Separation of GPRS PCU application from main OpenBTS code and changing PCU architecture (First step).

1. pcu - main program for  GPRS PCU.
2. gprs_rlcmac - RLC/MAC layer implementation for PCU. Added list for TBF, TBF allocation, establishment, release.
3. gprs_bssgp_pcu - BSSGP protocol implementation for PCU.
4. pcu_l1_if - interface for communication PCU application with OpenBTS.

10 files changed, 900 insertions, 719 deletions

diff --git a/GPRSSocket.cpp b/GPRSSocket.cpp
deleted file mode 100644
index 6bcf55d7..00000000
--- a/GPRSSocket.cpp
+++ /dev/null
@@ -1,421 +0,0 @@
-/*GPRSSocket.cpp
- *
- * Copyright (C) 2011 Ivan Klyuchnikov
- *
- * 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 <Sockets.h>
-#include <Threads.h>
-#include <BitVector.h>
-#include <gsmtap.h>
-#include "GPRSSocket.h"
-#include "bssgp.h"
-
-#define MAX_UDP_LENGTH 1500
-
-#define RLCMAC_DATA_BLOCK 0
-#define RLCMAC_CONTROL_BLOCK 1
-
-// TODO: We should take ports and IP from config.
-UDPSocket GPRSRLCMACSocket(5070, "127.0.0.1", 5934);
-UDPSocket GSMTAPSocket(5077, "127.0.0.1", 4729);
-
-void sendToGSMTAP(uint8_t * data, unsigned len)
-{
-	char buffer[MAX_UDP_LENGTH];
-	int ofs = 0;
-
-	// Build header
-	struct gsmtap_hdr *header = (struct gsmtap_hdr *)buffer;
-	header->version			= 2;
-	header->hdr_len			= sizeof(struct gsmtap_hdr) >> 2;
-	header->type			= 0x08;
-	header->timeslot		= 5;
-	header->arfcn			= 0;
-	header->signal_dbm		= 0;
-	header->snr_db			= 0;
-	header->frame_number	= 0;
-	header->sub_type		= 0;
-	header->antenna_nr		= 0;
-	header->sub_slot		= 0;
-	header->res				= 0;
-
-	ofs += sizeof(*header);
-
-	// Add frame data
-	unsigned j = 0;
-	for (unsigned i = ofs; i < len+ofs; i++)
-	{
-		buffer[i] = (char)data[j];
-		j++;
-	}
-	ofs += len;
-	// Write the GSMTAP packet
-	GSMTAPSocket.write(buffer, ofs);
-}
-
-
-void sendToOpenBTS(BitVector * vector)
-{
-	char buffer[MAX_UDP_LENGTH];
-	int ofs = 0;
-	vector->pack((unsigned char*)&buffer[ofs]);
-	ofs += vector->size() >> 3;
-	COUT("Send to OpenBTS: " << *vector);
-	GPRSRLCMACSocket.write(buffer, ofs);
-}
-
-void  writePDassignment(BitVector * dest, uint8_t TFI, uint32_t TLLI)
-{
-	// TODO We should use our implementation of encode RLC/MAC Control messages.
-	unsigned wp = 0;
-	dest->writeField(wp,0x1,2);  // Payload Type
-	dest->writeField(wp,0x0,2);  // Uplink block with TDMA framenumber
-	dest->writeField(wp,0x1,1);  // Suppl/Polling Bit
-	dest->writeField(wp,0x1,3);  // Uplink state flag
-	dest->writeField(wp,0x2,6);  // MESSAGE TYPE
-	dest->writeField(wp,0x0,2);  // Page Mode
-
-	dest->writeField(wp,0x0,1); // switch PERSIST_LEVEL: off
-	dest->writeField(wp,0x2,2); // switch TLLI   : on
-	dest->writeField(wp,TLLI,32); // TLLI
-
-	dest->writeField(wp,0x0,1); // Message escape
-	dest->writeField(wp,0x0,2); // Medium Access Method: Dynamic Allocation
-	dest->writeField(wp,0x0,1); // RLC acknowledged mode
-
-	dest->writeField(wp,0x0,1); // the network establishes no new downlink TBF for the mobile station
-	dest->writeField(wp,0x1,8); // timeslot 7
-	dest->writeField(wp,0x1,8); // TIMING_ADVANCE_INDEX
-
-	dest->writeField(wp,0x0,1); // switch TIMING_ADVANCE_VALUE = off
-	dest->writeField(wp,0x1,1); // switch TIMING_ADVANCE_INDEX = on
-	dest->writeField(wp,0xC,4); // TIMING_ADVANCE_INDEX
-	dest->writeField(wp,0x7,3); // TIMING_ADVANCE_TIMESLOT_NUMBER
-
-	dest->writeField(wp,0x0,1); // switch POWER CONTROL = off
-	dest->writeField(wp,0x1,1); // Frequency Parameters information elements = present
-
-	dest->writeField(wp,0x2,3); // Training Sequence Code (TSC) = 2
-	dest->writeField(wp,0x1,2); // Indirect encoding struct = present
-	dest->writeField(wp,0x0,6); // MAIO
-	dest->writeField(wp,0xE,4); // MA_Number
-	dest->writeField(wp,0x8,4); // CHANGE_MARK_1 CHANGE_MARK_2
-
-	dest->writeField(wp,0x1,1); // switch TFI   : on
-	dest->writeField(wp,0x14,5);// TFI
-
-	dest->writeField(wp,0x1,1); // Power Control Parameters IE = present
-	dest->writeField(wp,0x0,4); // ALPHA power control parameter
-	dest->writeField(wp,0x0,1); // switch GAMMA_TN0 = off
-	dest->writeField(wp,0x0,1); // switch GAMMA_TN1 = off
-	dest->writeField(wp,0x0,1); // switch GAMMA_TN2 = off
-	dest->writeField(wp,0x0,1); // switch GAMMA_TN3 = off
-	dest->writeField(wp,0x0,1); // switch GAMMA_TN4 = off
-	dest->writeField(wp,0x0,1); // switch GAMMA_TN5 = off
-	dest->writeField(wp,0x0,1); // switch GAMMA_TN6 = off
-	dest->writeField(wp,0x1,1); // switch GAMMA_TN7 = on
-	dest->writeField(wp,0x0,5); // GAMMA_TN7
-
-	dest->writeField(wp,0x0,1); // TBF Starting TIME IE not present
-	dest->writeField(wp,0x0,1); // Measurement Mapping struct not present
-}
-
-void  writePUassignment(BitVector * dest, uint8_t TFI, uint32_t TLLI)
-{
-	// TODO We should use our implementation of encode RLC/MAC Control messages.
-	unsigned wp = 0;
-	dest->writeField(wp,0x1,2);  // Payload Type
-	dest->writeField(wp,0x0,2);  // Uplink block with TDMA framenumber
-	dest->writeField(wp,0x1,1);  // Suppl/Polling Bit
-	dest->writeField(wp,0x1,3);  // Uplink state flag
-
-
-	dest->writeField(wp,0xa,6);  // MESSAGE TYPE
-
-	dest->writeField(wp,0x0,2);  // Page Mode
-
-	dest->writeField(wp,0x0,1); // switch PERSIST_LEVEL: off
-	dest->writeField(wp,0x2,2); // switch TLLI   : on
-	dest->writeField(wp,TLLI,32); // TLLI
-
-	dest->writeField(wp,0x0,1); // Message escape
-	dest->writeField(wp,0x0,2); // CHANNEL_CODING_COMMAND
-	dest->writeField(wp,0x0,1); // TLLI_BLOCK_CHANNEL_CODING 
-
-	dest->writeField(wp,0x1,1); // switch TIMING_ADVANCE_VALUE = on
-	dest->writeField(wp,0x0,6); // TIMING_ADVANCE_VALUE
-	dest->writeField(wp,0x0,1); // switch TIMING_ADVANCE_INDEX = off
-	
-	dest->writeField(wp,0x0,1); // Frequency Parameters = off
-
-	dest->writeField(wp,0x1,2); // Dynamic Allocation = off
-	
-	dest->writeField(wp,0x0,1); // Dynamic Allocation
-	dest->writeField(wp,0x0,1); // P0 = off
-	
-	dest->writeField(wp,0x1,1); // USF_GRANULARITY
-	dest->writeField(wp,0x1,1); // switch TFI   : on
-	dest->writeField(wp,TFI,5);// TFI
-
-	dest->writeField(wp,0x0,1); //
-	dest->writeField(wp,0x0,1); // TBF Starting Time = off
-	dest->writeField(wp,0x0,1); // Timeslot Allocation
-	
-	dest->writeField(wp,0x0,5); // USF_TN 0 - 4
-	dest->writeField(wp,0x1,1); // USF_TN 5
-	dest->writeField(wp,0x1,3); // USF_TN 5
-	dest->writeField(wp,0x0,2); // USF_TN 6 - 7
-//	dest->writeField(wp,0x0,1); // Measurement Mapping struct not present
-}
-
-void writeIARestOctetsDownlinkAssignment(BitVector * dest, uint8_t TFI, uint32_t TLLI)
-{
-	// GMS 04.08 10.5.2.37b 10.5.2.16
-	unsigned wp = 0;
-	dest->writeField(wp, 3, 2);    // "HH"
-	dest->writeField(wp, 1, 2);    // "01" Packet Downlink Assignment
-	dest->writeField(wp,TLLI,32); // TLLI
-	dest->writeField(wp,0x1,1);   // switch TFI   : on
-	dest->writeField(wp,TFI,5);   // TFI
-	dest->writeField(wp,0x0,1);   // RLC acknowledged mode
-	dest->writeField(wp,0x0,1);   // ALPHA = present
-	//dest->writeField(wp,0x0,4);   // ALPHA power control parameter
-	dest->writeField(wp,0x0,5);   // GAMMA power control parameter
-	dest->writeField(wp,0x1,1);   // Polling Bit
-	dest->writeField(wp,0x1,1);   // TA_VALID ???
-	dest->writeField(wp,0x1,1);   // switch TIMING_ADVANCE_INDEX = on
-	dest->writeField(wp,0xC,4);   // TIMING_ADVANCE_INDEX
-	dest->writeField(wp,0x1,1);   // TBF Starting TIME present
-	dest->writeField(wp,0xffff,16); // TBF Starting TIME (we should set it in OpenBTS)
-	dest->writeField(wp,0x0,1);   // P0 not present
-}
-
-void writePUack(BitVector * dest, uint8_t TFI, uint32_t TLLI, unsigned CV, unsigned BSN)
-{
-	// TODO We should use our implementation of encode RLC/MAC Control messages.
-	unsigned wp = 0;
-	dest->writeField(wp,0x1,2);  // payload
-	dest->writeField(wp,0x0,2);  // Uplink block with TDMA framenumber
-	if (CV == 0) dest->writeField(wp,0x1,1);  // Suppl/Polling Bit
-	else dest->writeField(wp,0x0,1);  //Suppl/Polling Bit
-	dest->writeField(wp,0x1,3);  // Uplink state flag
-	
-	//dest->writeField(wp,0x0,1);  // Reduced block sequence number
-	//dest->writeField(wp,BSN+6,5);  // Radio transaction identifier
