Radio Link Control (RLC) is a layer 2 Radio Link Protocol used in

UMTS The Universal Mobile Telecommunications System (UMTS) is a 3G mobile cellular system for networks based on the GSM standard. UMTS uses Wideband Code Division Multiple Access, wideband code-division multiple access (W-CDMA) radio access technolog ...

, LTE and 5G on the

Air interface The air interface, or access mode, is the communication link between the two stations in mobile or wireless communication. The air interface involves both the physical and data link layers (layer 1 and 2) of the OSI model for a connection. Phys ...

. This protocol is specified by

3GPP The 3rd Generation Partnership Project (3GPP) is an umbrella term for a number of standards organizations which develop protocols for mobile telecommunications. Its best known work is the development and maintenance of: * GSM and related 2G and ...

in TS 25.322 for UMTS, TS 36.322 for LTE and TS 38.3223GPP TS 38.322 NR; Radio Link Control (RLC) protocol specification
/ref> for 5G New Radio (NR). RLC is located on top of the 3GPP MAC-layer and below the PDCP-layer. The main tasks of the RLC protocol are: * Transfer of upper layer Protocol Data Units (PDUs) in one of three modes: Acknowledged Mode (AM), Unacknowledged Mode (UM) and Transparent Mode (TM) * Error correction through ARQ (only for AM data transfer) * Concatenation, segmentation and reassembly of RLC SDUs (UM and AM) * Re-segmentation of RLC data PDUs (AM) * Reordering of RLC data PDUs (UM and AM); * Duplicate detection (UM and AM); * RLC SDU discard (UM and AM) * RLC re-establishment * Protocol error detection and recovery RLC features specific to LTE only - 1) Re-segmentation. 2) RLC SDU discard is notified by upper layer.

References

{{Reflist Mobile telecommunications standards 3GPP standards UMTS 5G (telecommunication) Logical link control