TRX: PDTCH (GPRS) works now

Detection and transcoding of all four coding schemes are supported.

3 files changed, 140 insertions, 119 deletions

diff --git a/src/osmo-bts-trx/pxxch.c b/src/osmo-bts-trx/pxxch.c
index 17a7c947..07d011a9 100644
--- a/src/osmo-bts-trx/pxxch.c
+++ b/src/osmo-bts-trx/pxxch.c
@@ -6,6 +6,7 @@
 
 #include <stdio.h>
 #include <stdint.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include <osmocom/core/bits.h>
@@ -31,7 +32,7 @@ const struct osmo_crc64gen_code pxxch_crc40 = {
 
 
 /*
- * GSM PDTCH CS-2, CS-3 parity
+ * GSM PDTCH CS-2, CS-3, CS-4 parity
  *
  * g(x) = x^16 + x^12 + x^5 + 1
  */
@@ -189,35 +190,53 @@ pxxch_burst_map(ubit_t *iB, ubit_t *eB, ubit_t *hl, ubit_t *hn)
 		eB[58] = *hn;
 }
 
-static ubit_t pdtch_hl_hn[4][8] = {
+static ubit_t pdtch_hl_hn_ubit[4][8] = {
 	{ 1,1, 1,1, 1,1, 1,1 },
 	{ 1,1, 0,0, 1,0, 0,0 },
 	{ 0,0, 1,0, 0,0, 0,1 },
 	{ 0,0, 0,1, 0,1, 1,0 },
 };
 
+static sbit_t pdtch_hl_hn_sbit[4][8] = {
+	{ -127,-127, -127,-127, -127,-127, -127,-127 },
+	{ -127,-127,  127, 127, -127, 127,  127, 127 },
+	{  127, 127, -127, 127,  127, 127,  127,-127 },
+	{  127, 127,  127,-127,  127,-127, -127, 127 },
+};
+
 static ubit_t usf2six[8][6] = {
 	{ 0,0,0, 0,0,0 },
-	{ 0,0,1, 0,1,1 },
-	{ 0,1,0, 1,1,0 },
-	{ 0,1,1, 1,0,1 },
 	{ 1,0,0, 1,0,1 },
-	{ 1,0,1, 1,1,0 },
+	{ 0,1,0, 1,1,0 },
 	{ 1,1,0, 0,1,1 },
+	{ 0,0,1, 0,1,1 },
+	{ 1,0,1, 1,1,0 },
+	{ 0,1,1, 1,0,1 },
 	{ 1,1,1, 0,0,0 },
 };
 
-static ubit_t usf2twelve[8][12] = {
+static ubit_t usf2twelve_ubit[8][12] = {
 	{ 0,0,0, 0,0,0, 0,0,0, 0,0,0 },
-	{ 0,0,0, 0,1,1, 0,1,1, 1,0,1 },
-	{ 0,0,1, 1,0,1, 1,1,0, 1,1,0 },
-	{ 0,0,1, 1,1,0, 1,0,1, 0,1,1 },
 	{ 1,1,0, 1,0,0, 0,0,1, 0,1,1 },
-	{ 1,1,0, 1,1,1, 0,1,0, 1,1,0 },
+	{ 0,0,1, 1,0,1, 1,1,0, 1,1,0 },
 	{ 1,1,1, 0,0,1, 1,1,1, 1,0,1 },
+	{ 0,0,0, 0,1,1, 0,1,1, 1,0,1 },
+	{ 1,1,0, 1,1,1, 0,1,0, 1,1,0 },
+	{ 0,0,1, 1,1,0, 1,0,1, 0,1,1 },
 	{ 1,1,1, 0,1,0, 1,0,0, 0,0,0 },
 };
 
+static sbit_t usf2twelve_sbit[8][12] = {
+	{  127, 127, 127,  127, 127, 127,  127, 127, 127,  127, 127, 127 },
+	{ -127,-127, 127, -127, 127, 127,  127, 127,-127,  127,-127,-127 },
+	{  127, 127,-127, -127, 127,-127, -127,-127, 127, -127,-127, 127 },
+	{ -127,-127,-127,  127, 127,-127, -127,-127,-127, -127, 127,-127 },
+	{  127, 127, 127,  127,-127,-127,  127,-127,-127, -127, 127,-127 },
+	{ -127,-127, 127, -127,-127,-127,  127,-127, 127, -127,-127, 127 },
+	{  127, 127,-127, -127,-127, 127, -127, 127,-127,  127,-127,-127 },
+	{ -127,-127,-127,  127,-127, 127, -127, 127, 127,  127, 127, 127 },
+};
+
 static uint8_t puncture_cs2[588] = {
 	0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,1, 0,0,0,1, 0,0,0,1, 0,0,0,1, 0,0,0,1,
 	0,0,0,1, 0,0,0,0, 0,0,0,1, 0,0,0,1, 0,0,0,1, 0,0,0,1, 0,0,0,1, 0,0,0,1,
@@ -267,23 +286,23 @@ static uint8_t puncture_cs3[676] = {
 };
 
