ILteRlcUm

module interface

Interface module for the Unacknowledged Mode (UM) of the Radio Link Control (RLC) layer. It defines gates to the Packet Data Convergence Protocol (PDCP) module and the LteRlcMux module. UM enables segmentation and/or concatenation of RLC Service Data Units (SDUs) before transmission, according to the size of the RLC Protocol Data Unit (PDU) decided by the Medium Access Control (MAC) layer. On the receiving side, RLC SDUs are reassembled before being forwarded to the Packet Data Convergence Protocol (PDCP) layer. In-sequence delivery of RLC SDUs is also guaranteed.

Inheritance diagram

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

Implemented by

Name	Type	Description
LteRlcUm	simple module	This module implements the functionalities of the Unacknowledged Mode (UM) of the Radio Link Control (RLC) layer. Transmitting- and receiving-side functionalities are provided by the UmTxEntity and UmRxEntity submodules, respectively. The latter are created dynamically whenever a new connection is detected. This module is responsible for identifying the flow to which a RLC Service Data Unit (SDU) or Protocol Data Unit (PDU) belongs and routing it to the corresponding transmitting or receiving entity for further processing.
LteRlcUmD2D	simple module	This module implements the functionalities of the Unacknowledged Mode (UM) of the Radio Link Control (RLC) layer for User Equipments supporting Device-to-Device (D2D) communications. It extends the basic RLC functionalities with specific management functions necessary when a connection is switched from infrastructure mode to D2D mode, and vice versa.

Used in compound modules

Name	Type	Description
LteRlc	compound module	The LteRlc module implements the functionalities of the Radio Link Control (RLC) layer. It provides mechanisms for end-to-end connectivity over the radio interface. It sends and receives RLC Service Data Units (SDUs) to and from the Packet Data Convergence Protocol (PDCP) layer, and sends and receives RLC Protocol Data Units (PDUs) to and from the Medium Access Control (MAC) layer. Depending on the mode, this layer can provide segmentation, concatenation, in-sequence delivery, and retransmission of PDUs. Currently, only the Unacknowledged Mode (UM) has been implemented.

Parameters

Name	Type	Default value	Description
queueSize	int
mapAllLcidsToSingleBearer	bool

Source code

//
// Interface module for the Unacknowledged Mode (UM) of the Radio Link Control (RLC) layer.
// It defines gates to the Packet Data Convergence Protocol (PDCP) module and the ~LteRlcMux
// module. UM enables segmentation and/or concatenation of RLC Service Data Units (SDUs) before
// transmission, according to the size of the RLC Protocol Data Unit (PDU) decided by the Medium Access
// Control (MAC) layer. On the receiving side, RLC SDUs are reassembled before being
// forwarded to the Packet Data Convergence Protocol (PDCP) layer. In-sequence delivery of
// RLC SDUs is also guaranteed.
//
moduleinterface ILteRlcUm
{
    parameters:
        int queueSize @unit(B);
        bool mapAllLcidsToSingleBearer;
    gates:
        inout UM_Sap_up;    // Gate to PDCP
        inout UM_Sap_down;    // Gate to RLC Mux
}

File: src/stack/rlc/um/ILteRlcUm.ned