diff --git a/src/Makefile.am b/src/Makefile.am
index 4321b7c..19dcc0f 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -24,25 +24,25 @@
 noinst_LTLIBRARIES = libgprs.la
 
 libgprs_la_SOURCES = \
-	gprs_debug.cpp \
+	gprs_debug.c \
 	csn1.cpp \
-	gsm_rlcmac.cpp \
+	gsm_rlcmac.c \
 	gprs_bssgp_pcu.cpp \
-	gprs_rlcmac.cpp \
-	gprs_rlcmac_data.cpp \
+	gprs_rlcmac.c \
+	gprs_rlcmac_data.c \
 	gprs_rlcmac_ctrl.cpp \
-	gprs_rlcmac_sched.cpp \
-	gsm_timer.cpp \
+	gprs_rlcmac_sched.c \
+	gsm_timer.c \
 	bitvector.cpp \
-	pcu_l1_if.cpp \
+	pcu_l1_if.c \
 	pcu_vty.c
 
 if ENABLE_SYSMOBTS
 libgprs_la_SOURCES += \
-	sysmo_sock.cpp
+	sysmo_sock.c
 else
 libgprs_la_SOURCES += \
-	openbts_sock.cpp
+	openbts_sock.c
 endif
 
 noinst_PROGRAMS = \
@@ -57,6 +57,7 @@
 	gsm_rlcmac.h \
 	gprs_bssgp_pcu.h \
 	gprs_rlcmac.h \
+	gprs_rlcmac_ctrl.h \
 	pcuif_proto.h \
 	pcu_l1_if.h \
 	gsm_timer.h \
diff --git a/src/csn1.cpp b/src/csn1.cpp
index b0ed73d..2dfa6ca 100644
--- a/src/csn1.cpp
+++ b/src/csn1.cpp
@@ -33,7 +33,9 @@
 #include <assert.h>
 #include <string.h>
 #include "csn1.h"
+extern "C" {
 #include <gprs_debug.h>
+}
 
 
 #define pvDATA(_pv, _offset) ((void*) ((unsigned char*)_pv + _offset))
diff --git a/src/gprs_bssgp_pcu.cpp b/src/gprs_bssgp_pcu.cpp
index 9b977f2..1c3c658 100644
--- a/src/gprs_bssgp_pcu.cpp
+++ b/src/gprs_bssgp_pcu.cpp
@@ -1,4 +1,4 @@
-/* gprs_bssgp_pcu.cpp
+/* gprs_bssgp_pcu.c
  *
  * Copyright (C) 2012 Ivan Klyuchnikov
  *
@@ -17,9 +17,13 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
 
+#include <stdint.h>
+#include <bitvector.h>
+extern "C" {
 #include <gprs_rlcmac.h>
 #include <gprs_bssgp_pcu.h>
 #include <pcu_l1_if.h>
+}
 
 struct sgsn_instance *sgsn;
 void *tall_bsc_ctx;
diff --git a/src/gprs_bssgp_pcu.h b/src/gprs_bssgp_pcu.h
index 7d5f376..2136d89 100644
--- a/src/gprs_bssgp_pcu.h
+++ b/src/gprs_bssgp_pcu.h
@@ -21,7 +21,6 @@
 #define GPRS_BSSGP_PCU_H
 
 
-extern "C" {
 #include <osmocom/core/talloc.h>
 #include <osmocom/core/rate_ctr.h>
 #include <osmocom/core/logging.h>
@@ -36,7 +35,6 @@
 int bssgp_tx_ul_ud(struct bssgp_bvc_ctx *bctx, uint32_t tlli, const uint8_t *qos_profile, struct msgb *llc_pdu);
 
 struct bssgp_bvc_ctx *btsctx_alloc(uint16_t bvci, uint16_t nsei);
-}
 #include <gprs_debug.h>
 
 #define QOS_PROFILE 0
diff --git a/src/gprs_debug.cpp b/src/gprs_debug.c
similarity index 98%
rename from src/gprs_debug.cpp
rename to src/gprs_debug.c
index 2b9b690..c671251 100644
--- a/src/gprs_debug.cpp
+++ b/src/gprs_debug.c
@@ -1,4 +1,4 @@
-/* gprs_debug.cpp
+/* gprs_debug.c
  *
  * Copyright (C) 2012 Ivan Klyuchnikov
  *
diff --git a/src/gprs_debug.h b/src/gprs_debug.h
index 1a5f01a..e3bbf4f 100644
--- a/src/gprs_debug.h
+++ b/src/gprs_debug.h
@@ -21,10 +21,9 @@
 #define GPRS_DEBUG_H
 
 #include <stdio.h>
-extern "C" {
 #include <osmocom/core/linuxlist.h>
 #include <osmocom/core/logging.h>
-};
+
 /* Debug Areas of the code */
 enum {
 	DCSN1,
diff --git a/src/gprs_rlcmac.cpp b/src/gprs_rlcmac.c
similarity index 99%
rename from src/gprs_rlcmac.cpp
rename to src/gprs_rlcmac.c
index f5d91a9..2bd6af8 100644
--- a/src/gprs_rlcmac.cpp
+++ b/src/gprs_rlcmac.c
@@ -73,7 +73,7 @@
 
 LLIST_HEAD(gprs_rlcmac_ul_tbfs);
 LLIST_HEAD(gprs_rlcmac_dl_tbfs);
-llist_head *gprs_rlcmac_tbfs_lists[] = {
+struct llist_head *gprs_rlcmac_tbfs_lists[] = {
 	&gprs_rlcmac_ul_tbfs,
 	&gprs_rlcmac_dl_tbfs,
 	NULL
@@ -1047,7 +1047,7 @@
 }
 
 /* Send Uplink unit-data to SGSN. */
-int gprs_rlcmac_tx_ul_ud(gprs_rlcmac_tbf *tbf)
+int gprs_rlcmac_tx_ul_ud(struct gprs_rlcmac_tbf *tbf)
 {
 	const uint8_t qos_profile = QOS_PROFILE;
 	struct msgb *llc_pdu;
diff --git a/src/gprs_rlcmac.h b/src/gprs_rlcmac.h
index 89b3dc9..45ed9d0 100644
--- a/src/gprs_rlcmac.h
+++ b/src/gprs_rlcmac.h
@@ -20,15 +20,8 @@
 #ifndef GPRS_RLCMAC_H
 #define GPRS_RLCMAC_H
 
-#ifdef __cplusplus
-#include <gsm_rlcmac.h>
-#include <gsm_timer.h>
-
-extern "C" {
 #include <osmocom/core/linuxlist.h>
 #include <osmocom/core/timer.h>
-}
-#endif
 
 /* This special feature will delay assignment of downlink TBF by one second,
  * in case there is already a TBF.
@@ -82,7 +75,6 @@
 
 extern struct gprs_rlcmac_bts *gprs_rlcmac_bts;
 
-#ifdef __cplusplus
 /*
  * TBF instance
  */
@@ -196,7 +188,7 @@
 	unsigned int T; /* Txxxx number */
 	unsigned int num_T_exp; /* number of consecutive T expirations */
 	
