RLC protocol layer exists in UE & eNodeb, It is part of LTE air interface control and user planes.
The main services and functions of the RLC sublayer include:
- Transfer of upper layer PDUs;
- Error Correction through ARQ (only for AM data transfer);
- Concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer);
- Re-segmentation of RLC data PDUs (only for AM data transfer);
- In sequence delivery of upper layer PDUs (only for UM and AM data transfer);
- Duplicate detection (only for UM and AM data transfer);
- Protocol error detection and recovery;
- RLC SDU discard (only for UM and AM data transfer);
- RLC re-establishment.
Protocol specification
3GPP TS 36.322 - Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Link Control (RLC) protocol specification