[PATCH] osmo-bts[master]: Add 11-bit RACH support to osmo-bts-trx

[Max]

Review at  https://gerrit.osmocom.org/6315

Add 11-bit RACH support to osmo-bts-trx

Attempt to decode incoming RACH burst as 11-bit first and fallback to
8-bit if unsuccessful.

Change-Id: Ia28741603636406744e5e22ffff1fb7a9689955a
---
M src/osmo-bts-trx/scheduler_trx.c
1 file changed, 14 insertions(+), 9 deletions(-)


  git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/15/6315/1

diff --git a/src/osmo-bts-trx/scheduler_trx.c b/src/osmo-bts-trx/scheduler_trx.c
index 0f3272e..b95f594 100644
--- a/src/osmo-bts-trx/scheduler_trx.c
+++ b/src/osmo-bts-trx/scheduler_trx.c
@@ -719,6 +719,7 @@
 	uint8_t chan_nr;
 	struct osmo_phsap_prim l1sap;
 	uint8_t ra;
+	uint16_t ra11;
 	int rc;
 
 	chan_nr = trx_chan_desc[chan].chan_nr | tn;
@@ -726,10 +727,18 @@
 	LOGL1S(DL1P, LOGL_DEBUG, l1t, tn, chan, fn, "Received RACH toa=%.2f\n", toa);
 
 	/* decode */
-	rc = gsm0503_rach_decode(&ra, bits + 8 + 41, l1t->trx->bts->bsic);
-	if (rc) {
-		LOGL1S(DL1P, LOGL_DEBUG, l1t, tn, chan, fn, "Received bad AB frame\n");
-		return 0;
+	rc = gsm0503_rach_ext_decode(&ra11, bits + 8 + 41, l1t->trx->bts->bsic);
+	if (rc < 0) {
+		rc = gsm0503_rach_decode(&ra, bits + 8 + 41, l1t->trx->bts->bsic);
+		if (rc < 0) {
+			LOGL1S(DL1P, LOGL_DEBUG, l1t, tn, chan, fn, "Received bad AB frame\n");
+			return 0;
+		}
+		l1sap.u.rach_ind.is_11bit = 0;
+		l1sap.u.rach_ind.burst_type = GSM_L1_BURST_TYPE_ACCESS_0;
+	} else {
+		l1sap.u.rach_ind.is_11bit = 1;
+		l1sap.u.rach_ind.burst_type = GSM_L1_BURST_TYPE_ACCESS_0; /* FIXME: determine burst_type */
 	}
 
 	/* compose primitive */
@@ -738,17 +747,13 @@
 	osmo_prim_init(&l1sap.oph, SAP_GSM_PH, PRIM_PH_RACH, PRIM_OP_INDICATION,
 		NULL);
 	l1sap.u.rach_ind.chan_nr = chan_nr;
-	l1sap.u.rach_ind.ra = ra;
+	l1sap.u.rach_ind.ra = l1sap.u.rach_ind.is_11bit ? ra11 : ra;
 #ifdef TA_TEST
 #warning TIMING ADVANCE TEST-HACK IS ENABLED!!!
 	toa *= 10;
 #endif
 	l1sap.u.rach_ind.acc_delay = (toa >= 0) ? toa : 0;
 	l1sap.u.rach_ind.fn = fn;
-
-	/* 11bit RACH is not supported for osmo-trx */
-	l1sap.u.rach_ind.is_11bit = 0;
-	l1sap.u.rach_ind.burst_type = GSM_L1_BURST_TYPE_ACCESS_0;
 
 	/* forward primitive */
 	l1sap_up(l1t->trx, &l1sap);

-- 
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Gerrit-MessageType: newchange
Gerrit-Change-Id: Ia28741603636406744e5e22ffff1fb7a9689955a
Gerrit-PatchSet: 1
Gerrit-Project: osmo-bts
Gerrit-Branch: master
Gerrit-Owner: Max <msuraev at sysmocom.de>