AMPS: Fixes for multi transceiver support

- Fix channel assignment
- Voice channel sends test tone when idle
- Changed paging timeout
- Minor fix of SCC field in 2 messages

5 files changed, 121 insertions, 41 deletions

diff --git a/src/amps/amps.c b/src/amps/amps.c
index 1ccd66f..3404441 100644
--- a/src/amps/amps.c
+++ b/src/amps/amps.c
@@ -36,8 +36,8 @@
 #define SAT_TO1		5.0	/* 5 sec to detect after setup */
 #define SAT_TO2		5.0	/* 5 sec lost until abort (specs say 5) */
 #define PAGE_TRIES	2	/* how many times to page the phone */
-#define PAGE_TO1	5.0	/* max time to wait for paging reply */
-#define PAGE_TO2	7.0	/* max time to wait for last paging reply */
+#define PAGE_TO1	8.0	/* max time to wait for paging reply */
+#define PAGE_TO2	4.0	/* max time to wait for last paging reply */
 #define ALERT_TO	60.0	/* max time to wait for answer */
 #define RELEASE_TIMER	5.0	/* max time to send release messages */
 
@@ -297,6 +297,22 @@ const char *chan_type_long_name(enum amps_chan_type chan_type)
 	return "invalid";
 }
 
+static amps_t *search_channel(int channel)
+{
+	sender_t *sender;
+	amps_t *amps;
+
+	for (sender = sender_head; sender; sender = sender->next) {
+		if (sender->kanal != channel)
+			continue;
+		amps = (amps_t *) sender;
+		if (amps->state == STATE_IDLE)
+			return amps;
+	}
+
+	return NULL;
+}
+
 static amps_t *search_free_vc(void)
 {
 	sender_t *sender;
@@ -306,10 +322,10 @@ static amps_t *search_free_vc(void)
 		amps = (amps_t *) sender;
 		if (amps->state != STATE_IDLE)
 			continue;
-		/* return first free SpK */
+		/* return first free voice channel */
 		if (amps->chan_type == CHAN_TYPE_VC)
 			return amps;
-		/* remember OgK/SpK combined channel as second alternative */
+		/* remember combined voice/control/paging channel as second alternative */
 		if (amps->chan_type == CHAN_TYPE_CC_PC_VC)
 			cc_pc_vc = amps;
 	}
@@ -354,11 +370,17 @@ int amps_create(int channel, enum amps_chan_type chan_type, const char *sounddev
 		return -EINVAL;
 	}
 
+	/* no paging channel (without control channel) support */
+	if (chan_type == CHAN_TYPE_PC) {
+		PDEBUG(DAMPS, DEBUG_ERROR, "Dedicated paging channel currently not supported. Please select CC/PC or CC/PC/VC instead.\n");
+		return -EINVAL;
+	}
+
 	/* check if there is only one paging channel */
 	if (chan_type == CHAN_TYPE_PC || chan_type == CHAN_TYPE_CC_PC || chan_type == CHAN_TYPE_CC_PC_VC) {
 		for (sender = sender_head; sender; sender = sender->next) {
 			amps = (amps_t *)sender;
-			if (amps->chan_type == CHAN_TYPE_PC || chan_type == CHAN_TYPE_CC_PC || chan_type == CHAN_TYPE_CC_PC_VC) {
+			if (amps->chan_type == CHAN_TYPE_PC || amps->chan_type == CHAN_TYPE_CC_PC || amps->chan_type == CHAN_TYPE_CC_PC_VC) {
 				PDEBUG(DAMPS, DEBUG_ERROR, "Only one paging channel is currently supported. Please check your channel types.\n");
 				return -EINVAL;
 			}
@@ -377,11 +399,11 @@ int amps_create(int channel, enum amps_chan_type chan_type, const char *sounddev
 
 	/* check if sid machtes channel band */
 	band = amps_channel2band(channel);
-	if (band == 'A' && (sid & 1) == 0) {
+	if (band == 'A' && (sid & 1) == 0 && chan_type != CHAN_TYPE_VC) {
 		PDEBUG(DAMPS, DEBUG_ERROR, "Channel number %d belongs to system A, but your SID %d is even and belongs to system B. Please give odd SID.\n", channel, sid);
 		return -EINVAL;
 	}
-	if (band == 'B' && (sid & 1) == 1) {
+	if (band == 'B' && (sid & 1) == 1 && chan_type != CHAN_TYPE_VC) {
 		PDEBUG(DAMPS, DEBUG_ERROR, "Channel number %d belongs to system B, but your SID %d is odd and belongs to system A. Please give even SID.\n", channel, sid);
 		return -EINVAL;
 	}
@@ -479,13 +501,19 @@ static void amps_go_idle(amps_t *amps)
 		destroy_transaction(amps->trans_list);
 	}
 
