Added L1 interface between PCU and OpenBTS for communication (PCU side).

gsmL1prim.h

@@ -0,0 +1,410 @@
+/*
+* Copyright 2012 Thomas Cooper <tacooper@vt.edu>
+*
+* This software is distributed under the terms of the GNU Affero Public License.
+* See the COPYING file in the main directory for details.
+*
+* This use of this software may be subject to additional restrictions.
+* See the LEGAL file in the main directory for details.
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+#ifndef GSML1PRIM_H
+#define GSML1PRIM_H
+
+#include <stdint.h>
+
+typedef enum GsmL1_SubCh_t {
+GsmL1_SubCh_NA,
+} GsmL1_SubCh_t;
+
+typedef enum GsmL1_Sapi_t {
+GsmL1_Sapi_Fcch,
+GsmL1_Sapi_Sch,
+GsmL1_Sapi_Sacch,
+GsmL1_Sapi_Sdcch,
+GsmL1_Sapi_Bcch,
+GsmL1_Sapi_Pch,
+GsmL1_Sapi_Agch,
+GsmL1_Sapi_Cbch,
+GsmL1_Sapi_Rach,
+GsmL1_Sapi_TchF,
+GsmL1_Sapi_FacchF,
+GsmL1_Sapi_TchH,
+GsmL1_Sapi_FacchH,
+GsmL1_Sapi_Nch,
+GsmL1_Sapi_Pdtch,
+GsmL1_Sapi_Pacch,
+GsmL1_Sapi_Pbcch,
+GsmL1_Sapi_Pagch,
+GsmL1_Sapi_Ppch,
+GsmL1_Sapi_Pnch,
+GsmL1_Sapi_Ptcch,
+GsmL1_Sapi_Prach,
+GsmL1_Sapi_Idle,
+GsmL1_Sapi_NUM,
+} GsmL1_Sapi_t;
+
+typedef enum GsmL1_Status_t {
+GsmL1_Status_Success,
+GsmL1_Status_Generic,
+GsmL1_Status_NoMemory,
+GsmL1_Status_Timeout,
+GsmL1_Status_InvalidParam,
+GsmL1_Status_Busy,
+GsmL1_Status_NoRessource,
+GsmL1_Status_Uninitialized,
+GsmL1_Status_NullInterface,
+GsmL1_Status_NullFctnPtr,
+GsmL1_Status_BadCrc,
+GsmL1_Status_BadUsf,
+GsmL1_Status_InvalidCPS,
+GsmL1_Status_UnexpectedBurst,
+GsmL1_Status_UnavailCodec,
+GsmL1_Status_CriticalError,
+GsmL1_Status_OverheatError,
+GsmL1_Status_DeviceError,
+GsmL1_Status_FacchError,
+GsmL1_Status_AlreadyDeactivated,
+GsmL1_Status_TxBurstFifoOvrn,
+GsmL1_Status_TxBurstFifoUndr,
+GsmL1_Status_NotSynchronized,
+GsmL1_Status_Unsupported,
+GSML1_STATUS_NUM,
+} GsmL1_Status_t;
+
+typedef enum GsmL1_PrimId_t {
+GsmL1_PrimId_MphInitReq,
+GsmL1_PrimId_MphCloseReq,
+GsmL1_PrimId_MphConnectReq,
+GsmL1_PrimId_MphDisconnectReq,
+GsmL1_PrimId_MphActivateReq,
+GsmL1_PrimId_MphDeactivateReq,
+GsmL1_PrimId_MphConfigReq,
+GsmL1_PrimId_MphMeasureReq,
+GsmL1_PrimId_MphInitCnf,
+GsmL1_PrimId_MphCloseCnf,
+GsmL1_PrimId_MphConnectCnf,
+GsmL1_PrimId_MphDisconnectCnf,
+GsmL1_PrimId_MphActivateCnf,
+GsmL1_PrimId_MphDeactivateCnf,
+GsmL1_PrimId_MphConfigCnf,
+GsmL1_PrimId_MphMeasureCnf,
+GsmL1_PrimId_MphTimeInd,
+GsmL1_PrimId_MphSyncInd,