-	//dest->writeField(wp,0x1,1);  // Final segment
-	//dest->writeField(wp,0x1,1);  // Address control
-
-	//dest->writeField(wp,0x0,2);  // Power reduction: 0
-	//dest->writeField(wp,TFI,5);  // Temporary flow identifier
-	//dest->writeField(wp,0x1,1);  // Direction
-
-	dest->writeField(wp,0x09,6); // MESSAGE TYPE
-	dest->writeField(wp,0x0,2);  // Page Mode
-
-	dest->writeField(wp,0x0,2);
-	dest->writeField(wp,TFI,5); // Uplink TFI
-	dest->writeField(wp,0x0,1);
-	
-	dest->writeField(wp,0x0,2);  // CS1
-	if (CV == 0) dest->writeField(wp,0x1,1);  // FINAL_ACK_INDICATION
-	else dest->writeField(wp,0x0,1);  // FINAL_ACK_INDICATION
-	dest->writeField(wp,BSN+1,7); // STARTING_SEQUENCE_NUMBER
-	// RECEIVE_BLOCK_BITMAP
-	for (unsigned i=0; i<8; i++) {
-		dest->writeField(wp,0xff,8);
-	}
-	dest->writeField(wp,0x1,1);  // CONTENTION_RESOLUTION_TLLI = present
-	dest->writeField(wp,TLLI,8*4);
-	dest->writeField(wp,0x00,4); //spare
-}
-
-void RLCMACExtractData(uint8_t* tfi, uint32_t* tlli, RlcMacUplinkDataBlock_t * dataBlock, uint8_t* rlc_data, unsigned* dataIndex)
-{
-	unsigned blockDataLen = 0;
-	unsigned dataOctetNum = 0;
-	
-	*tfi = dataBlock->TFI;
-	if (dataBlock->E_1 == 0) // Extension octet follows immediately
-	{
-		// TODO We should implement case with several LLC PDU in one data block.
-		blockDataLen = dataBlock->LENGTH_INDICATOR[0];
-	}
-	else
-	{
-		blockDataLen = 20; // RLC data length without 3 header octets.
-		if(dataBlock->TI == 1) // TLLI field is present
-		{
-			*tlli = dataBlock->TLLI;
-			blockDataLen -= 4; // TLLI length
-			if (dataBlock->PI == 1) // PFI is present if TI field indicates presence of TLLI
-			{
-				blockDataLen -= 1; // PFI length
-			}
-		}
-	}
-
-	for (unsigned i = *dataIndex;  i < *dataIndex + blockDataLen; i++)
-	{
-		rlc_data[i] = dataBlock->RLC_DATA[dataOctetNum];
-		dataOctetNum++;
-	}
-	*dataIndex += blockDataLen;
-}
-
-void sendUplinkAck(uint8_t tfi, uint32_t tlli, RlcMacUplinkDataBlock_t * dataBlock)
-{
-	BitVector packetUplinkAck(23*8);
-	packetUplinkAck.unhex("2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
-	writePUack(&packetUplinkAck, tfi, tlli, dataBlock->CV, dataBlock->BSN);
-	COUT("RLCMAC_CONTROL_BLOCK>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>");
-	RlcMacDownlink_t * pUA = (RlcMacDownlink_t *)malloc(sizeof(RlcMacUplink_t));
-	decode_gsm_rlcmac_downlink(&packetUplinkAck, pUA);
-	free(pUA);
-	COUT("RLCMAC_CONTROL_BLOCK_END------------------------------");
-	sendToOpenBTS(&packetUplinkAck);
-}
-
-void RLCMACDispatchDataBlock(unsigned* waitData, BitVector *vector, uint8_t* tfi, uint32_t* tlli, uint8_t* rlc_data, unsigned* dataIndex)
-{
-	static DataBlockDispatcherState state = WaitSequenceStart;
-	static unsigned prevBSN = -1;
-	if ((*waitData == 1)&&(state == WaitNextSequence))
-	{
-		state = WaitSequenceStart;
-	}
-
-	COUT("RLCMAC_DATA_BLOCK<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<");
-	RlcMacUplinkDataBlock_t * dataBlock = (RlcMacUplinkDataBlock_t *)malloc(sizeof(RlcMacUplinkDataBlock_t));
-	decode_gsm_rlcmac_uplink_data(vector, dataBlock);
-	COUT("RLCMAC_DATA_BLOCK_END------------------------------");	
-
-	switch (state) {
-	case WaitSequenceStart: 
-		if (dataBlock->BSN == 0)
-		{
-			*dataIndex = 0;
-			RLCMACExtractData(tfi, tlli, dataBlock, rlc_data, dataIndex);
-			sendUplinkAck(*tfi, *tlli, dataBlock);
-			state = WaitNextBlock;
-			prevBSN = 0;
-		}
-		break;
-	case WaitNextBlock:
-		if (prevBSN == (dataBlock->BSN - 1))
-		{
-			RLCMACExtractData(tfi, tlli, dataBlock, rlc_data, dataIndex);
-			sendUplinkAck(*tfi, *tlli, dataBlock);
-			if (dataBlock->CV == 0)
-			{
-				// Recieved last Data Block in this sequence.
-				sendToGSMTAP(rlc_data, *dataIndex);
-				state = WaitNextSequence;
-				prevBSN = -1;
-				*waitData = 0;
-			}
-			else
-			{
-				prevBSN = dataBlock->BSN;
-				state = WaitNextBlock;
-			}
-		}
-		else
-		{
-			// Recieved Data Block with unexpected BSN.
-			// We should try to find nesessary Data Block. 
-			state = WaitNextBlock;
-		}
-		break;
-	case WaitNextSequence:
-		// Now we just ignore all Data Blocks and wait next Uplink TBF
-		break;
-	}
-	free(dataBlock);
-}
-
-void RLCMACDispatchControlBlock(unsigned* waitData, BitVector *vector, uint8_t* tfi, uint32_t* tlli, uint8_t* rlc_data, unsigned* dataIndex)
-{
-	static unsigned shutUp = 0;
-	COUT("RLCMAC_CONTROL_BLOCK<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<");
-	RlcMacUplink_t * controlBlock = (RlcMacUplink_t *)malloc(sizeof(RlcMacUplink_t));
-	decode_gsm_rlcmac_uplink(vector, controlBlock);
-	COUT("RLCMAC_CONTROL_BLOCK_END------------------------------");
-	switch (controlBlock->u.MESSAGE_TYPE) {
-	case MT_PACKET_CONTROL_ACK:
-		if (shutUp == 0)
-		{
-			COUT("SEND IA Rest Octets Downlink Assignment>>>>>>>>>>>>>>>>>>");
-			BitVector IARestOctetsDownlinkAssignment(23*8);
-			IARestOctetsDownlinkAssignment.unhex("2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
-			writeIARestOctetsDownlinkAssignment(&IARestOctetsDownlinkAssignment, 20, *tlli);
-			sendToOpenBTS(&IARestOctetsDownlinkAssignment);
-			usleep(500000);
-			sendToSGSN(*tfi, *tlli, rlc_data, *dataIndex);
-			//sendToGSMTAP(rlc_data, *dataIndex);
-			shutUp = 1;
-		}
-		break;
-	case MT_PACKET_DOWNLINK_ACK_NACK:
-		COUT("SEND PacketUplinkAssignment>>>>>>>>>>>>>>>>>>");
-		BitVector PacketUplinkAssignment(23*8);
-		PacketUplinkAssignment.unhex("2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
-		writePUassignment(&PacketUplinkAssignment, 21, *tlli);
-		sendToOpenBTS(&PacketUplinkAssignment);
-		*waitData = 1;
-		break;
-	}
-	free(controlBlock);
-	
-}
-
-void RLCMACDispatchBlock(BitVector *vector)
-{
-	static uint8_t rlc_data[60];
-	static uint8_t *tfi = (uint8_t *)malloc(sizeof(uint8_t));
-	static uint32_t *tlli = (uint32_t *)malloc(sizeof(uint32_t));
-	static unsigned *dataIndex = (unsigned *)malloc(sizeof(unsigned));
-	static unsigned waitData = 1;
-
-	unsigned readIndex = 0;
-	unsigned payload = vector->readField(readIndex, 2);
-
-	switch (payload) {
-	case RLCMAC_DATA_BLOCK:
-		RLCMACDispatchDataBlock(&waitData,vector, tfi, tlli, rlc_data, dataIndex);
-		break;
-	case RLCMAC_CONTROL_BLOCK:
-		RLCMACDispatchControlBlock(&waitData, vector, tfi, tlli, rlc_data, dataIndex);
-		break;
-	default:
-		COUT("Unknown RLCMAC block payload\n");
-	}
-}
-
-void *RLCMACSocket(void *)
-{
-	BitVector *vector = new BitVector(23*8);
-	GPRSRLCMACSocket.nonblocking();
-	while (1) {
-		char buf[MAX_UDP_LENGTH];
-		int count = GPRSRLCMACSocket.read(buf, 3000);
-		if (count>0) {
-			vector->unpack((const unsigned char*)buf);
-			COUT("Recieve from OpenBTS (MS): " << *vector);
-			RLCMACDispatchBlock(vector);
-		}
-	}
-}
diff --git a/GPRSSocket.h b/GPRSSocket.h
deleted file mode 100644
index decce6bc..00000000
--- a/GPRSSocket.h
+++ /dev/null
@@ -1,49 +0,0 @@
-/*GPRSSocket.h
- *
- * Copyright (C) 2011 Ivan Klyuchnikov
- *
- * 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.
- */
-
-#ifndef GPRSSOCKET_H
-#define GPRSSOCKET_H
-
-#include <BitVector.h>
-#include "gsm_rlcmac.h"
-
-
-enum DataBlockDispatcherState {
-	WaitSequenceStart,
-	WaitNextBlock,
-	WaitNextSequence
-};
-
-void sendToGSMTAP(uint8_t * data, unsigned len);
-
-void sendToOpenBTS(BitVector * vector);
-
-void writePUack(BitVector * dest, uint8_t TFI, uint32_t TLLI, unsigned CV, unsigned BSN);
-
-void RLCMACExtractData(uint8_t* tfi, uint32_t* tlli, RlcMacUplinkDataBlock_t * dataBlock, uint8_t* rlc_data, unsigned* dataIndex);
-
-void sendUplinkAck(uint8_t tfi, uint32_t tlli, RlcMacUplinkDataBlock_t * dataBlock);
-
-void RLCMACDispatchDataBlock(BitVector *vector, uint8_t* tfi, uint32_t* tlli, uint8_t* rlc_data, unsigned* dataIndex);
-
-void RLCMACDispatchBlock(BitVector *vector);
-
-void *RLCMACSocket(void *);
-
-#endif // GPRSSOCKET_H
diff --git a/Makefile.am b/Makefile.am
index 3808f835..3ecb896f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -28,29 +28,31 @@ noinst_LTLIBRARIES = libgprs.la
 libgprs_la_SOURCES = \
 	csn1.cpp \
 	gsm_rlcmac.cpp \
-	bssgp.cpp \
-	GPRSSocket.cpp
+	gprs_bssgp_pcu.cpp \
+	gprs_rlcmac.cpp \
+	pcu_l1_if.cpp
 
