Re: [e2e] HARQ

See http://en.wikipedia.org/wiki/Hybrid_ARQ

L.

Saratoga: http://www.ee.surrey.ac.uk/Personal/L.Wood/dtn/

<http://www.ee.surrey.ac.uk/Personal/L.Wood/><L.Wood(at)surrey.ac.uk>

-----Original Message-----
From: end2end-interest-bounces@postel.org on behalf of Detlef Bosau Sent: Mon 2007-08-27 9:23
To: end2end-interest list
Subject: [e2e] HARQ  

Hi to all.

I have some HARQ issues, I do not fully understand.

First of all, there are three kinds of HARQ. I do not fully understand the difference between HARQ Type 1 and ordinary ARQ (without a buzzy H in the beginning).

Do you need help?
In addition to our free technical library, Pantek provides professional IT services to companies who utilize Open Source software: Learn more about Pantek's Technical Support offerings Place an order for 24/7/365 Technical Support here Learn more about Pantek, who we are, and what we do Chat with a Live Operator Related postel.org Links end2end-interest Request more information about Pantek

The other two types are incremental redundancy and chase combining. Is this correct?

Now, HARQ often comes with adaptive channel coding.

To my understanding, chase combining requires any sending attempts for one PDU to be coded identically, in particular the MSCS/PS must not be changed for different sending attempts for the same PDU, although the channel properties may change in between.

Another concern is whether we have are restricted to a stop and wait scheme with IR / Chase combining. I don´t know a possibility to use sliding window here, because a receiver must know, which received Frames belong to the same original PDU.

This is particularly important as I´ve learned that in HSDPA the RLC endpoints are the RNC and the UE.
So, there is a transport line (Iub) between RNC and BS introduces storage capacity into the path and which makes the use of a stop´n wait scheme here questionable.

Can someone help me out here?

Thanks!

-- 
Detlef Bosau                          Mail:  detlef.bosau@web.de
Galileistrasse 30                     Web:   
http://www.detlef-bosau.de
70565 Stuttgart                       Skype: detlef.bosau
Mobile: +49 172 681 9937