-	struct osmo_gsm_timer_list	gsm_timer;
+//	struct osmo_gsm_timer_list	gsm_timer;
 	unsigned int fT; /* fTxxxx number */
 	unsigned int num_fT_exp; /* number of consecutive fT expirations */
 
@@ -256,7 +248,7 @@
 int gprs_rlcmac_rcv_block(uint8_t trx, uint8_t ts, uint8_t *data, uint8_t len,
 	uint32_t fn);
 
-int gprs_rlcmac_tx_ul_ud(gprs_rlcmac_tbf *tbf);
+int gprs_rlcmac_tx_ul_ud(struct gprs_rlcmac_tbf *tbf);
 
 void tbf_timer_cb(void *_tbf);
 
@@ -264,8 +256,8 @@
 
 int gprs_rlcmac_rcv_rach(uint8_t ra, uint32_t Fn, int16_t qta);
 
-int gprs_rlcmac_rcv_control_block(uint8_t trx, uint8_t ts, uint32_t fn,
-        uint8_t *data, uint8_t len);
+int gprs_rlcmac_rcv_control_ack(uint8_t trx, uint8_t ts, uint32_t fn,
+	uint32_t tlli);
 
 int gprs_rlcmac_rcv_downlink_ack(uint8_t trx, uint8_t ts, uint32_t fn, uint16_t tfi, uint8_t final, uint8_t ssn, uint8_t *rbb, uint8_t request);
 
@@ -298,18 +290,10 @@
 struct gprs_rlcmac_paging *gprs_rlcmac_dequeue_paging(
 	struct gprs_rlcmac_pdch *pdch);
 
-struct msgb *gprs_rlcmac_send_packet_paging_request(
-	struct gprs_rlcmac_pdch *pdch);
-
-extern "C" {
-#endif
 int alloc_algorithm_a(struct gprs_rlcmac_tbf *old_tbf,
 	struct gprs_rlcmac_tbf *tbf, uint32_t cust);
 
 int alloc_algorithm_b(struct gprs_rlcmac_tbf *old_tbf,
 	struct gprs_rlcmac_tbf *tbf, uint32_t cust);
-#ifdef __cplusplus
-}
-#endif
 
