From 4435af975df2fc40c87023c5c512c6e8b3090ad1 Mon Sep 17 00:00:00 2001
From: Andy CA6JAU <juribeparada@gmail.com>
Date: Sat, 3 Feb 2018 11:07:13 -0300
Subject: [PATCH 01/10] =?UTF-8?q?Fix=20bug=20=E2=80=9CDMR=20ghost=20privat?=
 =?UTF-8?q?e=20calls=E2=80=9D?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 DMRSlot.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/DMRSlot.cpp b/DMRSlot.cpp
index 3b0f2e1..a296574 100644
--- a/DMRSlot.cpp
+++ b/DMRSlot.cpp
@@ -1540,8 +1540,10 @@ void CDMRSlot::writeNetwork(const CDMRData& dmrData)
 			m_display->writeDMR(m_slotNo, src, gi, dst, "N");
 		}
     } else if (dataType == DT_RATE_12_DATA || dataType == DT_RATE_34_DATA || dataType == DT_RATE_1_DATA) {
-		if (m_netState != RS_NET_DATA || m_netFrames == 0U)
+		if (m_netState != RS_NET_DATA || m_netFrames == 0U) {
+			writeEndNet();
 			return;
+		}
 
 		// Regenerate the rate 1/2 payload
 		if (dataType == DT_RATE_12_DATA) {

From a6269c13e523bc7dc797fc81a4ecaea40dc39aba Mon Sep 17 00:00:00 2001
From: "Ralph A. Schmid" <ralph@schmid.xxx>
Date: Sun, 4 Feb 2018 14:30:23 +0100
Subject: [PATCH 02/10] Create RSSI_FC-302_RptrBldrV2.dat

One more RSSI table...
---
 RSSI/RSSI_FC-302_RptrBldrV2.dat | 41 +++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 RSSI/RSSI_FC-302_RptrBldrV2.dat

diff --git a/RSSI/RSSI_FC-302_RptrBldrV2.dat b/RSSI/RSSI_FC-302_RptrBldrV2.dat
new file mode 100644
index 0000000..aa1e523
--- /dev/null
+++ b/RSSI/RSSI_FC-302_RptrBldrV2.dat
@@ -0,0 +1,41 @@
+# This file maps the raw RSSI values to dBm values to send to the DMR network. A number of data
+# points should be entered and the software will use those to work out the in-between values.
+#
+# The format of the file is:
+# Raw RSSI Value		dBm Value
+#
+# The following values were taken with a Schlumberger Stabilock 4040 radio tester as transmitter
+# Radio is a Friendcom FC-302 UHF, 12.5 KHz BW, RSSI PIN 7 directly connected to board
+# Setup is MMDVM on a Pi3 with modem "Repeater-Builder STM32-DVM V2", RSSI POT at maximum
+# Ralph, dk5ras, 20180204
+
+1626	-46
+1622	-49
+1611	-52
+1591	-55
+1547	-58
+1486	-61
+1409	-64
+1344	-67
+1292	-70
+1235	-73
+1155	-76
+1068	-79
+1000	-82
+950	-85
+895	-88
+847	-91
+783	-94
+715	-97
+660	-100
+600	-103
+525	-106
+438	-109
+363	-112
+305	-115
+246	-118
+188	-121
+135	-124
+100	-127
+77	-130
+64	-133

From a0394afd9159b05e13127f1c189c1f006d020a02 Mon Sep 17 00:00:00 2001
From: Andy CA6JAU <juribeparada@gmail.com>
Date: Sun, 4 Feb 2018 14:46:09 -0300
Subject: [PATCH 03/10] Discard DMR audio frames with N > 5 (RF side)

---
 DMRSlot.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/DMRSlot.cpp b/DMRSlot.cpp
index a296574..7db9c53 100644
--- a/DMRSlot.cpp
+++ b/DMRSlot.cpp
@@ -562,6 +562,9 @@ bool CDMRSlot::writeModem(unsigned char *data, unsigned int len)
 		if (m_rfState == RS_RF_AUDIO) {
 			m_rfN = data[1U] & 0x0FU;
 
+			if(m_rfN > 5U)
+				return false;
+
 			unsigned int errors = 0U;
 			unsigned char fid = m_rfLC->getFID();
 			if (fid == FID_ETSI || fid == FID_DMRA) {
@@ -802,6 +805,9 @@ bool CDMRSlot::writeModem(unsigned char *data, unsigned int len)
 
 				m_rfN = data[1U] & 0x0FU;
 
+				if(m_rfN > 5U)
+					return false;
+
 				// Regenerate the EMB
 				emb.getData(data + 2U);
 

From 14a06e7182e0457c84ec86675159a6d60ed3ff91 Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Mon, 5 Feb 2018 19:07:23 +0000
Subject: [PATCH 04/10] Calculate the RSSI and BER correctly on the Nextion.

---
 Nextion.cpp | 114 ++++++----------------------------------------------
 1 file changed, 13 insertions(+), 101 deletions(-)

diff --git a/Nextion.cpp b/Nextion.cpp
index d0495ba..cbdc9c1 100644
--- a/Nextion.cpp
+++ b/Nextion.cpp
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2016,2017,2018 by Jonathan Naylor G4KLX
  *
  *   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
@@ -205,15 +205,6 @@ void CNextion::writeDStarInt(const char* my1, const char* my2, const char* your,
 
 void CNextion::writeDStarRSSIInt(unsigned char rssi)
 {
-	if (m_rssiCount1 == 0U) {
-		char text[20U];
-		::sprintf(text, "t3.txt=\"-%udBm\"", rssi);
-		sendCommand(text);
-		sendCommandAction(47U);
-		m_rssiCount1 = 1U;
-		return;
-	}
-
 	m_rssiAccum1 += rssi;
 	m_rssiCount1++;
 
@@ -223,21 +214,12 @@ void CNextion::writeDStarRSSIInt(unsigned char rssi)
 		sendCommand(text);
 		sendCommandAction(47U);
 		m_rssiAccum1 = 0U;
-		m_rssiCount1 = 1U;
+		m_rssiCount1 = 0U;
 	}
 }
 
 void CNextion::writeDStarBERInt(float ber)
 {
-	if (m_berCount1 == 0U) {
-		char text[20U];
-		::sprintf(text, "t4.txt=\"%.1f%%\"", ber);
-		sendCommand(text);
-		sendCommandAction(48U);
-		m_berCount1 = 1U;
-		return;
-	}
-
 	m_berAccum1 += ber;
 	m_berCount1++;
 
@@ -247,7 +229,7 @@ void CNextion::writeDStarBERInt(float ber)
 		sendCommand(text);
 		sendCommandAction(48U);
 		m_berAccum1 = 0.0F;
-		m_berCount1 = 1U;
+		m_berCount1 = 0U;
 	}
 }
 
@@ -339,15 +321,6 @@ void CNextion::writeDMRInt(unsigned int slotNo, const std::string& src, bool gro
 void CNextion::writeDMRRSSIInt(unsigned int slotNo, unsigned char rssi)
 {
 	if (slotNo == 1U) {
-		if (m_rssiCount1 == 0U) {
-			char text[20U];
-			::sprintf(text, "t4.txt=\"-%udBm\"", rssi);
-			sendCommand(text);
-			sendCommandAction(66U);
-			m_rssiCount1 = 1U;
-			return;
-		}
-
 		m_rssiAccum1 += rssi;
 		m_rssiCount1++;
     
@@ -357,18 +330,9 @@ void CNextion::writeDMRRSSIInt(unsigned int slotNo, unsigned char rssi)
 			sendCommand(text);
 			sendCommandAction(66U);
 			m_rssiAccum1 = 0U;
-			m_rssiCount1 = 1U;
+			m_rssiCount1 = 0U;
 		}
 	} else {
-		if (m_rssiCount2 == 0U) {
-			char text[20U];
-			::sprintf(text, "t5.txt=\"-%udBm\"", rssi);
-			sendCommandAction(74U);
-			sendCommand(text);
-			m_rssiCount2 = 1U;
-			return;
-		}
-
 		m_rssiAccum2 += rssi;
 		m_rssiCount2++;
 
@@ -378,7 +342,7 @@ void CNextion::writeDMRRSSIInt(unsigned int slotNo, unsigned char rssi)
 			sendCommand(text);
 			sendCommandAction(74U);
 			m_rssiAccum2 = 0U;
-			m_rssiCount2 = 1U;
+			m_rssiCount2 = 0U;
 		}
 	}
 }
@@ -396,6 +360,7 @@ void CNextion::writeDMRTAInt(unsigned int slotNo, unsigned char* talkerAlias, co
 			if (m_screenLayout == 2U) sendCommand("t2.pco=33808");
 			sendCommandAction(72U);
 		}
+
 		return;
 	}
 