 int
-pdch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p)
+pdtch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p)
 {
 	sbit_t iB[456], cB[676], hl_hn[8];
 	ubit_t conv[456];
-	int i, j, k, rv, best, cs, usf;
+	int i, j, k, rv, best = 0, cs = 0, usf = 0; /* make GCC happy */
 
 	for (i=0; i<4; i++)
 		pxxch_burst_unmap(&iB[i * 114], &bursts[i * 116], hl_hn + i*2,
 			hl_hn + i*2 + 1);
 
-	for (i=0, best=0, cs=1; i<4; j++) {
-		for (j=0, k=0; j<4; j++) {
-			if (pdtch_hl_hn[i][j] == hl_hn[j])
-				k++;
-		}
-		if (k > best)
+	for (i=0; i<4; i++) {
+		for (j=0, k=0; j<8; j++)
+			k += abs(((int)pdtch_hl_hn_sbit[i][j]) - ((int)hl_hn[j]));
+		if (i == 0 || k < best) {
+			best = k;
 			cs = i+1;
+		}
 	}
 
 	pxxch_deinterleave(cB, iB);
@@ -301,7 +320,7 @@ pdch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p)
 
 		return 23;
 	case 2:
-		for (i=587, j=455; i>=0; i++)
+		for (i=587, j=455; i>=0; i--)
 			if (!puncture_cs2[i])
 				cB[i] = cB[j--];
 			else
@@ -309,31 +328,31 @@ pdch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p)
 
 		osmo_conv_decode(&conv_cs2, cB, conv);
 
-		for (i=0, best=0, usf=0; i<8; j++) {
-			for (j=0, k=0; j<6; j++) {
-				if (usf2six[i][j] == conv[j])
-					k++;
-			}
-			if (k > best)
+		for (i=0; i<8; i++) {
+			for (j=0, k=0; j<6; j++)
+				k += abs(((int)usf2six[i][j]) - ((int)conv[j]));
+			if (i == 0 || k < best) {
+				best = k;
 				usf = i;
+			}
 		}
 
-		conv[3] = (usf >> 2) & 1;
+		conv[3] = usf & 1;
 		conv[4] = (usf >> 1) & 1;
-		conv[5] = usf & 1;
+		conv[5] = (usf >> 2) & 1;
 		if (usf_p)
 			*usf_p = usf;
 
-		rv = osmo_crc64gen_check_bits(&pxxch_crc40, conv+3, 271,
+		rv = osmo_crc16gen_check_bits(&pdtch_crc16, conv+3, 271,
 			conv+3+271);
 		if (rv)
 			return -1;
 
-		osmo_ubit2pbit_ext(l2_data, 0, conv, 0, 271, 1);
+		osmo_ubit2pbit_ext(l2_data, 0, conv, 3, 271, 1);
 
 		return 34;
 	case 3:
-		for (i=675, j=455; i>=0; i++)
+		for (i=675, j=455; i>=0; i--)
 			if (!puncture_cs3[i])
 				cB[i] = cB[j--];
 			else
@@ -341,54 +360,55 @@ pdch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p)
 
 		osmo_conv_decode(&conv_cs3, cB, conv);
 
-		for (i=0, best=0, usf=0; i<8; j++) {
-			for (j=0, k=0; j<6; j++) {
-				if (usf2six[i][j] == conv[j])
-					k++;
-			}
-			if (k > best)
+		for (i=0; i<8; i++) {
+			for (j=0, k=0; j<6; j++)
+				k += abs(((int)usf2six[i][j]) - ((int)conv[j]));
+			if (i == 0 || k < best) {
+				best = k;
 				usf = i;
+			}
 		}
 
-		conv[3] = (usf >> 2) & 1;
+		conv[3] = usf & 1;
 		conv[4] = (usf >> 1) & 1;
-		conv[5] = usf & 1;
+		conv[5] = (usf >> 2) & 1;
 		if (usf_p)
 			*usf_p = usf;
 