 #endif // GPRS_RLCMAC_H
diff --git a/src/gprs_rlcmac_ctrl.cpp b/src/gprs_rlcmac_ctrl.cpp
new file mode 100644
index 0000000..e2ad002
--- /dev/null
+++ b/src/gprs_rlcmac_ctrl.cpp
@@ -0,0 +1,662 @@
+/* gprs_rlcmac_ctrl.cpp
+ *
+ * Copyright (C) 2012 Ivan Klyuchnikov
+ * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include <errno.h>
+#include <arpa/inet.h>
+#include "bitvector.h"
+#include "gsm_rlcmac.h"
+extern "C" {
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/talloc.h>
+#include "gprs_debug.h"
+#include "gprs_rlcmac.h"
+}
+#include "gprs_rlcmac_ctrl.h"
+
+extern void *tall_pcu_ctx;
+
+// GSM 04.08 9.1.18 Immediate assignment
+static uint8_t write_immediate_assignment(bitvec * dest, uint8_t downlink,
+	uint8_t ra, uint32_t fn, uint8_t ta, uint16_t arfcn, uint8_t ts,
+	uint8_t tsc, uint8_t tfi, uint8_t usf, uint32_t tlli, uint8_t polling,
+	uint32_t poll_fn)
+{
+	unsigned wp = 0;
+	uint8_t plen;
+
+	bitvec_write_field(dest, wp,0x0,4);  // Skip Indicator
+	bitvec_write_field(dest, wp,0x6,4);  // Protocol Discriminator
+	bitvec_write_field(dest, wp,0x3F,8); // Immediate Assignment Message Type
+
+	// 10.5.2.25b Dedicated mode or TBF
+	bitvec_write_field(dest, wp,0x0,1);      // spare
+	bitvec_write_field(dest, wp,0x0,1);      // TMA : Two-message assignment: No meaning
+	bitvec_write_field(dest, wp,downlink,1); // Downlink : Downlink assignment to mobile in packet idle mode
+	bitvec_write_field(dest, wp,0x1,1);      // T/D : TBF or dedicated mode: this message assigns a Temporary Block Flow (TBF).
+
+	bitvec_write_field(dest, wp,0x0,4); // Page Mode
+
+	// GSM 04.08 10.5.2.25a Packet Channel Description
+	bitvec_write_field(dest, wp,0x1,5);                               // Channel type
+	bitvec_write_field(dest, wp,ts,3);     // TN
+	bitvec_write_field(dest, wp,tsc,3);    // TSC
+	bitvec_write_field(dest, wp,0x0,3);                               // non-hopping RF channel configuraion
+	bitvec_write_field(dest, wp,arfcn,10); // ARFCN
+
+	//10.5.2.30 Request Reference
+	bitvec_write_field(dest, wp,ra,8);                    // RA
+	bitvec_write_field(dest, wp,(fn / (26 * 51)) % 32,5); // T1'
+	bitvec_write_field(dest, wp,fn % 51,6);               // T3
+	bitvec_write_field(dest, wp,fn % 26,5);               // T2
+
+	// 10.5.2.40 Timing Advance
+	bitvec_write_field(dest, wp,0x0,2); // spare
+	bitvec_write_field(dest, wp,ta,6);  // Timing Advance value
+
+	// No mobile allocation in non-hopping systems.
+	// A zero-length LV.  Just write L=0.
+	bitvec_write_field(dest, wp,0,8);
+
+	if ((wp % 8)) {
+		LOGP(DRLCMACUL, LOGL_ERROR, "Length of IMM.ASS without rest "
+			"octets is not multiple of 8 bits, PLEASE FIX!\n");
+		exit (0);
+	}
+	plen = wp / 8;
+
+	if (downlink)
+	{
+		// GSM 04.08 10.5.2.16 IA Rest Octets
+		bitvec_write_field(dest, wp, 3, 2);   // "HH"
+		bitvec_write_field(dest, wp, 1, 2);   // "01" Packet Downlink Assignment
+		bitvec_write_field(dest, wp,tlli,32); // TLLI
+		bitvec_write_field(dest, wp,0x1,1);   // switch TFI   : on
+		bitvec_write_field(dest, wp,tfi,5);   // TFI
+		bitvec_write_field(dest, wp,0x0,1);   // RLC acknowledged mode
+		bitvec_write_field(dest, wp,0x0,1);   // ALPHA = not present
+		bitvec_write_field(dest, wp,0x0,5);   // GAMMA power control parameter
+		bitvec_write_field(dest, wp,polling,1);   // Polling Bit
+		bitvec_write_field(dest, wp,!polling,1);   // TA_VALID ???
+		bitvec_write_field(dest, wp,0x1,1);   // switch TIMING_ADVANCE_INDEX = on
+		bitvec_write_field(dest, wp,0x0,4);   // TIMING_ADVANCE_INDEX
+		if (polling) {
+			bitvec_write_field(dest, wp,0x1,1);   // TBF Starting TIME present
+			bitvec_write_field(dest, wp,(poll_fn / (26 * 51)) % 32,5); // T1'
+			bitvec_write_field(dest, wp,poll_fn % 51,6);               // T3
+			bitvec_write_field(dest, wp,poll_fn % 26,5);               // T2
+		} else {
+			bitvec_write_field(dest, wp,0x0,1);   // TBF Starting TIME present
+		}
+		bitvec_write_field(dest, wp,0x0,1);   // P0 not present
+//		bitvec_write_field(dest, wp,0x1,1);   // P0 not present
+//		bitvec_write_field(dest, wp,0xb,4);
+	}
+	else
+	{
+		struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
+		// GMS 04.08 10.5.2.37b 10.5.2.16
+		bitvec_write_field(dest, wp, 3, 2);    // "HH"
+		bitvec_write_field(dest, wp, 0, 2);    // "0" Packet Uplink Assignment
+		bitvec_write_field(dest, wp, 1, 1);    // Block Allocation : Not Single Block Allocation
+		bitvec_write_field(dest, wp, tfi, 5);  // TFI_ASSIGNMENT Temporary Flow Identity
+		bitvec_write_field(dest, wp, 0, 1);    // POLLING
+		bitvec_write_field(dest, wp, 0, 1);    // ALLOCATION_TYPE: dynamic
+		bitvec_write_field(dest, wp, usf, 3);    // USF
+		bitvec_write_field(dest, wp, 0, 1);    // USF_GRANULARITY
+		bitvec_write_field(dest, wp, 0 , 1);   // "0" power control: Not Present
+		bitvec_write_field(dest, wp, bts->initial_cs-1, 2);    // CHANNEL_CODING_COMMAND 
+		bitvec_write_field(dest, wp, 1, 1);    // TLLI_BLOCK_CHANNEL_CODING
+		bitvec_write_field(dest, wp, 1 , 1);   // "1" Alpha : Present
+		bitvec_write_field(dest, wp, 0, 4);    // Alpha
+		bitvec_write_field(dest, wp, 0, 5);    // Gamma
+		bitvec_write_field(dest, wp, 0, 1);    // TIMING_ADVANCE_INDEX_FLAG
+		bitvec_write_field(dest, wp, 0, 1);    // TBF_STARTING_TIME_FLAG
+	}
+
+	return plen;
+}
+
+extern "C"
+int write_immediate_assignment_uplink(uint8_t *data, uint8_t ra, uint32_t fn,
+	uint8_t ta, uint16_t arfcn, uint8_t ts, uint8_t tsc, uint8_t tfi,
+	uint8_t usf, uint8_t polling, uint32_t poll_fn)
+{
+	bitvec *ass_vec;
+	uint8_t plen;
+
+	ass_vec = bitvec_alloc(22); /* without plen */
+	if (!ass_vec)
+		return -ENOMEM;
+	bitvec_unhex(ass_vec, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+
+	plen = write_immediate_assignment(ass_vec, 0, ra, fn, ta, arfcn,
+		ts, tsc, tfi, usf, 0, polling, poll_fn);
+	bitvec_pack(ass_vec, data + 1);
+	data[0] = (plen << 2) | 0x01;
+	bitvec_free(ass_vec);
+
+	return 0;
+}
+
+extern "C"
+int write_immediate_assignment_downlink(uint8_t *data, uint8_t ra, uint32_t fn,
+	uint8_t ta, uint16_t arfcn, uint8_t ts, uint8_t tsc, uint8_t tfi,
+	uint32_t tlli, uint8_t polling, uint32_t poll_fn)
+{
+	bitvec *ass_vec;
+	uint8_t plen;
+
+	ass_vec = bitvec_alloc(22); /* without plen */
+	if (!ass_vec)
+		return -ENOMEM;
+	bitvec_unhex(ass_vec, "2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+
+	plen = write_immediate_assignment(ass_vec, 1, ra, fn, ta, arfcn,
+		ts, tsc, tfi, 0, tlli, polling, poll_fn);
+	bitvec_pack(ass_vec, data + 1);
+	data[0] = (plen << 2) | 0x01;
+	bitvec_free(ass_vec);
+
+	return 0;
+}
+
+/* generate uplink assignment */
+extern "C"
+struct msgb *write_packet_uplink_assignment(uint8_t old_tfi,
+	uint8_t old_downlink, uint32_t tlli, uint8_t use_tlli,
+	struct gprs_rlcmac_tbf *tbf, uint8_t poll)
+{