 noinst_PROGRAMS = \
 	RLCMACTest \
-	RLCMAC
+	pcu
 
 noinst_HEADERS = \
 	csn1.h \
 	gsm_rlcmac.h \
-	bssgp.h \
-	GPRSSocket.h
+	gprs_bssgp_pcu.h \
+	gprs_rlcmac.h \
+	pcu_l1_if.h
 
 RLCMACTest_SOURCES = RLCMACTest.cpp
 RLCMACTest_LDADD = \
 	libgprs.la \
 	$(COMMON_LA) 
 
-#OPENBSC_DIR = /path to OpenBSC dir
-#OPENGGSN_DIR = /path to OpenGGGSN dir
+OPENBSC_DIR = /home/ivan/work/openbsc/openbsc/openbsc
+OPENGGSN_DIR = /home/ivan/work/openbsc/openggsn
 
-RLCMAC_SOURCES = RLCMAC.cpp
-RLCMAC_LDADD = \
+pcu_SOURCES = pcu_main.cpp
+pcu_LDADD = \
 	libgprs.la \
 	$(OPENBSC_DIR)/src/libgb/gprs_ns.o \
 	$(OPENBSC_DIR)/src/libgb/gprs_bssgp.o \
diff --git a/bssgp.cpp b/gprs_bssgp_pcu.cpp
index 696e194f..4ccea440 100644
--- a/bssgp.cpp
+++ b/gprs_bssgp_pcu.cpp
@@ -1,6 +1,6 @@
-/* bssgp.cpp
+/* gprs_bssgp_pcu.cpp
  *
- * Copyright (C) 2011 Ivan Klyuchnikov
+ * Copyright (C) 2012 Ivan Klyuchnikov
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -17,98 +17,62 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
 
-#include <arpa/inet.h>
-#include <Threads.h>
-#include "GPRSSocket.h"
-#include "gsm_rlcmac.h"
-#include "bssgp.h"
+#include <gprs_rlcmac.h>
+#include <gprs_bssgp_pcu.h>
+#include <pcu_l1_if.h>
 
-// TODO: We should move this parameters to config file.
-#define SGSN_IP "127.0.0.1"
-#define SGSN_PORT 23000
-#define CELL_ID 3
-#define BVCI 7
-#define NSEI 3
-#define NSVCI 4
-#define MNC 1
-#define MCC 1
-#define LAC 1000
-#define RAC 1
-
-#define QOS_PROFILE 0
-#define BSSGP_HDR_LEN 20
-#define NS_HDR_LEN 4
-#define MAX_LEN_PDU 100
-#define IE_PDU 14
-#define BLOCK_DATA_LEN 19
-
-#define BLOCK_LEN 23
-
-uint16_t bvci = BVCI;
-uint16_t nsei = NSEI;
-uint8_t TFI;
-struct bssgp_bvc_ctx *bctx = btsctx_alloc(bvci, nsei);
-struct gprs_nsvc *nsvc;
-struct gprs_ns_inst *sgsn_nsi;
 struct sgsn_instance *sgsn;
 void *tall_bsc_ctx;
+struct bssgp_bvc_ctx *bctx = btsctx_alloc(BVCI, NSEI);
 
-// Send RLC data to OpenBTS.
-void sendRLC(uint32_t tlli, uint8_t *pdu, unsigned startIndex, unsigned endIndex, unsigned bsn, unsigned fbi)
+int gprs_bssgp_pcu_rx_dl_ud(struct msgb *msg)
 {
-	unsigned spareLen = 0;
-	BitVector resultVector(BLOCK_LEN*8);
-	resultVector.unhex("2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
-	RlcMacDownlinkDataBlock_t * dataBlock = (RlcMacDownlinkDataBlock_t *)malloc(sizeof(RlcMacDownlinkDataBlock_t));
-	dataBlock->PAYLOAD_TYPE = 0;
-	dataBlock->RRBP = 0;
-	dataBlock->SP = 1;
-	dataBlock->USF = 1;
-	dataBlock->PR = 0;
-	dataBlock->TFI = 20;
-	dataBlock->FBI = fbi;
-	dataBlock->BSN = bsn;
-	if ((endIndex-startIndex) < 20)
-	{
-		dataBlock->E_1 = 0;
-		dataBlock->LENGTH_INDICATOR[0] = endIndex-startIndex;
-		dataBlock->M[0] = 0;
-		dataBlock->E[0] = 1;
-		spareLen = 19 - dataBlock->LENGTH_INDICATOR[0];
-	}
-	else
-	{
-		dataBlock->E_1 = 1; 
-	}
-	unsigned j = 0;
-	for(unsigned i = startIndex; i < endIndex; i++)
+	struct bssgp_ud_hdr *budh;
+	int tfi;
+	int data_index = 0;
+	int i = 0;
+	int pdu_index = 0;
+
+	budh = (struct bssgp_ud_hdr *)msgb_bssgph(msg);
+	struct gprs_rlcmac_tbf *tbf;
+	// Create new TBF
+	tfi = tfi_alloc();
+	if (tfi < 0) {
+		return tfi;
+	}
+	tbf = tbf_alloc(tfi);
+	tbf->direction = GPRS_RLCMAC_DL_TBF;
+	tbf->state = GPRS_RLCMAC_WAIT_DATA_SEQ_START;
+	tbf->tlli = ntohl(budh->tlli);
+
+	LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP TLLI=0x%08x \n", ntohl(budh->tlli));
+	for (i = 4; i < MAX_LEN_PDU; i++)
 	{
-		dataBlock->RLC_DATA[j] = pdu[i];
-		j++;
+		//LOGP(DBSSGP, LOGL_NOTICE, "SERCH data = -0x%02x\n", budh ->data[i]);
+		if(budh->data[i] == IE_PDU)
+		{
+			pdu_index = i + 2;
+			break;
+		}
 	}
-	for(unsigned i = j; i < j + spareLen; i++)
+	for (i = pdu_index; i < pdu_index + (budh->data[pdu_index-1]&0x7f); i++)
 	{
-		dataBlock->RLC_DATA[i] = 0x2b;
-	}
-	encode_gsm_rlcmac_downlink_data(&resultVector, dataBlock);
-	free(dataBlock);
-	sendToOpenBTS(&resultVector);
+		//LOGP(DBSSGP, LOGL_NOTICE, "-0x%02x\n", budh ->data[i]);
+		tbf->rlc_data[data_index] = budh->data[i];
+		data_index++;
+	}
+	DEBUGP(DBSSGP, "BSSGP Catch from SGSN=%u octets. Send it to OpenBTS.\n", data_index);
+	gsmtap_send_llc(tbf->rlc_data,data_index);
+	tbf->data_index = data_index;
+	gprs_rlcmac_segment_llc_pdu(tbf);
 }
 