@@ -413,6 +378,7 @@ void CNextion::writeDMRTAInt(unsigned int slotNo, unsigned char* talkerAlias, co
 
 			sendCommand("t0.pco=1024");
 		}
+
 		sendCommand(text);
 		sendCommandAction(63U);
 	} else {
@@ -437,15 +403,6 @@ void CNextion::writeDMRTAInt(unsigned int slotNo, unsigned char* talkerAlias, co
 void CNextion::writeDMRBERInt(unsigned int slotNo, float ber)
 {
 	if (slotNo == 1U) {
-		if (m_berCount1 == 0U) {
-			char text[20U];
-			::sprintf(text, "t6.txt=\"%.1f%%\"", ber);
-			sendCommand(text);
-			sendCommandAction(67U);
-			m_berCount1 = 1U;
-			return;
-		}
-
 		m_berAccum1 += ber;
 		m_berCount1++;
 
@@ -455,18 +412,9 @@ void CNextion::writeDMRBERInt(unsigned int slotNo, float ber)
 			sendCommand(text);
 			sendCommandAction(67U);
 			m_berAccum1 = 0U;
-			m_berCount1 = 1U;
+			m_berCount1 = 0U;
 		}
 	} else {
-		if (m_berCount2 == 0U) {
-			char text[20U];
-			::sprintf(text, "t7.txt=\"%.1f%%\"", ber);
-			sendCommand(text);
-			sendCommandAction(75U);
-			m_berCount2 = 1U;
-			return;
-		}
-
 		m_berAccum2 += ber;
 		m_berCount2++;
 
@@ -476,7 +424,7 @@ void CNextion::writeDMRBERInt(unsigned int slotNo, float ber)
 			sendCommand(text);
 			sendCommandAction(75U);
 			m_berAccum2 = 0U;
-			m_berCount2 = 1U;
+			m_berCount2 = 0U;
 		}
 	}
 }
@@ -551,15 +499,6 @@ void CNextion::writeFusionInt(const char* source, const char* dest, const char*
 
 void CNextion::writeFusionRSSIInt(unsigned char rssi)
 {
-	if (m_rssiCount1 == 0U) {
-		char text[20U];
-		::sprintf(text, "t3.txt=\"-%udBm\"", rssi);
-		sendCommand(text);
-		sendCommandAction(85U);
-		m_rssiCount1 = 1U;
-		return;
-	}
-
 	m_rssiAccum1 += rssi;
 	m_rssiCount1++;
 
@@ -569,21 +508,12 @@ void CNextion::writeFusionRSSIInt(unsigned char rssi)
 		sendCommand(text);
 		sendCommandAction(85U);
 		m_rssiAccum1 = 0U;
-		m_rssiCount1 = 1U;
+		m_rssiCount1 = 0U;
 	}
 }
 
 void CNextion::writeFusionBERInt(float ber)
 {
-	if (m_berCount1 == 0U) {
-		char text[20U];
-		::sprintf(text, "t4.txt=\"%.1f%%\"", ber);
-		sendCommand(text);
-		sendCommandAction(86U);
-		m_berCount1 = 1U;
-		return;
-	}
-
 	m_berAccum1 += ber;
 	m_berCount1++;
 
@@ -593,7 +523,7 @@ void CNextion::writeFusionBERInt(float ber)
 		sendCommand(text);
 		sendCommandAction(86U);
 		m_berAccum1 = 0.0F;
-		m_berCount1 = 1U;
+		m_berCount1 = 0U;
 	}
 }
 
@@ -640,15 +570,6 @@ void CNextion::writeP25Int(const char* source, bool group, unsigned int dest, co
 
 void CNextion::writeP25RSSIInt(unsigned char rssi)
 {
-	if (m_rssiCount1 == 0U) {
-		char text[20U];
-		::sprintf(text, "t2.txt=\"-%udBm\"", rssi);
-		sendCommand(text);
-		sendCommandAction(104U);
-		m_rssiCount1 = 1U;
-		return;
-	}
-
 	m_rssiAccum1 += rssi;
 	m_rssiCount1++;
 
@@ -658,21 +579,12 @@ void CNextion::writeP25RSSIInt(unsigned char rssi)
 		sendCommand(text);
 		sendCommandAction(104U);
 		m_rssiAccum1 = 0U;
-		m_rssiCount1 = 1U;
+		m_rssiCount1 = 0U;
 	}
 }
 
 void CNextion::writeP25BERInt(float ber)
 {
-	if (m_berCount1 == 0U) {
-		char text[20U];
-		::sprintf(text, "t3.txt=\"%.1f%%\"", ber);
-		sendCommand(text);
-		sendCommandAction(105U);
-		m_berCount1 = 1U;
-		return;
-	}
-
 	m_berAccum1 += ber;
 	m_berCount1++;
 
@@ -682,7 +594,7 @@ void CNextion::writeP25BERInt(float ber)
 		sendCommand(text);
 		sendCommandAction(105U);
 		m_berAccum1 = 0.0F;
-		m_berCount1 = 1U;
+		m_berCount1 = 0U;
 	}
 }
 

From 4323c02a0aca78d06681e04411c39b7deccb7b64 Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Mon, 5 Feb 2018 19:46:27 +0000
Subject: [PATCH 05/10] Add a proper bypass for the jitter buffer if wanted.

---
 DMRNetwork.cpp            |  30 +++++++--
 DMRNetwork.h              |   2 +
 Defines.h                 |   8 ++-
 DelayBuffer.cpp           | 137 ++++++++++++++++++++++++++++++++++++++
 DelayBuffer.h             |  57 ++++++++++++++++
 JitterBuffer.cpp          |  12 ++--
 JitterBuffer.h            |   9 +--
 MMDVMHost.vcxproj         |   2 +
 MMDVMHost.vcxproj.filters |   6 ++
 Makefile                  |  11 +--
 Makefile.Pi               |  11 +--
 Makefile.Pi.Adafruit      |  11 +--
 Makefile.Pi.HD44780       |  11 +--
 Makefile.Pi.OLED          |  11 +--
 Makefile.Pi.PCF8574       |  11 +--
 Makefile.Solaris          |  11 +--
 16 files changed, 287 insertions(+), 53 deletions(-)
 create mode 100644 DelayBuffer.cpp
 create mode 100644 DelayBuffer.h

diff --git a/DMRNetwork.cpp b/DMRNetwork.cpp
index c9f251a..0b1edcf 100644
--- a/DMRNetwork.cpp
+++ b/DMRNetwork.cpp
@@ -46,6 +46,7 @@ m_slot1(slot1),
 m_slot2(slot2),
 m_jitterEnabled(jitterEnabled),
 m_jitterBuffers(NULL),
+m_delayBuffers(NULL),
 m_hwType(hwType),
 m_status(WAITING_CONNECT),
 m_retryTimer(1000U, 10U),
@@ -79,11 +80,16 @@ m_beacon(false)
 	m_salt          = new unsigned char[sizeof(uint32_t)];
 	m_id            = new uint8_t[4U];
 	m_streamId      = new uint32_t[2U];
+
 	m_jitterBuffers = new CJitterBuffer*[3U];
+	m_delayBuffers  = new CDelayBuffer*[3U];
 
 	m_jitterBuffers[1U] = new CJitterBuffer("DMR Slot 1", 60U, DMR_SLOT_TIME, jitter, 256U, debug);
 	m_jitterBuffers[2U] = new CJitterBuffer("DMR Slot 2", 60U, DMR_SLOT_TIME, jitter, 256U, debug);
 
+	m_delayBuffers[1U] = new CDelayBuffer("DMR Slot 1", 60U, DMR_SLOT_TIME, jitter, debug);
+	m_delayBuffers[2U] = new CDelayBuffer("DMR Slot 2", 60U, DMR_SLOT_TIME, jitter, debug);
+
 	m_id[0U] = id >> 24;
 	m_id[1U] = id >> 16;
 	m_id[2U] = id >> 8;
@@ -101,11 +107,16 @@ CDMRNetwork::~CDMRNetwork()
 	delete m_jitterBuffers[1U];
 	delete m_jitterBuffers[2U];
 