+	// TODO We should use our implementation of encode RLC/MAC Control messages.
+	struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
+	unsigned wp = 0;
+	uint8_t ts;
+	struct msgb *msg;
+	bitvec *ass_vec;
+	RlcMacDownlink_t *block;
+
+	msg = msgb_alloc(23, "rlcmac_ul_ass");
+	if (!msg)
+		return NULL;
+	ass_vec = bitvec_alloc(23);
+	if (!ass_vec) {
+		msgb_free(msg);
+		return NULL;
+	}
+	bitvec_unhex(ass_vec,
+		"2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+	block = (RlcMacDownlink_t *)talloc_zero(tall_pcu_ctx, RlcMacDownlink_t);
+	if (!block) {
+		bitvec_free(ass_vec);
+		msgb_free(msg);
+		return NULL;
+	}
+
+	bitvec_write_field(ass_vec, wp,0x1,2);  // Payload Type
+	bitvec_write_field(ass_vec, wp,0x0,2);  // Uplink block with TDMA framenumber (N+13)
+	bitvec_write_field(ass_vec, wp,poll,1);  // Suppl/Polling Bit
+	bitvec_write_field(ass_vec, wp,0x0,3);  // Uplink state flag
+	bitvec_write_field(ass_vec, wp,0xa,6);  // MESSAGE TYPE
+
+	bitvec_write_field(ass_vec, wp,0x0,2);  // Page Mode
+
+	bitvec_write_field(ass_vec, wp,0x0,1); // switch PERSIST_LEVEL: off
+	if (use_tlli) {
+		bitvec_write_field(ass_vec, wp,0x2,2); // switch TLLI   : on
+		bitvec_write_field(ass_vec, wp,tlli,32); // TLLI
+	} else {
+		bitvec_write_field(ass_vec, wp,0x0,1); // switch TFI : on
+		bitvec_write_field(ass_vec, wp,old_downlink,1); // 0=UPLINK TFI, 1=DL TFI
+		bitvec_write_field(ass_vec, wp,old_tfi,5); // TFI
+	}
+
+	bitvec_write_field(ass_vec, wp,0x0,1); // Message escape
+	bitvec_write_field(ass_vec, wp,bts->initial_cs-1, 2); // CHANNEL_CODING_COMMAND 
+	bitvec_write_field(ass_vec, wp,0x1,1); // TLLI_BLOCK_CHANNEL_CODING 
+
+	bitvec_write_field(ass_vec, wp,0x1,1); // switch TIMING_ADVANCE_VALUE = on
+	bitvec_write_field(ass_vec, wp,tbf->ta,6); // TIMING_ADVANCE_VALUE
+	bitvec_write_field(ass_vec, wp,0x0,1); // switch TIMING_ADVANCE_INDEX = off
+
+#if 1
+	bitvec_write_field(ass_vec, wp,0x1,1); // Frequency Parameters information elements = present
+	bitvec_write_field(ass_vec, wp,tbf->tsc,3); // Training Sequence Code (TSC)
+	bitvec_write_field(ass_vec, wp,0x0,2); // ARFCN = present
+	bitvec_write_field(ass_vec, wp,tbf->arfcn,10); // ARFCN
+#else
+	bitvec_write_field(ass_vec, wp,0x0,1); // Frequency Parameters = off
+#endif
+
+	bitvec_write_field(ass_vec, wp,0x1,2); // Dynamic Allocation
+	
+	bitvec_write_field(ass_vec, wp,0x0,1); // Extended Dynamic Allocation = off
+	bitvec_write_field(ass_vec, wp,0x0,1); // P0 = off
+	
+	bitvec_write_field(ass_vec, wp,0x0,1); // USF_GRANULARITY
+	bitvec_write_field(ass_vec, wp,0x1,1); // switch TFI   : on
+	bitvec_write_field(ass_vec, wp,tbf->tfi,5);// TFI
+
+	bitvec_write_field(ass_vec, wp,0x0,1); //
+	bitvec_write_field(ass_vec, wp,0x0,1); // TBF Starting Time = off
+	bitvec_write_field(ass_vec, wp,0x0,1); // Timeslot Allocation
+	
+	for (ts = 0; ts < 8; ts++) {
+		if (tbf->pdch[ts]) {
+			bitvec_write_field(ass_vec, wp,0x1,1); // USF_TN(i): on
+			bitvec_write_field(ass_vec, wp,tbf->dir.ul.usf[ts],3); // USF_TN(i)
+		} else
+			bitvec_write_field(ass_vec, wp,0x0,1); // USF_TN(i): off
+	}
+//	bitvec_write_field(ass_vec, wp,0x0,1); // Measurement Mapping struct not present
+
+	bitvec_pack(ass_vec, msgb_put(msg, 23));
+	LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Uplink Assignment +++++++++++++++++++++++++\n");
+	decode_gsm_rlcmac_downlink(ass_vec, block);
+	LOGPC(DCSN1, LOGL_NOTICE, "\n");
+	LOGP(DRLCMAC, LOGL_DEBUG, "------------------------- TX : Packet Uplink Assignment -------------------------\n");
+	bitvec_free(ass_vec);
+	talloc_free(block);
+
+	return msg;
+}
+
+
+/* generate downlink assignment */
+extern "C"
+struct msgb *write_packet_downlink_assignment(uint8_t old_tfi,
+	uint8_t old_downlink, struct gprs_rlcmac_tbf *tbf, uint8_t poll)
+{
+	// Packet downlink assignment TS 44.060 11.2.7
+
+	uint8_t tn;
+	struct msgb *msg;
+	bitvec *ass_vec;
+	RlcMacDownlink_t *block;
+
+	msg = msgb_alloc(23, "rlcmac_dl_ass");
+	if (!msg)
+		return NULL;
+	ass_vec = bitvec_alloc(23);
+	if (!ass_vec) {
+		msgb_free(msg);
+		return NULL;
+	}
+	bitvec_unhex(ass_vec,
+		"2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+	block = (RlcMacDownlink_t *)talloc_zero(tall_pcu_ctx, RlcMacDownlink_t);
+	if (!block) {
+		bitvec_free(ass_vec);
+		msgb_free(msg);
+		return NULL;
+	}
+
+	block->PAYLOAD_TYPE = 0x1;  // RLC/MAC control block that does not include the optional octets of the RLC/MAC control header
+	block->RRBP         = 0x0;  // N+13
+	block->SP           = poll; // RRBP field is valid
+	block->USF          = 0x0;  // Uplink state flag
+
+	block->u.Packet_Downlink_Assignment.MESSAGE_TYPE = 0x2;  // Packet Downlink Assignment
+	block->u.Packet_Downlink_Assignment.PAGE_MODE    = 0x0;  // Normal Paging
+
+	block->u.Packet_Downlink_Assignment.Exist_PERSISTENCE_LEVEL      = 0x0;          // PERSISTENCE_LEVEL: off
+
+	block->u.Packet_Downlink_Assignment.ID.UnionType                 = 0x0;          // TFI = on
+	block->u.Packet_Downlink_Assignment.ID.u.Global_TFI.UnionType    = old_downlink; // 0=UPLINK TFI, 1=DL TFI
+	block->u.Packet_Downlink_Assignment.ID.u.Global_TFI.u.UPLINK_TFI = old_tfi;      // TFI
+
+	block->u.Packet_Downlink_Assignment.MAC_MODE            = 0x0;          // Dynamic Allocation
+	block->u.Packet_Downlink_Assignment.RLC_MODE            = 0x0;          // RLC acknowledged mode
+	block->u.Packet_Downlink_Assignment.CONTROL_ACK         = old_downlink; // NW establishes no new DL TBF for the MS with running timer T3192
+	block->u.Packet_Downlink_Assignment.TIMESLOT_ALLOCATION = 0;   // timeslot(s)
+	for (tn = 0; tn < 8; tn++) {
+		if (tbf->pdch[tn])
+			block->u.Packet_Downlink_Assignment.TIMESLOT_ALLOCATION |= 0x80 >> tn;   // timeslot(s)
+	}
+
+	block->u.Packet_Downlink_Assignment.Packet_Timing_Advance.Exist_TIMING_ADVANCE_VALUE = 0x1; // TIMING_ADVANCE_VALUE = on
+	block->u.Packet_Downlink_Assignment.Packet_Timing_Advance.TIMING_ADVANCE_VALUE       = tbf->ta;  // TIMING_ADVANCE_VALUE
+	block->u.Packet_Downlink_Assignment.Packet_Timing_Advance.Exist_IndexAndtimeSlot     = 0x0; // TIMING_ADVANCE_INDEX = off
+
+	block->u.Packet_Downlink_Assignment.Exist_P0_and_BTS_PWR_CTRL_MODE = 0x0;   // POWER CONTROL = off
+
+	block->u.Packet_Downlink_Assignment.Exist_Frequency_Parameters     = 0x1;   // Frequency Parameters = on
+	block->u.Packet_Downlink_Assignment.Frequency_Parameters.TSC       = tbf->tsc;   // Training Sequence Code (TSC)
+	block->u.Packet_Downlink_Assignment.Frequency_Parameters.UnionType = 0x0;   // ARFCN = on
+	block->u.Packet_Downlink_Assignment.Frequency_Parameters.u.ARFCN   = tbf->arfcn; // ARFCN
+
+	block->u.Packet_Downlink_Assignment.Exist_DOWNLINK_TFI_ASSIGNMENT  = 0x1;     // DOWNLINK TFI ASSIGNMENT = on
+	block->u.Packet_Downlink_Assignment.DOWNLINK_TFI_ASSIGNMENT        = tbf->tfi; // TFI