 /* Receive a BSSGP PDU from a BSS on a PTP BVCI */
-int gprs_bssgp_bss_rx_ptp(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_bvc_ctx *bctx)
+int gprs_bssgp_pcu_rx_ptp(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_bvc_ctx *bctx)
 {
 	struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
 	uint8_t pdu_type = bgph->pdu_type;
-	uint8_t pdu[MAX_LEN_PDU];
 	unsigned rc = 0;
-	unsigned dataIndex = 0;
-	unsigned numBlocks = 0;
-	unsigned i = 0;
-	unsigned j = 0;
-	unsigned pduIndex = 0;
-	unsigned fbi = 0;
-	struct bssgp_ud_hdr *budh;
 
 	/* If traffic is received on a BVC that is marked as blocked, the
 	* received PDU shall not be accepted and a STATUS PDU (Cause value:
@@ -123,55 +87,7 @@ int gprs_bssgp_bss_rx_ptp(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_
 	switch (pdu_type) {
 	case BSSGP_PDUT_DL_UNITDATA:
 		LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_DL_UNITDATA\n");
-		budh = (struct bssgp_ud_hdr *) msgb_bssgph(msg);
-		LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP TLLI=0x%08x \n", ntohl(budh->tlli));
-		for (i = 4; i < MAX_LEN_PDU; i++)
-		{
-			//LOGP(DBSSGP, LOGL_NOTICE, "SERCH data = -0x%02x\n", budh ->data[i]);
-			if(budh ->data[i] == IE_PDU)
-			{
-				pduIndex = i+2;
-				break;
-			}
-		}
-		for (i = pduIndex; i < pduIndex + (budh->data[pduIndex-1]&0x7f); i++)
-		{
-			//LOGP(DBSSGP, LOGL_NOTICE, "-0x%02x\n", budh ->data[i]);
-			pdu[dataIndex] = budh ->data[i];
-			dataIndex++;
-		}
-		DEBUGP(DBSSGP, "BSSGP Catch from SGSN=%u octets. Send it to OpenBTS.\n", dataIndex);
-		sendToGSMTAP(pdu,dataIndex);
-		if (dataIndex > BLOCK_DATA_LEN + 1)
-		{
-			int blockDataLen = BLOCK_DATA_LEN;
-			numBlocks = dataIndex/BLOCK_DATA_LEN;
-			int ost = dataIndex%BLOCK_DATA_LEN;
-			int startIndex = 0;
-			int endIndex = 0;
-			if (dataIndex%BLOCK_DATA_LEN > 0)
-			{
-				numBlocks++;
-			}
-			for (i = 0; i < numBlocks; i++)
-			{
-				if (i == numBlocks-1)
-				{
-					if (ost > 0)
-					{
-						blockDataLen = ost;
-					}
-					fbi = 1;
-				}
-				endIndex = startIndex + blockDataLen;
-				sendRLC(ntohl(budh->tlli), pdu, startIndex, endIndex, i, fbi);
-				startIndex += blockDataLen;
-			}
-		}
-		else
-		{
-			sendRLC(ntohl(budh->tlli), pdu, 0, dataIndex, 0, 1);
-		}
+		gprs_bssgp_pcu_rx_dl_ud(msg);
 		break;
 	case BSSGP_PDUT_PAGING_PS:
 		LOGP(DBSSGP, LOGL_NOTICE, "rx BSSGP_PDUT_PAGING_PS\n");
@@ -197,7 +113,7 @@ int gprs_bssgp_bss_rx_ptp(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_
 }
 
 /* Receive a BSSGP PDU from a SGSN on a SIGNALLING BVCI */
-int gprs_bssgp_bss_rx_sign(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_bvc_ctx *bctx)
+int gprs_bssgp_pcu_rx_sign(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_bvc_ctx *bctx)
 {
 	struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
 	int rc = 0;
@@ -248,7 +164,7 @@ int gprs_bssgp_bss_rx_sign(struct msgb *msg, struct tlv_parsed *tp, struct bssgp
 	return rc;
 }
 
-int gprs_bssgp_bss_rcvmsg(struct msgb *msg)
+int gprs_bssgp_pcu_rcvmsg(struct msgb *msg)
 {
 	struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
 	struct bssgp_ud_hdr *budh = (struct bssgp_ud_hdr *) msgb_bssgph(msg);
@@ -299,7 +215,7 @@ int gprs_bssgp_bss_rcvmsg(struct msgb *msg)
 	if (ns_bvci == BVCI_SIGNALLING)
 	{
 		LOGP(DBSSGP, LOGL_NOTICE, "rx BVCI_SIGNALLING gprs_bssgp_rx_sign\n");
-		rc = gprs_bssgp_bss_rx_sign(msg, &tp, bctx);
+		rc = gprs_bssgp_pcu_rx_sign(msg, &tp, bctx);
 	}
 	else if (ns_bvci == BVCI_PTM)
 	{
@@ -309,94 +225,7 @@ int gprs_bssgp_bss_rcvmsg(struct msgb *msg)
 	else
 	{
 		LOGP(DBSSGP, LOGL_NOTICE, "rx BVCI_PTP gprs_bssgp_rx_ptp\n");
-		rc = gprs_bssgp_bss_rx_ptp(msg, &tp, bctx);
-	}
-	return rc;
-}
-
-
-int sgsn_ns_cb(enum gprs_ns_evt event, struct gprs_nsvc *nsvc, struct msgb *msg, uint16_t bvci)
-{
-	int rc = 0;
-	switch (event) {
-	case GPRS_NS_EVT_UNIT_DATA:
-		/* hand the message into the BSSGP implementation */
-		rc = gprs_bssgp_bss_rcvmsg(msg);
-		break;
-	default:
-		LOGP(DGPRS, LOGL_ERROR, "RLCMAC: Unknown event %u from NS\n", event);
-		if (msg)
-			talloc_free(msg);
-		rc = -EIO;
-		break;
+		rc = gprs_bssgp_pcu_rx_ptp(msg, &tp, bctx);
 	}
 	return rc;
 }
-
-// Send RLC data to SGSN.
-void sendToSGSN(uint8_t tfi, uint32_t tlli, uint8_t * rlc_data, unsigned dataLen)
-{
-	const uint8_t qos_profile = QOS_PROFILE;
-	struct msgb *llc_pdu;
-	unsigned msgLen = NS_HDR_LEN + BSSGP_HDR_LEN + dataLen;
-	TFI = tfi;
-	bctx->cell_id = CELL_ID;
-	bctx->nsei = NSEI;
-	bctx->ra_id.mnc = MNC;
-	bctx->ra_id.mcc = MCC;
-	bctx->ra_id.lac = LAC;
-	bctx->ra_id.rac = RAC;
-	bctx->bvci = BVCI;
-	LOGP(DBSSGP, LOGL_DEBUG, "Data len %u TLLI 0x%08x , TFI 0x%02x", dataLen, tlli, tfi);
-	//for (unsigned i = 0; i < dataLen; i++)
-	//	LOGP(DBSSGP, LOGL_DEBUG, " Data[%u] = %u", i, rlc_data[i]);
-	llc_pdu = msgb_alloc_headroom(msgLen, msgLen,"llc_pdu");
-	msgb_tvlv_push(llc_pdu, BSSGP_IE_LLC_PDU, sizeof(uint8_t)*dataLen, rlc_data);
-	bssgp_tx_ul_ud(bctx, tlli, &qos_profile, llc_pdu);
-}
-
-void RLCMACServer()
-{
-	uint16_t nsvci = NSVCI;
-
-	// Socket for reading BitVectors (RLC/MAC Frames) from OpenBTS application.
-	Thread RLCMACInterface;
-	RLCMACInterface.start(RLCMACSocket,NULL);
-
-	osmo_init_logging(&log_info);
-	sgsn_nsi = gprs_ns_instantiate(&sgsn_ns_cb);
-	bssgp_nsi = sgsn_nsi;
-
-	if (!bssgp_nsi)
-	{
-		LOGP(DGPRS, LOGL_ERROR, "Unable to instantiate NS\n");
-		exit(1);
-	}
-
-	bctx->cell_id = CELL_ID;
-	bctx->nsei = NSEI;
-	bctx->ra_id.mnc = MNC;
-	bctx->ra_id.mcc = MCC;
-	bctx->ra_id.lac = LAC;
-	bctx->ra_id.rac = RAC;
-	bctx->bvci = BVCI;
-	uint8_t cause = 39;
-	gprs_ns_nsip_listen(sgsn_nsi);
-
-	struct sockaddr_in dest;
-	dest.sin_family = AF_INET;
-	dest.sin_port = htons(SGSN_PORT);
-	inet_aton(SGSN_IP, &dest.sin_addr);
-
-	nsvc = nsip_connect(sgsn_nsi, &dest, nsei, nsvci);
-	unsigned i = 0;
-	while (1) 
-	{
-		osmo_select_main(0);
-		if (i == 7)
-		{
-			bssgp_tx_bvc_reset(bctx, bvci, cause);
-		}
-		i++;
-	}
-}
diff --git a/bssgp.h b/gprs_bssgp_pcu.h
index 1a6c1b1e..1308cf7a 100644
--- a/bssgp.h
+++ b/gprs_bssgp_pcu.h
@@ -1,6 +1,6 @@
-/* bssgp.h
+/* gprs_bssgp_pcu.h
  *
- * Copyright (C) 2011 Ivan Klyuchnikov
+ * Copyright (C) 2012 Ivan Klyuchnikov
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -16,9 +16,10 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
- 
-#ifndef BSSGP_H
-#define BSSGP_H
+
+#ifndef GPRS_BSSGP_PCU_H
+#define GPRS_BSSGP_PCU_H
+
 
 extern "C" {
 #include <osmocom/core/talloc.h>
@@ -36,18 +37,32 @@ int bssgp_tx_ul_ud(struct bssgp_bvc_ctx *bctx, uint32_t tlli, const uint8_t *qos
 struct bssgp_bvc_ctx *btsctx_alloc(uint16_t bvci, uint16_t nsei);
 }
 