+	delete m_delayBuffers[1U];
+	delete m_delayBuffers[2U];
+
 	delete[] m_buffer;
 	delete[] m_salt;
 	delete[] m_streamId;
 	delete[] m_id;
+
 	delete[] m_jitterBuffers;
+	delete[] m_delayBuffers;
 }
 
 void CDMRNetwork::setOptions(const std::string& options)
@@ -151,8 +162,14 @@ bool CDMRNetwork::read(CDMRData& data)
 
 	for (unsigned int slotNo = 1U; slotNo <= 2U; slotNo++) {
 		unsigned int length = 0U;
-		JB_STATUS status = m_jitterBuffers[slotNo]->getData(m_buffer, length);
-		if (status != JBS_NO_DATA) {
+		B_STATUS status = BS_NO_DATA;
+
+		if (m_jitterEnabled)
+			status = m_jitterBuffers[slotNo]->getData(m_buffer, length);
+		else
+			status = m_delayBuffers[slotNo]->getData(m_buffer, length);
+
+		if (status != BS_NO_DATA) {
 			unsigned char seqNo = m_buffer[4U];
 
 			unsigned int srcId = (m_buffer[5U] << 16) | (m_buffer[6U] << 8) | (m_buffer[7U] << 0);
@@ -166,7 +183,7 @@ bool CDMRNetwork::read(CDMRData& data)
 			data.setSrcId(srcId);
 			data.setDstId(dstId);
 			data.setFLCO(flco);
-			data.setMissing(status == JBS_MISSING);
+			data.setMissing(status == BS_MISSING);
 
 			bool dataSync = (m_buffer[15U] & 0x20U) == 0x20U;
 			bool voiceSync = (m_buffer[15U] & 0x10U) == 0x10U;
@@ -331,6 +348,9 @@ void CDMRNetwork::clock(unsigned int ms)
 	m_jitterBuffers[1U]->clock(ms);
 	m_jitterBuffers[2U]->clock(ms);
 
+	m_delayBuffers[1U]->clock(ms);
+	m_delayBuffers[2U]->clock(ms);
+
 	if (m_status == WAITING_CONNECT) {
 		m_retryTimer.clock(ms);
 		if (m_retryTimer.isRunning() && m_retryTimer.hasExpired()) {
@@ -475,9 +495,11 @@ void CDMRNetwork::reset(unsigned int slotNo)
 
 	if (slotNo == 1U) {
 		m_jitterBuffers[1U]->reset();
+		m_delayBuffers[1U]->reset();
 		m_streamId[0U] = ::rand() + 1U;
 	} else {
 		m_jitterBuffers[2U]->reset();
+		m_delayBuffers[2U]->reset();
 		m_streamId[1U] = ::rand() + 1U;
 	}
 }
@@ -514,7 +536,7 @@ void CDMRNetwork::receiveData(const unsigned char* data, unsigned int length)
 			m_jitterBuffers[slotNo]->addData(data, length, seqNo);
 		}
 	} else {
-		m_jitterBuffers[slotNo]->appendData(data, length);
+		m_delayBuffers[slotNo]->addData(data, length);
 	}
 }
 
diff --git a/DMRNetwork.h b/DMRNetwork.h
index cfacb77..799b2bc 100644
--- a/DMRNetwork.h
+++ b/DMRNetwork.h
@@ -20,6 +20,7 @@
 #define	DMRNetwork_H
 
 #include "JitterBuffer.h"
+#include "DelayBuffer.h"
 #include "UDPSocket.h"
 #include "Timer.h"
 #include "DMRData.h"
@@ -72,6 +73,7 @@ private:
 	bool            m_slot2;
 	bool            m_jitterEnabled;
 	CJitterBuffer** m_jitterBuffers;
+	CDelayBuffer**  m_delayBuffers;
 	HW_TYPE         m_hwType;
 
 	enum STATUS {
diff --git a/Defines.h b/Defines.h
index 9285789..852fd3e 100644
--- a/Defines.h
+++ b/Defines.h
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2018 by Jonathan Naylor G4KLX
  *
  *   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
@@ -57,4 +57,10 @@ enum RPT_NET_STATE {
 	RS_NET_DATA
 };
 
+enum B_STATUS {
+	BS_NO_DATA,
+	BS_DATA,
+	BS_MISSING
+};
+
 #endif
diff --git a/DelayBuffer.cpp b/DelayBuffer.cpp
new file mode 100644
index 0000000..e38125b
--- /dev/null
+++ b/DelayBuffer.cpp
@@ -0,0 +1,137 @@
+/*
+*   Copyright (C) 2018 by Jonathan Naylor G4KLX
+*
+*   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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "DelayBuffer.h"
+
+#include "Log.h"
+
+#include <cstdio>
+#include <cassert>
+#include <cstring>
+
+CDelayBuffer::CDelayBuffer(const std::string& name, unsigned int blockSize, unsigned int blockTime, unsigned int jitterTime, bool debug) :
+m_name(name),
+m_blockSize(blockSize),
+m_blockTime(blockTime),
+m_debug(debug),
+m_timer(1000U, 0U, jitterTime),
+m_stopWatch(),
+m_running(false),
+m_buffer(1000U, name.c_str()),
+m_outputCount(0U),
+m_lastData(NULL),
+m_lastDataLength(0U)
+{
+	assert(blockSize > 0U);
+	assert(blockTime > 0U);
+	assert(jitterTime > 0U);
+
+	m_lastData = new unsigned char[m_blockSize];
+
+	reset();
+}
+
+CDelayBuffer::~CDelayBuffer()
+{
+	delete[] m_lastData;
+}
+
+bool CDelayBuffer::addData(const unsigned char* data, unsigned int length)
+{
+	assert(data != NULL);
+	assert(length > 0U);
+	assert(length == m_blockSize);
+
+	if (m_debug)
+		LogDebug("%s, DelayBuffer: appending data", m_name.c_str());
+
+	m_buffer.addData(data, length);
+
+	if (!m_timer.isRunning()) {
+		LogDebug("%s, DelayBuffer: starting the timer from append", m_name.c_str());
+		m_timer.start();
+	}
+
+	return true;
+}
+
+B_STATUS CDelayBuffer::getData(unsigned char* data, unsigned int& length)
+{
+	assert(data != NULL);
+
+	if (!m_running)
+		return BS_NO_DATA;
+
+	unsigned int needed = m_stopWatch.elapsed() / m_blockTime + 2U;
+	if (needed <= m_outputCount)
+		return BS_NO_DATA;
+
+	if (!m_buffer.isEmpty()) {
+		if (m_debug)
+			LogDebug("%s, DelayBuffer: returning data, elapsed=%ums", m_name.c_str(), m_stopWatch.elapsed());
+
+		length = m_buffer.getData(data, m_blockSize);
+
+		// Save this data in case no more data is available next time
+		::memcpy(m_lastData, data, length);
+		m_lastDataLength = length;
+
+		m_outputCount++;
+
+		return BS_DATA;
+	}
+
+	LogDebug("%s, DelayBuffer: no data available, elapsed=%ums", m_name.c_str(), m_stopWatch.elapsed());
+
+	// Return the last data frame if we have it
+	if (m_lastDataLength > 0U) {
+		LogDebug("%s, DelayBuffer: returning the last received frame", m_name.c_str());
+		::memcpy(data, m_lastData, m_lastDataLength);
+		length = m_lastDataLength;
+
+		m_outputCount++;
+
+		return BS_MISSING;
+	}
+
+	return BS_NO_DATA;
+}
+
+void CDelayBuffer::reset()
+{
+	m_buffer.clear();
+
+	m_lastDataLength = 0U;
+
+	m_outputCount = 0U;
+
+	m_timer.stop();
+
+	m_running = false;
+}
+
+void CDelayBuffer::clock(unsigned int ms)
+{
+	m_timer.clock(ms);
+	if (m_timer.isRunning() && m_timer.hasExpired()) {
+		if (!m_running) {
+			m_stopWatch.start();
+			m_running = true;
+		}
+	}
+}
diff --git a/DelayBuffer.h b/DelayBuffer.h
new file mode 100644
index 0000000..d773f26
--- /dev/null
+++ b/DelayBuffer.h
@@ -0,0 +1,57 @@
+/*
+*   Copyright (C) 2018 by Jonathan Naylor G4KLX
+*
+*   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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#if !defined(DELAYBUFFER_H)
+#define	DELAYBUFFER_H
+
+#include "RingBuffer.h"
+#include "StopWatch.h"
+#include "Defines.h"
+#include "Timer.h"
+
+#include <string>
+
+class CDelayBuffer {
+public:
+	CDelayBuffer(const std::string& name, unsigned int blockSize, unsigned int blockTime, unsigned int jitterTime, bool debug);
+	~CDelayBuffer();
+
+	bool addData(const unsigned char* data, unsigned int length);
+
+	B_STATUS getData(unsigned char* data, unsigned int& length);
+
+	void reset();
+
+	void clock(unsigned int ms);
+
+private:
+	std::string  m_name;
+	unsigned int m_blockSize;
+	unsigned int m_blockTime;
+	bool         m_debug;
+	CTimer       m_timer;
+	CStopWatch   m_stopWatch;
+	bool         m_running;
+	CRingBuffer<unsigned char> m_buffer;
+	unsigned int m_outputCount;
+
+	unsigned char* m_lastData;
+	unsigned int   m_lastDataLength;
+};
+
+#endif
diff --git a/JitterBuffer.cpp b/JitterBuffer.cpp
index 25522ec..3af4f48 100644
--- a/JitterBuffer.cpp
+++ b/JitterBuffer.cpp
@@ -162,16 +162,16 @@ bool CJitterBuffer::appendData(const unsigned char* data, unsigned int length)
 	return true;
 }
 
