top button
Flag Notify
    Connect to us
      Facebook Login
      Site Registration Why to Join

Facebook Login
Site Registration

LTE: What is the significance of different RoHC modes such as U-Mode O-Mode and R-Mode ?

+4 votes
LTE: What is the significance of different RoHC modes such as U-Mode O-Mode and R-Mode ?
posted Jul 27, 2018 by Harshita

Share this question
Facebook Share Button Twitter Share Button Google+ Share Button LinkedIn Share Button Multiple Social Share Button

1 Answer

0 votes

ROHC having three modes which is based on availability of feedback channel, error probabilities and header size variation.
U-Mode- Packets are only sent in one direction: from compressor to decompressor, this is suitable where return path is not available.
O-mode/Bi-directional Optimistic- There is feedback channel is used to send error recovery NACK & ACK.
R-Mode/Bidirectional Reliable- In this, feedback channel is used frequently to avoid packet loss due to context invalidation.The periodic context updating packets reduce compression efficiency compared to O-mode.
The ROHC compressor starts in U- mode & depends on availability of the feedback channel, error on link the modes changes also its a system implementation specific.

answer Jul 30, 2018 by Mohit Mohan
Similar Questions
+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.

+1 vote

I would like to change PDCP SN to 12 bits ( 7 bits is current) but not clear the effect.

From my understanding, if i increase the PDCP size to 12 bits (4096) for UE side it would be easier to decode packets correctly because sequence number will be identified with more bits.

What is your opinion?

Also since we increase the header for PDCP sn then data payload will be smaller so we can affect the throughput.

Contact Us
+91 9880187415
#280, 3rd floor, 5th Main
6th Sector, HSR Layout
Karnataka INDIA.