-void sendRLC(uint32_t tlli, uint8_t *pdu, unsigned startIndex, unsigned endIndex, unsigned bsn);
+#define BVCI 7
+#define NSEI 3
+
+#define QOS_PROFILE 0
+#define BSSGP_HDR_LEN 20
+#define NS_HDR_LEN 4
+#define MAX_LEN_PDU 60
+#define IE_PDU 14
+#define BLOCK_DATA_LEN 19
+#define BLOCK_LEN 23
+
+#define CELL_ID 3
+#define MNC 55
+#define MCC 905
+#define PCU_LAC 1000
+#define PCU_RAC 1
 
-int gprs_bssgp_bss_rx_ptp(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_bvc_ctx *bctx);
 
-int gprs_bssgp_bss_rx_sign(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_bvc_ctx *bctx);
+extern struct bssgp_bvc_ctx *bctx;
 
-int gprs_bssgp_bss_rcvmsg(struct msgb *msg);
+int gprs_bssgp_pcu_rx_dl_ud(struct msgb *msg);
 
-int sgsn_ns_cb(enum gprs_ns_evt event, struct gprs_nsvc *nsvc, struct msgb *msg, uint16_t bvci);
+int gprs_bssgp_pcu_rx_ptp(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_bvc_ctx *bctx);
 
-void sendToSGSN(uint8_t tfi, uint32_t tlli, uint8_t * rlc_data, unsigned dataLen);
+int gprs_bssgp_pcu_rx_sign(struct msgb *msg, struct tlv_parsed *tp, struct bssgp_bvc_ctx *bctx);
 
-void RLCMACServer();
+int gprs_bssgp_pcu_rcvmsg(struct msgb *msg);
 