-	PDEBUG(DAMPS, DEBUG_INFO, "Entering IDLE state, sending Overhead/Filler frames on %s.\n", chan_type_long_name(amps->chan_type));
-	if (amps->sender.loopback)
-		frame_length = 441; /* bits after sync (FOCC) */
-	else
-		frame_length = 247; /* bits after sync (RECC) */
 	amps_new_state(amps, STATE_IDLE);
-	amps_set_dsp_mode(amps, DSP_MODE_FRAME_RX_FRAME_TX, frame_length);
+
+	if (amps->chan_type != CHAN_TYPE_VC) {
+		PDEBUG(DAMPS, DEBUG_INFO, "Entering IDLE state, sending Overhead/Filler frames on %s.\n", chan_type_long_name(amps->chan_type));
+		if (amps->sender.loopback)
+			frame_length = 441; /* bits after sync (FOCC) */
+		else
+			frame_length = 247; /* bits after sync (RECC) */
+		amps_set_dsp_mode(amps, DSP_MODE_FRAME_RX_FRAME_TX, frame_length);
+	} else {
+		PDEBUG(DAMPS, DEBUG_INFO, "Entering IDLE state, sending test tone on %s.\n", chan_type_long_name(amps->chan_type));
+		amps_set_dsp_mode(amps, DSP_MODE_OFF, 0);
+	}
 }
 
 /* Abort connection towards mobile station by sending FOCC/FVC pattern. */
@@ -913,18 +941,18 @@ void transaction_timeout(struct timer *timer)
 }
 
 /* assigning voice channel and moving transaction+callref to that channel */
-static void assign_voice_channel(transaction_t *trans)
+static amps_t *assign_voice_channel(transaction_t *trans)
 {
 	amps_t *amps = trans->amps, *vc;
 	const char *callerid = amps_min2number(trans->min1, trans->min2);
 	int callref = ++new_callref;
 	int rc;
 
-	vc = search_free_vc();
+	vc = search_channel(trans->chan);
 	if (!vc) {
-		PDEBUG(DAMPS, DEBUG_NOTICE, "No free channel, rejecting call\n");
+		PDEBUG(DAMPS, DEBUG_NOTICE, "Channel %d is not free anymore, rejecting call\n", trans->chan);
 		amps_release(trans, CAUSE_NOCHANNEL);
-		return;
+		return NULL;
 	}
 
 	if (vc == amps)
@@ -938,7 +966,7 @@ static void assign_voice_channel(transaction_t *trans)
 		if (rc < 0) {
 			PDEBUG(DAMPS, DEBUG_NOTICE, "Call rejected (cause %d), releasing.\n", rc);
 			amps_release(trans, 0);
-			return;
+			return NULL;
 		}
 		trans->callref = callref;
 	}
@@ -950,11 +978,14 @@ static void assign_voice_channel(transaction_t *trans)
 	link_transaction(trans, vc);
 	/* flush all other transactions, if any (in case of combined VC + CC) */
 	amps_flush_other_transactions(vc, trans);
+
+	return vc;
 }
 
 transaction_t *amps_tx_frame_focc(amps_t *amps)
 {
 	transaction_t *trans;
+	amps_t *vc;
 	
 again:
 	trans = amps->trans_list;
@@ -981,22 +1012,28 @@ again:
 		trans_new_state(trans, TRANS_CALL_MO_ASSIGN_SEND);
 		return trans;
 	case TRANS_CALL_MO_ASSIGN_SEND:
-		trans_new_state(trans, TRANS_CALL);
-		amps_set_dsp_mode(amps, DSP_MODE_AUDIO_RX_AUDIO_TX, 0);
-		assign_voice_channel(trans);
+		vc = assign_voice_channel(trans);
+		if (vc) {
+			PDEBUG(DAMPS, DEBUG_INFO, "Assignment complete, voice connected\n");
+			trans_new_state(trans, TRANS_CALL);
+			amps_set_dsp_mode(vc, DSP_MODE_AUDIO_RX_AUDIO_TX, 0);
+		}
 		return NULL;
 	case TRANS_CALL_MT_ASSIGN:
 		PDEBUG(DAMPS, DEBUG_INFO, "Assigning channel to call to mobile station\n");
 		trans_new_state(trans, TRANS_CALL_MT_ASSIGN_SEND);
 		return trans;
 	case TRANS_CALL_MT_ASSIGN_SEND:
-		trans_new_state(trans, TRANS_CALL_MT_ALERT);
-		trans->chan = 0;
-		trans->msg_type = 0;
-		trans->ordq = 0;
-		trans->order = 1;
-		amps_set_dsp_mode(amps, DSP_MODE_AUDIO_RX_FRAME_TX, 0);
-		assign_voice_channel(trans);
+		vc = assign_voice_channel(trans);
+		if (vc) {
+			PDEBUG(DAMPS, DEBUG_INFO, "Assignment complete, next: sending altering on VC\n");
+			trans->chan = 0;
+			trans->msg_type = 0;
+			trans->ordq = 0;
+			trans->order = 1;
+			trans_new_state(trans, TRANS_CALL_MT_ALERT);
+			amps_set_dsp_mode(vc, DSP_MODE_AUDIO_RX_FRAME_TX, 0);
+		}
 		return NULL;
 	case TRANS_PAGE:
 		PDEBUG(DAMPS, DEBUG_INFO, "Paging the phone\n");
@@ -1022,14 +1059,16 @@ again:
 
