top button
Flag Notify
    Connect to us
      Site Registration

Site Registration

LTE: What is the t-reordering in rlc layer ?

+3 votes
LTE: What is the t-reordering in rlc layer ?
posted Dec 3, 2013 by Harshita

Share this question
Facebook Share Button Twitter Share Button LinkedIn Share Button

1 Answer

+1 vote

Reordering: When the receiving RLC entity receives RLC PDUs, it first reorders them if they are received out of sequence. Out-of sequence reception is unavoidable due to the fact that the HARQ operation in the MAC layer uses multiple HARQ processes. Any RLC PDUs received out of sequence
are stored in the reception buffer until all the previous RLC PDUs are received and delivered to the upper layer.

During the reordering process, any duplicate RLC PDUs received are detected by checking the SN's and discarded. This ensures that the upper layer receives upper layer PDUs only once.

To detect reception failures and avoid excessive reordering delays, a reordering timer is used in the receiving RLC entity to set the maximum time to wait for the reception of RLC PDUs that have not been received in sequence. The receiving RLC entity starts the reordering timer when a missing RLC PDU is detected, and it waits for the missing RLC PDUs until the timer expires. When the timer expires, the receiving UM RLC entity declares the missing RLC PDUs as lost and starts to reassemble the next available RLC SDU's from the RLC PDUs stored in the reception buffer.

The reordering is not applicable to RLC entities using the Multicast Control CHannel (MCCH) or Multicast Traffic CHannel (MTCH). This is because the HARQ operation in the MAC layer is not used for these channels.

answer Dec 24, 2014 by Pavankumar Survepalli
Is it possible to trigger rrcConnectionResatblishment procedure if more number of PDUs are lost?
Similar Questions
+4 votes

Can someone please put some light on this feature of LTE RLC layer ? I read about "Protocol error detection and recovery" at many places but couldn't understand well.

+6 votes

While going through 3GPP 36.322 specification. I saw a routing box inside the figure. Can anyone please explain the uses of it ?

+1 vote

As per 3gpp 36.322 Release 12.0 RLC specification, Extended RLC LI field = 15 bit is newly included in AM mode.
Can anyone please explain, exactly in what condition this 15-bit LI value will be used.