+
+	block->u.Packet_Downlink_Assignment.Exist_Power_Control_Parameters = 0x1;   // Power Control Parameters = on
+	block->u.Packet_Downlink_Assignment.Power_Control_Parameters.ALPHA = 0x0;   // ALPHA
+
+	for (tn = 0; tn < 8; tn++)
+	{
+		if (tbf->pdch[tn])
+		{
+			block->u.Packet_Downlink_Assignment.Power_Control_Parameters.Slot[tn].Exist    = 0x1; // Slot[i] = on
+			block->u.Packet_Downlink_Assignment.Power_Control_Parameters.Slot[tn].GAMMA_TN = 0x0; // GAMMA_TN
+		}
+		else
+		{
+			block->u.Packet_Downlink_Assignment.Power_Control_Parameters.Slot[tn].Exist    = 0x0; // Slot[i] = off
+		}
+	}
+
+	block->u.Packet_Downlink_Assignment.Exist_TBF_Starting_Time   = 0x0; // TBF Starting TIME = off
+	block->u.Packet_Downlink_Assignment.Exist_Measurement_Mapping = 0x0; // Measurement_Mapping = off
+	block->u.Packet_Downlink_Assignment.Exist_AdditionsR99        = 0x0; // AdditionsR99 = off
+
+	LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Downlink Assignment +++++++++++++++++++++++++\n");
+	encode_gsm_rlcmac_downlink(ass_vec, block);
+	LOGPC(DCSN1, LOGL_NOTICE, "\n");
+	LOGP(DRLCMAC, LOGL_DEBUG, "------------------------- TX : Packet Downlink Assignment -------------------------\n");
+	bitvec_pack(ass_vec, msgb_put(msg, 23));
+	bitvec_free(ass_vec);
+	talloc_free(block);
+
+	return msg;
+}
+
+/* generate uplink ack */
+extern "C"
+struct msgb *write_packet_uplink_ack(struct gprs_rlcmac_tbf *tbf, uint8_t final)
+{
+	// Packet Uplink Ack/Nack  TS 44.060 11.2.28
+
+	char show_v_n[65];
+
+	struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
+	uint8_t rbb = 0;
+	uint16_t i, bbn;
+	uint16_t mod_sns_half = (tbf->sns >> 1) - 1;
+	char bit;
+	struct msgb *msg;
+	bitvec *ack_vec;
+	RlcMacDownlink_t *block;
+
+	LOGP(DRLCMACUL, LOGL_DEBUG, "Sending Ack/Nack for TBF=%d "
+		"(final=%d)\n", tbf->tfi, final);
+
+	msg = msgb_alloc(23, "rlcmac_ul_ack");
+	if (!msg)
+		return NULL;
+	ack_vec = bitvec_alloc(23);
+	if (!ack_vec) {
+		msgb_free(msg);
+		return NULL;
+	}
+	bitvec_unhex(ack_vec,
+		"2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+	block = (RlcMacDownlink_t *)talloc_zero(tall_pcu_ctx, RlcMacDownlink_t);
+	if (!block) {
+		bitvec_free(ack_vec);
+		msgb_free(msg);
+		return NULL;
+	}
+
+	block->PAYLOAD_TYPE = 0x1;   // RLC/MAC control block that does not include the optional octets of the RLC/MAC control header
+	block->RRBP         = 0x0;   // N+13
+	block->SP           = final; // RRBP field is valid, if it is final ack
+	block->USF          = 0x0;   // Uplink state flag
+
+	block->u.Packet_Uplink_Ack_Nack.MESSAGE_TYPE = 0x9;      // Packet Downlink Assignment
+	block->u.Packet_Uplink_Ack_Nack.PAGE_MODE    = 0x0;      // Normal Paging
+	block->u.Packet_Uplink_Ack_Nack.UPLINK_TFI   = tbf->tfi; // Uplink TFI
+
+	block->u.Packet_Uplink_Ack_Nack.UnionType    = 0x0;      // PU_AckNack_GPRS = on
+	block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.CHANNEL_CODING_COMMAND                        = bts->initial_cs - 1;             // CS1
+	block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.Ack_Nack_Description.FINAL_ACK_INDICATION     = final;           // FINAL ACK INDICATION
+	block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.Ack_Nack_Description.STARTING_SEQUENCE_NUMBER = tbf->dir.ul.v_r; // STARTING_SEQUENCE_NUMBER
+	// RECEIVE_BLOCK_BITMAP
+	for (i = 0, bbn = (tbf->dir.ul.v_r - 64) & mod_sns_half; i < 64;
+	     i++, bbn = (bbn + 1) & mod_sns_half) {
+	     	bit = tbf->dir.ul.v_n[bbn];
+		if (bit == 0)
+			bit = ' ';
+		show_v_n[i] = bit;
+		if (bit == 'R')
+			rbb = (rbb << 1)|1;
+		else
+			rbb = (rbb << 1);
+		if((i%8) == 7)
+		{
+			block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.Ack_Nack_Description.RECEIVED_BLOCK_BITMAP[i/8] = rbb;
+			rbb = 0;
+		}
+	}
+	show_v_n[64] = '\0';
+	LOGP(DRLCMACUL, LOGL_DEBUG, "- V(N): \"%s\" R=Received "
+		"N=Not-Received\n", show_v_n);
+
+	block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.UnionType              = 0x0; // Fixed Allocation Dummy = on
+	block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.u.FixedAllocationDummy = 0x0; // Fixed Allocation Dummy
+	block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.Exist_AdditionsR99     = 0x0; // AdditionsR99 = off
+
+	block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.Common_Uplink_Ack_Nack_Data.Exist_CONTENTION_RESOLUTION_TLLI = 0x1;
+	block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.Common_Uplink_Ack_Nack_Data.CONTENTION_RESOLUTION_TLLI       = tbf->tlli;
+	block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.Common_Uplink_Ack_Nack_Data.Exist_Packet_Timing_Advance      = 0x0;
+	block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.Common_Uplink_Ack_Nack_Data.Exist_Extension_Bits             = 0x0;
+	block->u.Packet_Uplink_Ack_Nack.u.PU_AckNack_GPRS_Struct.Common_Uplink_Ack_Nack_Data.Exist_Power_Control_Parameters   = 0x0;
+
+	LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Uplink Ack/Nack +++++++++++++++++++++++++\n");
+	encode_gsm_rlcmac_downlink(ack_vec, block);
+	LOGPC(DCSN1, LOGL_NOTICE, "\n");
+	LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Uplink Ack/Nack +++++++++++++++++++++++++\n");
+	bitvec_pack(ack_vec, msgb_put(msg, 23));
+	bitvec_free(ack_vec);
+	talloc_free(block);
+
+	return msg;
+}
+
+static unsigned write_packet_paging_request(bitvec * dest)
+{
+	unsigned wp = 0;
+
+	bitvec_write_field(dest, wp,0x1,2);  // Payload Type
+	bitvec_write_field(dest, wp,0x0,3);  // No polling
+	bitvec_write_field(dest, wp,0x0,3);  // Uplink state flag
+	bitvec_write_field(dest, wp,0x22,6);  // MESSAGE TYPE
+
+	bitvec_write_field(dest, wp,0x0,2);  // Page Mode
+
+	bitvec_write_field(dest, wp,0x0,1);  // No PERSISTENCE_LEVEL
+	bitvec_write_field(dest, wp,0x0,1);  // No NLN
+
+	return wp;
+}
+
+static unsigned write_repeated_page_info(bitvec * dest, unsigned& wp,
+	uint8_t len, uint8_t *identity, uint8_t chan_needed)
+{
+	bitvec_write_field(dest, wp,0x1,1);  // Repeated Page info exists
+
+	bitvec_write_field(dest, wp,0x1,1);  // RR connection paging
+
+	if ((identity[0] & 0x07) == 4) {
+		bitvec_write_field(dest, wp,0x0,1);  // TMSI
+		identity++;
+		len--;
+	} else {
+		bitvec_write_field(dest, wp,0x0,1);  // MI
+		bitvec_write_field(dest, wp,len,4);  // MI len
+	}
+	while (len) {
+		bitvec_write_field(dest, wp,*identity++,8);  // MI data
+		len--;
+	}
+	bitvec_write_field(dest, wp,chan_needed,2);  // CHANNEL_NEEDED
+	bitvec_write_field(dest, wp,0x0,1);  // No eMLPP_PRIORITY
+
+	return wp;
+}
+
+extern "C"
+struct msgb *gprs_rlcmac_send_packet_paging_request(
+	struct gprs_rlcmac_pdch *pdch)
+{
+	struct gprs_rlcmac_paging *pag;
+	struct msgb *msg;
+	unsigned wp = 0, len;
+
+	/* no paging, no message */
+	pag = gprs_rlcmac_dequeue_paging(pdch);
+	if (!pag)