-JB_STATUS CJitterBuffer::getData(unsigned char* data, unsigned int& length)
+B_STATUS CJitterBuffer::getData(unsigned char* data, unsigned int& length)
 {
 	assert(data != NULL);
 
 	if (!m_running)
-		return JBS_NO_DATA;
+		return BS_NO_DATA;
 
 	unsigned int sequenceNumber = m_stopWatch.elapsed() / m_blockTime + 2U;
 	if (m_headSequenceNumber > sequenceNumber)
-		return JBS_NO_DATA;
+		return BS_NO_DATA;
 	
 	unsigned int head = m_headSequenceNumber % m_blockCount;
 
@@ -190,7 +190,7 @@ JB_STATUS CJitterBuffer::getData(unsigned char* data, unsigned int& length)
 
 		m_buffer[head].m_length = 0U;
 
-		return JBS_DATA;
+		return BS_DATA;
 	}
 
 	m_buffer[head].m_length = 0U;
@@ -203,10 +203,10 @@ JB_STATUS CJitterBuffer::getData(unsigned char* data, unsigned int& length)
 		::memcpy(data, m_lastData, m_lastDataLength);
 		length = m_lastDataLength;
 
-		return JBS_MISSING;
+		return BS_MISSING;
 	}
 
-	return JBS_NO_DATA;
+	return BS_NO_DATA;
 }
 
 void CJitterBuffer::reset()
diff --git a/JitterBuffer.h b/JitterBuffer.h
index 46575ee..9a9f1fe 100644
--- a/JitterBuffer.h
+++ b/JitterBuffer.h
@@ -20,16 +20,11 @@
 #define	JITTERBUFFER_H
 
 #include "StopWatch.h"
+#include "Defines.h"
 #include "Timer.h"
 
 #include <string>
 
-enum JB_STATUS {
-	JBS_NO_DATA,
-	JBS_DATA,
-	JBS_MISSING
-};
-
 class CJitterBuffer {
 public:
 	CJitterBuffer(const std::string& name, unsigned int blockSize, unsigned int blockTime, unsigned int jitterTime, unsigned int topSequenceNumber, bool debug);
@@ -38,7 +33,7 @@ public:
 	bool addData(const unsigned char* data, unsigned int length, unsigned int sequenceNumber);
 	bool appendData(const unsigned char* data, unsigned int length);
 
-	JB_STATUS getData(unsigned char* data, unsigned int& length);
+	B_STATUS getData(unsigned char* data, unsigned int& length);
 	
 	void reset();
 	
diff --git a/MMDVMHost.vcxproj b/MMDVMHost.vcxproj
index 62fd668..b5b8162 100644
--- a/MMDVMHost.vcxproj
+++ b/MMDVMHost.vcxproj
@@ -158,6 +158,7 @@
     <ClInclude Include="Conf.h" />
     <ClInclude Include="CRC.h" />
     <ClInclude Include="Defines.h" />
+    <ClInclude Include="DelayBuffer.h" />
     <ClInclude Include="Display.h" />
     <ClInclude Include="DMRAccessControl.h" />
     <ClInclude Include="DMRControl.h" />
@@ -232,6 +233,7 @@
     <ClCompile Include="BPTC19696.cpp" />
     <ClCompile Include="Conf.cpp" />
     <ClCompile Include="CRC.cpp" />
+    <ClCompile Include="DelayBuffer.cpp" />
     <ClCompile Include="Display.cpp" />
     <ClCompile Include="DMRAccessControl.cpp" />
     <ClCompile Include="DMRControl.cpp" />
diff --git a/MMDVMHost.vcxproj.filters b/MMDVMHost.vcxproj.filters
index d6ba4f3..6f28b05 100644
--- a/MMDVMHost.vcxproj.filters
+++ b/MMDVMHost.vcxproj.filters
@@ -230,6 +230,9 @@
     <ClInclude Include="P25Trellis.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="DelayBuffer.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="BPTC19696.cpp">
@@ -430,5 +433,8 @@
     <ClCompile Include="P25Trellis.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="DelayBuffer.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/Makefile b/Makefile
index 1a45e69..43c1476 100644
--- a/Makefile
+++ b/Makefile
@@ -7,11 +7,12 @@ LIBS    = -lpthread
 LDFLAGS = -g
 
 OBJECTS = \
-		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o DMRLookup.o DMRLC.o \
-		DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o DStarSlowData.o Golay2087.o \
-		Golay24128.o Hamming.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o Nextion.o NullDisplay.o P25Audio.o P25Control.o \
-		P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o RSSIInterpolator.o SerialController.o SerialPort.o SHA256.o \
-		StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
+		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o DelayBuffer.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o \
+		DMRLookup.o DMRLC.o DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o \
+		DStarSlowData.o Golay2087.o Golay24128.o Hamming.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o Nextion.o \
+		NullDisplay.o P25Audio.o P25Control.o P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o \
+		RSSIInterpolator.o SerialController.o SerialPort.o SHA256.o StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o \
+		YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
 
 all:		MMDVMHost
 
diff --git a/Makefile.Pi b/Makefile.Pi
index f28cda0..22fc628 100644
--- a/Makefile.Pi
+++ b/Makefile.Pi
@@ -7,11 +7,12 @@ LIBS    = -lwiringPi -lwiringPiDev -lpthread
 LDFLAGS = -g -L/usr/local/lib
 
 OBJECTS = \
-		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o DMRLookup.o DMRLC.o \
-		DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o DStarSlowData.o Golay2087.o \
-		Golay24128.o Hamming.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o Nextion.o NullDisplay.o P25Audio.o P25Control.o \
-		P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o RSSIInterpolator.o SerialController.o SerialPort.o SHA256.o \
-		StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
+		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o DelayBuffer.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o \
+		DMRLookup.o DMRLC.o DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o \
+		DStarSlowData.o Golay2087.o Golay24128.o Hamming.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o Nextion.o \
+		NullDisplay.o P25Audio.o P25Control.o P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o \
+		RSSIInterpolator.o SerialController.o SerialPort.o SHA256.o StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o \
+		YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
 
 all:		MMDVMHost
 
diff --git a/Makefile.Pi.Adafruit b/Makefile.Pi.Adafruit
index 9f69fee..390d07d 100644
--- a/Makefile.Pi.Adafruit
+++ b/Makefile.Pi.Adafruit
@@ -7,11 +7,12 @@ LIBS    = -lwiringPi -lwiringPiDev -lpthread
 LDFLAGS = -g -L/usr/local/lib
 
 OBJECTS = \
-		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o DMRLookup.o DMRLC.o \
-		DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o DStarSlowData.o Golay2087.o \
-		Golay24128.o Hamming.o HD44780.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o Nextion.o NullDisplay.o P25Audio.o \
-		P25Control.o P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o RSSIInterpolator.o SerialController.o \
-		SerialPort.o SHA256.o StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
+		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o DelayBuffer.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o \
+		DMRLookup.o DMRLC.o DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o \
+		DStarSlowData.o Golay2087.o Golay24128.o Hamming.o HD44780.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o \
+		Nextion.o NullDisplay.o P25Audio.o P25Control.o P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o \
+		RSSIInterpolator.o SerialController.o SerialPort.o SHA256.o StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o \
+		YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
 
 all:		MMDVMHost
 
diff --git a/Makefile.Pi.HD44780 b/Makefile.Pi.HD44780
index 4548ee4..ae7266e 100644
--- a/Makefile.Pi.HD44780
+++ b/Makefile.Pi.HD44780
@@ -7,11 +7,12 @@ LIBS    = -lwiringPi -lwiringPiDev -lpthread
 LDFLAGS = -g -L/usr/local/lib
 
 OBJECTS = \
-		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o DMRLookup.o DMRLC.o \
-		DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o DStarSlowData.o Golay2087.o \
-		Golay24128.o Hamming.o HD44780.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o Nextion.o NullDisplay.o P25Audio.o \
-		P25Control.o P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o RSSIInterpolator.o SerialController.o \
-		SerialPort.o SHA256.o StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
+		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o DelayBuffer.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o \
+		DMRLookup.o DMRLC.o DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o \
+		DStarSlowData.o Golay2087.o Golay24128.o Hamming.o HD44780.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o \
+		Nextion.o NullDisplay.o P25Audio.o P25Control.o P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o \
+		RSSIInterpolator.o SerialController.o SerialPort.o SHA256.o StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o \
+		YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
 
 all:		MMDVMHost
 
diff --git a/Makefile.Pi.OLED b/Makefile.Pi.OLED
index 4cf1b2e..ff61b18 100644
--- a/Makefile.Pi.OLED
+++ b/Makefile.Pi.OLED
@@ -7,11 +7,12 @@ LIBS    = -lArduiPi_OLED -li2c -lpthread
 LDFLAGS = -g -L/usr/local/lib
 
