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<TITLE>RE: [e2e] HARQ</TITLE>
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<P><FONT SIZE=2>See <A HREF="http://en.wikipedia.org/wiki/Hybrid_ARQ">http://en.wikipedia.org/wiki/Hybrid_ARQ</A><BR>
<BR>
L.<BR>
<BR>
Saratoga: <A HREF="http://www.ee.surrey.ac.uk/Personal/L.Wood/dtn/">http://www.ee.surrey.ac.uk/Personal/L.Wood/dtn/</A><BR>
<BR>
<<A HREF="http://www.ee.surrey.ac.uk/Personal/L.Wood/">http://www.ee.surrey.ac.uk/Personal/L.Wood/</A>><L.Wood@surrey.ac.uk><BR>
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-----Original Message-----<BR>
From: end2end-interest-bounces@postel.org on behalf of Detlef Bosau<BR>
Sent: Mon 2007-08-27 9:23<BR>
To: end2end-interest list<BR>
Subject: [e2e] HARQ<BR>
<BR>
Hi to all.<BR>
<BR>
I have some HARQ issues, I do not fully understand.<BR>
<BR>
First of all, there are three kinds of HARQ. I do not fully understand<BR>
the difference between HARQ Type 1 and ordinary ARQ (without a buzzy H<BR>
in the beginning).<BR>
<BR>
The other two types are incremental redundancy and chase combining. Is<BR>
this correct?<BR>
<BR>
Now, HARQ often comes with adaptive channel coding.<BR>
<BR>
To my understanding, chase combining requires any sending attempts for<BR>
one PDU to be coded identically, in particular the MSCS/PS must not be<BR>
changed for different sending attempts for the same PDU, although the<BR>
channel properties may change in between.<BR>
<BR>
Another concern is whether we have are restricted to a stop and wait<BR>
scheme with IR / Chase combining. I don´t know a possibility to use<BR>
sliding window here, because a receiver must know, which received Frames<BR>
belong to the same original PDU.<BR>
<BR>
This is particularly important as I´ve learned that in HSDPA the RLC<BR>
endpoints are the RNC and the UE.<BR>
So, there is a transport line (Iub) between RNC and BS introduces<BR>
storage capacity into the path and which makes the use of a stop´n wait<BR>
scheme here questionable.<BR>
<BR>
Can someone help me out here?<BR>
<BR>
Thanks!<BR>
<BR>
--<BR>
Detlef Bosau Mail: detlef.bosau@web.de<BR>
Galileistrasse 30 Web: <A HREF="http://www.detlef-bosau.de">http://www.detlef-bosau.de</A><BR>
70565 Stuttgart Skype: detlef.bosau<BR>
Mobile: +49 172 681 9937<BR>
<BR>
<BR>
<BR>
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