RLC

RLC Protocol is a layer 2 protocol that provides a range of transport services between an RLC entity in the UE and a peer RLC entity in the RNC. RLC provides three transport modes which are TM, UM and AM

RLC Functions:
- Segmentation and reassembly of higher-layer PDUs into/from smaller RLC payload units

- Concatenation

- Padding

- Transfer of user data

- Error correction

- In-sequence delivery of higher-layer PDUs

- Duplicate detection

- Flow control

- Sequence number check in UM

- Protocol error detection and recovery

- Ciphering in UM & AM modes

- Suspend and resume function

RLC services to upper layers:
Transparent Data Transfer Service

- Segmentation and reassembly

- Transfer of user data

- SDU discard

Unacknowledged Data Transfer Service

- Segmentation and reassembly

- Concatenation

- Padding

- Transfer of user data

- Ciphering

- Sequence number check

- SDU discard

Acknowledged Data Transfer Service

- Segmentation and reassembly

- Concatenation

- Padding

- Transfer of user data

- Error correction

- In-sequence delivery of higher-layer PDUs

- Duplicate detection

- Flow control

- Protocol error detection and recovery

- Ciphering

- SDU discard

Maintenance of Quality of Service (QoS) as defined by upper layers

Notification of Unrecoverable Errors

Related Topics:
TM, RRC, MAC