+GsmL1_PrimId_PhEmptyFrameReq,
+GsmL1_PrimId_PhDataReq,
+GsmL1_PrimId_PhConnectInd,
+GsmL1_PrimId_PhReadyToSendInd,
+GsmL1_PrimId_PhDataInd,
+GsmL1_PrimId_PhRaInd,
+GsmL1_PrimId_NUM,
+} GsmL1_PrimId_t;
+
+typedef enum GsmL1_Dir_t {
+GsmL1_Dir_TxDownlink,
+GsmL1_Dir_RxUplink,
+} GsmL1_Dir_t;
+
+typedef enum GsmL1_DevType_t {
+GsmL1_DevType_TxdRxu,
+} GsmL1_DevType_t;
+
+typedef enum GsmL1_TchPlType_t {
+GsmL1_TchPlType_NA,
+GsmL1_TchPlType_Efr,
+GsmL1_TchPlType_Fr,
+GsmL1_TchPlType_Hr,
+GsmL1_TchPlType_Amr,
+GsmL1_TchPlType_Amr_SidBad,
+GsmL1_TchPlType_Amr_Onset,
+GsmL1_TchPlType_Amr_Ratscch,
+GsmL1_TchPlType_Amr_SidUpdateInH,
+GsmL1_TchPlType_Amr_SidFirstP1,
+GsmL1_TchPlType_Amr_SidFirstP2,
+GsmL1_TchPlType_Amr_SidFirstInH,
+GsmL1_TchPlType_Amr_RatscchMarker,
+GsmL1_TchPlType_Amr_RatscchData,
+} GsmL1_TchPlType_t;
+
+typedef enum GsmL1_ConfigParamId_t {
+GsmL1_ConfigParamId_SetNbTsc,
+GsmL1_ConfigParamId_SetTxPowerLevel,
+GsmL1_ConfigParamId_SetLogChParams,
+GsmL1_ConfigParamId_SetCipheringParams,
+} GsmL1_ConfigParamId_t;
+
+typedef struct GsmL1_DeviceParam_t {
+enum GsmL1_DevType_t devType;
+int freqBand;
+uint16_t u16Arfcn;
+uint16_t u16BcchArfcn;
+uint8_t u8NbTsc;
+uint8_t u8Ncc;
+float fRxPowerLevel;
+float fTxPowerLevel;
+} GsmL1_DeviceParam_t;
+
+typedef struct GsmL1_MsgUnitParam_t {
+uint8_t u8Buffer[256];
+uint8_t u8Size;
+} GsmL1_MsgUnitParam_t;
+
+typedef struct GsmL1_MeasParam_t {
+float fRssi;
+float fLinkQuality;
+float fBer;
+int16_t i16BurstTiming;
+} GsmL1_MeasParam_t;
+
+typedef struct GsmL1_LogChParam_t {
+union {
+struct {
+enum GsmL1_TchPlType_t tchPlType;
+        
+enum {
+GsmL1_AmrCmiPhase_NA,
+GsmL1_AmrCmiPhase_Odd,
+} amrCmiPhase;
+        
+enum {
+GsmL1_AmrCodecMode_Unset,
+} amrInitCodecMode;
+
+enum {
+GsmL1_AmrCodec_Unset,
+GsmL1_AmrCodec_4_75,
+GsmL1_AmrCodec_5_15,
+GsmL1_AmrCodec_5_9,
+GsmL1_AmrCodec_6_7,
+GsmL1_AmrCodec_7_4,
+GsmL1_AmrCodec_7_95,
+GsmL1_AmrCodec_10_2,
+GsmL1_AmrCodec_12_2,
+} amrActiveCodecSet[8];
+} tch;
+
+struct {
+uint8_t u8Bsic;
+uint8_t u8NbrOfAgch;
+} rach;
+
+struct {
+uint8_t u8MsPowerLevel;
+} sacch;
+
+struct {
+uint8_t u8NbrOfAgch;
+} agch;
+};
+} GsmL1_LogChParam_t;
+
+typedef enum GsmL1_LogChComb_t {
+GsmL1_LogChComb_0,
+GsmL1_LogChComb_I,
+GsmL1_LogChComb_II,
+GsmL1_LogChComb_IV,
+GsmL1_LogChComb_V,
+GsmL1_LogChComb_VII,
+GsmL1_LogChComb_XIII,