-#endif // BSSGP_H
+#endif // GPRS_BSSGP_PCU_H
diff --git a/gprs_rlcmac.cpp b/gprs_rlcmac.cpp
new file mode 100644
index 00000000..c350a7bc
--- /dev/null
+++ b/gprs_rlcmac.cpp
@@ -0,0 +1,527 @@
+/* gprs_rlcmac.cpp
+ *
+ * Copyright (C) 2012 Ivan Klyuchnikov
+ *
+ * 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 <gprs_bssgp_pcu.h>
+#include <pcu_l1_if.h>
+#include <Threads.h>
+#include <gprs_rlcmac.h>
+
+
+LLIST_HEAD(gprs_rlcmac_tbfs);
+void *rlcmac_tall_ctx;
+
+int tfi_alloc()
+{
+	struct gprs_rlcmac_tbf *tbf;
+	uint32_t tfi_map = 0;
+	uint32_t tfi_ind = 0;
+	uint32_t mask = 1;
+	uint8_t i;
+
+	llist_for_each_entry(tbf, &gprs_rlcmac_tbfs, list) {
+		tfi_ind = 1 << tbf->tfi;
+		tfi_map = tfi_map|tfi_ind;
+	}
+	
+	for (i = 0; i < 32; i++) {
+		if(((tfi_map >> i) & mask) == 0) {
+			return i;
+		}
+	}
+	return -1;
+}
+
+/* lookup TBF Entity (by TFI) */
+static struct gprs_rlcmac_tbf *tbf_by_tfi(uint8_t tfi)
+{
+	struct gprs_rlcmac_tbf *tbf;
+
+	llist_for_each_entry(tbf, &gprs_rlcmac_tbfs, list) {
+		if (tbf->tfi == tfi)
+			return tbf;
+	}
+	return NULL;
+}
+
+static struct gprs_rlcmac_tbf *tbf_by_tlli(uint8_t tlli)
+{
+	struct gprs_rlcmac_tbf *tbf;
+
+	llist_for_each_entry(tbf, &gprs_rlcmac_tbfs, list) {
+		if ((tbf->tlli == tlli)&&(tbf->direction == GPRS_RLCMAC_UL_TBF))
+			return tbf;
+	}
+	return NULL;
+}
+
+struct gprs_rlcmac_tbf *tbf_alloc(uint8_t tfi)
+{
+	struct gprs_rlcmac_tbf *tbf;
+
+	tbf = talloc_zero(rlcmac_tall_ctx, struct gprs_rlcmac_tbf);
+	if (!tbf)
+		return NULL;
+
+	tbf->tfi = tfi;
+
+	llist_add(&tbf->list, &gprs_rlcmac_tbfs);
+
+	return tbf;
+}
+
+static void tbf_free(struct gprs_rlcmac_tbf *tbf)
+{
+	llist_del(&tbf->list);
+	talloc_free(tbf);
+}
+
+void  write_packet_downlink_assignment(BitVector * dest, uint8_t tfi, uint32_t tlli)
+{
+	// TODO We should use our implementation of encode RLC/MAC Control messages.
+	unsigned wp = 0;
+	dest->writeField(wp,0x1,2);  // Payload Type
+	dest->writeField(wp,0x0,2);  // Uplink block with TDMA framenumber
+	dest->writeField(wp,0x1,1);  // Suppl/Polling Bit
+	dest->writeField(wp,0x1,3);  // Uplink state flag
+	dest->writeField(wp,0x2,6);  // MESSAGE TYPE
+	dest->writeField(wp,0x0,2);  // Page Mode
+
+	dest->writeField(wp,0x0,1); // switch PERSIST_LEVEL: off
+	dest->writeField(wp,0x2,2); // switch TLLI   : on
+	dest->writeField(wp,tlli,32); // TLLI
+
+	dest->writeField(wp,0x0,1); // Message escape
+	dest->writeField(wp,0x0,2); // Medium Access Method: Dynamic Allocation
+	dest->writeField(wp,0x0,1); // RLC acknowledged mode
+
+	dest->writeField(wp,0x0,1); // the network establishes no new downlink TBF for the mobile station
+	dest->writeField(wp,0x1,8); // timeslot 7
+	dest->writeField(wp,0x1,8); // TIMING_ADVANCE_INDEX
+
+	dest->writeField(wp,0x0,1); // switch TIMING_ADVANCE_VALUE = off
+	dest->writeField(wp,0x1,1); // switch TIMING_ADVANCE_INDEX = on
+	dest->writeField(wp,0xC,4); // TIMING_ADVANCE_INDEX
+	dest->writeField(wp,0x7,3); // TIMING_ADVANCE_TIMESLOT_NUMBER
+
+	dest->writeField(wp,0x0,1); // switch POWER CONTROL = off
+	dest->writeField(wp,0x1,1); // Frequency Parameters information elements = present
+
+	dest->writeField(wp,0x2,3); // Training Sequence Code (TSC) = 2
+	dest->writeField(wp,0x1,2); // Indirect encoding struct = present
+	dest->writeField(wp,0x0,6); // MAIO
+	dest->writeField(wp,0xE,4); // MA_Number
+	dest->writeField(wp,0x8,4); // CHANGE_MARK_1 CHANGE_MARK_2
+
+	dest->writeField(wp,0x1,1); // switch TFI   : on
+	dest->writeField(wp,tfi,5);// TFI
+
+	dest->writeField(wp,0x1,1); // Power Control Parameters IE = present
+	dest->writeField(wp,0x0,4); // ALPHA power control parameter
+	dest->writeField(wp,0x0,1); // switch GAMMA_TN0 = off
+	dest->writeField(wp,0x0,1); // switch GAMMA_TN1 = off
+	dest->writeField(wp,0x0,1); // switch GAMMA_TN2 = off
+	dest->writeField(wp,0x0,1); // switch GAMMA_TN3 = off
+	dest->writeField(wp,0x0,1); // switch GAMMA_TN4 = off
+	dest->writeField(wp,0x0,1); // switch GAMMA_TN5 = off
+	dest->writeField(wp,0x0,1); // switch GAMMA_TN6 = off
+	dest->writeField(wp,0x1,1); // switch GAMMA_TN7 = on
+	dest->writeField(wp,0x0,5); // GAMMA_TN7
+
+	dest->writeField(wp,0x0,1); // TBF Starting TIME IE not present
+	dest->writeField(wp,0x0,1); // Measurement Mapping struct not present
+}
+
+void  write_packet_uplink_assignment(BitVector * dest, uint8_t tfi, uint32_t tlli)
+{
+	// TODO We should use our implementation of encode RLC/MAC Control messages.
+	unsigned wp = 0;
+	dest->writeField(wp,0x1,2);  // Payload Type
+	dest->writeField(wp,0x0,2);  // Uplink block with TDMA framenumber
+	dest->writeField(wp,0x1,1);  // Suppl/Polling Bit
+	dest->writeField(wp,0x1,3);  // Uplink state flag
+
+
+	dest->writeField(wp,0xa,6);  // MESSAGE TYPE
+
+	dest->writeField(wp,0x0,2);  // Page Mode
+
+	dest->writeField(wp,0x0,1); // switch PERSIST_LEVEL: off
+	dest->writeField(wp,0x2,2); // switch TLLI   : on
+	dest->writeField(wp,tlli,32); // TLLI
+
+	dest->writeField(wp,0x0,1); // Message escape
+	dest->writeField(wp,0x0,2); // CHANNEL_CODING_COMMAND
+	dest->writeField(wp,0x0,1); // TLLI_BLOCK_CHANNEL_CODING 
+
+	dest->writeField(wp,0x1,1); // switch TIMING_ADVANCE_VALUE = on
+	dest->writeField(wp,0x0,6); // TIMING_ADVANCE_VALUE
+	dest->writeField(wp,0x0,1); // switch TIMING_ADVANCE_INDEX = off
+	
+	dest->writeField(wp,0x0,1); // Frequency Parameters = off
+
+	dest->writeField(wp,0x1,2); // Dynamic Allocation = off
+	
+	dest->writeField(wp,0x0,1); // Dynamic Allocation
+	dest->writeField(wp,0x0,1); // P0 = off
+	
+	dest->writeField(wp,0x1,1); // USF_GRANULARITY
+	dest->writeField(wp,0x1,1); // switch TFI   : on
+	dest->writeField(wp,tfi,5);// TFI
+
+	dest->writeField(wp,0x0,1); //
+	dest->writeField(wp,0x0,1); // TBF Starting Time = off
+	dest->writeField(wp,0x0,1); // Timeslot Allocation
+	
+	dest->writeField(wp,0x0,5); // USF_TN 0 - 4
+	dest->writeField(wp,0x1,1); // USF_TN 5
+	dest->writeField(wp,0x1,3); // USF_TN 5
+	dest->writeField(wp,0x0,2); // USF_TN 6 - 7
+//	dest->writeField(wp,0x0,1); // Measurement Mapping struct not present
+}
+
+void write_ia_rest_octets_downlink_assignment(BitVector * dest, uint8_t tfi, uint32_t tlli)
+{
+	// GMS 04.08 10.5.2.37b 10.5.2.16
+	unsigned wp = 0;
+	dest->writeField(wp, 3, 2);    // "HH"
+	dest->writeField(wp, 1, 2);    // "01" Packet Downlink Assignment
+	dest->writeField(wp,tlli,32); // TLLI
+	dest->writeField(wp,0x1,1);   // switch TFI   : on
+	dest->writeField(wp,tfi,5);   // TFI
+	dest->writeField(wp,0x0,1);   // RLC acknowledged mode
+	dest->writeField(wp,0x0,1);   // ALPHA = present
+	//dest->writeField(wp,0x0,4);   // ALPHA power control parameter
+	dest->writeField(wp,0x0,5);   // GAMMA power control parameter
+	dest->writeField(wp,0x1,1);   // Polling Bit
+	dest->writeField(wp,0x1,1);   // TA_VALID ???
+	dest->writeField(wp,0x1,1);   // switch TIMING_ADVANCE_INDEX = on
+	dest->writeField(wp,0xC,4);   // TIMING_ADVANCE_INDEX
+	dest->writeField(wp,0x1,1);   // TBF Starting TIME present
+	dest->writeField(wp,0xffff,16); // TBF Starting TIME (we should set it in OpenBTS)
+	dest->writeField(wp,0x0,1);   // P0 not present
+}
+
+void write_packet_uplink_ack(BitVector * dest, uint8_t tfi, uint32_t tlli, unsigned cv, unsigned bsn)
+{
+	// TODO We should use our implementation of encode RLC/MAC Control messages.
+	unsigned wp = 0;
+	dest->writeField(wp,0x1,2);  // payload
+	dest->writeField(wp,0x0,2);  // Uplink block with TDMA framenumber
+	if (cv == 0) dest->writeField(wp,0x1,1);  // Suppl/Polling Bit
+	else dest->writeField(wp,0x0,1);  //Suppl/Polling Bit
+	dest->writeField(wp,0x1,3);  // Uplink state flag
+	
+	//dest->writeField(wp,0x0,1);  // Reduced block sequence number
+	//dest->writeField(wp,BSN+6,5);  // Radio transaction identifier
+	//dest->writeField(wp,0x1,1);  // Final segment
+	//dest->writeField(wp,0x1,1);  // Address control
+
+	//dest->writeField(wp,0x0,2);  // Power reduction: 0
+	//dest->writeField(wp,TFI,5);  // Temporary flow identifier
+	//dest->writeField(wp,0x1,1);  // Direction
+
+	dest->writeField(wp,0x09,6); // MESSAGE TYPE
+	dest->writeField(wp,0x0,2);  // Page Mode
+
+	dest->writeField(wp,0x0,2);
+	dest->writeField(wp,tfi,5); // Uplink TFI
+	dest->writeField(wp,0x0,1);
+	
+	dest->writeField(wp,0x0,2);  // CS1
+	if (cv == 0) dest->writeField(wp,0x1,1);  // FINAL_ACK_INDICATION
+	else dest->writeField(wp,0x0,1);  // FINAL_ACK_INDICATION
+	dest->writeField(wp,bsn + 1,7); // STARTING_SEQUENCE_NUMBER
+	// RECEIVE_BLOCK_BITMAP
+	for (unsigned i=0; i<8; i++) {
+		dest->writeField(wp,0xff,8);
+	}
+	dest->writeField(wp,0x1,1);  // CONTENTION_RESOLUTION_TLLI = present
+	dest->writeField(wp,tlli,8*4);
+	dest->writeField(wp,0x00,4); //spare
+}
+
+void gprs_rlcmac_tx_ul_ack(uint8_t tfi, uint32_t tlli, RlcMacUplinkDataBlock_t * ul_data_block)
+{
+	BitVector packet_uplink_ack_vec(23*8);
+	packet_uplink_ack_vec.unhex("2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+	write_packet_uplink_ack(&packet_uplink_ack_vec, tfi, tlli, ul_data_block->CV, ul_data_block->BSN);
+	COUT("RLCMAC_CONTROL_BLOCK>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>");
+	RlcMacDownlink_t * packet_uplink_ack = (RlcMacDownlink_t *)malloc(sizeof(RlcMacUplink_t));
+	decode_gsm_rlcmac_downlink(&packet_uplink_ack_vec, packet_uplink_ack);
+	free(packet_uplink_ack);
+	COUT("RLCMAC_CONTROL_BLOCK_END------------------------------");
+	pcu_l1if_tx(&packet_uplink_ack_vec);
+}
+
+void gprs_rlcmac_data_block_parse(gprs_rlcmac_tbf* tbf, RlcMacUplinkDataBlock_t * ul_data_block)
+{
+	unsigned block_data_len = 0;
+	unsigned data_octet_num = 0;
+	
+	if (ul_data_block->E_1 == 0) // Extension octet follows immediately
+	{
+		// TODO We should implement case with several LLC PDU in one data block.
+		block_data_len = ul_data_block->LENGTH_INDICATOR[0];
+	}
+	else
+	{
+		block_data_len = 20; // RLC data length without 3 header octets.
+		if(ul_data_block->TI == 1) // TLLI field is present
+		{
+			tbf->tlli = ul_data_block->TLLI;
+			block_data_len -= 4; // TLLI length
+			if (ul_data_block->PI == 1) // PFI is present if TI field indicates presence of TLLI
+			{
+				block_data_len -= 1; // PFI length
+			}
+		}
+	}
+
+	for (unsigned i = tbf->data_index;  i < tbf->data_index + block_data_len; i++)
+	{
+		tbf->rlc_data[i] = ul_data_block->RLC_DATA[data_octet_num];
+		data_octet_num++;
+	}
+	tbf->data_index += block_data_len;
+}
+
+/* Received Uplink RLC data block. */
+int gprs_rlcmac_rcv_data_block(BitVector *rlc_block)
+{
+	struct gprs_rlcmac_tbf *tbf;
+
+	COUT("RLCMAC_DATA_BLOCK<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<");
+	RlcMacUplinkDataBlock_t * ul_data_block = (RlcMacUplinkDataBlock_t *)malloc(sizeof(RlcMacUplinkDataBlock_t));
+	decode_gsm_rlcmac_uplink_data(rlc_block, ul_data_block);
+	COUT("RLCMAC_DATA_BLOCK_END------------------------------");
+
+	tbf = tbf_by_tfi(ul_data_block->TFI);
+	if (!tbf) {
+		tbf = tbf_alloc(ul_data_block->TFI);
