diff --git a/sdrdaemon/channel/sdrdaemondatablock.h b/sdrdaemon/channel/sdrdaemondatablock.h
new file mode 100644
index 000000000..6d3c93de1
--- /dev/null
+++ b/sdrdaemon/channel/sdrdaemondatablock.h
@@ -0,0 +1,100 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018 Edouard Griffiths, F4EXB.                                  //
+//                                                                               //
+// SDRdaemon sink channel (Rx) data block                                        //
+//                                                                               //
+// SDRdaemon is a detached SDR front end that handles the interface with a       //
+// physical device and sends or receives the I/Q samples stream to or from a     //
+// SDRangel instance via UDP. It is controlled via a Web REST API.               //
+//                                                                               //
+// 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 as version 3 of the License, or                  //
+//                                                                               //
+// 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 V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRDAEMON_CHANNEL_SDRDAEMONDATABLOCK_H_
+#define SDRDAEMON_CHANNEL_SDRDAEMONDATABLOCK_H_
+
+#include <stdint.h>
+#include <string.h>
+#include "dsp/dsptypes.h"
+
+#define UDPSINKFEC_UDPSIZE 512
+#define UDPSINKFEC_NBORIGINALBLOCKS 128
+#define UDPSINKFEC_NBTXBLOCKS 8
+
+namespace SDRDaemon {
+
+#pragma pack(push, 1)
+struct MetaDataFEC
+{
+    uint32_t m_centerFrequency;   //!<  4 center frequency in kHz
+    uint32_t m_sampleRate;        //!<  8 sample rate in Hz
+    uint8_t  m_sampleBytes;       //!<  9 MSB(4): indicators, LSB(4) number of bytes per sample
+    uint8_t  m_sampleBits;        //!< 10 number of effective bits per sample
+    uint8_t  m_nbOriginalBlocks;  //!< 11 number of blocks with original (protected) data
+    uint8_t  m_nbFECBlocks;       //!< 12 number of blocks carrying FEC
+    uint32_t m_tv_sec;            //!< 16 seconds of timestamp at start time of super-frame processing
+    uint32_t m_tv_usec;           //!< 20 microseconds of timestamp at start time of super-frame processing
+    uint32_t m_crc32;             //!< 24 CRC32 of the above
+
+    bool operator==(const MetaDataFEC& rhs)
+    {
+        return (memcmp((const void *) this, (const void *) &rhs, 12) == 0); // Only the 12 first bytes are relevant
+    }
+
+    void init()
+    {
+        memset((void *) this, 0, sizeof(MetaDataFEC));
+        m_nbFECBlocks = -1;
+    }
+};
+
+struct Header
+{
+    uint16_t m_frameIndex;
+    uint8_t  m_blockIndex;
+    uint8_t  m_filler;
+};
+
+static const int samplesPerBlock = (UDPSINKFEC_UDPSIZE - sizeof(Header)) / sizeof(Sample);
+
+struct ProtectedBlock
+{
+    Sample m_samples[samplesPerBlock];
+};
+
+struct SuperBlock
+{
+    Header         m_header;
+    ProtectedBlock m_protectedBlock;
+};
+#pragma pack(pop)
+
+struct TxControlBlock
+{
+    bool m_processed;
+    uint16_t m_frameIndex;
+    int m_nbBlocksFEC;
+    int m_txDelay;
+};
+
+class DataBlock
+{
+    SuperBlock     m_superBlock;
+    TxControlBlock m_controlBlock;
+};
+
+} // namespace SDRDaemon
+
+
+
+#endif /* SDRDAEMON_CHANNEL_SDRDAEMONDATABLOCK_H_ */
diff --git a/sdrdaemon/channel/sdrdaemondataqueue.h b/sdrdaemon/channel/sdrdaemondataqueue.h
new file mode 100644
index 000000000..d83346ad1
--- /dev/null
+++ b/sdrdaemon/channel/sdrdaemondataqueue.h
@@ -0,0 +1,55 @@
+///////////////////////////////////////////////////////////////////////////////////
+// Copyright (C) 2018 Edouard Griffiths, F4EXB.                                  //
+//                                                                               //
+// SDRdaemon sink channel (Rx) data blocks queue                                 //
+//                                                                               //
+// SDRdaemon is a detached SDR front end that handles the interface with a       //
+// physical device and sends or receives the I/Q samples stream to or from a     //
+// SDRangel instance via UDP. It is controlled via a Web REST API.               //
+//                                                                               //
+// 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 as version 3 of the License, or                  //
+//                                                                               //
+// 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 V3 for more details.                               //
+//                                                                               //
+// You should have received a copy of the GNU General Public License             //
+// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
+///////////////////////////////////////////////////////////////////////////////////
+
+#ifndef SDRDAEMON_CHANNEL_SDRDAEMONDATAQUEUE_H_
+#define SDRDAEMON_CHANNEL_SDRDAEMONDATAQUEUE_H_
+
+#include <QObject>
+
+class DataBlock;
+
+namespace SDRDaemon {
+
+class DataQueue : public QObject {
+    Q_OBJECT
+
+public:
+    DataQueue(QObject* parent = NULL);
+    ~DataQueue();
+
+    void push(DataBlock* message, bool emitSignal = true);  //!< Push daa block onto queue
+    DataBlock* pop(); //!< Pop message from queue
+
+    int size(); //!< Returns queue size
+    void clear(); //!< Empty queue
+
+signals:
+    void dataBlockEnqueued();
+
+private:
+    QMutex m_lock;
+    QQueue<DataBlock*> m_queue;
+};
+
+} // namespace SDRDaemon
+
+#endif /* SDRDAEMON_CHANNEL_SDRDAEMONDATAQUEUE_H_ */