Link quality control mode

[usama0795]

Hey can anyone highlight the effect of changing link quality control mode from LA to IR in both good and bad RF quality conditions on both TBF Drop Rate and throughput as some of the benefits are highlighted below

Ø IR adjusts the physical layer code rate to actual channel conditions by incrementally transmitting redundant information until decoding is successful. Automatic Repeat Request take cares of requesting and retransmitting incorrectly received blocks. ARQ reduces retransmissions delays and is better equipped to handle degraded air interface quality.
Ø With incremental redundancy, the incorrectly transmitted block is not repeated but the data is transmitted with the next puncturing scheme. Both blocks are then used for error correction. This increases the probability of correcting transmission errors.

As I wanted to in IR data is sent through puncturing schemes as in bad RF quality conditions if data is not recieved without error after puncturing scheme 3 has been exhausted what parameters would it use to downgrade the coding scheme.....OR if BEP and CV BEP would still be utilized in IR to select the coding scheme? and what about initail coding scheme selelction would it intervene when coding scheme is changed to IR? are there any other parameters dependent on IR? in addition LA works burst by burst as each burst in radio block can be transmitted with a seperate coding scheme is the same applicable to IR?.....

[usama0795]

Calling for GPRS/EDGE experts to the forum.....need some help....

[mohyedeen_alkousy]

I tried to change before in Huawei from LA to IR but it gave no impact neither on Throughput or drop
any way according to recommendation it should be IR as you said it will bring many features

did u try to change it

[usama0795]

Nah baisacally looking for a justification for the customer....but did u try the parameter in good radio conditions as initially MCS9 would be used and if packet is successfulling decoded MCS9 would be kept on using but in case of LA u have to send the first radio block using default initial conding scheme.....u in short it should effect throughput....