LTE RLC Sub Layer Functions

LTE RLC Sub Layer Functions (Work of the RLC protocol in LTE): Main task of LTE RLC sub layer is transfer PDUs in three modes of LTE upper layer.

RLC Sub Layer Functions

  1. Protocol Data Units (PDUs) Transfer in upper layer any of three modes: Acknowledged Mode (AM), Unacknowledged Mode (UM) and Transparent Mode (TM)
  1. For AM data transfer correction of Error through ARQ (automatic repeat request )
  1. In Unacknowledged Mode – UM and Acknowledged Mode – AM : RLC SDUs Concatenation, segmentation and reassembly.
  1. RLC data PDUs AM – Acknowledged Mode for Re-segmentation
  1. Reordering of RLC data PDUs in Unacknowledged Mode and Acknowledged Mode
  1. Duplicate detection in Unacknowledged Mode and Acknowledged Mode.
  1. RLC SDU discards in both Unacknowledged Mode and Acknowledged Mode.
  1. RLC re-establishment in LTE
  1. Protocol error detection and recovery in LTE

LTE RLC Sub Layer Functions

The Radio Link Control (RLC) sub-layer in LTE handles the data link layer functionality between the User Equipment (UE) and the Evolved NodeB (eNB). It is responsible for ensuring reliable data transmission across the radio interface. There are three primary functions performed by the RLC sub-layer:

First, RLC is responsible for segmentation and reassembly. When large data packets need to be transmitted, RLC splits them into smaller segments that fit the radio link’s capacity and then reassembles them at the receiving end. Second, RLC provides error correction through Automatic Repeat Request (ARQ), where it ensures data is correctly received by retransmitting lost or corrupted packets. Lastly, RLC handles the flow control of data transmission, making sure that data is sent at a rate that the network can handle, preventing congestion and maintaining smooth transmission.