 	switch (trans->state) {
 	case TRANS_CALL_RELEASE:
-		PDEBUG(DAMPS, DEBUG_INFO, "Releasing call to mobile station\n");
+		PDEBUG(DAMPS, DEBUG_INFO, "Releasing call towards mobile station\n");
 		trans_new_state(trans, TRANS_CALL_RELEASE_SEND);
 		return trans;
 	case TRANS_CALL_RELEASE_SEND:
+		PDEBUG(DAMPS, DEBUG_INFO, "Release call was sent, destroying call\n");
 		destroy_transaction(trans);
 		amps_go_idle(amps);
 		goto again;
 	case TRANS_CALL_MT_ALERT:
+		PDEBUG(DAMPS, DEBUG_INFO, "Sending altering\n");
 		return trans;
 	default:
 		return NULL;
diff --git a/src/amps/amps.h b/src/amps/amps.h
index e219c21..4c47f09 100644
--- a/src/amps/amps.h
+++ b/src/amps/amps.h
@@ -140,6 +140,8 @@ typedef struct amps {
 	int			sat_detect_count;	/* current number of consecutive detections/losses */
 	int			sig_detected;		/* current detection state flag */
 	int			sig_detect_count;	/* current number of consecutive detections/losses */
+	double			test_phaseshift256;	/* how much the phase of sine wave changes per sample */
+	double			test_phase256;		/* current phase */
 
 	transaction_t		*trans_list;		/* list of transactions */
 
diff --git a/src/amps/dsp.c b/src/amps/dsp.c
index 6ced01d..20fc9fd 100644
--- a/src/amps/dsp.c
+++ b/src/amps/dsp.c
@@ -89,6 +89,8 @@
 #include "frame.h"
 #include "dsp.h"
 
+#define CHAN amps->sender.kanal
+
 /* uncomment this to debug the encoding process */
 //#define DEBUG_ENCODER
 
@@ -124,6 +126,7 @@ static double sat_freq[5] = {
 };
 
 static int dsp_sine_sat[256];
+static int dsp_sine_test[256];
 
 static uint8_t dsp_sync_check[0x800];
 
@@ -137,6 +140,7 @@ void dsp_init(void)
 	for (i = 0; i < 256; i++) {
 		s = sin((double)i / 256.0 * 2.0 * PI);
 		dsp_sine_sat[i] = (int)(s * SAT_DEVIATION);
+		dsp_sine_test[i] = (int)(s * FSK_DEVIATION);
 	}
 
 	/* sync checker */
@@ -245,6 +249,10 @@ int dsp_init_sender(amps_t *amps, int high_pass, int tolerant)
 	}
 	sat_reset(amps, "Initial state");
 
+	/* test tone */
+	amps->test_phaseshift256 = 256.0 / ((double)amps->sender.samplerate / 1000.0);
+	PDEBUG(DDSP, DEBUG_DEBUG, "test_phaseshift256 = %.4f\n", amps->test_phaseshift256);
+
 	/* use this filter to remove dc level for 0-crossing detection
 	 * if we have de-emphasis, we don't need it, so high_pass is not set. */
 	if (high_pass) {
@@ -442,6 +450,24 @@ static void sat_encode(amps_t *amps, int16_t *samples, int length)
 	amps->sat_phase256 = phase;
 }
 