-		rv = osmo_crc64gen_check_bits(&pxxch_crc40, conv+3, 315,
+		rv = osmo_crc16gen_check_bits(&pdtch_crc16, conv+3, 315,
 			conv+3+315);
 		if (rv)
 			return -1;
 
-		osmo_ubit2pbit_ext(l2_data, 0, conv, 0, 315, 1);
+		osmo_ubit2pbit_ext(l2_data, 0, conv, 3, 315, 1);
 
 		return 40;
 	case 4:
-		for (i=0; i<456;i++)
+		for (i=12; i<456;i++)
 			conv[i] = (cB[i] < 0) ? 1:0;
 
-		for (i=0, best=0, usf=0; i<8; j++) {
-			for (j=0, k=0; j<12; j++) {
-				if (usf2twelve[i][j] == conv[j])
-					k++;
-			}
-			if (k > best)
+		for (i=0; i<8; i++) {
+			for (j=0, k=0; j<12; j++)
+				k += abs(((int)usf2twelve_sbit[i][j]) -
+								((int)cB[j]));
+			if (i == 0 || k < best) {
+				best = k;
 				usf = i;
+			}
 		}
 
-		conv[9] = (usf >> 2) & 1;
+		conv[9] = usf & 1;
 		conv[10] = (usf >> 1) & 1;
-		conv[11] = usf & 1;
+		conv[11] = (usf >> 2) & 1;
 		if (usf_p)
 			*usf_p = usf;
 
-		rv = osmo_crc64gen_check_bits(&pxxch_crc40, conv+9, 431,
+		rv = osmo_crc16gen_check_bits(&pdtch_crc16, conv+9, 431,
 			conv+9+431);
 		if (rv)
 			return -1;
 
-		osmo_ubit2pbit_ext(l2_data, 0, conv, 0, 431, 1);
+		osmo_ubit2pbit_ext(l2_data, 0, conv, 9, 431, 1);
 
 		return 54;
 	}
@@ -411,12 +431,12 @@ pdtch_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len)
 
 		osmo_conv_encode(&conv_cs1, conv, cB);
 
-		hl_hn = pdtch_hl_hn[0];
+		hl_hn = pdtch_hl_hn_ubit[0];
 
 		break;
 	case 34:
 		osmo_pbit2ubit_ext(conv, 3, l2_data, 0, 271, 1);
-		usf = (conv[3] << 2) | (conv[4] << 1) | conv[5];
+		usf = l2_data[0] & 0x7;
 
 		osmo_crc16gen_set_bits(&pdtch_crc16, conv+3, 271, conv+3+271);
 
@@ -428,12 +448,12 @@ pdtch_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len)
 			if (!puncture_cs2[i])
 				cB[j++] = cB[i];
 
-		hl_hn = pdtch_hl_hn[1];
+		hl_hn = pdtch_hl_hn_ubit[1];
 
 		break;
 	case 40:
 		osmo_pbit2ubit_ext(conv, 3, l2_data, 0, 315, 1);
-		usf = (conv[3] << 2) | (conv[4] << 1) | conv[5];
+		usf = l2_data[0] & 0x7;
 
 		osmo_crc16gen_set_bits(&pdtch_crc16, conv+3, 315, conv+3+315);
 
@@ -445,18 +465,18 @@ pdtch_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len)
 			if (!puncture_cs3[i])
 				cB[j++] = cB[i];
 
-		hl_hn = pdtch_hl_hn[2];
+		hl_hn = pdtch_hl_hn_ubit[2];
 
 		break;
 	case 54:
 		osmo_pbit2ubit_ext(cB, 9, l2_data, 0, 431, 1);
-		usf = (cB[9] << 2) | (cB[10] << 1) | conv[11];
+		usf = l2_data[0] & 0x7;
 
 		osmo_crc16gen_set_bits(&pdtch_crc16, cB+9, 431, cB+9+431);
 
-		memcpy(cB, usf2twelve[usf], 12);
+		memcpy(cB, usf2twelve_ubit[usf], 12);
 
-		hl_hn = pdtch_hl_hn[3];
+		hl_hn = pdtch_hl_hn_ubit[3];
 
 		break;
 	default:
diff --git a/src/osmo-bts-trx/pxxch.h b/src/osmo-bts-trx/pxxch.h
index 313fbf59..990bd36d 100644
--- a/src/osmo-bts-trx/pxxch.h
+++ b/src/osmo-bts-trx/pxxch.h
@@ -1,7 +1,7 @@
 #ifndef _PXXCH_H
 #define _PXXCH_H
 
