From f5cb11b467e23ef5bc5953c2a0393ba4c971cef9 Mon Sep 17 00:00:00 2001
From: Bryan Biedenkapp <gatekeep@gmail.com>
Date: Sat, 12 Mar 2022 14:35:51 -0500
Subject: [PATCH] correct issue where TDULC for Call Termination was
 incorrectly being sent while in simplex mode (should fix issue #3); add
 configuration option called "simplexSameFrequency" to control whether simplex
 operation takes place on a split frequency pair or a single frequency; fix
 issue where P25 nulls may be incorrectly transmitted in simplex mode;

---
 config.example.yml  |  1 +
 host/Host.cpp       | 25 +++++++++++++------------
 p25/Control.cpp     |  2 +-
 p25/TrunkPacket.cpp |  4 ++++
 4 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/config.example.yml b/config.example.yml
index e369733d..db039eae 100644
--- a/config.example.yml
+++ b/config.example.yml
@@ -78,6 +78,7 @@ system:
     identity: ABCD123
     timeout: 180
     duplex: true
+    simplexSameFrequency: false
     modeHang: 10
 #    rfModeHang: 10
 #    netModeHang: 10
diff --git a/host/Host.cpp b/host/Host.cpp
index c072f424..ba5f01c5 100644
--- a/host/Host.cpp
+++ b/host/Host.cpp
@@ -1306,6 +1306,7 @@ bool Host::readParams()
 
     yaml::Node systemConf = m_conf["system"];
     m_duplex = systemConf["duplex"].as<bool>(true);
+    bool simplexSameFreq = systemConf["simplexSameFrequency"].as<bool>(false);
 
     m_timeout = systemConf["timeout"].as<uint32_t>(120U);
     m_rfModeHang = systemConf["rfModeHang"].as<uint32_t>(10U);
@@ -1332,6 +1333,9 @@ bool Host::readParams()
     LogInfo("    P25: %s", m_p25Enabled ? "enabled" : "disabled");
     LogInfo("    Duplex: %s", m_duplex ? "yes" : "no");
     if (!udpMasterMode) {
+        if (!m_duplex) {
+            LogInfo("    Simplex Same Frequency: %s", simplexSameFreq ? "yes" : "no");
+        }
         LogInfo("    Timeout: %us", m_timeout);
         LogInfo("    RF Mode Hang: %us", m_rfModeHang);
         LogInfo("    RF Talkgroup Hang: %us", m_rfTalkgroupHang);
@@ -1391,21 +1395,18 @@ bool Host::readParams()
             m_channelNo = 4095U;
         }
 
-        if (m_duplex) {
-            if (entry.txOffsetMhz() == 0U) {
-                ::LogError(LOG_HOST, "Channel Id %u has an invalid Tx offset.", m_channelId);
-                return false;
-            }
+        if (entry.txOffsetMhz() == 0U) {
+            ::LogError(LOG_HOST, "Channel Id %u has an invalid Tx offset.", m_channelId);
+            return false;
+        }
 
-            uint32_t calcSpace = (uint32_t)(entry.chSpaceKhz() / 0.125);
-            float calcTxOffset = entry.txOffsetMhz() * 1000000;
+        uint32_t calcSpace = (uint32_t)(entry.chSpaceKhz() / 0.125);
+        float calcTxOffset = entry.txOffsetMhz() * 1000000;
 
-            m_rxFrequency = (uint32_t)((entry.baseFrequency() + ((calcSpace * 125) * m_channelNo)) + calcTxOffset);
-            m_txFrequency = (uint32_t)((entry.baseFrequency() + ((calcSpace * 125) * m_channelNo)));
-        }
-        else {
-            uint32_t calcSpace = (uint32_t)(entry.chSpaceKhz() / 0.125);
+        m_rxFrequency = (uint32_t)((entry.baseFrequency() + ((calcSpace * 125) * m_channelNo)) + calcTxOffset);
+        m_txFrequency = (uint32_t)((entry.baseFrequency() + ((calcSpace * 125) * m_channelNo)));
 
+        if (!m_duplex && simplexSameFreq) {
             m_rxFrequency = (uint32_t)((entry.baseFrequency() + ((calcSpace * 125) * m_channelNo)));
             m_txFrequency = m_rxFrequency;
         }
diff --git a/p25/Control.cpp b/p25/Control.cpp
index e74065bb..ce6eca39 100644
--- a/p25/Control.cpp
+++ b/p25/Control.cpp
@@ -573,7 +573,7 @@ bool Control::writeEndRF()
     if (m_netState == RS_NET_IDLE && m_rfState == RS_RF_LISTENING) {
         if (m_tailOnIdle) {
             bool ret = m_voice->writeEndRF();
-            if (!m_control) {
+            if (!m_control && m_duplex) {
                 writeRF_Nulls();
             }
 
diff --git a/p25/TrunkPacket.cpp b/p25/TrunkPacket.cpp
index d41cd572..6d998a33 100644
--- a/p25/TrunkPacket.cpp
+++ b/p25/TrunkPacket.cpp
@@ -1496,6 +1496,10 @@ void TrunkPacket::writeRF_TDULC(lc::TDULC lc, bool noNetwork)
 /// <param name="dstId"></param>
 void TrunkPacket::writeRF_TDULC_ChanRelease(bool grp, uint32_t srcId, uint32_t dstId)
 {
+    if (!m_p25->m_duplex) {
+        return;
+    }
+
     uint32_t count = m_p25->m_hangCount / 2;
     lc::TDULC lc = lc::TDULC(m_p25->m_siteData, m_p25->m_idenEntry, m_dumpTSBK);