+} GsmL1_LogChComb_t;
+
+enum {
+GsmL1_FreqBand_850,
+GsmL1_FreqBand_900,
+GsmL1_FreqBand_1800,
+GsmL1_FreqBand_1900,
+};
+
+typedef struct GsmL1_MphInitReq_t {
+struct GsmL1_DeviceParam_t deviceParam;
+} GsmL1_MphInitReq_t;
+
+typedef struct GsmL1_MphCloseReq_t {
+uint32_t hLayer1;
+} GsmL1_MphCloseReq_t;
+
+typedef struct GsmL1_MphConnectReq_t {
+uint32_t hLayer1;
+uint8_t u8Tn;
+enum GsmL1_LogChComb_t logChComb;
+} GsmL1_MphConnectReq_t;
+
+typedef struct GsmL1_MphDisconnectReq_t {
+uint32_t hLayer1;
+} GsmL1_MphDisconnectReq_t;
+
+typedef struct GsmL1_MphActivateReq_t {
+uint32_t hLayer1;
+struct GsmL1_LogChParam_t logChPrm;
+uint8_t u8Tn;
+enum GsmL1_SubCh_t subCh;
+enum GsmL1_Dir_t dir;
+enum GsmL1_Sapi_t sapi;
+uint32_t hLayer2;
+float fBFILevel;
+} GsmL1_MphActivateReq_t;
+
+typedef struct GsmL1_MphDeactivateReq_t {
+uint32_t hLayer1;
+uint8_t u8Tn;
+enum GsmL1_SubCh_t subCh;
+enum GsmL1_Dir_t dir;
+enum GsmL1_Sapi_t sapi;
+} GsmL1_MphDeactivateReq_t;
+
+typedef struct GsmL1_ConfigParam_t {
+struct {
+enum GsmL1_Sapi_t sapi;
+uint8_t u8Tn;
+enum GsmL1_SubCh_t subCh;
+enum GsmL1_Dir_t dir;
+struct GsmL1_LogChParam_t logChParams;
+} setLogChParams;
+} GsmL1_ConfigParam_t;
+
+typedef struct GsmL1_MphConfigReq_t {
+uint32_t hLayer1;
+enum GsmL1_ConfigParamId_t cfgParamId;
+struct GsmL1_ConfigParam_t cfgParams;
+} GsmL1_MphConfigReq_t;
+
+typedef struct GsmL1_MphConfigCnf_t {
+enum GsmL1_Status_t status;
+enum GsmL1_ConfigParamId_t cfgParamId;
+struct GsmL1_ConfigParam_t cfgParams;
+} GsmL1_MphConfigCnf_t;
+
+typedef struct GsmL1_MphMeasureReq_t {
+uint32_t hLayer1;
+} GsmL1_MphMeasureReq_t;
+
+typedef struct GsmL1_MphInitCnf_t {
+uint32_t hLayer1;
+enum GsmL1_Status_t status;
+} GsmL1_MphInitCnf_t;
+
+typedef struct GsmL1_MphCloseCnf_t {
+enum GsmL1_Status_t status;
+} GsmL1_MphCloseCnf_t;
+
+typedef struct GsmL1_MphConnectCnf_t {
+enum GsmL1_Status_t status;
+} GsmL1_MphConnectCnf_t;
+
+typedef struct GsmL1_MphDisconnectCnf_t {
+enum GsmL1_Status_t status;
+} GsmL1_MphDisconnectCnf_t;
+
+typedef struct GsmL1_MphActivateCnf_t {
+enum GsmL1_Status_t status;
+uint8_t u8Tn;
+int sapi;
+} GsmL1_MphActivateCnf_t;
+
+typedef struct GsmL1_MphDeactivateCnf_t {
+enum GsmL1_Status_t status;
+uint8_t u8Tn;
+enum GsmL1_Sapi_t sapi;
+} GsmL1_MphDeactivateCnf_t;
+
+typedef struct GsmL1_MphMeasureCnf_t {
+enum GsmL1_Status_t status;