-int pdch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p);
+int pdtch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p);
 int pdtch_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len);
 
 #endif /* _PXXCH_H */
diff --git a/src/osmo-bts-trx/scheduler.c b/src/osmo-bts-trx/scheduler.c
index 629f8788..f44df519 100644
--- a/src/osmo-bts-trx/scheduler.c
+++ b/src/osmo-bts-trx/scheduler.c
@@ -138,6 +138,7 @@ static const ubit_t sch_train[64] = {
  */
 
 struct trx_chan_desc {
+	int			pdch;
 	enum trx_chan_type	chan;
 	uint8_t			chan_nr;
 	uint8_t			link_id;
@@ -148,44 +149,44 @@ struct trx_chan_desc {
 	int			auto_active;
 };
 struct trx_chan_desc trx_chan_desc[_TRX_CHAN_MAX] = {
-      {	TRXC_IDLE,	0,	0,	"IDLE",		NULL,		tx_idle_fn,	NULL,		1 },
-      {	TRXC_FCCH,	0,	0,	"FCCH",		NULL,		tx_fcch_fn,	NULL,		1 },
-      {	TRXC_SCH,	0,	0,	"SCH",		NULL,		tx_sch_fn,	NULL,		1 },
-      {	TRXC_BCCH,	0x80,	0x00,	"BCCH",		rts_data_fn,	tx_data_fn,	NULL,		1 },
-      {	TRXC_RACH,	0x88,	0x00,	"RACH",		NULL,		NULL,		rx_rach_fn,	1 },
-      {	TRXC_CCCH,	0x90,	0x00,	"CCCH",		rts_data_fn,	tx_data_fn,	NULL,		1 },
-      {	TRXC_TCHF,	0x08,	0x00,	"TCH/F",	rts_tch_fn,	tx_tchf_fn,	rx_tchf_fn,	0 },
-      {	TRXC_TCHH_0,	0x10,	0x00,	"TCH/H(0)",	rts_tch_fn,	tx_tchh_fn,	rx_tchh_fn,	0 },
-      {	TRXC_TCHH_1,	0x18,	0x00,	"TCH/H(1)",	rts_tch_fn,	tx_tchh_fn,	rx_tchh_fn,	0 },
-      {	TRXC_SDCCH4_0,	0x20,	0x00,	"SDCCH/4(0)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SDCCH4_1,	0x28,	0x00,	"SDCCH/4(1)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SDCCH4_2,	0x30,	0x00,	"SDCCH/4(2)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SDCCH4_3,	0x38,	0x00,	"SDCCH/4(3)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SDCCH8_0,	0x40,	0x00,	"SDCCH/8(0)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SDCCH8_1,	0x48,	0x00,	"SDCCH/8(1)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },    
-      {	TRXC_SDCCH8_2,	0x50,	0x00,	"SDCCH/8(2)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SDCCH8_3,	0x58,	0x00,	"SDCCH/8(3)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SDCCH8_4,	0x60,	0x00,	"SDCCH/8(4)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SDCCH8_5,	0x68,	0x00,	"SDCCH/8(5)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SDCCH8_6,	0x70,	0x00,	"SDCCH/8(6)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SDCCH8_7,	0x78,	0x00,	"SDCCH/8(7)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCHTF,	0x08,	0x40,	"SACCH/TF",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCHTH_0,	0x10,	0x40,	"SACCH/TH(0)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCHTH_1,	0x18,	0x40,	"SACCH/TH(1)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCH4_0, 	0x20,	0x40,	"SACCH/4(0)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCH4_1,	0x28,	0x40,	"SACCH/4(1)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCH4_2,	0x30,	0x40,	"SACCH/4(2)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCH4_3,	0x38,	0x40,	"SACCH/4(3)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCH8_0,	0x40,	0x40,	"SACCH/8(0)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 }, 
-      {	TRXC_SACCH8_1,	0x48,	0x40,	"SACCH/8(1)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCH8_2,	0x50,	0x40,	"SACCH/8(2)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCH8_3,	0x58,	0x40,	"SACCH/8(3)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCH8_4,	0x60,	0x40,	"SACCH/8(4)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCH8_5,	0x68,	0x40,	"SACCH/8(5)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCH8_6,	0x70,	0x40,	"SACCH/8(6)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_SACCH8_7,	0x68,	0x40,	"SACCH/8(7)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
