conform to P25 standards for composite control channel when VoC mode is enabled, and transmit LC_RFSS_STS_BCAST every 3 superframes;

p25/TrunkPacket.cpp

@@ -216,6 +216,9 @@ void TrunkPacket::setServiceClass(bool control, bool voiceOnControl)
 
     m_rfTDULC.setServiceClass(serviceClass);
     m_netTDULC.setServiceClass(serviceClass);
+
+    m_p25->m_voice->m_rfLC.setServiceClass(serviceClass);
+    m_p25->m_voice->m_netLC.setServiceClass(serviceClass);
 }
 
 /// <summary>

p25/VoicePacket.cpp

@@ -46,6 +46,12 @@ using namespace p25;
 #include <cstring>
 #include <ctime>
 
+// ---------------------------------------------------------------------------
+//  Constants
+// ---------------------------------------------------------------------------
+
+const uint32_t VOC_LDU1_COUNT = 3U;
+
 // ---------------------------------------------------------------------------
 //  Public Class Members
 // ---------------------------------------------------------------------------
@@ -62,6 +68,7 @@ void VoicePacket::resetRF()
     m_rfErrs = 0U;
     m_rfBits = 1U;
     m_rfUndecodableLC = 0U;
+    m_vocLDU1Count = 0U;
 }
 
 /// <summary>
@@ -73,6 +80,7 @@ void VoicePacket::resetNet()
     m_netLastLDU1.reset();
     m_netFrames = 0U;
     m_netLost = 0U;
+    m_vocLDU1Count = 0U;
 }
 
 /// <summary>
@@ -373,6 +381,7 @@ bool VoicePacket::process(uint8_t* data, uint32_t len)
             m_rfErrs = 0U;
             m_rfBits = 1U;
             m_rfUndecodableLC = 0U;
+            m_vocLDU1Count = 0U;
             m_p25->m_rfTimeout.start();
             m_lastDUID = P25_DUID_HDU;
 
@@ -436,6 +445,16 @@ bool VoicePacket::process(uint8_t* data, uint32_t len)
                 m_p25->m_trunk->touchDstIdGrant(m_rfLC.getDstId());
             }
 
+            // single-channel trunking or voice on control support?
+            if (m_p25->m_control && m_p25->m_voiceOnControl) {
+                // per TIA-102.AABD-B transmit RFSS_STS_BCAST every 3 superframes (e.g. every 3 LDU1s)
+                m_vocLDU1Count++;
+                if (m_vocLDU1Count > VOC_LDU1_COUNT) {
+                    m_vocLDU1Count = 0U;
+                    m_rfLC.setLCO(LC_RFSS_STS_BCAST);
+                }
+            }
+
             // Generate Sync
             Sync::addP25Sync(data + 2U);
 
@@ -865,6 +884,7 @@ VoicePacket::VoicePacket(Control* p25, network::BaseNetwork* network, bool debug
     m_lastRejectId(0U),
     m_lastPatchGroup(0U),
     m_silenceThreshold(124U),
+    m_vocLDU1Count(0U),
     m_verbose(verbose),
     m_debug(debug)
 {
@@ -1201,6 +1221,7 @@ void VoicePacket::writeNet_LDU1(const lc::LC& control, const data::LowSpeedData&
         m_p25->m_netTimeout.start();
         m_netFrames = 0U;
         m_netLost = 0U;
+        m_vocLDU1Count = 0U;
 
         if (!m_p25->m_disableNetworkHDU) {
             uint8_t buffer[P25_HDU_FRAME_LENGTH_BYTES + 2U];
@@ -1237,6 +1258,16 @@ void VoicePacket::writeNet_LDU1(const lc::LC& control, const data::LowSpeedData&
         }
     }
 
+    // single-channel trunking or voice on control support?
+    if (m_p25->m_control && m_p25->m_voiceOnControl) {
+        // per TIA-102.AABD-B transmit RFSS_STS_BCAST every 3 superframes (e.g. every 3 LDU1s)
+        m_vocLDU1Count++;
+        if (m_vocLDU1Count > VOC_LDU1_COUNT) {
+            m_vocLDU1Count = 0U;
+            m_netLC.setLCO(LC_RFSS_STS_BCAST);
+        }
+    }
+
     insertMissingAudio(m_netLDU1);
 
     uint8_t buffer[P25_LDU_FRAME_LENGTH_BYTES + 2U];

p25/VoicePacket.h

@@ -103,6 +103,8 @@ namespace p25
 
         uint32_t m_silenceThreshold;
 
+        uint8_t m_vocLDU1Count;
+
         bool m_verbose;
         bool m_debug;
 

p25/lc/LC.cpp

@@ -57,6 +57,7 @@ LC::LC() :
     m_mfId(P25_MFG_STANDARD),
     m_srcId(0U),
     m_dstId(0U),
+    m_serviceClass(P25_SVC_CLS_VOICE | P25_SVC_CLS_DATA),
     m_emergency(false),
     m_encrypted(false),
     m_priority(4U),
@@ -97,6 +98,8 @@ LC& LC::operator=(const LC& data)
         m_srcId = data.m_srcId;
         m_dstId = data.m_dstId;
 
+        m_serviceClass = data.m_serviceClass;
+
         m_grpVchNo = data.m_grpVchNo;
 
         m_emergency = data.m_emergency;
@@ -633,6 +636,16 @@ void LC::encodeLC(uint8_t * rs)
         rsValue = (rsValue << 16) + m_callTimer;                                    // Call Timer
         rsValue = (rsValue << 24) + m_srcId;                                        // Source/Target Radio Address
         break;
+    case LC_RFSS_STS_BCAST:
+        rs[0U] |= 0x40U;                                                            // Implicit Operation
+        rsValue = m_siteData.lra();                                                 // Location Registration Area
+        rsValue = (rsValue << 12) + m_siteData.sysId();                             // System ID
+        rsValue = (rsValue << 8) + m_siteData.rfssId();                             // RF Sub-System ID
+        rsValue = (rsValue << 8) + m_siteData.siteId();                             // Site ID
+        rsValue = (rsValue << 4) + m_siteData.channelId();                          // Channel ID
+        rsValue = (rsValue << 12) + m_siteData.channelNo();                         // Channel Number
+        rsValue = (rsValue << 8) + m_serviceClass;                                  // System Service Class
+        break;
     default:
         LogError(LOG_P25, "unknown LC value, mfId = $%02X, lco = $%02X", m_mfId, m_lco);
         break;

p25/lc/LC.h

@@ -107,6 +107,9 @@ namespace p25
             /// <summary>Destination ID.</summary>
             __PROPERTY(uint32_t, dstId, DstId);
 
+            /// <summary>Service class.</summary>
+            __PROPERTY(uint8_t, serviceClass, ServiceClass);
+
             /// <summary>Voice channel number.</summary>
             __PROPERTY(uint32_t, grpVchNo, GrpVchNo);