+} GsmL1_MphMeasureCnf_t;
+
+typedef struct GsmL1_MphTimeInd_t {
+uint32_t u32Fn;
+} GsmL1_MphTimeInd_t;
+
+typedef struct GsmL1_MphSyncInd_t {
+} GsmL1_MphSyncInd_t;
+
+typedef struct GsmL1_PhEmptyFrameReq_t {
+uint32_t hLayer1;
+uint8_t u8Tn;
+uint32_t u32Fn;
+enum GsmL1_Sapi_t sapi;
+enum GsmL1_SubCh_t subCh;
+uint8_t u8BlockNbr;
+} GsmL1_PhEmptyFrameReq_t;
+
+typedef struct GsmL1_PhDataReq_t {
+uint32_t hLayer1;
+uint8_t u8Tn;
+uint32_t u32Fn;
+enum GsmL1_Sapi_t sapi;
+enum GsmL1_SubCh_t subCh;
+uint8_t u8BlockNbr;
+struct GsmL1_MsgUnitParam_t msgUnitParam;
+} GsmL1_PhDataReq_t;
+
+typedef struct GsmL1_PhConnectInd_t {
+} GsmL1_PhConnectInd_t;
+
+typedef struct GsmL1_PhReadyToSendInd_t {
+uint32_t hLayer1;
+uint8_t u8Tn;
+uint32_t u32Fn;
+enum GsmL1_Sapi_t sapi;
+enum GsmL1_SubCh_t subCh;
+uint8_t u8BlockNbr;
+uint32_t hLayer2;
+} GsmL1_PhReadyToSendInd_t;
+
+typedef struct GsmL1_PhDataInd_t {
+struct GsmL1_MeasParam_t measParam;
+struct GsmL1_MsgUnitParam_t msgUnitParam;
+enum GsmL1_Sapi_t sapi;
+uint32_t hLayer2;
+} GsmL1_PhDataInd_t;
+
+typedef struct GsmL1_PhRaInd_t {
+struct GsmL1_MeasParam_t measParam;
+struct GsmL1_MsgUnitParam_t msgUnitParam;
+uint32_t u32Fn;
+uint32_t hLayer2;
+} GsmL1_PhRaInd_t;
+
+typedef struct GsmL1_Prim_t {
+union {
+struct GsmL1_MphInitReq_t mphInitReq;
+struct GsmL1_MphCloseReq_t mphCloseReq;
+struct GsmL1_MphConnectReq_t mphConnectReq;
+struct GsmL1_MphDisconnectReq_t mphDisconnectReq;
+struct GsmL1_MphActivateReq_t mphActivateReq;
+struct GsmL1_MphDeactivateReq_t mphDeactivateReq;
+struct GsmL1_MphConfigReq_t mphConfigReq;
+struct GsmL1_MphMeasureReq_t mphMeasureReq;
+struct GsmL1_MphInitCnf_t mphInitCnf;
+struct GsmL1_MphCloseCnf_t mphCloseCnf;
+struct GsmL1_MphConnectCnf_t mphConnectCnf;
+struct GsmL1_MphDisconnectCnf_t mphDisconnectCnf;
+struct GsmL1_MphActivateCnf_t mphActivateCnf;
+struct GsmL1_MphDeactivateCnf_t mphDeactivateCnf;
+struct GsmL1_MphConfigCnf_t mphConfigCnf;
+struct GsmL1_MphMeasureCnf_t mphMeasureCnf;
+struct GsmL1_MphTimeInd_t mphTimeInd;
+struct GsmL1_MphSyncInd_t mphSyncInd;
+struct GsmL1_PhEmptyFrameReq_t phEmptyFrameReq;
+struct GsmL1_PhDataReq_t phDataReq;
+struct GsmL1_PhConnectInd_t phConnectInd;
+struct GsmL1_PhReadyToSendInd_t phReadyToSendInd;
+struct GsmL1_PhDataInd_t phDataInd;
+struct GsmL1_PhRaInd_t phRaInd;
+} u;
+
+enum GsmL1_PrimId_t id;
+} GsmL1_Prim_t;