-      {	TRXC_PDTCH,	0x08,	0x00,	"PDTCH",	rts_data_fn,	tx_pdtch_fn,	rx_pdtch_fn,	0 },
-      {	TRXC_PTCCH,	0x08,	0x00,	"PTCCH",	rts_data_fn,	tx_pdtch_fn,	rx_pdtch_fn,	0 },
+      {	0,	TRXC_IDLE,	0,	0,	"IDLE",		NULL,		tx_idle_fn,	NULL,		1 },
+      {	0,	TRXC_FCCH,	0,	0,	"FCCH",		NULL,		tx_fcch_fn,	NULL,		1 },
+      {	0,	TRXC_SCH,	0,	0,	"SCH",		NULL,		tx_sch_fn,	NULL,		1 },
+      {	0,	TRXC_BCCH,	0x80,	0x00,	"BCCH",		rts_data_fn,	tx_data_fn,	NULL,		1 },
+      {	0,	TRXC_RACH,	0x88,	0x00,	"RACH",		NULL,		NULL,		rx_rach_fn,	1 },
+      {	0,	TRXC_CCCH,	0x90,	0x00,	"CCCH",		rts_data_fn,	tx_data_fn,	NULL,		1 },
+      {	0,	TRXC_TCHF,	0x08,	0x00,	"TCH/F",	rts_tch_fn,	tx_tchf_fn,	rx_tchf_fn,	0 },
+      {	0,	TRXC_TCHH_0,	0x10,	0x00,	"TCH/H(0)",	rts_tch_fn,	tx_tchh_fn,	rx_tchh_fn,	0 },
+      {	0,	TRXC_TCHH_1,	0x18,	0x00,	"TCH/H(1)",	rts_tch_fn,	tx_tchh_fn,	rx_tchh_fn,	0 },
+      {	0,	TRXC_SDCCH4_0,	0x20,	0x00,	"SDCCH/4(0)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SDCCH4_1,	0x28,	0x00,	"SDCCH/4(1)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SDCCH4_2,	0x30,	0x00,	"SDCCH/4(2)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SDCCH4_3,	0x38,	0x00,	"SDCCH/4(3)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SDCCH8_0,	0x40,	0x00,	"SDCCH/8(0)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SDCCH8_1,	0x48,	0x00,	"SDCCH/8(1)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },    
+      {	0,	TRXC_SDCCH8_2,	0x50,	0x00,	"SDCCH/8(2)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SDCCH8_3,	0x58,	0x00,	"SDCCH/8(3)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SDCCH8_4,	0x60,	0x00,	"SDCCH/8(4)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SDCCH8_5,	0x68,	0x00,	"SDCCH/8(5)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SDCCH8_6,	0x70,	0x00,	"SDCCH/8(6)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SDCCH8_7,	0x78,	0x00,	"SDCCH/8(7)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCHTF,	0x08,	0x40,	"SACCH/TF",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCHTH_0,	0x10,	0x40,	"SACCH/TH(0)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCHTH_1,	0x18,	0x40,	"SACCH/TH(1)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCH4_0, 	0x20,	0x40,	"SACCH/4(0)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCH4_1,	0x28,	0x40,	"SACCH/4(1)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCH4_2,	0x30,	0x40,	"SACCH/4(2)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCH4_3,	0x38,	0x40,	"SACCH/4(3)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCH8_0,	0x40,	0x40,	"SACCH/8(0)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 }, 
+      {	0,	TRXC_SACCH8_1,	0x48,	0x40,	"SACCH/8(1)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCH8_2,	0x50,	0x40,	"SACCH/8(2)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCH8_3,	0x58,	0x40,	"SACCH/8(3)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCH8_4,	0x60,	0x40,	"SACCH/8(4)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCH8_5,	0x68,	0x40,	"SACCH/8(5)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCH8_6,	0x70,	0x40,	"SACCH/8(6)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	0,	TRXC_SACCH8_7,	0x68,	0x40,	"SACCH/8(7)",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
+      {	1,	TRXC_PDTCH,	0x08,	0x00,	"PDTCH",	rts_data_fn,	tx_pdtch_fn,	rx_pdtch_fn,	0 },
+      {	1,	TRXC_PTCCH,	0x08,	0x00,	"PTCCH",	rts_data_fn,	tx_data_fn,	rx_data_fn,	0 },
 };
 
