diff --git a/include/openbsc/gsm_data.h b/include/openbsc/gsm_data.h
new file mode 100644
index 0000000..51e246c
--- /dev/null
+++ b/include/openbsc/gsm_data.h
@@ -0,0 +1,74 @@
+#ifndef _GSM_DATA_H
+#define _GSM_DATA_H
+
+#include <sys/types.h>
+
+#define GSM_MAX_BTS	8
+#define BTS_MAX_TRX	8
+
+#define HARDCODED_ARFCN 123
+
+/* communications link with a BTS */
+struct gsm_bts_link {
+	struct gsm_bts *bts;
+};
+
+#define BTS_TRX_F_ACTIVATED	0x0001
+/* One Timeslot in a TRX */
+struct gsm_bts_trx_ts {
+	struct gsm_bts_trx *trx;
+	/* number of this timeslot at the TRX */
+	u_int8_t nr;
+
+	unsigned int flags;
+};
+
+/* One TRX in a BTS */
+struct gsm_bts_trx {
+	struct gsm_bts *bts;
+	/* number of this TRX in the BTS */
+	u_int8_t nr;
+
+	u_int16_t arfcn;
+	struct gsm_bts_trx_ts ts[8];
+};
+
+/* One BTS */
+struct gsm_bts {
+	struct gsm_network *network;
+	/* number of ths BTS in network */
+	u_int8_t nr;
+	/* location area code of this BTS */
+	u_int8_t location_area_code;
+
+	/* Abis network management O&M handle */
+	struct abis_nm_h *nmh;
+	/* number of this BTS on given E1 link */
+	u_int8_t bts_nr;
+
+	/* CCCH is on C0 */
+	struct gsm_bts_trx *c0;
+	/* transceivers */
+	int num_trx;
+	struct gsm_bts_trx trx[BTS_MAX_TRX+1];
+};
+
+struct gsm_ms {
+	unsigned long imei;
+};
+
+struct gsm_network {
+	/* global parameters */
+	u_int8_t country_code;
+	u_int8_t network_code;
+
+	unsigned int num_bts;
+	/* private lists */
+	struct gsm_bts	bts[GSM_MAX_BTS+1];
+	struct gsm_ms	*ms;
+	struct gsm_subscriber *subscriber;
+};
+
+struct gsm_network *gsm_network_init(unsigned int num_bts, u_int8_t country_code,
+				     u_int8_t network_code);
+#endif