+static void test_tone_encode(amps_t *amps, int16_t *samples, int length)
+{
+        double phaseshift, phase;
+	int i;
+
+	phaseshift = amps->test_phaseshift256;
+	phase = amps->test_phase256;
+
+	for (i = 0; i < length; i++) {
+		*samples++ = dsp_sine_test[((uint8_t)phase) & 0xff];
+		phase += phaseshift;
+		if (phase >= 256)
+			phase -= 256;
+	}
+
+	amps->test_phase256 = phase;
+}
+
 /* Provide stream of audio toward radio unit */
 void sender_send(sender_t *sender, int16_t *samples, int length)
 {
@@ -451,8 +477,8 @@ void sender_send(sender_t *sender, int16_t *samples, int length)
 again:
 	switch (amps->dsp_mode) {
 	case DSP_MODE_OFF:
-		/* silence, if transmitter is off */
-		memset(samples, 0, length * sizeof(*samples));
+		/* test tone, if transmitter is off */
+		test_tone_encode(amps, samples, length);
 		break;
 	case DSP_MODE_AUDIO_RX_AUDIO_TX:
 		jitter_load(&amps->sender.audio, samples, length);
@@ -717,9 +743,9 @@ static void sat_decode(amps_t *amps, int16_t *samples, int length)
 	if (quality[1] < 0)
 		quality[1] = 0;
 
-	PDEBUG(DDSP, DEBUG_NOTICE, "SAT level %.2f%% quality %.0f%%\n", result[0] * 32767.0 / SAT_DEVIATION / 0.63662 * 100.0, quality[0] * 100.0);
+	PDEBUG_CHAN(DDSP, DEBUG_NOTICE, "SAT level %.2f%% quality %.0f%%\n", result[0] * 32767.0 / SAT_DEVIATION / 0.63662 * 100.0, quality[0] * 100.0);
 	if (amps->sender.loopback || debuglevel == DEBUG_DEBUG) {
-		PDEBUG(DDSP, debuglevel, "Signaling Tone level %.2f%% quality %.0f%%\n", result[2] * 32767.0 / FSK_DEVIATION / 0.63662 * 100.0, quality[1] * 100.0);
+		PDEBUG_CHAN(DDSP, debuglevel, "Signaling Tone level %.2f%% quality %.0f%%\n", result[2] * 32767.0 / FSK_DEVIATION / 0.63662 * 100.0, quality[1] * 100.0);
 	}
 	if (quality[0] > SAT_QUALITY) {
 		if (amps->sat_detected == 0) {
@@ -727,7 +753,7 @@ static void sat_decode(amps_t *amps, int16_t *samples, int length)
 			if (amps->sat_detect_count == SAT_DETECT_COUNT) {
 				amps->sat_detected = 1;
 				amps->sat_detect_count = 0;
-				PDEBUG(DDSP, DEBUG_DEBUG, "SAT signal detected with level=%.0f%%, quality=%.0f%%.\n", result[0] / 0.63662 * 100.0, quality[0] * 100.0);
+				PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "SAT signal detected with level=%.0f%%, quality=%.0f%%.\n", result[0] / 0.63662 * 100.0, quality[0] * 100.0);
 				amps_rx_sat(amps, 1, quality[0]);
 			}
 		} else
@@ -738,7 +764,7 @@ static void sat_decode(amps_t *amps, int16_t *samples, int length)
 			if (amps->sat_detect_count == SAT_LOST_COUNT) {
 				amps->sat_detected = 0;
 				amps->sat_detect_count = 0;
-				PDEBUG(DDSP, DEBUG_DEBUG, "SAT signal lost.\n");
+				PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "SAT signal lost.\n");
 				amps_rx_sat(amps, 0, 0.0);
 			}
 		} else
@@ -750,7 +776,7 @@ static void sat_decode(amps_t *amps, int16_t *samples, int length)
 			if (amps->sig_detect_count == SIG_DETECT_COUNT) {
 				amps->sig_detected = 1;
 				amps->sig_detect_count = 0;
-				PDEBUG(DDSP, DEBUG_DEBUG, "Signaling Tone detected with level=%.0f%%, quality=%.0f%%.\n", result[2] / 0.63662 * 100.0, quality[1] * 100.0);
+				PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Signaling Tone detected with level=%.0f%%, quality=%.0f%%.\n", result[2] / 0.63662 * 100.0, quality[1] * 100.0);
 				amps_rx_signaling_tone(amps, 1, quality[1]);
 			}
 		} else
@@ -761,7 +787,7 @@ static void sat_decode(amps_t *amps, int16_t *samples, int length)
 			if (amps->sig_detect_count == SIG_LOST_COUNT) {
 				amps->sig_detected = 0;
 				amps->sig_detect_count = 0;
-				PDEBUG(DDSP, DEBUG_DEBUG, "Signaling Tone lost.\n");
+				PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "Signaling Tone lost.\n");
 				amps_rx_signaling_tone(amps, 0, 0.0);
 			}
 		} else
@@ -870,7 +896,7 @@ void sender_receive(sender_t *sender, int16_t *samples, int length)
 /* Reset SAT detection states, so ongoing tone will be detected again. */
 static void sat_reset(amps_t *amps, const char *reason)
 {
-	PDEBUG(DDSP, DEBUG_DEBUG, "SAT detector reset: %s.\n", reason);
+	PDEBUG_CHAN(DDSP, DEBUG_DEBUG, "SAT detector reset: %s.\n", reason);
 	amps->sat_detected = 0;
 	amps->sat_detect_count = 0;
 	amps->sig_detected = 0;
@@ -887,11 +913,24 @@ void amps_set_dsp_mode(amps_t *amps, enum dsp_mode mode, int frame_length)
 	if (mode == DSP_MODE_FRAME_RX_FRAME_TX) {
 		/* reset SAT detection */
 		sat_reset(amps, "Change to FOCC");
+		PDEBUG_CHAN(DDSP, DEBUG_INFO, "Change mode to FOCC\n");
 	}
 	if (amps->dsp_mode == DSP_MODE_FRAME_RX_FRAME_TX
 	 && (mode == DSP_MODE_AUDIO_RX_AUDIO_TX || mode == DSP_MODE_AUDIO_RX_FRAME_TX)) {
 		/* reset SAT detection */
 		sat_reset(amps, "Change from FOCC to FVC");
+		PDEBUG_CHAN(DDSP, DEBUG_INFO, "Change mode from FOCC to FVC\n");
+	}
+	if (amps->dsp_mode == DSP_MODE_OFF
+	 && (mode == DSP_MODE_AUDIO_RX_AUDIO_TX || mode == DSP_MODE_AUDIO_RX_FRAME_TX)) {
+		/* reset SAT detection */
+		sat_reset(amps, "Enable FVC");
+		PDEBUG_CHAN(DDSP, DEBUG_INFO, "Change mode from OFF to FVC\n");
+	}
+	if (mode == DSP_MODE_OFF) {
+		/* reset SAT detection */
+		sat_reset(amps, "Disable FVC");
+		PDEBUG_CHAN(DDSP, DEBUG_INFO, "Change mode from FVC to OFF\n");
 	}
 