 OBJECTS = \
-		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o DMRLookup.o DMRLC.o \
-		DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o DStarSlowData.o Golay2087.o \
-		Golay24128.o Hamming.o JitterBuffer.o OLED.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o Nextion.o NullDisplay.o P25Audio.o \
-		P25Control.o P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o RSSIInterpolator.o SerialController.o \
-		SerialPort.o SHA256.o StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
+		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o DelayBuffer.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o \
+		DMRLookup.o DMRLC.o DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o \
+		DStarSlowData.o Golay2087.o Golay24128.o Hamming.o JitterBuffer.o OLED.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o \
+		Nextion.o NullDisplay.o P25Audio.o P25Control.o P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o \
+		RSSIInterpolator.o SerialController.o SerialPort.o SHA256.o StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o \
+		YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
 
 all:		MMDVMHost
 
diff --git a/Makefile.Pi.PCF8574 b/Makefile.Pi.PCF8574
index d1fa047..5aea72c 100644
--- a/Makefile.Pi.PCF8574
+++ b/Makefile.Pi.PCF8574
@@ -7,11 +7,12 @@ LIBS    = -lwiringPi -lwiringPiDev -lpthread
 LDFLAGS = -g -L/usr/local/lib
 
 OBJECTS = \
-		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o DMRLookup.o DMRLC.o \
-		DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o DStarSlowData.o Golay2087.o \
-		Golay24128.o Hamming.o HD44780.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o Nextion.o NullDisplay.o P25Audio.o \
-		P25Control.o P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o RSSIInterpolator.o SerialController.o \
-		SerialPort.o SHA256.o StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
+		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o DelayBuffer.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o \
+		DMRLookup.o DMRLC.o DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o \
+		DStarSlowData.o Golay2087.o Golay24128.o Hamming.o HD44780.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o \
+		Nextion.o NullDisplay.o P25Audio.o P25Control.o P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o \
+		RSSIInterpolator.o SerialController.o SerialPort.o SHA256.o StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o \
+		YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
 
 all:		MMDVMHost
 
diff --git a/Makefile.Solaris b/Makefile.Solaris
index 9e8769f..4c47f85 100644
--- a/Makefile.Solaris
+++ b/Makefile.Solaris
@@ -7,11 +7,12 @@ LIBS    = -lpthread -lsocket
 LDFLAGS = -g
 
 OBJECTS = \
-		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o DMRLookup.o DMRLC.o \
-		DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o DStarSlowData.o Golay2087.o \
-		Golay24128.o Hamming.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o Nextion.o NullDisplay.o P25Audio.o P25Control.o \
-		P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o RSSIInterpolator.o SerialController.o SerialPort.o SHA256.o \
-		StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
+		AMBEFEC.o BCH.o BPTC19696.o Conf.o CRC.o DelayBuffer.o Display.o DMRControl.o DMRCSBK.o DMRData.o DMRDataHeader.o DMREMB.o DMREmbeddedData.o DMRFullLC.o \
+		DMRLookup.o DMRLC.o DMRNetwork.o DMRShortLC.o DMRSlot.o DMRSlotType.o DMRAccessControl.o DMRTrellis.o DStarControl.o DStarHeader.o DStarNetwork.o \
+		DStarSlowData.o Golay2087.o Golay24128.o Hamming.o JitterBuffer.o LCDproc.o Log.o MMDVMHost.o Modem.o ModemSerialPort.o Mutex.o NetworkInfo.o Nextion.o \
+		NullDisplay.o P25Audio.o P25Control.o P25Data.o P25LowSpeedData.o P25Network.o P25NID.o P25Trellis.o P25Utils.o QR1676.o RS129.o RS241213.o \
+		RSSIInterpolator.o SerialController.o SerialPort.o SHA256.o StopWatch.o Sync.o TFTSerial.o Thread.o Timer.o UDPSocket.o UMP.o Utils.o YSFControl.o \
+		YSFConvolution.o YSFFICH.o YSFNetwork.o YSFPayload.o
 
 all:		MMDVMHost
 

From 7737659729fb091b7a3f675fb9971bbfd7867210 Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Mon, 5 Feb 2018 20:42:43 +0000
Subject: [PATCH 06/10] Add code for handling NXDN data calls and remove unused
 YSF code.

---
 NXDNControl.cpp | 374 ++++++++++--------------------------------------
 NXDNLayer3.cpp  |   8 +-
 NXDNLayer3.h    |   2 +-
 3 files changed, 77 insertions(+), 307 deletions(-)

diff --git a/NXDNControl.cpp b/NXDNControl.cpp
index 0ab043c..a612475 100644
--- a/NXDNControl.cpp
+++ b/NXDNControl.cpp
@@ -200,15 +200,16 @@ bool CNXDNControl::processVoice(unsigned char usc, unsigned char option, unsigne
 				m_rfLayer3.reset();
 				return false;
 			}
-		} else {
-			bool hasInfo = layer3.getHasInfo();
-			if (m_rfState == RS_RF_LISTENING && m_selfOnly && hasInfo) {
+		} else if (type == NXDN_MESSAGE_TYPE_VCALL) {
+			if (m_rfState == RS_RF_LISTENING && m_selfOnly) {
 				unsigned short srcId = layer3.getSourceUnitId();
 				if (srcId != m_id) {
 					m_rfState = RS_RF_REJECTED;
 					return false;
 				}
 			}
+		} else {
+			return false;
 		}
 
 		data[0U] = type == NXDN_MESSAGE_TYPE_TX_REL ? TAG_EOT : TAG_DATA;
@@ -299,7 +300,7 @@ bool CNXDNControl::processVoice(unsigned char usc, unsigned char option, unsigne
 				CNXDNLayer3 layer3;
 				layer3.decode(buffer, NXDN_FACCH1_LENGTH_BITS);
 
-				hasInfo = layer3.getHasInfo();
+				hasInfo = layer3.getMessageType() == NXDN_MESSAGE_TYPE_VCALL;
 				if (!hasInfo)
 					return false;
 
@@ -335,8 +336,8 @@ bool CNXDNControl::processVoice(unsigned char usc, unsigned char option, unsigne
 				if (m_rfMask != 0x0FU)
 					return false;
 
-				hasInfo = m_rfLayer3.getHasInfo();
-				if (!hasInfo)
+				unsigned char type = m_rfLayer3.getMessageType();
+				if (type != NXDN_MESSAGE_TYPE_VCALL)
 					return false;
 			}
 
@@ -531,199 +532,92 @@ bool CNXDNControl::processData(unsigned char option, unsigned char *data)
 {
 	CNXDNUDCH udch;
 	bool valid = udch.decode(data + 2U);
+	if (m_rfState == RS_RF_LISTENING && !valid)
+		return false;
+
 	if (valid) {
 		unsigned char ran = udch.getRAN();
 		if (ran != m_ran && ran != 0U)
 			return false;
+	}
 
-		data[0U] = TAG_DATA;
-		data[1U] = 0x00U;
+	// The layer3 data will only be correct if valid is true
+	unsigned char buffer[23U];
+	udch.getData(buffer);
 
-		CSync::addNXDNSync(data + 2U);
+	CNXDNLayer3 layer3;
+	layer3.decode(buffer, 184U);
 
-		CNXDNLICH lich;
-		lich.setRFCT(NXDN_LICH_RFCT_RDCH);
-		lich.setFCT(NXDN_LICH_USC_UDCH);
-		lich.setOption(option);
-		lich.setDirection(m_remoteGateway ? NXDN_LICH_DIRECTION_INBOUND : NXDN_LICH_DIRECTION_OUTBOUND);
-		lich.encode(data + 2U);
+	if (m_rfState == RS_RF_LISTENING) {
+		unsigned char type = layer3.getMessageType();
+		if (type != NXDN_MESSAGE_TYPE_DCALL_HDR)
+			return false;
 