 
@@ -926,7 +927,7 @@ static int rx_data_fn(struct trx_l1h *l1h, uint8_t tn, uint32_t fn,
 			return -ENOMEM;
 	}
 
-	/* store frame number of first burst */
+	/* clear burst & store frame number of first burst */
 	if (bid == 0) {
 		memset(*bursts_p, 0, 464);
 		*mask = 0x0;
@@ -980,7 +981,6 @@ static int rx_pdtch_fn(struct trx_l1h *l1h, uint8_t tn, uint32_t fn,
 {
 	struct trx_chan_state *chan_state = &l1h->chan_states[tn][chan];
 	sbit_t *burst, **bursts_p = &chan_state->ul_bursts;
-	uint32_t *first_fn = &chan_state->ul_first_fn;
 	uint8_t *mask = &chan_state->ul_mask;
 	uint8_t l2[54+1];
 	int rc;
@@ -995,11 +995,10 @@ static int rx_pdtch_fn(struct trx_l1h *l1h, uint8_t tn, uint32_t fn,
 			return -ENOMEM;
 	}
 
-	/* store frame number of first burst */
+	/* clear burst */
 	if (bid == 0) {
 		memset(*bursts_p, 0, 464);
 		*mask = 0x0;
-		*first_fn = fn;
 	}
 
 	/* update mask */
@@ -1018,29 +1017,26 @@ static int rx_pdtch_fn(struct trx_l1h *l1h, uint8_t tn, uint32_t fn,
 
 	/* check for complete set of bursts */
 	if ((*mask & 0xf) != 0xf) {
-		LOGP(DL1C, LOGL_NOTICE, "Received incomplete PDTCH block at "
-			"fn=%u (%u/%u) for %s\n", *first_fn,
-			(*first_fn) % l1h->mf_period[tn], l1h->mf_period[tn],
+		LOGP(DL1C, LOGL_NOTICE, "Received incomplete PDTCH block "
+			"ending at fn=%u (%u/%u) for %s\n", fn,
+			fn % l1h->mf_period[tn], l1h->mf_period[tn],
 			trx_chan_desc[chan].name);
-		/* we require first burst to have correct FN */
-		if (!(*mask & 0x1)) {
-			*mask = 0x0;
-			return 0;
-		}
 	}
 	*mask = 0x0;
 
 	/* decode */
-	rc = pdch_decode(l2 + 1, *bursts_p, NULL);
+	rc = pdtch_decode(l2 + 1, *bursts_p, NULL);
 	if (rc <= 0) {
-		LOGP(DL1C, LOGL_NOTICE, "Received bad PDTCH block at fn=%u for "
-			"%s\n", *first_fn, trx_chan_desc[chan].name);
-		l2[0] = 0; /* bad frame */
-		rc = 0;
-	} else
-		l2[0] = 7; /* valid frame */
+		LOGP(DL1C, LOGL_NOTICE, "Received bad PDTCH block ending at "
+			"fn=%u (%u/%u) for %s\n", fn, fn % l1h->mf_period[tn],
+			l1h->mf_period[tn], trx_chan_desc[chan].name);
+		return 0;
+	}
 
-	return compose_ph_data_ind(l1h, tn, *first_fn, chan, l2, rc + 1);
+	l2[0] = 7; /* valid frame */
+
+	return compose_ph_data_ind(l1h, tn, (fn + 2715648 -3) % 2715648, chan,
+		l2, rc + 1);
 }
 
 static int rx_tchf_fn(struct trx_l1h *l1h, uint8_t tn, uint32_t fn,
@@ -1927,6 +1923,11 @@ int trx_sched_set_lchan(struct trx_l1h *l1h, uint8_t chan_nr, uint8_t link_id,
 
 	/* look for all matching chan_nr/link_id */
 	for (i = 0; i < _TRX_CHAN_MAX; i++) {
+		/* skip if pchan type does not match pdch flag */
+		if ((trx_sched_multiframes[l1h->mf_index[tn]].pchan
+							== GSM_PCHAN_PDCH)
+						!= trx_chan_desc[i].pdch)
+			continue;
 		if (trx_chan_desc[i].chan_nr == (chan_nr & 0xf8)
 		 && trx_chan_desc[i].link_id == link_id) {
 			LOGP(DL1C, LOGL_NOTICE, "%s %s %s on trx=%d ts=%d\n",