 	amps->dsp_mode = mode;
diff --git a/src/amps/frame.c b/src/amps/frame.c
index 06e851f..f7ce9a5 100644
--- a/src/amps/frame.c
+++ b/src/amps/frame.c
@@ -2919,7 +2919,7 @@ static uint64_t amps_encode_word1_extended_address_word_a(uint16_t min2, uint8_t
 
 	memset(&frame, 0, sizeof(frame));
 	frame.ie[AMPS_IE_T1T2] = 2;
-	frame.ie[AMPS_IE_SCC] = 11;
+	frame.ie[AMPS_IE_SCC] = 3;
 	frame.ie[AMPS_IE_MIN2] = min2;
 	frame.ie[AMPS_IE_EF] = 0;
 	frame.ie[AMPS_IE_LOCAL_MSG_TYPE] = msg_type;
@@ -2947,7 +2947,7 @@ static uint64_t amps_encode_mobile_station_control_message_word1_a(uint8_t pscc,
 
 	memset(&frame, 0, sizeof(frame));
 	frame.ie[AMPS_IE_T1T2] = 2;
-	frame.ie[AMPS_IE_SCC] = 11;
+	frame.ie[AMPS_IE_SCC] = 3;
 	frame.ie[AMPS_IE_PSCC] = pscc;
 	frame.ie[AMPS_IE_EF] = 0;
 	frame.ie[AMPS_IE_LOCAL_MSG_TYPE] = msg_type;
diff --git a/src/amps/main.c b/src/amps/main.c
index 2ad283f..7561a8f 100644
--- a/src/amps/main.c
+++ b/src/amps/main.c
@@ -354,7 +354,7 @@ int main(int argc, char *argv[])
 			fprintf(stderr, "Failed to create \"Sender\" instance. Quitting!\n");
 			goto fail;
 		}
-		printf("Base station on channel %d ready, please tune transmitter to %.3f MHz and receiver to %.3f MHz.\n", kanal[i], amps_channel2freq(kanal[i], 0), amps_channel2freq(kanal[i], 1));
+		printf("Base station on channel %d ready (%s), please tune transmitter to %.3f MHz and receiver to %.3f MHz.\n", kanal[i], chan_type_long_name(chan_type[i]), amps_channel2freq(kanal[i], 0), amps_channel2freq(kanal[i], 1));
 	}
 
 	signal(SIGINT,sighandler);