+		unsigned short srcId = layer3.getSourceUnitId();
+		unsigned short dstId = layer3.getDestinationGroupId();
+		bool grp             = layer3.getIsGroup();
+
+		if (m_selfOnly) {
+			if (srcId != m_id)
+				return false;
+		}
+
+		unsigned char frames = layer3.getDataBlocks();
+
+		std::string source = m_lookup->find(srcId);
+
+		m_display->writeNXDN(source.c_str(), grp, dstId, "R");
+		m_display->writeNXDNRSSI(m_rssi);
+
+		LogMessage("NXDN, received RF data header from %s to %s%u, %u blocks", source.c_str(), grp ? "TG " : "", dstId, frames);
+
+		m_rfState = RS_RF_DATA;
+
+#if defined(DUMP_NXDN)
+		openFile();
+#endif
+	}
+
+	if (m_rfState != RS_RF_DATA)
+		return false;
+
+	data[0U] = TAG_DATA;
+	data[1U] = 0x00U;
+
+	CSync::addNXDNSync(data + 2U);
+
+	CNXDNLICH lich;
+	lich.setRFCT(NXDN_LICH_RFCT_RDCH);
+	lich.setFCT(NXDN_LICH_USC_UDCH);
+	lich.setOption(option);
+	lich.setDirection(m_remoteGateway ? NXDN_LICH_DIRECTION_INBOUND : NXDN_LICH_DIRECTION_OUTBOUND);
+	lich.encode(data + 2U);
+
+	if (valid) {
 		udch.setRAN(m_ran);
 		udch.encode(data + 2U);
-
-		scrambler(data + 2U);
-
-		writeQueueNet(data);
-
-		if (m_duplex)
-			writeQueueRF(data);
-#if defined(DUMP_NXDN)
-		writeFile(data + 2U);
-#endif
-		return true;
 	}
 
-#ifdef notdef
-	unsigned char fi = m_lastFICH.getFI();
-	if (valid && fi == YSF_FI_HEADER) {
-		if (m_rfState == RS_RF_LISTENING) {
-			valid = m_rfPayload.processHeaderData(data + 2U);
-			if (!valid)
-				return false;
+	scrambler(data + 2U);
 
-			m_rfSource = m_rfPayload.getSource();
+	writeQueueNet(data);
 
-			if (m_selfOnly) {
-				bool ret = checkCallsign(m_rfSource);
-				if (!ret) {
-					LogMessage("NXDN, invalid access attempt from %10.10s", m_rfSource);
-					m_rfState = RS_RF_REJECTED;
-					return false;
-				}
-			}
-
-			unsigned char cm = m_lastFICH.getCM();
-			if (cm == YSF_CM_GROUP1 || cm == YSF_CM_GROUP2)
-				m_rfDest = (unsigned char*)"ALL       ";
-			else
-				m_rfDest = m_rfPayload.getDest();
-
-			m_rfFrames = 0U;
-			m_rfState = RS_RF_DATA;
-
-			m_minRSSI = m_rssi;
-			m_maxRSSI = m_rssi;
-			m_aveRSSI = m_rssi;
-			m_rssiCount = 1U;
-#if defined(DUMP_NXDN)
-			openFile();
-#endif
-
-			m_display->writeFusion((char*)m_rfSource, (char*)m_rfDest, "R", "          ");
-			LogMessage("NXDN, received RF header from %10.10s to %10.10s", m_rfSource, m_rfDest);
-
-			CSync::addNXDNSync(data + 2U);
-
-			CYSFFICH fich = m_lastFICH;
-
-			// Remove any DSQ information
-			fich.setSQL(false);
-			fich.setSQ(0U);
-			fich.encode(data + 2U);
-
-			data[0U] = TAG_DATA;
-			data[1U] = 0x00U;
-
-			writeNetwork(data, m_rfFrames);
+	if (m_duplex)
+		writeQueueRF(data);
 
 #if defined(DUMP_NXDN)
-			writeFile(data + 2U);
+	writeFile(data + 2U);
 #endif
 
-			if (m_duplex) {
-				fich.setMR(m_remoteGateway ? YSF_MR_NOT_BUSY : YSF_MR_BUSY);
-				fich.encode(data + 2U);
-				writeQueueRF(data);
-			}
-
-			m_rfFrames++;
-
-			m_display->writeFusionRSSI(m_rssi);
-
-			return true;
-		}
-	} else if (valid && fi == YSF_FI_TERMINATOR) {
-		if (m_rfState == RS_RF_REJECTED) {
-			m_rfPayload.reset();
-			m_rfSource = NULL;
-			m_rfDest   = NULL;
-			m_rfState  = RS_RF_LISTENING;
-		} else if (m_rfState == RS_RF_DATA) {
-			m_rfPayload.processHeaderData(data + 2U);
-
-			CSync::addNXDNSync(data + 2U);
-
-			CYSFFICH fich = m_lastFICH;
-
-			// Remove any DSQ information
-			fich.setSQL(false);
-			fich.setSQ(0U);
-			fich.encode(data + 2U);
-
-			data[0U] = TAG_EOT;
-			data[1U] = 0x00U;
-
-			writeNetwork(data, m_rfFrames);
-
-#if defined(DUMP_NXDN)
-			writeFile(data + 2U);
-#endif
-
-			if (m_duplex) {
-				fich.setMR(m_remoteGateway ? YSF_MR_NOT_BUSY : YSF_MR_BUSY);
-				fich.encode(data + 2U);
-				writeQueueRF(data);
-			}
-
-			m_rfFrames++;
-
-			if (m_rssi != 0U)
-				LogMessage("NXDN, received RF end of transmission, %.1f seconds, RSSI: -%u/-%u/-%u dBm", float(m_rfFrames) / 10.0F, m_minRSSI, m_maxRSSI, m_aveRSSI / m_rssiCount);
-			else
-				LogMessage("NXDN, received RF end of transmission, %.1f seconds", float(m_rfFrames) / 10.0F);
-
+	if (valid) {
+		unsigned char type = layer3.getMessageType();
+		if (type == NXDN_MESSAGE_TYPE_TX_REL) {
+			LogMessage("NXDN, ended RF data transmission");
 			writeEndRF();
 		}
-	} else {
-		if (m_rfState == RS_RF_DATA) {
-			// If valid is false, update the m_lastFICH for this transmission
-			if (!valid) {
-				unsigned char ft = m_lastFICH.getFT();
-				unsigned char fn = m_lastFICH.getFN() + 1U;
-
-				if (fn > ft)
-					fn = 0U;
-
-				m_lastFICH.setFN(fn);
-			}
-
-			CSync::addNXDNSync(data + 2U);
-
-			unsigned char fn = m_lastFICH.getFN();
-
-			m_rfPayload.processDataFRModeData(data + 2U, fn);
-
-			CYSFFICH fich = m_lastFICH;
-
-			// Remove any DSQ information
-			fich.setSQL(false);
-			fich.setSQ(0U);
-			fich.encode(data + 2U);
-
-			data[0U] = TAG_DATA;
-			data[1U] = 0x00U;
-
-			writeNetwork(data, m_rfFrames);
-
-			if (m_duplex) {
-				fich.setMR(m_remoteGateway ? YSF_MR_NOT_BUSY : YSF_MR_BUSY);
-				fich.encode(data + 2U);
-				writeQueueRF(data);
-			}
-
-#if defined(DUMP_NXDN)
-			writeFile(data + 2U);
-#endif
-
-			m_rfFrames++;
-
-			m_display->writeFusionRSSI(m_rssi);
-
-			return true;
-		}
 	}
-#endif
-	return false;
+
+	return true;
 }
 
 unsigned int CNXDNControl::readModem(unsigned char* data)
@@ -776,10 +670,9 @@ void CNXDNControl::writeEndNet()
 		m_network->reset();
 }
 
-#ifdef notdef
-
 void CNXDNControl::writeNetwork()
 {
+#ifdef notdef
 	unsigned char data[200U];
 	unsigned int length = m_network->read(data);
 	if (length == 0U)
@@ -789,132 +682,13 @@ void CNXDNControl::writeNetwork()
 		return;
 