+		if (tbf) {
+			tbf->direction = GPRS_RLCMAC_UL_TBF;
+			tbf->state = GPRS_RLCMAC_WAIT_DATA_SEQ_START;
+		} else {
+			return 0;
+		}
+	}
+
+	switch (tbf->state) {
+	case GPRS_RLCMAC_WAIT_DATA_SEQ_START: 
+		if (ul_data_block->BSN == 0) {
+			tbf->data_index = 0;
+			gprs_rlcmac_data_block_parse(tbf, ul_data_block);
+			gprs_rlcmac_tx_ul_ack(tbf->tfi, tbf->tlli, ul_data_block);
+			tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK;
+			tbf->bsn = ul_data_block->BSN;
+		}
+		break;
+	case GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK:
+		if (tbf->bsn == (ul_data_block->BSN - 1)) {
+			gprs_rlcmac_data_block_parse(tbf, ul_data_block);
+			gprs_rlcmac_tx_ul_ack(tbf->tfi, tbf->tlli, ul_data_block);
+			if (ul_data_block->CV == 0) {
+				// Recieved last Data Block in this sequence.
+				gsmtap_send_llc(tbf->rlc_data, tbf->data_index);
+				tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_SEQ;
+			} else {
+				tbf->bsn = ul_data_block->BSN;
+				tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK;
+			}
+		} else {
+			// Recieved Data Block with unexpected BSN.
+			// We should try to find nesessary Data Block. 
+			tbf->state = GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK;
+		}
+		break;
+	case GPRS_RLCMAC_WAIT_NEXT_DATA_SEQ:
+		// Now we just ignore all Data Blocks and wait next Uplink TBF
+		break;
+	}
+
+	free(ul_data_block);
+	return 1;
+}
+
+/* Received Uplink RLC control block. */
+int gprs_rlcmac_rcv_control_block(BitVector *rlc_block)
+{
+	//static unsigned shutUp = 0;
+	uint8_t tfi = 0;
+	uint32_t tlli = 0;
+	struct gprs_rlcmac_tbf *tbf;
+
+	COUT("RLCMAC_CONTROL_BLOCK<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<");
+	RlcMacUplink_t * ul_control_block = (RlcMacUplink_t *)malloc(sizeof(RlcMacUplink_t));
+	decode_gsm_rlcmac_uplink(rlc_block, ul_control_block);
+	COUT("RLCMAC_CONTROL_BLOCK_END------------------------------");
+
+	//gprs_rlcmac_control_block_get_tfi_tlli(ul_control_block, &tfi, &tlli);
+	tbf = tbf_by_tfi(tfi);
+	if (!tbf) {
+			return 0;
+	}
+
+	switch (ul_control_block->u.MESSAGE_TYPE) {
+	case MT_PACKET_CONTROL_ACK:
+		/*
+		COUT("SEND IA Rest Octets Downlink Assignment>>>>>>>>>>>>>>>>>>");
+		BitVector IARestOctetsDownlinkAssignment(23*8);
+		IARestOctetsDownlinkAssignment.unhex("2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+		writeIARestOctetsDownlinkAssignment(&IARestOctetsDownlinkAssignment, 20, *tlli);
+		sendToOpenBTS(&IARestOctetsDownlinkAssignment);
+		*/
+		//usleep(500000);
+		tlli = ul_control_block->u.Packet_Control_Acknowledgement.TLLI;
+		tbf = tbf_by_tlli(tlli);
+		if (!tbf) {
+			return 0;
+		}
+		gprs_rlcmac_tx_ul_ud(tbf);
+		tbf_free(tbf);
+		break;
+	case MT_PACKET_DOWNLINK_ACK_NACK:
+		tfi = ul_control_block->u.Packet_Downlink_Ack_Nack.DOWNLINK_TFI;
+		tbf = tbf_by_tfi(tfi);
+		if (!tbf) {
+			return 0;
+		}
+		//COUT("SEND PacketUplinkAssignment>>>>>>>>>>>>>>>>>>");
+		//BitVector PacketUplinkAssignment(23*8);
+		//PacketUplinkAssignment.unhex("2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+		//writePUassignment(&PacketUplinkAssignment, tbf->tfi, tbf->tlli);
+		//sendToOpenBTS(&PacketUplinkAssignment);
+		break;
+	}
+	free(ul_control_block);
+	return 1;
+}
+
+void gprs_rlcmac_rcv_block(BitVector *rlc_block)
+{
+	unsigned readIndex = 0;
+	unsigned payload = rlc_block->readField(readIndex, 2);
+
+	switch (payload) {
+	case GPRS_RLCMAC_DATA_BLOCK:
+		gprs_rlcmac_rcv_data_block(rlc_block);
+		break;
+	case GPRS_RLCMAC_CONTROL_BLOCK:
+		gprs_rlcmac_rcv_control_block(rlc_block);
+		break;
+	case GPRS_RLCMAC_CONTROL_BLOCK_OPT:
+		COUT("GPRS_RLCMAC_CONTROL_BLOCK_OPT block payload is not supported.\n");
+	default:
+		COUT("Unknown RLCMAC block payload.\n");
+	}
+}
+
+// Send RLC data to OpenBTS.
+void gprs_rlcmac_tx_dl_data_block(uint32_t tlli, uint8_t *pdu, int start_index, int end_index, uint8_t bsn, uint8_t fbi)
+{
+	int spare_len = 0;
+	BitVector data_block_vector(BLOCK_LEN*8);
+	data_block_vector.unhex("2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b2b");
+	RlcMacDownlinkDataBlock_t * data_block = (RlcMacDownlinkDataBlock_t *)malloc(sizeof(RlcMacDownlinkDataBlock_t));
+	data_block->PAYLOAD_TYPE = 0;
+	data_block->RRBP = 0;
+	data_block->SP = 1;
+	data_block->USF = 1;
+	data_block->PR = 0;
+	data_block->TFI = 20;
+	data_block->FBI = fbi;
+	data_block->BSN = bsn;
+	if ((end_index - start_index) < 20) {
+		data_block->E_1 = 0;
+		data_block->LENGTH_INDICATOR[0] = end_index-start_index;
+		data_block->M[0] = 0;
+		data_block->E[0] = 1;
+		spare_len = 19 - data_block->LENGTH_INDICATOR[0];
+	} else {
+		data_block->E_1 = 1; 
+	}
+	int j = 0;
+	int i = 0;
+	for(i = start_index; i < end_index; i++) {
+		data_block->RLC_DATA[j] = pdu[i];
+		j++;
+	}
+	
+	for(i = j; i < j + spare_len; i++) {
+		data_block->RLC_DATA[i] = 0x2b;
+	}
+	encode_gsm_rlcmac_downlink_data(&data_block_vector, data_block);
+	free(data_block);
+	pcu_l1if_tx(&data_block_vector);
+}
+
+int gprs_rlcmac_segment_llc_pdu(struct gprs_rlcmac_tbf *tbf)
+{
+	int fbi = 0;
+	int num_blocks = 0;
+	int i;
+
+	if (tbf->data_index > BLOCK_DATA_LEN + 1)
+	{
+		int block_data_len = BLOCK_DATA_LEN;
+		num_blocks = tbf->data_index/BLOCK_DATA_LEN;
+		int rest_len = tbf->data_index%BLOCK_DATA_LEN;
+		int start_index = 0;
+		int end_index = 0;
+		if (tbf->data_index%BLOCK_DATA_LEN > 0)
+		{
+			num_blocks++;
+		}
+		for (i = 0; i < num_blocks; i++)
+		{
+			if (i == num_blocks-1)
+			{
+				if (rest_len > 0)
+				{
+					block_data_len = rest_len;
+				}
+				fbi = 1;
+			}
+			end_index = start_index + block_data_len;
+			gprs_rlcmac_tx_dl_data_block(tbf->tlli, tbf->rlc_data, start_index, end_index, i, fbi);
+			start_index += block_data_len;
+		}
+	}
+	else
+	{
+		gprs_rlcmac_tx_dl_data_block(tbf->tlli, tbf->rlc_data, 0, tbf->data_index, 0, 1);
+	}
+}
+
+/* Send Uplink unit-data to SGSN. */
+void gprs_rlcmac_tx_ul_ud(gprs_rlcmac_tbf *tbf)
+{
+	const uint8_t qos_profile = QOS_PROFILE;
+	struct msgb *llc_pdu;
+	unsigned msg_len = NS_HDR_LEN + BSSGP_HDR_LEN + tbf->data_index;
+
+	LOGP(DBSSGP, LOGL_DEBUG, "Data len %u TLLI 0x%08x , TFI 0x%02x", tbf->data_index, tbf->tlli, tbf->tfi);
+	//for (unsigned i = 0; i < dataLen; i++)
+	//	LOGP(DBSSGP, LOGL_DEBUG, " Data[%u] = %u", i, rlc_data[i]);
+
+	llc_pdu = msgb_alloc_headroom(msg_len, msg_len,"llc_pdu");
+	msgb_tvlv_push(llc_pdu, BSSGP_IE_LLC_PDU, sizeof(uint8_t)*tbf->data_index, tbf->rlc_data);
+	bssgp_tx_ul_ud(bctx, tbf->tlli, &qos_profile, llc_pdu);
+}
+
diff --git a/gprs_rlcmac.h b/gprs_rlcmac.h
new file mode 100644
index 00000000..c67363c9
--- /dev/null
+++ b/gprs_rlcmac.h
@@ -0,0 +1,88 @@
+/* gprs_rlcmac.h
+ *
+ * Copyright (C) 2012 Ivan Klyuchnikov
+ *
+ * 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.
+ */
+ 
+#ifndef GPRS_RLCMAC_H
+#define GPRS_RLCMAC_H
+
+#include <BitVector.h>
+#include <gsm_rlcmac.h>
+
+extern "C" {
+#include <osmocom/core/linuxlist.h>
+}
+
+enum gprs_rlcmac_tbf_state {
+	GPRS_RLCMAC_WAIT_DATA_SEQ_START,
+	GPRS_RLCMAC_WAIT_NEXT_DATA_BLOCK,
+	GPRS_RLCMAC_WAIT_NEXT_DATA_SEQ
+};
+
+enum gprs_rlcmac_tbf_direction {
+	GPRS_RLCMAC_DL_TBF,
+	GPRS_RLCMAC_UL_TBF
+};
+
+struct gprs_rlcmac_tbf {
+	struct llist_head list;
+	enum gprs_rlcmac_tbf_state state;
+	enum gprs_rlcmac_tbf_direction direction;
+	uint8_t tfi;
+	uint32_t tlli;
+	uint8_t rlc_data[60];
+	uint16_t data_index;
+	uint8_t bsn;
+};
+
+extern struct llist_head gprs_rlcmac_tbfs;
+
+int tfi_alloc();
+
+struct gprs_rlcmac_tbf *tbf_alloc(uint8_t tfi);
+
+static struct gprs_rlcmac_tbf *tbf_by_tfi(uint8_t tfi);
+
+static struct gprs_rlcmac_tbf *tbf_by_tlli(uint8_t tlli);
+
+static void tbf_free(struct gprs_rlcmac_tbf *tbf);
+
+/* TS 44.060 Section 10.4.7 Table 10.4.7.1: Payload Type field */
+enum gprs_rlcmac_block_type {
+	GPRS_RLCMAC_DATA_BLOCK = 0x0,
+	GPRS_RLCMAC_CONTROL_BLOCK = 0x1, 
+	GPRS_RLCMAC_CONTROL_BLOCK_OPT = 0x2,
+	GPRS_RLCMAC_RESERVED = 0x3
+};
+
+void gprs_rlcmac_tx_ul_ack(uint8_t tfi, uint32_t tlli, RlcMacUplinkDataBlock_t * ul_data_block);
+
+void gprs_rlcmac_data_block_parse(gprs_rlcmac_tbf* tbf, RlcMacUplinkDataBlock_t * ul_data_block);
+
+int gprs_rlcmac_rcv_data_block(BitVector *rlc_block);
+
+int gprs_rlcmac_rcv_control_block(BitVector *rlc_block);
+
+void gprs_rlcmac_rcv_block(BitVector *rlc_block);
+
+void gprs_rlcmac_tx_dl_data_block(uint32_t tlli, uint8_t *pdu, int start_index, int end_index, uint8_t bsn, uint8_t fbi);
+
+int gprs_rlcmac_segment_llc_pdu(struct gprs_rlcmac_tbf *tbf);
+
+void gprs_rlcmac_tx_ul_ud(gprs_rlcmac_tbf *tbf);
+
+#endif // GPRS_RLCMAC_H
diff --git a/pcu_l1_if.cpp b/pcu_l1_if.cpp
new file mode 100644
index 00000000..54c5b368
--- /dev/null
+++ b/pcu_l1_if.cpp
@@ -0,0 +1,91 @@
+/* pcu_l1_if.cpp
+ *
+ * Copyright (C) 2012 Ivan Klyuchnikov
+ *
+ * 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 <Sockets.h>
+#include <gsmtap.h>
+#include <gprs_rlcmac.h>
+#include <Threads.h>
+#include <pcu_l1_if.h>
+
+#define MAX_UDP_LENGTH 1500
+
+// TODO: We should take ports and IP from config.
+UDPSocket pcu_l1if_socket(5070, "127.0.0.1", 5934);
+UDPSocket pcu_gsmtap_socket(5077, "127.0.0.1", 4729);
+
+// Send RLC/MAC block to OpenBTS.
+void pcu_l1if_tx(BitVector * block)
+{
+	char buffer[MAX_UDP_LENGTH];
+	int ofs = 0;
+	block->pack((unsigned char*)&buffer[ofs]);
+	ofs += block->size() >> 3;
+	COUT("Send to OpenBTS: " << *block);
+	pcu_l1if_socket.write(buffer, ofs);
+}
+
+// Recieve RLC/MAC block from OpenBTS.
+void *pcu_l1if_rx(void *)
+{
+	BitVector *block = new BitVector(23*8);
+	pcu_l1if_socket.nonblocking();
+	while (1) {
+		char buf[MAX_UDP_LENGTH];
+		int count = pcu_l1if_socket.read(buf, 3000);
+		if (count>0) {
+			block->unpack((const unsigned char*)buf);
+			COUT("Recieve from OpenBTS (MS): " << *block);
+			gprs_rlcmac_rcv_block(block);
+		}
+	}
+}
+
+void gsmtap_send_llc(uint8_t * data, unsigned len)
+{
+	char buffer[MAX_UDP_LENGTH];
+	int ofs = 0;
+
+	// Build header
+	struct gsmtap_hdr *header = (struct gsmtap_hdr *)buffer;
+	header->version			= 2;
+	header->hdr_len			= sizeof(struct gsmtap_hdr) >> 2;
+	header->type			= 0x08;
+	header->timeslot		= 5;
+	header->arfcn			= 0;
+	header->signal_dbm		= 0;
+	header->snr_db			= 0;
+	header->frame_number	= 0;
+	header->sub_type		= 0;
+	header->antenna_nr		= 0;
+	header->sub_slot		= 0;
+	header->res				= 0;
+
+	ofs += sizeof(*header);
+
+	// Add frame data
+	unsigned j = 0;
+	for (unsigned i = ofs; i < len+ofs; i++)
+	{
+		buffer[i] = (char)data[j];
+		j++;
+	}
+	ofs += len;
+	// Write the GSMTAP packet
+	pcu_gsmtap_socket.write(buffer, ofs);
+}
diff --git a/RLCMAC.cpp b/pcu_l1_if.h
index 4a174685..e618cba9 100644
--- a/RLCMAC.cpp
+++ b/pcu_l1_if.h
@@ -1,6 +1,6 @@
-/* RLCMAC.cpp
+/* pcu_l1_if.h
  *
- * Copyright (C) 2011 Ivan Klyuchnikov
+ * Copyright (C) 2012 Ivan Klyuchnikov
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -17,10 +17,15 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  */
 
