LteMacEnbD2D

simple module

This module extends LTE MAC functionalities at the eNodeB side to support device-to-device (D2D) communications. Specifically, it enhances resource allocation procedures to enable direct communication between User Equipments (UEs), i.e., it allocates resources for D2D transmissions. Network-assisted D2D is only implemented (out-of-coverage D2D is not supported).

Inheritance diagram

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

Known subclasses

Name	Type	Description
NRMacGnb	simple module	This module provides functionalities for the Medium Access Control (MAC) of the New Radio (NR) protocol stack at the gNodeB (gNB) side. In particular, it extends the LteMacEnbD2D module by initializing the NR version of the uplink scheduler and using, by default, the NR version of the Adaptive Modulation and Coding (AMC) module.

Extends

Name	Type	Description
LteMacEnb	simple module	This module extends the LteMacBase(1,2) module by providing specific MAC functions on the eNodeB side. Specifically, it initializes and manages the scheduling classes responsible for resource allocation operations in both uplink and downlink directions, while also supporting Carrier Aggregation (CA). It manages the Random Access procedure (RAC) and the reception of Buffer Status Reports (BSRs) from UEs, as well as the transmission of scheduling grants to UEs allocated within the uplink bandwidth. For downlink connections, it notifies the Radio Link Control (RLC) layer when it is ready to receive MAC Service Data Units (SDUs) to build MAC Protocol Data Units (PDUs) and transmit them to the physical layer.

Parameters

Name	Type	Default value	Description
binderModule	string	"binder"
packetFlowManagerModule	string	"^.packetFlowManager"	TODO or nrPacketFlowManager
queueSize	int	2MiB
muMimo	bool	true
harqProcesses	int	8
maxHarqRtx	int	3
harqFbEvaluationTimer	int	4	number of slots for sending back HARQ FB
statDisplay	bool	false
amcType	string	"LteAmc"	AMC Type: "LteAmc", "NRAmc"
amcMode	string	"AUTO"	AMC Mode: "auto", "piloted", "multi", "das", "D2D"
rbAllocationType	string	"localized"	resource allocation type ("distributed" or "localized")
summaryLowerBound	double	5ms	summary feedback confidence function lower bound
summaryUpperBound	double	20ms	summary feedback confidence function upper bound
fbhbCapacityDl	int	5	FeedBack Historical Base capacity in DL (number of stored feedback samples per UE)
fbhbCapacityUl	int	5	FeedBack Historical Base capacity in UL (number of stored feedback samples per UE)
fbhbCapacityD2D	int	5	FeedBack Historical Base capacity in D2D (number of stored feedback samples per UE)
pmiWeight	double	0.0	wideband PMI generation parameter (0.0 means "use the mean value" )
cqiWeight	double	0.0	wideband CQI generation parameter (0.0 means "use the mean value" )
eNodeBCount	int	0	number of eNodeBs - set to 0 if unknown
schedulingDisciplineDl	string	"MAXCI"	Scheduling discipline. See LteCommon.h for discipline meaning.
schedulingDisciplineUl	string	"MAXCI"
pfAlpha	double	0.95	Proportional Fair parameters
pilotMode	string	"ROBUST_CQI"
cellInfoModule	string
rlcUmModule	string	"^.rlc.um"
pdcpRrcModule	string	"^.pdcpRrc"
usePreconfiguredTxParams	bool	false
d2dCqi	int	7
reuseD2D	bool	false	frequency reuse parameters
reuseD2DMulti	bool	false
conflictGraphUpdatePeriod	double	1s
conflictGraphThreshold	double	90	CG thresholds can be defined in either dBm or meters if distances are set to -1.0, then dBm thresholds are used, otherwise distances have priority on dBm thresholds
conflictGraphD2DInterferenceRadius	double	-1.0m	meters
conflictGraphD2DMultiTxRadius	double	-1.0m	meters
conflictGraphD2DMultiInterferenceRadius	double	-1.0m	meters
msHarqInterrupt	bool	true	handling of D2D mode switch
msClearRlcBuffer	bool	true

Properties

Name	Value	Description
display	i=block/mac
class	LteMacEnbD2D

Gates

Name	Direction	Description
RLC_to_MAC	input	RLC to MAC
MAC_to_RLC	output	MAC to RLC
PHY_to_MAC	input	PHY to MAC
MAC_to_PHY	output	MAC to PHY

Signals

Name	Type	Unit	Description
macCellThroughputD2D
macCellPacketLossD2D

Statistics

Name	Title	Source	Record	Unit	Interpolation Mode	Description
macCellThroughputD2D	Cell Throughput at the MAC layer D2D	macCellThroughputD2D	mean	Bps
macCellPacketLossD2D	Mac Cell Packet Loss D2D	macCellPacketLossD2D	mean

Source code

//
// This module extends LTE MAC functionalities at the eNodeB side to support device-to-device (D2D)
// communications. Specifically, it enhances resource allocation procedures to enable direct
// communication between User Equipments (UEs), i.e., it allocates resources for D2D transmissions.
// Network-assisted D2D is only implemented (out-of-coverage D2D is not supported).
//
simple LteMacEnbD2D extends LteMacEnb
{
    parameters:
        @class("LteMacEnbD2D");

        bool usePreconfiguredTxParams = default(false);
        int d2dCqi = default(7);

        // frequency reuse parameters
        bool reuseD2D = default(false);
        bool reuseD2DMulti = default(false);
        double conflictGraphUpdatePeriod @unit(s) = default(1s);

        // CG thresholds can be defined in either dBm or meters
        // if distances are set to -1.0, then dBm thresholds are used,
        // otherwise distances have priority on dBm thresholds
        double conflictGraphThreshold = default(90);                       // dBm
        double conflictGraphD2DInterferenceRadius @unit(m) = default(-1.0m);         // meters
        double conflictGraphD2DMultiTxRadius @unit(m) = default(-1.0m);              // meters
        double conflictGraphD2DMultiInterferenceRadius @unit(m) = default(-1.0m);    // meters

        // handling of D2D mode switch
        bool msHarqInterrupt = default(true);
        bool msClearRlcBuffer = default(true);

        @signal[macCellThroughputD2D];
        @statistic[macCellThroughputD2D](title="Cell Throughput at the MAC layer D2D"; unit="Bps"; source="macCellThroughputD2D"; record=mean);
        @signal[macCellPacketLossD2D];
        @statistic[macCellPacketLossD2D](title="Mac Cell Packet Loss D2D"; unit=""; source="macCellPacketLossD2D"; record=mean);
}

File: src/stack/mac/LteMacEnbD2D.ned