LTE (TS 36.322) transmission side of the Acknowledged Mode (AM) of the RLC layer: one AMD PDU per MAC grant built by concatenation (FI framing), the built PDU as the ARQ unit, NACK-driven retransmission with re-segmentation into AMD PDU segments, pollPDU/pollByte-driven status polling with t-PollRetransmit, and radio link failure at maxRtxThreshold retransmissions. Shares the common RlcAmTxEntityBase shell with the NR profile NrRlcAmTxEntity, whose ARQ skeleton it deliberately mirrors. Bound by default inside the LteRlcAmEntity compound.

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Parameters

Name	Type	Default value	Description
AM_Window_Size	int	512	TS 36.322: 512 (10-bit SN space)
pollByte	int	125kB
pollPDU	int	64
maxRtxThreshold	int	4
t_PollRetransmit	double	80ms
bearerManagementModule	string		Notified when maxRtxThreshold is reached; set by the enclosing entity

Properties

Name	Value	Description
dynamic	true
display	i=block/layer

Gates

Name	Direction	Size	Description
in	input		SDUs from the PDCP layer (direct per-DRB connection, not via a mux)
macIn	input		MAC SDU requests, via the RlcMux
out	output		PDUs and new-data notifications to MAC, via the RlcMux
feedbackIn	input		STATUS PDUs received from the peer, from the co-located RX side (to ARQ)
statusIn	input		Locally generated STATUS reports, from the co-located RX side (to transmit)

Signals

Name	Type	Unit	Description
receivedPacketFromUpperLayer
sentPacketToLowerLayer
txWindowOccupation
wastedGrantedBytes
requestedPduSize
enqueuedSduSize
enqueuedSduRate
txWindowFull
retransmissionPdu

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode	Description
receivedPacketFromUpperLayer		receivedPacketFromUpperLayer	count, sum(packetBytes)		none
sentPacketToLowerLayer		sentPacketToLowerLayer	count, sum(packetBytes)		none
txWindowOccupation	TX window occupation	txWindowOccupation	mean
wastedGrantedBytes	Wasted granted bytes	wastedGrantedBytes	sum	B
requestedPduSize	Requested PDU size	requestedPduSize	mean	B
enqueuedSduSize	Enqueued SDU size	enqueuedSduSize	mean	B
enqueuedSduRate	Enqueued SDU rate	enqueuedSduRate	mean
txWindowFull	TX window full events	txWindowFull	count
retransmissionPdu	Retransmitted PDUs	retransmissionPdu	count

Source code

//
// LTE (TS 36.322) transmission side of the Acknowledged Mode (AM) of the RLC
// layer: one AMD PDU per MAC grant built by concatenation (FI framing), the
// built PDU as the ARQ unit, NACK-driven retransmission with re-segmentation
// into AMD PDU segments, pollPDU/pollByte-driven status polling with
// t-PollRetransmit, and radio link failure at maxRtxThreshold retransmissions.
// Shares the common RlcAmTxEntityBase shell with the NR profile
// ~NrRlcAmTxEntity, whose ARQ skeleton it deliberately mirrors. Bound by
// default inside the ~LteRlcAmEntity compound.
//
simple LteRlcAmTxEntity like simu5g.stack.rlc.IRlcAmTxEntity
{
    parameters:
        @dynamic(true);
        @display("i=block/layer");
        int AM_Window_Size = default(512);       // TS 36.322: 512 (10-bit SN space)
        int pollByte @unit(B) = default(125kB);
        int pollPDU = default(64);
        int maxRtxThreshold = default(4);
        double t_PollRetransmit @unit(s) = default(80ms);
        string bearerManagementModule;   // Notified when maxRtxThreshold is reached; set by the enclosing entity

        @signal[receivedPacketFromUpperLayer];
        @statistic[receivedPacketFromUpperLayer](source="receivedPacketFromUpperLayer"; record=count,"sum(packetBytes)"; interpolationmode=none);
        @signal[sentPacketToLowerLayer];
        @statistic[sentPacketToLowerLayer](source="sentPacketToLowerLayer"; record=count,"sum(packetBytes)"; interpolationmode=none);
        @signal[txWindowOccupation];
        @statistic[txWindowOccupation](title="TX window occupation"; source="txWindowOccupation"; record=mean);
        @signal[wastedGrantedBytes];
        @statistic[wastedGrantedBytes](title="Wasted granted bytes"; unit="B"; source="wastedGrantedBytes"; record=sum);
        @signal[requestedPduSize];
        @statistic[requestedPduSize](title="Requested PDU size"; unit="B"; source="requestedPduSize"; record=mean);
        @signal[enqueuedSduSize];
        @statistic[enqueuedSduSize](title="Enqueued SDU size"; unit="B"; source="enqueuedSduSize"; record=mean);
        @signal[enqueuedSduRate];
        @statistic[enqueuedSduRate](title="Enqueued SDU rate"; source="enqueuedSduRate"; record=mean);
        @signal[txWindowFull];
        @statistic[txWindowFull](title="TX window full events"; source="txWindowFull"; record=count);
        @signal[retransmissionPdu];
        @statistic[retransmissionPdu](title="Retransmitted PDUs"; source="retransmissionPdu"; record=count);

    gates:
        input in;       // SDUs from the PDCP layer (direct per-DRB connection, not via a mux)
        input macIn;    // MAC SDU requests, via the RlcMux
        output out;     // PDUs and new-data notifications to MAC, via the RlcMux
        input feedbackIn;   // STATUS PDUs received from the peer, from the co-located RX side (to ARQ)
        input statusIn; // Locally generated STATUS reports, from the co-located RX side (to transmit)
}

File: src/simu5g/stack/rlc/am/LteRlcAmTxEntity.ned

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