+		return NULL;
+
+	LOGP(DRLCMAC, LOGL_DEBUG, "Scheduling paging\n");
+
+	/* alloc message */
+	msg = msgb_alloc(23, "pag ctrl block");
+	if (!msg)
+		return NULL;
+	bitvec *pag_vec = bitvec_alloc(23);
+	if (!pag_vec) {
+		msgb_free(msg);
+		return NULL;
+	}
+	wp = write_packet_paging_request(pag_vec);
+
+	/* loop until message is full */
+	while (pag) {
+		/* try to add paging */
+		if ((pag->identity_lv[1] & 0x07) == 4) {
+			/* TMSI */
+			LOGP(DRLCMAC, LOGL_DEBUG, "- TMSI=0x%08x\n",
+				ntohl(*((uint32_t *)(pag->identity_lv + 1))));
+			len = 1 + 1 + 1 + 32 + 2 + 1;
+			if (pag->identity_lv[0] != 5) {
+				LOGP(DRLCMAC, LOGL_ERROR, "TMSI paging with "
+					"MI != 5 octets!\n");
+				break;
+			}
+		} else {
+			/* MI */
+			LOGP(DRLCMAC, LOGL_DEBUG, "- MI=%s\n",
+				osmo_hexdump(pag->identity_lv + 1,
+					pag->identity_lv[0]));
+			len = 1 + 1 + 1 + 4 + (pag->identity_lv[0]<<3) + 2 + 1;
+			if (pag->identity_lv[0] > 8) {
+				LOGP(DRLCMAC, LOGL_ERROR, "Paging with "
+					"MI > 8 octets!\n");
+				break;
+			}
+		}
+		if (wp + len > 184) {
+			LOGP(DRLCMAC, LOGL_DEBUG, "- Does not fit, so schedule "
+				"next time\n");
+			/* put back paging record, because does not fit */
+			llist_add_tail(&pag->list, &pdch->paging_list);
+			break;
+		}
+		write_repeated_page_info(pag_vec, wp, pag->identity_lv[0],
+			pag->identity_lv + 1, pag->chan_needed);
+
+		pag = gprs_rlcmac_dequeue_paging(pdch);
+	}
+
+	bitvec_pack(pag_vec, msgb_put(msg, 23));
+	RlcMacDownlink_t * mac_control_block = (RlcMacDownlink_t *)talloc_zero(tall_pcu_ctx, RlcMacDownlink_t);
+	LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Paging Request +++++++++++++++++++++++++\n");
+	decode_gsm_rlcmac_downlink(pag_vec, mac_control_block);
+	LOGPC(DCSN1, LOGL_NOTICE, "\n");
+	LOGP(DRLCMAC, LOGL_DEBUG, "------------------------- TX : Packet Paging Request -------------------------\n");
+	bitvec_free(pag_vec);
+	talloc_free(mac_control_block);
+
+	return msg;
+}
+
+/* Received Uplink RLC control block. */
+extern "C"
+int gprs_rlcmac_rcv_control_block(uint8_t trx, uint8_t ts, uint32_t fn,
+	uint8_t *data, uint8_t len)
+{
+	uint32_t tlli = 0;
+	int8_t tfi = 0; /* must be signed */
+	struct gprs_rlcmac_tbf *tbf;
+	bitvec *block;
+	RlcMacUplink_t * ul_control_block;
+
+	block = bitvec_alloc(len);
+	if (!block)
+		return -ENOMEM;
+	bitvec_unpack(block, data);
+
+	ul_control_block = (RlcMacUplink_t *)talloc_zero(tall_pcu_ctx, RlcMacUplink_t);
+	if (!ul_control_block) {
+		bitvec_free(block);
+		return -ENOMEM;
+	}
+
+	LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ RX : Uplink Control Block +++++++++++++++++++++++++\n");
+	decode_gsm_rlcmac_uplink(block, ul_control_block);
+	LOGPC(DCSN1, LOGL_NOTICE, "\n");
+	LOGP(DRLCMAC, LOGL_DEBUG, "------------------------- RX : Uplink Control Block -------------------------\n");
+	switch (ul_control_block->u.MESSAGE_TYPE) {
+	case MT_PACKET_CONTROL_ACK:
+		tlli = ul_control_block->u.Packet_Control_Acknowledgement.TLLI;
+		gprs_rlcmac_rcv_control_ack(trx, ts, fn, tlli);
+		break;
+	case MT_PACKET_DOWNLINK_ACK_NACK:
+		tfi = ul_control_block->u.Packet_Downlink_Ack_Nack.DOWNLINK_TFI;
+		gprs_rlcmac_rcv_downlink_ack(trx, ts, fn, tfi,
+			ul_control_block->u.Packet_Downlink_Ack_Nack.Ack_Nack_Description.FINAL_ACK_INDICATION,
+			ul_control_block->u.Packet_Downlink_Ack_Nack.Ack_Nack_Description.STARTING_SEQUENCE_NUMBER,
+			ul_control_block->u.Packet_Downlink_Ack_Nack.Ack_Nack_Description.RECEIVED_BLOCK_BITMAP,
+			ul_control_block->u.Packet_Downlink_Ack_Nack.Exist_Channel_Request_Description);
+		break;
+	case MT_PACKET_RESOURCE_REQUEST:
+		if (ul_control_block->u.Packet_Resource_Request.ID.UnionType) {
+			tlli = ul_control_block->u.Packet_Resource_Request.ID.u.TLLI;
+			tbf = tbf_by_tlli(tlli, GPRS_RLCMAC_UL_TBF);
+			if (!tbf) {
+				LOGP(DRLCMAC, LOGL_NOTICE, "PACKET RESSOURCE REQ unknown uplink TLLI=0x%08x\n", tlli);
+				break;
+			}
+			tfi = tbf->tfi;
+		} else {
+			if (ul_control_block->u.Packet_Resource_Request.ID.u.Global_TFI.UnionType) {
+				tfi = ul_control_block->u.Packet_Resource_Request.ID.u.Global_TFI.u.DOWNLINK_TFI;
+				tbf = tbf_by_tfi(tfi, trx, ts, GPRS_RLCMAC_DL_TBF);
+				if (!tbf) {
+					LOGP(DRLCMAC, LOGL_NOTICE, "PACKET RESSOURCE REQ unknown downlink TBF=%d\n", tlli);
+					break;
+				}
+			} else {
+				tfi = ul_control_block->u.Packet_Resource_Request.ID.u.Global_TFI.u.UPLINK_TFI;
+				tbf = tbf_by_tfi(tfi, trx, ts, GPRS_RLCMAC_UL_TBF);
+				if (!tbf) {
+					LOGP(DRLCMAC, LOGL_NOTICE, "PACKET RESSOURCE REQ unknown uplink TBF=%d\n", tlli);
+					break;
+				}
+			}
+			tlli = tbf->tlli;
+		}
+		LOGP(DRLCMAC, LOGL_ERROR, "RX: [PCU <- BTS] %s TFI: %u TLLI: 0x%08x FIXME: Packet ressource request\n", (tbf->direction == GPRS_RLCMAC_UL_TBF) ? "UL" : "DL", tbf->tfi, tbf->tlli);
+		break;
+	default:
+		LOGP(DRLCMAC, LOGL_NOTICE, "RX: [PCU <- BTS] unknown control block received\n");
+	}
+	talloc_free(ul_control_block);
+	bitvec_free(block);
+	return 1;
+}
+
diff --git a/src/gprs_rlcmac_ctrl.h b/src/gprs_rlcmac_ctrl.h
new file mode 100644
index 0000000..795736b
--- /dev/null
+++ b/src/gprs_rlcmac_ctrl.h
@@ -0,0 +1,49 @@
+#ifndef _GPRS_RLCMAC_CTRL_H
+#define _GPRS_RLCMAC_CTRL_H
+
+#ifdef __cplusplus
+extern "C"
+#endif
+int write_immediate_assignment_uplink(uint8_t *data, uint8_t ra, uint32_t fn,
+	uint8_t ta, uint16_t arfcn, uint8_t ts, uint8_t tsc, uint8_t tfi,
+	uint8_t usf, uint8_t polling, uint32_t poll_fn);
+
+#ifdef __cplusplus
+extern "C"
+#endif
+int write_immediate_assignment_downlink(uint8_t *data, uint8_t ra, uint32_t fn,
+	uint8_t ta, uint16_t arfcn, uint8_t ts, uint8_t tsc, uint8_t tfi,
+	uint32_t tlli, uint8_t polling, uint32_t poll_fn);
+
+#ifdef __cplusplus
+extern "C"
+#endif
+struct msgb *write_packet_uplink_assignment(uint8_t old_tfi,
+	uint8_t old_downlink, uint32_t tlli, uint8_t use_tlli,
+	struct gprs_rlcmac_tbf *tbf, uint8_t poll);
+
+#ifdef __cplusplus
+extern "C"
+#endif
+struct msgb *write_packet_downlink_assignment(uint8_t old_tfi,
+	uint8_t old_downlink, struct gprs_rlcmac_tbf *tbf, uint8_t poll);
+
+#ifdef __cplusplus
+extern "C"
+#endif
+struct msgb *write_packet_uplink_ack(struct gprs_rlcmac_tbf *tbf,
+	uint8_t final);
+
+#ifdef __cplusplus
+extern "C"
+#endif
+struct msgb *gprs_rlcmac_send_packet_paging_request(
+	struct gprs_rlcmac_pdch *pdch);
+
+#ifdef __cplusplus
+extern "C"
+#endif
+int gprs_rlcmac_rcv_control_block(uint8_t trx, uint8_t ts, uint32_t fn,
+        uint8_t *data, uint8_t len);
+
+#endif /* _GPRS_RLCMAC_CTRL_H */
diff --git a/src/gprs_rlcmac_data.cpp b/src/gprs_rlcmac_data.c
similarity index 99%
rename from src/gprs_rlcmac_data.cpp
rename to src/gprs_rlcmac_data.c
index e7ba13f..0efcb79 100644
--- a/src/gprs_rlcmac_data.cpp
+++ b/src/gprs_rlcmac_data.c
@@ -25,10 +25,8 @@
 