pcu_l1_if.cpp

@@ -26,34 +26,99 @@
 #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);
 
+
+struct msgb *l1p_msgb_alloc(void)
+{
+	struct msgb *msg = msgb_alloc(sizeof(GsmL1_Prim_t), "l1_prim");
+
+	if (msg)
+		msg->l1h = msgb_put(msg, sizeof(GsmL1_Prim_t));
+
+	return msg;
+}
+
 // 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]);
+	struct msgb *msg = l1p_msgb_alloc();
+	GsmL1_Prim_t *prim = msgb_l1prim(msg);
+	
+	prim->id = GsmL1_PrimId_PhDataReq;
+	block->pack((unsigned char*)&(prim->u.phDataReq.msgUnitParam.u8Buffer[ofs]));
 	ofs += block->size() >> 3;
+	prim->u.phDataReq.msgUnitParam.u8Size = ofs;
+	
 	COUT("Send to OpenBTS: " << *block);
-	pcu_l1if_socket.write(buffer, ofs);
+	osmo_wqueue_enqueue(&l1fh->udp_wq, msg);
 }
 
-// Recieve RLC/MAC block from OpenBTS.
-void *pcu_l1if_rx(void *)
+int pcu_l1if_rx_pdch(GsmL1_PhDataInd_t *data_ind)
 {
 	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);
-		}
+	block->unpack((const unsigned char*)data_ind->msgUnitParam.u8Buffer);
+	COUT("Recieve from OpenBTS (MS): " << *block);
+	
+	gprs_rlcmac_rcv_block(block);
+}
+
+static int handle_ph_data_ind(struct femtol1_hdl *fl1, GsmL1_PhDataInd_t *data_ind,
+			struct msgb *l1p_msg)
+{
+	int rc = 0;
+	switch (data_ind->sapi) {
+	case GsmL1_Sapi_Rach:
+		break;
+	case GsmL1_Sapi_Pdtch:
+	case GsmL1_Sapi_Pacch:
+		pcu_l1if_rx_pdch(data_ind);
+		break;
+	case GsmL1_Sapi_Pbcch:
+	case GsmL1_Sapi_Pagch:
+	case GsmL1_Sapi_Ppch:
+	case GsmL1_Sapi_Pnch:
+	case GsmL1_Sapi_Ptcch:
+	case GsmL1_Sapi_Prach:
+		break;
+	default:
+		//LOGP(DGPRS, LOGL_NOTICE, "Rx PH-DATA.ind for unknown L1 SAPI %u \n", data_ind->sapi);
+		break;
 	}
+
+	return rc;
+}
+
+/* handle any random indication from the L1 */
+int pcu_l1if_handle_l1prim(struct femtol1_hdl *fl1, struct msgb *msg)
+{
+	GsmL1_Prim_t *l1p = msgb_l1prim(msg);
+	int rc = 0;
+
+	switch (l1p->id) {
+	case GsmL1_PrimId_MphTimeInd:
+		break;
+	case GsmL1_PrimId_MphSyncInd:
+		break;
+	case GsmL1_PrimId_PhConnectInd:
+		break;
+	case GsmL1_PrimId_PhReadyToSendInd:
+		break;
+	case GsmL1_PrimId_PhDataInd:
+		rc = handle_ph_data_ind(fl1, &l1p->u.phDataInd, msg);
+		break;
+	case GsmL1_PrimId_PhRaInd:
+		break;
+	default:
+		break;
+	}
+
+	/* Special return value '1' means: do not free */
+	if (rc != 1)
+		msgb_free(msg);
+
+	return rc;
 }
 
 void gsmtap_send_llc(uint8_t * data, unsigned len)

pcu_l1_if.h

@@ -20,11 +20,48 @@
 #ifndef PCU_L1_IF_H
 #define PCU_L1_IF_H
 
+
 #include <BitVector.h>
+#include <gsmL1prim.h>
+extern "C" {
+#include <osmocom/core/write_queue.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/gsm/gsm_utils.h>
+}
+
+#define msgb_l1prim(msg)	((GsmL1_Prim_t *)(msg)->l1h)
+
+struct femtol1_hdl {
+	struct gsm_time gsm_time;
+	uint32_t hLayer1;			/* handle to the L1 instance in the DSP */
+	uint32_t dsp_trace_f;
+	uint16_t clk_cal;
+	struct llist_head wlc_list;
+
+	void *priv;			/* user reference */
+
+	struct osmo_timer_list alive_timer;
+	unsigned int alive_prim_cnt;
+
+	struct osmo_fd read_ofd;	/* osmo file descriptors */
+	struct osmo_wqueue write_q;
+};
+
+struct l1fwd_hdl {
+	struct sockaddr_storage remote_sa;
+	socklen_t remote_sa_len;
+
+	struct osmo_wqueue udp_wq;
+
+	struct femtol1_hdl *fl1h;
+};
+
+extern struct l1fwd_hdl *l1fh;
 
 void pcu_l1if_tx(BitVector * block);
 
-void *pcu_l1if_rx(void *);
+int pcu_l1if_handle_l1prim(struct femtol1_hdl *fl1h, struct msgb *msg);
 
 void gsmtap_send_llc(uint8_t * data, unsigned len);
 

pcu_main.cpp

@@ -26,7 +26,9 @@
 #define SGSN_IP "127.0.0.1"
 #define SGSN_PORT 23000
 #define NSVCI 4
+#define PCU_L1_IF_PORT 5944
 
