[alloc] Assign a TCH for LU when all SDCCHs are occupied.
When the cell becomes visible we will be bombed with location
updating requests and to reduce the load on the network we should
assign as many channels for it as possible. During load peek it
is even more important than to have a spare voice channel and in
general the LU procedure is pretty fast.
diff --git a/openbsc/src/abis_rsl.c b/openbsc/src/abis_rsl.c
index 7068422..d83af4a 100644
--- a/openbsc/src/abis_rsl.c
+++ b/openbsc/src/abis_rsl.c
@@ -1167,6 +1167,7 @@
enum gsm_chreq_reason_t chreq_reason;
struct gsm_lchan *lchan;
u_int8_t rqd_ta;
+ int is_lu;
u_int16_t arfcn;
u_int8_t ts_number, subch;
@@ -1189,8 +1190,14 @@
counter_inc(bts->network->stats.chreq.total);
+ /*
+ * We want LOCATION UPDATES to succeed and will assign a TCH
+ * if we have no SDCCH available.
+ */
+ is_lu = !!(chreq_reason == GSM_CHREQ_REASON_LOCATION_UPD);
+
/* check availability / allocate channel */
- lchan = lchan_alloc(bts, lctype);
+ lchan = lchan_alloc(bts, lctype, is_lu);
if (!lchan) {
LOGP(DRSL, LOGL_NOTICE, "BTS %d CHAN RQD: no resources for %s 0x%x\n",
msg->lchan->ts->trx->bts->nr, gsm_lchant_name(lctype), rqd_ref->ra);