 extern void *tall_pcu_ctx;
 
-extern "C" {
 int bssgp_tx_llc_discarded(struct bssgp_bvc_ctx *bctx, uint32_t tlli,
                            uint8_t num_frames, uint32_t num_octets);
-}
 
 /* After receiving these frames, we send ack/nack. */
 #define SEND_ACK_AFTER_FRAMES 20
@@ -39,7 +37,6 @@
 /* If acknowledgement to uplink/downlin assignmentshould be polled */
 #define POLLING_ASSIGNMENT 0
 
-extern "C" {
 /* TS 04.60  10.2.2 */
 struct rlc_ul_header {
 	uint8_t	r:1,
@@ -71,7 +68,6 @@
 		 m:1,
 		 li:6;
 } __attribute__ ((packed));
-}
 
 int gprs_rlcmac_poll_timeout(struct gprs_rlcmac_tbf *tbf)
 {
@@ -1400,8 +1396,8 @@
 	return msg;
 }
 
-static void gprs_rlcmac_downlink_assignment(gprs_rlcmac_tbf *tbf, uint8_t poll,
-	char *imsi)
+static void gprs_rlcmac_downlink_assignment(struct gprs_rlcmac_tbf *tbf,
+	uint8_t poll, char *imsi)
 {
 	uint8_t imm_ass[23];
 	int rc;
diff --git a/src/gprs_rlcmac_sched.cpp b/src/gprs_rlcmac_sched.c
similarity index 99%
rename from src/gprs_rlcmac_sched.cpp
rename to src/gprs_rlcmac_sched.c
index 9ffdfb6..edc2937 100644
--- a/src/gprs_rlcmac_sched.cpp
+++ b/src/gprs_rlcmac_sched.c
@@ -19,6 +19,7 @@
  
 #include <gprs_bssgp_pcu.h>
 #include <gprs_rlcmac.h>
+#include <gprs_rlcmac_ctrl.h>
 #include <pcu_l1_if.h>
 
 uint32_t sched_poll(uint8_t trx, uint8_t ts, uint32_t fn, uint8_t block_nr,
diff --git a/src/gsm_rlcmac.cpp b/src/gsm_rlcmac.cpp
index e4afd7b..84f77e6 100644
--- a/src/gsm_rlcmac.cpp
+++ b/src/gsm_rlcmac.cpp
@@ -34,7 +34,9 @@
 */
 #include <iostream>
 #include <cstdlib>
+extern "C" {
 #include <gprs_debug.h>
+}
 using namespace std;
 