+struct l1fwd_hdl *l1fh = talloc_zero(NULL, struct l1fwd_hdl);
 
 int sgsn_ns_cb(enum gprs_ns_evt event, struct gprs_nsvc *nsvc, struct msgb *msg, uint16_t bvci)
 {
@@ -46,16 +48,100 @@ int sgsn_ns_cb(enum gprs_ns_evt event, struct gprs_nsvc *nsvc, struct msgb *msg,
 	return rc;
 }
 
+/* data has arrived on the udp socket */
+static int udp_read_cb(struct osmo_fd *ofd)
+{
+	struct msgb *msg = msgb_alloc_headroom(2048, 128, "udp_rx");
+	struct l1fwd_hdl *l1fh = (l1fwd_hdl *)ofd->data;
+	struct femtol1_hdl *fl1h = l1fh->fl1h;
+	int rc;
+
+	if (!msg)
+		return -ENOMEM;
+
+	msg->l1h = msg->data;
+
+	l1fh->remote_sa_len = sizeof(l1fh->remote_sa);
+	rc = recvfrom(ofd->fd, msg->l1h, msgb_tailroom(msg), 0,
+			(struct sockaddr *) &l1fh->remote_sa, &l1fh->remote_sa_len);
+	if (rc < 0) {
+		perror("read from udp");
+		msgb_free(msg);
+		return rc;
+	} else if (rc == 0) {
+		perror("len=0 read from udp");
+		msgb_free(msg);
+		return rc;
+	}
+	msgb_put(msg, rc);
+
+	rc = pcu_l1if_handle_l1prim(fl1h, msg);
+	return rc;
+}
+
+/* callback when we can write to the UDP socket */
+static int udp_write_cb(struct osmo_fd *ofd, struct msgb *msg)
+{
+	int rc;
+	struct l1fwd_hdl *l1fh = (l1fwd_hdl *)ofd->data;
+
+	DEBUGP(DGPRS, "UDP: Writing %u bytes for MQ_L1_WRITE queue\n", msgb_l1len(msg));
+
+	rc = sendto(ofd->fd, msg->l1h, msgb_l1len(msg), 0,
+			(const struct sockaddr *)&l1fh->remote_sa, l1fh->remote_sa_len);
+	if (rc < 0) {
+		LOGP(DGPRS, LOGL_ERROR, "error writing to L1 msg_queue: %s\n",
+			strerror(errno));
+		return rc;
+	} else if (rc < msgb_l1len(msg)) {
+		LOGP(DGPRS, LOGL_ERROR, "short write to L1 msg_queue: "
+			"%u < %u\n", rc, msgb_l1len(msg));
+		return -EIO;
+	}
+
+	return 0;
+}
+
+int pcu_l1if_open()
+{
+	//struct l1fwd_hdl *l1fh;
+	struct femtol1_hdl *fl1h;
+	int rc;
+
+	/* allocate new femtol1_handle */
+	fl1h = talloc_zero(NULL, struct femtol1_hdl);
+	INIT_LLIST_HEAD(&fl1h->wlc_list);
+
+	l1fh->fl1h = fl1h;
+	fl1h->priv = l1fh;
+
+	/* Open UDP */
+	struct osmo_wqueue *wq = &l1fh->udp_wq;
+
+	osmo_wqueue_init(wq, 10);
+	wq->write_cb = udp_write_cb;
+	wq->read_cb = udp_read_cb;
+	wq->bfd.when |= BSC_FD_READ;
+	wq->bfd.data = l1fh;
+	wq->bfd.priv_nr = 0;
+	rc = osmo_sock_init_ofd(&wq->bfd, AF_UNSPEC, SOCK_DGRAM,
+				IPPROTO_UDP, NULL, PCU_L1_IF_PORT,
+				OSMO_SOCK_F_BIND);
+	if (rc < 0) {
+		perror("sock_init");
+		exit(1);
+	}
+}
+
 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);
+	pcu_l1if_open();
+
 	sgsn_nsi = gprs_ns_instantiate(&sgsn_ns_cb);
 	bssgp_nsi = sgsn_nsi;
 
@@ -92,3 +178,4 @@ int main(int argc, char *argv[])
 		i++;
 	}
 }
+