-#include "bssgp.h"
+#ifndef PCU_L1_IF_H
+#define PCU_L1_IF_H
 
-int main(int argc, char *argv[])
-{
-	// Start RLC/MAC server for communication with OpenBTS and OsmoSGSN.
-	RLCMACServer();
-}
+#include <BitVector.h>
+
+void pcu_l1if_tx(BitVector * block);
+
+void *pcu_l1if_rx(void *);
+
+void gsmtap_send_llc(uint8_t * data, unsigned len);
+
+#endif // PCU_L1_IF_H
diff --git a/pcu_main.cpp b/pcu_main.cpp
new file mode 100644
index 00000000..939e1140
--- /dev/null
+++ b/pcu_main.cpp
@@ -0,0 +1,94 @@
+/* pcu_main.cpp
+ *
+ * Copyright (C) 2012 Ivan Klyuchnikov
+ *
+ * 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 <gprs_bssgp_pcu.h>
+#include <Threads.h>
+#include <Sockets.h>
+#include <pcu_l1_if.h>
+
+// TODO: We should move this parameters to config file.
+#define SGSN_IP "127.0.0.1"
+#define SGSN_PORT 23000
+#define NSVCI 4
+
+
+int sgsn_ns_cb(enum gprs_ns_evt event, struct gprs_nsvc *nsvc, struct msgb *msg, uint16_t bvci)
+{
+	int rc = 0;
+	switch (event) {
+	case GPRS_NS_EVT_UNIT_DATA:
+		/* hand the message into the BSSGP implementation */
+		rc = gprs_bssgp_pcu_rcvmsg(msg);
+		break;
+	default:
+		LOGP(DGPRS, LOGL_ERROR, "RLCMAC: Unknown event %u from NS\n", event);
+		if (msg)
+			talloc_free(msg);
+		rc = -EIO;
+		break;
+	}
+	return rc;
+}
+
+int main(int argc, char *argv[])
+{
+	uint16_t nsvci = NSVCI;
+	struct gprs_ns_inst *sgsn_nsi;
+	struct gprs_nsvc *nsvc;
+	// Socket for reading BitVectors (RLC/MAC Frames) from OpenBTS application.
+	Thread pcu_l1if;
+	pcu_l1if.start(pcu_l1if_rx, NULL);
+
+	osmo_init_logging(&log_info);
+	sgsn_nsi = gprs_ns_instantiate(&sgsn_ns_cb);
+	bssgp_nsi = sgsn_nsi;
+
+	if (!bssgp_nsi)
+	{
+		LOGP(DGPRS, LOGL_ERROR, "Unable to instantiate NS\n");
+		exit(1);
+	}
+	bctx = btsctx_alloc(BVCI, NSEI);
+	bctx->cell_id = CELL_ID;
+	bctx->nsei = NSEI;
+	bctx->ra_id.mnc = MNC;
+	bctx->ra_id.mcc = MCC;
+	bctx->ra_id.lac = PCU_LAC;
+	bctx->ra_id.rac = PCU_RAC;
+	bctx->bvci = BVCI;
+	uint8_t cause = 39;
+	gprs_ns_nsip_listen(sgsn_nsi);
+
+	struct sockaddr_in dest;
+	dest.sin_family = AF_INET;
+	dest.sin_port = htons(SGSN_PORT);
+	inet_aton(SGSN_IP, &dest.sin_addr);
+
+	nsvc = nsip_connect(sgsn_nsi, &dest, NSEI, nsvci);
+	unsigned i = 0;
+	while (1) 
+	{
+		osmo_select_main(0);
+		if (i == 7)
+		{
+			bssgp_tx_bvc_reset(bctx, BVCI, cause);
+		}
+		i++;
+	}
+}