 00:47:29 +0200 |
|---|---|---|
| committer | Neels Hofmeyr <neels@hofmeyr.de> | 2018-09-11 02:08:41 +0200 |
| commit | 526b4a5f350725d312c6739cf6abdcef040b698c (patch) | |
| tree | 6045e7fbc6e2c147a525f8ba6c973565305b2205 /src/osmo-bsc/timeslot_fsm.c | |
| parent | 021971781de88bb9cd58f18c79a71379a6cfa920 (diff) | |
ts,lchan_fsm: do not attempt to allocate CBCH subslots
In case a given channel combination contains a CBCH, it replaces sub-slot 2
with a CBCH, i.e. we must not attempt to allocate the same for SDCCH.
On timeslot initialization, immediately place such an lchan FSM into new state
LCHAN_ST_CBCH, so that it never appears unused and never is picked during
lchan_select(). Also set lchan->type = GSM_LCHAN_CBCH.
Verified by configuring CBCH timeslots and watching 'show lchan summary'.
Immediately after RSL and OML are up, these pchan types show lchan 2 in state
CBCH:
BTS 0, TRX 0, Timeslot 0 CCCH+SDCCH4+CBCH, Lchan 2, Type CBCH, State CBCH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
BTS 0, TRX 0, Timeslot 1 SDCCH8+CBCH, Lchan 2, Type CBCH, State CBCH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
With a 'phys_chan_config ccch+sdcch4+cbch' and three phones simultaneously
requesting USSD, I see:
BTS 0, TRX 0, Timeslot 0 CCCH+SDCCH4+CBCH, Lchan 0, Type SDCCH, State ESTABLISHED - L1 MS Power: 14 dBm RXL-FULL-dl: -53 dBm RXL-FULL-ul: -47 dBm
BTS 0, TRX 0, Timeslot 0 CCCH+SDCCH4+CBCH, Lchan 1, Type SDCCH, State ESTABLISHED - L1 MS Power: 30 dBm RXL-FULL-dl: -47 dBm RXL-FULL-ul: -47 dBm
BTS 0, TRX 0, Timeslot 0 CCCH+SDCCH4+CBCH, Lchan 2, Type CBCH, State CBCH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
BTS 0, TRX 0, Timeslot 0 CCCH+SDCCH4+CBCH, Lchan 3, Type SDCCH, State ESTABLISHED - L1 MS Power: 16 dBm RXL-FULL-dl: -47 dBm RXL-FULL-ul: -47 dBm
With 'phys_chan_config SDCCH8+CBCH' and three phones simultaneously attaching,
I see:
BTS 0, TRX 0, Timeslot 1 SDCCH8+CBCH, Lchan 0, Type SDCCH, State WAIT_RLL_RTP_ESTABLISH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
BTS 0, TRX 0, Timeslot 1 SDCCH8+CBCH, Lchan 1, Type SDCCH, State WAIT_RLL_RTP_ESTABLISH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
BTS 0, TRX 0, Timeslot 1 SDCCH8+CBCH, Lchan 2, Type CBCH, State CBCH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
BTS 0, TRX 0, Timeslot 1 SDCCH8+CBCH, Lchan 3, Type SDCCH, State WAIT_RLL_RTP_ESTABLISH - L1 MS Power: 0 dBm RXL-FULL-dl: -110 dBm RXL-FULL-ul: -110 dBm
i.e. in all cases the CBCH lchan remains occupied and is not allocated as
SDCCH.
Detaching and re-attaching the BTS reliably brings back the CBCH state. Also
verified that changing the osmo-bsc config from telnet vty and dropping oml
followed by the BTS re-attaching brings back the CBCH state.
Change-Id: I2bafc5f696e818e38f8907ad0c8f38494df0623d
Diffstat (limited to 'src/osmo-bsc/timeslot_fsm.c')
| -rw-r--r-- | src/osmo-bsc/timeslot_fsm.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/src/osmo-bsc/timeslot_fsm.c b/src/osmo-bsc/timeslot_fsm.c index 56b335773..fc2546003 100644 --- a/src/osmo-bsc/timeslot_fsm.c +++ b/src/osmo-bsc/timeslot_fsm.c @@ -295,6 +295,15 @@ static void ts_fsm_unused_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) T_CHAN_ACT_DEACT); break; + case GSM_PCHAN_CCCH_SDCCH4_CBCH: + case GSM_PCHAN_SDCCH8_SACCH8C_CBCH: + /* For any pchans containing a CBCH, lchan[2] is reserved for CBCH and cannot be + * allocated for SDCCH. */ + OSMO_ASSERT(ts->lchan[2].fi); + ts->lchan[2].type = GSM_LCHAN_CBCH; + osmo_fsm_inst_state_chg(ts->lchan[2].fi, LCHAN_ST_CBCH, 0, 0); + break; + default: /* nothing to do */ break; |