diff --git a/openbsc/include/openbsc/gsm_data.h b/openbsc/include/openbsc/gsm_data.h
index 4a6acb5..573ce5f 100644
--- a/openbsc/include/openbsc/gsm_data.h
+++ b/openbsc/include/openbsc/gsm_data.h
@@ -648,6 +648,7 @@
 		   u_int8_t e1_ts, u_int8_t e1_ts_ss);
 enum gsm_bts_type parse_btstype(const char *arg);
 const char *btstype2str(enum gsm_bts_type type);
+struct gsm_bts_trx *gsm_bts_trx_by_nr(struct gsm_bts *bts, int nr);
 struct gsm_bts *gsm_bts_by_lac(struct gsm_network *net, unsigned int lac,
 				struct gsm_bts *start_bts);
 
diff --git a/openbsc/src/gsm_data.c b/openbsc/src/gsm_data.c
index 446a820..d2676db 100644
--- a/openbsc/src/gsm_data.c
+++ b/openbsc/src/gsm_data.c
@@ -365,6 +365,17 @@
 	return bts_types[type];
 }
 
+struct gsm_bts_trx *gsm_bts_trx_by_nr(struct gsm_bts *bts, int nr)
+{
+	struct gsm_bts_trx *trx;
+
+	llist_for_each_entry(trx, &bts->trx_list, list) {
+		if (trx->nr == nr)
+			return trx;
+	}
+	return NULL;
+}
+
 /* Search for a BTS in the given Location Area; optionally start searching
  * with start_bts (for continuing to search after the first result) */
 struct gsm_bts *gsm_bts_by_lac(struct gsm_network *net, unsigned int lac,