RE: [rohc] default algorithm, redux

"Surtees, Abigail" <abigail.surtees@roke.co.uk> Mon, 18 February 2002 11:46 UTC

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From: "Surtees, Abigail" <abigail.surtees@roke.co.uk>
To: "'hans.hannu@epl.ericsson.se'" <hans.hannu@epl.ericsson.se>, "'rohc@ietf.org'" <rohc@ietf.org>
Subject: RE: [rohc] default algorithm, redux
Date: Mon, 18 Feb 2002 11:40:29 -0000
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Hans,

Thanks for these clarifications.

For completeness here are the results for the same files with no dynamic compression and no sharing - just each file compressed independently of everything else.

message		static		dynamic
forward direction
1			587			502
4			457			395
6			434			377
7			216			200
9			249			232
12			227			213

reverse direction
2			223			210
3			685			576
5			227			214
8			266			245
10			216			203
11			239			225

Best Regards,

Abbie

> I think we have been talking (again) about different things.
> What I meant with dynamic compression, regardless of the compression
> algorithm used, is that:
> (Referring to an old expired draft SigComp -02)
> 
> "5.3. Dynamic compression
>    A compressing entity MAY choose to use previously sent messages in
>    the compression process in an attempt to improve the compression
>    efficiency. This is referred to as dynamic compression."
> 
> "5.4. Shared compression
> 
>    Shared compression is referred to the case when a 
> compressor 'A' make
>    use of decompressed messages received by the decompressor 
> located at
>    the same SigComp entity. These decompressed messages MUST originate
>    from the corresponding SigComp entity, which decompressor is
>    controlled by compressor 'A'."
> 
> So, the figures you present in this mail, would be with the above
> definition, compressed using "dynamic" compression, and in 
> your previous
> mail, both "shared" and "dynamic" compression were used.
> 
> BR
> /Hans H
> 
>