#defines for GSM48 channel modes
diff --git a/include/openbsc/gsm_04_08.h b/include/openbsc/gsm_04_08.h
index de48fe8..3b343c3 100644
--- a/include/openbsc/gsm_04_08.h
+++ b/include/openbsc/gsm_04_08.h
@@ -40,6 +40,15 @@
u_int8_t mode;
} __attribute__ ((packed));
+#define GSM48_CMODE_SIGN 0x00
+#define GSM48_CMODE_SPEECH_V1 0x01
+#define GSM48_CMODE_SPEECH_EFR 0x21
+#define GSM48_CMODE_SPEECH_AMR 0x41
+#define GSM48_CMODE_DATA_14k5 0x0f
+#define GSM48_CMODE_DATA_12k0 0x03
+#define GSM48_CMODE_DATA_6k0 0x0b
+#define GSM48_CMODE_DATA_3k6 0x23
+
/* Chapter 9.1.18 */
struct gsm48_imm_ass {
u_int8_t l2_plen;