diff --git a/pcu_l1_if.h b/pcu_l1_if.h
index cdd3642..0d326d5 100644
--- a/pcu_l1_if.h
+++ b/pcu_l1_if.h
@@ -47,6 +47,14 @@
 
 	struct osmo_fd read_ofd;	/* osmo file descriptors */
 	struct osmo_wqueue write_q;
+
+	struct {
+		uint16_t arfcn;
+		uint8_t tn;
+		uint8_t tsc;
+		uint16_t ta;
+	} channel_info;
+
 };
 
 struct l1fwd_hdl {
@@ -62,7 +70,7 @@
 
 int get_current_fn();
 
-void pcu_l1if_tx(BitVector * block);
+void pcu_l1if_tx(BitVector * block, GsmL1_Sapi_t sapi, int len = 23);
 
 int pcu_l1if_handle_l1prim(struct femtol1_hdl *fl1h, struct msgb *msg);