 	m_networkWatchdog.start();
-
-	unsigned char n = (data[5U] & 0xFEU) >> 1;
-	bool end = (data[5U] & 0x01U) == 0x01U;
-
-	if (!m_netTimeoutTimer.isRunning()) {
-		if (end)
-			return;
-
-		m_display->writeFusion((char*)m_netSource, (char*)m_netDest, "N", (char*)(data + 4U));
-		LogMessage("NXDN, received network data from %10.10s to %10.10s at %10.10s", m_netSource, m_netDest, data + 4U);
-
-		m_netTimeoutTimer.start();
-		m_packetTimer.start();
-		m_elapsed.start();
-		m_netState  = RS_NET_AUDIO;
-		m_netFrames = 0U;
-		m_netLost   = 0U;
-		m_netErrs   = 0U;
-		m_netBits   = 1U;
-		m_netN      = 0U;
-	} else {
-		// Check for duplicate frames, if we can
-		if (m_netN == n)
-			return;
-
-		bool changed = false;
-
-		if (::memcmp(data + 14U, "          ", YSF_CALLSIGN_LENGTH) != 0 && ::memcmp(m_netSource, "??????????", YSF_CALLSIGN_LENGTH) == 0) {
-			::memcpy(m_netSource, data + 14U, YSF_CALLSIGN_LENGTH);
-			changed = true;
-		}
-
-		if (::memcmp(data + 24U, "          ", YSF_CALLSIGN_LENGTH) != 0 && ::memcmp(m_netDest, "??????????", YSF_CALLSIGN_LENGTH) == 0) {
-			::memcpy(m_netDest, data + 24U, YSF_CALLSIGN_LENGTH);
-			changed = true;
-		}
-
-		if (changed) {
-			m_display->writeFusion((char*)m_netSource, (char*)m_netDest, "N", (char*)(data + 4U));
-			LogMessage("YSF, received network data from %10.10s to %10.10s at %10.10s", m_netSource, m_netDest, data + 4U);
-		}
-	}
-
-	data[33U] = end ? TAG_EOT : TAG_DATA;
-	data[34U] = 0x00U;
-
-	CYSFFICH fich;
-	bool valid = fich.decode(data + 35U);
-	if (valid) {
-		unsigned char dt = fich.getDT();
-		unsigned char fn = fich.getFN();
-		unsigned char ft = fich.getFT();
-		unsigned char fi = fich.getFI();
-
-		fich.setVoIP(true);
-		fich.setMR(m_remoteGateway ? YSF_MR_NOT_BUSY : YSF_MR_BUSY);
-		fich.encode(data + 35U);
-
-		// Set the downlink callsign
-		switch (fi) {
-		case YSF_FI_HEADER:
-		case YSF_FI_TERMINATOR:
-			m_netPayload.processHeaderData(data + 35U);
-			break;
-
-		case YSF_FI_COMMUNICATIONS:
-			switch (dt) {
-			case YSF_DT_VD_MODE1: {
-					m_netPayload.processVDMode1Data(data + 35U, fn, gateway);
-					unsigned int errors = m_netPayload.processVDMode1Audio(data + 35U);
-					m_netErrs += errors;
-					m_netBits += 235U;
-				}
-				break;
-
-			case YSF_DT_VD_MODE2: {
-					m_netPayload.processVDMode2Data(data + 35U, fn, gateway);
-					unsigned int errors = m_netPayload.processVDMode2Audio(data + 35U);
-					m_netErrs += errors;
-					m_netBits += 135U;
-				}
-				break;
-
-			case YSF_DT_DATA_FR_MODE:
-				m_netPayload.processDataFRModeData(data + 35U, fn, gateway);
-				break;
-
-			case YSF_DT_VOICE_FR_MODE:
-				if (fn != 0U || ft != 1U) {
-					// The first packet after the header is odd, don't try and regenerate it
-					unsigned int errors = m_netPayload.processVoiceFRModeAudio(data + 35U);
-					m_netErrs += errors;
-					m_netBits += 720U;
-				}
-				break;
-
-			default:
-				break;
-			}
-			break;
-
-		default:
-			break;
-		}
-	}
-
-	writeQueueNet(data + 33U);
-
-	m_packetTimer.start();
-	m_netFrames++;
-	m_netN = n;
-
-	if (end) {
-		LogMessage("NXDN, received network end of transmission, %.1f seconds, %u%% packet loss, BER: %.1f%%", float(m_netFrames) / 10.0F, (m_netLost * 100U) / m_netFrames, float(m_netErrs * 100U) / float(m_netBits));
-		writeEndNet();
-	}
-}
-
 #endif
+}
 
 void CNXDNControl::clock(unsigned int ms)
 {
-#ifdef notdef
 	if (m_network != NULL)
 		writeNetwork();
-#endif
 
 	m_rfTimeoutTimer.clock(ms);
 	m_netTimeoutTimer.clock(ms);
diff --git a/NXDNLayer3.cpp b/NXDNLayer3.cpp
index cf32008..f1b98f3 100644
--- a/NXDNLayer3.cpp
+++ b/NXDNLayer3.cpp
@@ -92,13 +92,9 @@ unsigned char CNXDNLayer3::getCallOptions() const
 	return m_data[2U] & 0x1FU;
 }
 
-bool CNXDNLayer3::getHasInfo() const
+unsigned char CNXDNLayer3::getDataBlocks() const
 {
-	unsigned char type = getMessageType();
-
-	return type != NXDN_MESSAGE_TYPE_IDLE &&
-		   type != NXDN_MESSAGE_TYPE_VCALL_IV &&
-		   type != NXDN_MESSAGE_TYPE_SDCALL_IV;
+	return m_data[8U] & 0x0FU;
 }
 
 void CNXDNLayer3::getData(unsigned char* data) const
diff --git a/NXDNLayer3.h b/NXDNLayer3.h
index 827deee..d39a41b 100644
--- a/NXDNLayer3.h
+++ b/NXDNLayer3.h
@@ -34,7 +34,7 @@ public:
 	unsigned short getDestinationGroupId() const;
 	bool           getIsGroup() const;
 	unsigned char  getCallOptions() const;
-	bool           getHasInfo() const;
+	unsigned char  getDataBlocks() const;
 
 	void           getData(unsigned char* data) const;
 

From bdc35d02bd5cf8f51fef4e13438459333aea8b35 Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Mon, 5 Feb 2018 21:07:06 +0000
Subject: [PATCH 07/10] Regenerate more NXDN voice data elements.

---
 NXDNControl.cpp | 44 ++++++++++++++++++++++++++++++++------------
 NXDNControl.h   |  2 +-
 NXDNLayer3.cpp  |  4 ++--
 NXDNLayer3.h    |  2 +-
 4 files changed, 36 insertions(+), 16 deletions(-)

diff --git a/NXDNControl.cpp b/NXDNControl.cpp
index a612475..74627fd 100644
--- a/NXDNControl.cpp
+++ b/NXDNControl.cpp
@@ -158,16 +158,16 @@ bool CNXDNControl::writeModem(unsigned char *data, unsigned int len)
 	if (usc == NXDN_LICH_USC_UDCH)
 		ret = processData(option, data);
 	else
-		ret = processVoice(usc, option, data);
+		ret = processVoice(valid, usc, option, data);
 
 	return ret;
 }
 
-bool CNXDNControl::processVoice(unsigned char usc, unsigned char option, unsigned char *data)
+bool CNXDNControl::processVoice(bool validLICH, unsigned char usc, unsigned char option, unsigned char *data)
 {
 	CNXDNSACCH sacch;
-	bool valid = sacch.decode(data + 2U);
-	if (valid) {
+	bool validSACCH = sacch.decode(data + 2U);
+	if (validSACCH) {
 		unsigned char ran = sacch.getRAN();
 		if (ran != m_ran && ran != 0U)
 			return false;
@@ -175,7 +175,21 @@ bool CNXDNControl::processVoice(unsigned char usc, unsigned char option, unsigne
 		return false;
 	}
 
-	// XXX Reconstruct invalid LICH
+	// Reconstruct invalid LICH
+	if (!validLICH) {
+		if (usc == NXDN_LICH_USC_SACCH_NS) {
+			option = NXDN_LICH_STEAL_NONE;
+			usc    = NXDN_LICH_USC_SACCH_SS;
+		} else {
+			if (option == NXDN_LICH_STEAL_FACCH)
+				option = NXDN_LICH_STEAL_NONE;
+			else if (option == NXDN_LICH_STEAL_NONE)
+				option = NXDN_LICH_STEAL_FACCH;
+		}
+
+		m_rfLastLICH.setFCT(usc);
+		m_rfLastLICH.setOption(option);
+	}
 
 	if (usc == NXDN_LICH_USC_SACCH_NS) {
 		// The SACCH on a non-superblock frame is usually an idle and not interesting apart from the RAN.
@@ -425,10 +439,16 @@ bool CNXDNControl::processVoice(unsigned char usc, unsigned char option, unsigne
 		lich.setDirection(m_remoteGateway ? NXDN_LICH_DIRECTION_INBOUND : NXDN_LICH_DIRECTION_OUTBOUND);
 		lich.encode(data + 2U);
 
-		// XXX Regenerate SACCH here
+		// Regenerate SACCH if it's valid
+		CNXDNSACCH sacch;
+		bool validSACCH = sacch.decode(data + 2U);
+		if (validSACCH) {
+			sacch.setRAN(m_ran);
+			sacch.encode(data + 2U);
+		}
 
 		// Regenerate the audio and interpret the FACCH1 data
-		unsigned char voiceMode = m_rfLayer3.getCallOptions() & 0x07U;
+		unsigned char voiceMode = m_rfLayer3.getVoiceMode();
 
 		if (option == NXDN_LICH_STEAL_NONE) {
 			CAMBEFEC ambe;
@@ -531,11 +551,11 @@ bool CNXDNControl::processVoice(unsigned char usc, unsigned char option, unsigne
 bool CNXDNControl::processData(unsigned char option, unsigned char *data)
 {
 	CNXDNUDCH udch;
-	bool valid = udch.decode(data + 2U);
-	if (m_rfState == RS_RF_LISTENING && !valid)
+	bool validUDCH = udch.decode(data + 2U);
+	if (m_rfState == RS_RF_LISTENING && !validUDCH)
 		return false;
 