 /* Payload type as defined in TS 44.060 / 10.4.7 */
diff --git a/src/gsm_timer.cpp b/src/gsm_timer.c
similarity index 99%
rename from src/gsm_timer.cpp
rename to src/gsm_timer.c
index 95513b4..bc614ae 100644
--- a/src/gsm_timer.cpp
+++ b/src/gsm_timer.c
@@ -1,4 +1,4 @@
-/* gsm_timer.cpp
+/* gsm_timer.c
  *
  * Copyright (C) 2012 Ivan Klyuchnikov
  *
diff --git a/src/gsm_timer.h b/src/gsm_timer.h
index fc42caf..1aa179d 100644
--- a/src/gsm_timer.h
+++ b/src/gsm_timer.h
@@ -27,10 +27,8 @@
 #ifndef GSM_TIMER_H
 #define GSM_TIMER_H
 
-extern "C" {
 #include <osmocom/core/linuxlist.h>
 #include <osmocom/core/linuxrbtree.h>
-}
 /**
  * Timer management:
  *      - Create a struct osmo_gsm_timer_list
diff --git a/src/pcu_l1_if.cpp b/src/pcu_l1_if.c
similarity index 96%
rename from src/pcu_l1_if.cpp
rename to src/pcu_l1_if.c
index 352fc0d..22f18c2 100644
--- a/src/pcu_l1_if.cpp
+++ b/src/pcu_l1_if.c
@@ -1,4 +1,4 @@
-/* pcu_l1_if.cpp
+/* pcu_l1_if.c
  *
  * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
  *
@@ -25,11 +25,9 @@
 #include <assert.h>
 #include <sys/socket.h>
 #include <sys/un.h>
-extern "C" {
 #include <osmocom/core/talloc.h>
 #include <osmocom/core/select.h>
 #include <osmocom/core/msgb.h>
-}
 
 #include <gprs_rlcmac.h>
 #include <pcu_l1_if.h>
@@ -123,16 +121,16 @@
 	return pcu_sock_send(msg);
 }
 
-void pcu_l1if_tx_pdtch(msgb *msg, uint8_t trx, uint8_t ts, uint16_t arfcn,
-	uint32_t fn, uint8_t block_nr)
+void pcu_l1if_tx_pdtch(struct msgb *msg, uint8_t trx, uint8_t ts,
+	uint16_t arfcn, uint32_t fn, uint8_t block_nr)
 {
 	pcu_tx_data_req(trx, ts, PCU_IF_SAPI_PDTCH, arfcn, fn, block_nr,
 		msg->data, msg->len);
 	msgb_free(msg);
 }
 
-void pcu_l1if_tx_ptcch(msgb *msg, uint8_t trx, uint8_t ts, uint16_t arfcn,
-	uint32_t fn, uint8_t block_nr)
+void pcu_l1if_tx_ptcch(struct msgb *msg, uint8_t trx, uint8_t ts,
+	uint16_t arfcn, uint32_t fn, uint8_t block_nr)
 {
 	pcu_tx_data_req(trx, ts, PCU_IF_SAPI_PTCCH, arfcn, fn, block_nr,
 		msg->data, msg->len);
@@ -146,18 +144,18 @@
 
 void pcu_l1if_tx_pch(uint8_t *data, char *imsi)
 {
-	uint8_t pch_data[23+3];
+	uint8_t pch_data[3+23];
 
 	/* paging group */
 	if (!imsi || strlen(imsi) < 3)
 		return;
 	imsi += strlen(imsi) - 3;
-	data[0] = imsi[0];
-	data[1] = imsi[1];
-	data[2] = imsi[2];
+	pch_data[0] = imsi[0];
+	pch_data[1] = imsi[1];
+	pch_data[2] = imsi[2];
 
 	memcpy(pch_data + 3, data, 23);
-	pcu_tx_data_req(0, 0, PCU_IF_SAPI_PCH, 0, 0, 0, data, 23+3);
+	pcu_tx_data_req(0, 0, PCU_IF_SAPI_PCH, 0, 0, 0, pch_data, 23+3);
 }
 
 static void pcu_l1if_tx_bcch(uint8_t *data, int len)
diff --git a/src/pcu_l1_if.h b/src/pcu_l1_if.h
index 4549782..7525167 100644
--- a/src/pcu_l1_if.h
+++ b/src/pcu_l1_if.h
@@ -21,20 +21,19 @@
 #define PCU_L1_IF_H
 
 #include <stdint.h>
-extern "C" {
 #include <osmocom/core/write_queue.h>
 #include <osmocom/core/socket.h>
 #include <osmocom/core/timer.h>
 #include <osmocom/core/bitvec.h>
 #include <osmocom/gsm/gsm_utils.h>
-}
+#include <pcuif_proto.h>
 
 int get_current_fn();
 
-void pcu_l1if_tx_pdtch(msgb *msg, uint8_t trx, uint8_t ts, uint16_t arfcn, 
-        uint32_t fn, uint8_t block_nr);
-void pcu_l1if_tx_ptcch(msgb *msg, uint8_t trx, uint8_t ts, uint16_t arfcn, 
-        uint32_t fn, uint8_t block_nr);
+void pcu_l1if_tx_pdtch(struct msgb *msg, uint8_t trx, uint8_t ts,
+	uint16_t arfcn, uint32_t fn, uint8_t block_nr);
+void pcu_l1if_tx_ptcch(struct msgb *msg, uint8_t trx, uint8_t ts,
+	uint16_t arfcn, uint32_t fn, uint8_t block_nr);
 void pcu_l1if_tx_agch(uint8_t *data);
 
 void pcu_l1if_tx_pch(uint8_t *data, char *imsi);
diff --git a/src/pcu_main.cpp b/src/pcu_main.cpp
index 2d7e8ff..d176a78 100644
--- a/src/pcu_main.cpp
+++ b/src/pcu_main.cpp
@@ -17,6 +17,7 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
 
+extern "C" {
 #include <gprs_bssgp_pcu.h>
 #include <arpa/inet.h>
 #include <pcu_l1_if.h>
@@ -26,11 +27,9 @@
 #include <unistd.h>
 #include <getopt.h>
 #include <signal.h>
-extern "C" {
 #include "pcu_vty.h"
 #include <osmocom/vty/telnet_interface.h>
 #include <osmocom/vty/logging.h>
-}
 
 struct gprs_rlcmac_bts *gprs_rlcmac_bts;
 extern struct gprs_nsvc *nsvc;
@@ -128,6 +127,8 @@
 	}
 }
 
+} /* extern "C" */
+
 int main(int argc, char *argv[])
 {
 	struct gprs_rlcmac_bts *bts;
diff --git a/src/sysmo_sock.cpp b/src/sysmo_sock.c
similarity index 99%
rename from src/sysmo_sock.cpp
rename to src/sysmo_sock.c
index 6b390ed..f3bd3a7 100644
--- a/src/sysmo_sock.cpp
+++ b/src/sysmo_sock.c
@@ -25,11 +25,9 @@
 #include <assert.h>
 #include <sys/socket.h>
 #include <sys/un.h>
-extern "C" {
 #include <osmocom/core/talloc.h>
 #include <osmocom/core/select.h>
 #include <osmocom/core/msgb.h>
-}
 
 #include <gprs_rlcmac.h>
 #include <pcu_l1_if.h>