diff --git a/include/osmocom/gsm/gsm0411_smc.h b/include/osmocom/gsm/gsm0411_smc.h
new file mode 100644
index 0000000..e1508a2
--- /dev/null
+++ b/include/osmocom/gsm/gsm0411_smc.h
@@ -0,0 +1,62 @@
+#ifndef _GSM0411_SMC_H
+#define _GSM0411_SMC_H
+
+#include <osmocom/gsm/protocol/gsm_04_11.h>
+
+#define GSM411_MMSMS_EST_REQ		0x310
+#define GSM411_MMSMS_EST_IND		0x312
+#define GSM411_MMSMS_EST_CNF		0x311
+#define GSM411_MMSMS_REL_REQ		0x320
+#define GSM411_MMSMS_REL_IND		0x322
+#define GSM411_MMSMS_DATA_REQ		0x330
+#define GSM411_MMSMS_DATA_IND		0x332
+#define GSM411_MMSMS_UNIT_DATA_REQ	0x340
+#define GSM411_MMSMS_UNIT_DATA_IND	0x342
+#define GSM411_MMSMS_ERR_IND		0x372
+
+#define GSM411_MNSMS_ABORT_REQ		0x101
+#define GSM411_MNSMS_DATA_REQ		0x102
+#define GSM411_MNSMS_DATA_IND		0x103
+#define GSM411_MNSMS_EST_REQ		0x104
+#define GSM411_MNSMS_EST_IND		0x105
+#define GSM411_MNSMS_ERROR_IND		0x106
+#define GSM411_MNSMS_REL_REQ		0x107
+
+struct gsm411_smc_inst {
+	int network;		/* is this a MO (0) or MT (1) transfer */
+	int (*mn_recv) (struct gsm411_smc_inst *inst, int msg_type,
+			struct msgb *msg);
+	int (*mm_send) (struct gsm411_smc_inst *inst, int msg_type,
+			struct msgb *msg, int cp_msg_type);
+
+	enum gsm411_cp_state cp_state;
+	struct osmo_timer_list cp_timer;
+	struct msgb *cp_msg;	/* store pending message */
+	int cp_rel;		/* store pending release */
+	int cp_retx;		/* retry counter */
+	int cp_max_retr;	/* maximum retry */
+	int cp_tc1;		/* timer value TC1* */
+
+};
+
+extern const struct value_string gsm411_cp_cause_strs[];
+
+/* init a new instance */
+void gsm411_smc_init(struct gsm411_smc_inst *inst, int network,
+	int (*mn_recv) (struct gsm411_smc_inst *inst, int msg_type,
+			struct msgb *msg),
+	int (*mm_send) (struct gsm411_smc_inst *inst, int msg_type,
+			struct msgb *msg, int cp_msg_type));
+
+/* clear instance */
+void gsm411_smc_clear(struct gsm411_smc_inst *inst);
+
+/* message from upper layer */
+int gsm411_smc_send(struct gsm411_smc_inst *inst, int msg_type,
+	struct msgb *msg);
+
+/* message from lower layer */
+int gsm411_smc_recv(struct gsm411_smc_inst *inst, int msg_type,
+	struct msgb *msg, int cp_msg_type);
+
+#endif /* _GSM0411_SMC_H */