diff --git a/openbsc/src/e1_config.c b/openbsc/src/e1_config.c
index addc9fe..d7b4268 100644
--- a/openbsc/src/e1_config.c
+++ b/openbsc/src/e1_config.c
@@ -25,18 +25,35 @@
 	struct e1inp_ts *sign_ts;
 	struct e1inp_sign_link *oml_link, *rsl_link;
 	struct gsm_bts_trx *trx = bts->c0;
+	int base_ts;
+
+	switch (bts->nr) {
+	case 0:
+		/* First BTS uses E1 TS 01,02,03,04,05 */
+		base_ts = 1 - 1;
+		break;
+	case 1:
+		/* Second BTS uses E1 TS 11,12,13,14,15 */
+		base_ts = 11 - 1;
+		break;
+	case 2:
+		/* Third BTS uses E1 TS 21,22,23,24,25 */
+		base_ts = 21 - 1;
+	default:
+		return -EINVAL;
+	}
 
 	line = talloc_zero(tall_bsc_ctx, struct e1inp_line);
 	if (!line)
 		return -ENOMEM;
 
 	/* create E1 timeslots for signalling and TRAU frames */
-	e1inp_ts_config(&line->ts[1-1], line, E1INP_TS_TYPE_SIGN);
-	e1inp_ts_config(&line->ts[2-1], line, E1INP_TS_TYPE_TRAU);
-	e1inp_ts_config(&line->ts[3-1], line, E1INP_TS_TYPE_TRAU);
+	e1inp_ts_config(&line->ts[base_ts+1-1], line, E1INP_TS_TYPE_SIGN);
+	e1inp_ts_config(&line->ts[base_ts+2-1], line, E1INP_TS_TYPE_TRAU);
+	e1inp_ts_config(&line->ts[base_ts+3-1], line, E1INP_TS_TYPE_TRAU);
 
 	/* create signalling links for TS1 */
-	sign_ts = &line->ts[1-1];
+	sign_ts = &line->ts[base_ts+1-1];
 	oml_link = e1inp_sign_link_create(sign_ts, E1INP_SIGN_OML,
 					  trx, TEI_OML, SAPI_OML);
 	rsl_link = e1inp_sign_link_create(sign_ts, E1INP_SIGN_RSL,
@@ -47,40 +64,40 @@
 	trx->rsl_link = rsl_link;
 
 	/* enable subchannel demuxer on TS2 */
-	subch_demux_activate(&line->ts[2-1].trau.demux, 1);
-	subch_demux_activate(&line->ts[2-1].trau.demux, 2);
-	subch_demux_activate(&line->ts[2-1].trau.demux, 3);
+	subch_demux_activate(&line->ts[base_ts+2-1].trau.demux, 1);
+	subch_demux_activate(&line->ts[base_ts+2-1].trau.demux, 2);
+	subch_demux_activate(&line->ts[base_ts+2-1].trau.demux, 3);
 
 	/* enable subchannel demuxer on TS3 */
-	subch_demux_activate(&line->ts[3-1].trau.demux, 0);
-	subch_demux_activate(&line->ts[3-1].trau.demux, 1);
-	subch_demux_activate(&line->ts[3-1].trau.demux, 2);
-	subch_demux_activate(&line->ts[3-1].trau.demux, 3);
+	subch_demux_activate(&line->ts[base_ts+3-1].trau.demux, 0);
+	subch_demux_activate(&line->ts[base_ts+3-1].trau.demux, 1);
+	subch_demux_activate(&line->ts[base_ts+3-1].trau.demux, 2);
+	subch_demux_activate(&line->ts[base_ts+3-1].trau.demux, 3);
 
 	trx = gsm_bts_trx_num(bts, 1);
 	if (trx) {
 		/* create E1 timeslots for TRAU frames of TRX1 */
-		e1inp_ts_config(&line->ts[4-1], line, E1INP_TS_TYPE_TRAU);
-		e1inp_ts_config(&line->ts[5-1], line, E1INP_TS_TYPE_TRAU);
+		e1inp_ts_config(&line->ts[base_ts+4-1], line, E1INP_TS_TYPE_TRAU);
+		e1inp_ts_config(&line->ts[base_ts+5-1], line, E1INP_TS_TYPE_TRAU);
 
 		/* create RSL signalling link for TRX1 */
-		sign_ts = &line->ts[1-1];
+		sign_ts = &line->ts[base_ts+1-1];
 		rsl_link = e1inp_sign_link_create(sign_ts, E1INP_SIGN_RSL,
 					  trx, TEI_RSL+1, SAPI_RSL);
 		/* create back-links from trx */
 		trx->rsl_link = rsl_link;
 
 		/* enable subchannel demuxer on TS2 */
-		subch_demux_activate(&line->ts[4-1].trau.demux, 0);
-		subch_demux_activate(&line->ts[4-1].trau.demux, 1);
-		subch_demux_activate(&line->ts[4-1].trau.demux, 2);
-		subch_demux_activate(&line->ts[4-1].trau.demux, 3);
+		subch_demux_activate(&line->ts[base_ts+4-1].trau.demux, 0);
+		subch_demux_activate(&line->ts[base_ts+4-1].trau.demux, 1);
+		subch_demux_activate(&line->ts[base_ts+4-1].trau.demux, 2);
+		subch_demux_activate(&line->ts[base_ts+4-1].trau.demux, 3);
 
 		/* enable subchannel demuxer on TS3 */
-		subch_demux_activate(&line->ts[5-1].trau.demux, 0);
-		subch_demux_activate(&line->ts[5-1].trau.demux, 1);
-		subch_demux_activate(&line->ts[5-1].trau.demux, 2);
-		subch_demux_activate(&line->ts[5-1].trau.demux, 3);
+		subch_demux_activate(&line->ts[base_ts+5-1].trau.demux, 0);
+		subch_demux_activate(&line->ts[base_ts+5-1].trau.demux, 1);
+		subch_demux_activate(&line->ts[base_ts+5-1].trau.demux, 2);
+		subch_demux_activate(&line->ts[base_ts+5-1].trau.demux, 3);
 	}
 
 	return mi_setup(cardnr, line, release_l2);