-	if (valid) {
+	if (validUDCH) {
 		unsigned char ran = udch.getRAN();
 		if (ran != m_ran && ran != 0U)
 			return false;
@@ -593,7 +613,7 @@ bool CNXDNControl::processData(unsigned char option, unsigned char *data)
 	lich.setDirection(m_remoteGateway ? NXDN_LICH_DIRECTION_INBOUND : NXDN_LICH_DIRECTION_OUTBOUND);
 	lich.encode(data + 2U);
 
-	if (valid) {
+	if (validUDCH) {
 		udch.setRAN(m_ran);
 		udch.encode(data + 2U);
 	}
@@ -609,7 +629,7 @@ bool CNXDNControl::processData(unsigned char option, unsigned char *data)
 	writeFile(data + 2U);
 #endif
 
-	if (valid) {
+	if (validUDCH) {
 		unsigned char type = layer3.getMessageType();
 		if (type == NXDN_MESSAGE_TYPE_TX_REL) {
 			LogMessage("NXDN, ended RF data transmission");
diff --git a/NXDNControl.h b/NXDNControl.h
index 5f000e7..8dfaedd 100644
--- a/NXDNControl.h
+++ b/NXDNControl.h
@@ -81,7 +81,7 @@ private:
 	unsigned int               m_rssiCount;
 	FILE*                      m_fp;
 
-	bool processVoice(unsigned char usc, unsigned char option, unsigned char *data);
+	bool processVoice(bool validLICH, unsigned char usc, unsigned char option, unsigned char *data);
 	bool processData(unsigned char option, unsigned char *data);
 
 	void writeQueueRF(const unsigned char* data);
diff --git a/NXDNLayer3.cpp b/NXDNLayer3.cpp
index f1b98f3..72b938a 100644
--- a/NXDNLayer3.cpp
+++ b/NXDNLayer3.cpp
@@ -87,9 +87,9 @@ bool CNXDNLayer3::getIsGroup() const
 	return (m_data[2U] & 0x80U) != 0x80U;
 }
 
-unsigned char CNXDNLayer3::getCallOptions() const
+unsigned char CNXDNLayer3::getVoiceMode() const
 {
-	return m_data[2U] & 0x1FU;
+	return m_data[2U] & 0x07U;
 }
 
 unsigned char CNXDNLayer3::getDataBlocks() const
diff --git a/NXDNLayer3.h b/NXDNLayer3.h
index d39a41b..b0749a2 100644
--- a/NXDNLayer3.h
+++ b/NXDNLayer3.h
@@ -33,7 +33,7 @@ public:
 	unsigned short getSourceUnitId() const;
 	unsigned short getDestinationGroupId() const;
 	bool           getIsGroup() const;
-	unsigned char  getCallOptions() const;
+	unsigned char  getVoiceMode() const;
 	unsigned char  getDataBlocks() const;
 
 	void           getData(unsigned char* data) const;

From d2504172f960e30620b0b232181b08021f825700 Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Mon, 5 Feb 2018 21:21:08 +0000
Subject: [PATCH 08/10] Small optimisation of the CRC calculations.

---
 NXDNCRC.cpp | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/NXDNCRC.cpp b/NXDNCRC.cpp
index 29da35c..7ffc456 100644
--- a/NXDNCRC.cpp
+++ b/NXDNCRC.cpp
@@ -142,13 +142,12 @@ uint8_t CNXDNCRC::createCRC6(const unsigned char* in, unsigned int length)
 		bool bit2 = (crc & 0x20U) == 0x20U;
 
 		crc <<= 1;
-		crc &= 0x3EU;
 
 		if (bit1 ^ bit2)
 			crc ^= 0x27U;
 	}
 
-	return crc;
+	return crc & 0x3FU;
 }
 
 uint16_t CNXDNCRC::createCRC12(const unsigned char* in, unsigned int length)
@@ -160,7 +159,6 @@ uint16_t CNXDNCRC::createCRC12(const unsigned char* in, unsigned int length)
 		bool bit2 = (crc & 0x0800U) == 0x0800U;
 
 		crc <<= 1;
-		crc &= 0x0FFEU;
 
 		if (bit1 ^ bit2)
 			crc ^= 0x080FU;
@@ -178,7 +176,6 @@ uint16_t CNXDNCRC::createCRC15(const unsigned char* in, unsigned int length)
 		bool bit2 = (crc & 0x4000U) == 0x4000U;
 
 		crc <<= 1;
-		crc &= 0x7FFEU;
 
 		if (bit1 ^ bit2)
 			crc ^= 0x4CC5U;

From a5c61daa736f9f6032478676c22b795d6233acce Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Mon, 5 Feb 2018 21:33:36 +0000
Subject: [PATCH 09/10] Fix the data tag for the end of NXDN data
 transmissions.

---
 NXDNControl.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/NXDNControl.cpp b/NXDNControl.cpp
index 74627fd..c1198a4 100644
--- a/NXDNControl.cpp
+++ b/NXDNControl.cpp
@@ -601,9 +601,6 @@ bool CNXDNControl::processData(unsigned char option, unsigned char *data)
 	if (m_rfState != RS_RF_DATA)
 		return false;
 
-	data[0U] = TAG_DATA;
-	data[1U] = 0x00U;
-
 	CSync::addNXDNSync(data + 2U);
 
 	CNXDNLICH lich;
@@ -614,8 +611,14 @@ bool CNXDNControl::processData(unsigned char option, unsigned char *data)
 	lich.encode(data + 2U);
 
 	if (validUDCH) {
+		unsigned char type = layer3.getMessageType();
+		data[0U] = type == NXDN_MESSAGE_TYPE_TX_REL ? TAG_EOT : TAG_DATA;
+
 		udch.setRAN(m_ran);
 		udch.encode(data + 2U);
+	} else {
+		data[0U] = TAG_DATA;
+		data[1U] = 0x00U;
 	}
 
 	scrambler(data + 2U);

From ff71383ac78ba0905ff7fb1391b7c0471d40676b Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Mon, 5 Feb 2018 21:39:50 +0000
Subject: [PATCH 10/10] Not happy about LICH reconstruction, remove it.

---
 NXDNControl.cpp | 24 ++++--------------------
 NXDNControl.h   |  2 +-
 2 files changed, 5 insertions(+), 21 deletions(-)

diff --git a/NXDNControl.cpp b/NXDNControl.cpp
index c1198a4..4eeea24 100644
--- a/NXDNControl.cpp
+++ b/NXDNControl.cpp
@@ -158,16 +158,16 @@ bool CNXDNControl::writeModem(unsigned char *data, unsigned int len)
 	if (usc == NXDN_LICH_USC_UDCH)
 		ret = processData(option, data);
 	else
-		ret = processVoice(valid, usc, option, data);
+		ret = processVoice(usc, option, data);
 
 	return ret;
 }
 
-bool CNXDNControl::processVoice(bool validLICH, unsigned char usc, unsigned char option, unsigned char *data)
+bool CNXDNControl::processVoice(unsigned char usc, unsigned char option, unsigned char *data)
 {
 	CNXDNSACCH sacch;
-	bool validSACCH = sacch.decode(data + 2U);
-	if (validSACCH) {
+	bool valid = sacch.decode(data + 2U);
+	if (valid) {
 		unsigned char ran = sacch.getRAN();
 		if (ran != m_ran && ran != 0U)
 			return false;
@@ -175,22 +175,6 @@ bool CNXDNControl::processVoice(bool validLICH, unsigned char usc, unsigned char
 		return false;
 	}
 
-	// Reconstruct invalid LICH
-	if (!validLICH) {
-		if (usc == NXDN_LICH_USC_SACCH_NS) {
-			option = NXDN_LICH_STEAL_NONE;
-			usc    = NXDN_LICH_USC_SACCH_SS;
-		} else {
-			if (option == NXDN_LICH_STEAL_FACCH)
-				option = NXDN_LICH_STEAL_NONE;
-			else if (option == NXDN_LICH_STEAL_NONE)
-				option = NXDN_LICH_STEAL_FACCH;
-		}
-
-		m_rfLastLICH.setFCT(usc);
-		m_rfLastLICH.setOption(option);
-	}
-
 	if (usc == NXDN_LICH_USC_SACCH_NS) {
 		// The SACCH on a non-superblock frame is usually an idle and not interesting apart from the RAN.
 		CNXDNFACCH1 facch;
diff --git a/NXDNControl.h b/NXDNControl.h
index 8dfaedd..5f000e7 100644
--- a/NXDNControl.h
+++ b/NXDNControl.h
@@ -81,7 +81,7 @@ private:
 	unsigned int               m_rssiCount;
 	FILE*                      m_fp;
 
-	bool processVoice(bool validLICH, unsigned char usc, unsigned char option, unsigned char *data);
+	bool processVoice(unsigned char usc, unsigned char option, unsigned char *data);
 	bool processData(unsigned char option, unsigned char *data);
 
 	void writeQueueRF(const unsigned char* data);