Subject: [manet] Thoughts about schema-based address compression

From: Henning Rogge <[email-masked]>
Date: Wed, 30 Jan 2013 09:03:12 +0100

I worked a bit on adding address compression to the schema-based system 
we are discussing at the moment.

The idea is simple:

- A schema can contain up to 14 addresses (up to 16 bytes) in addition 
to information about the message header and TLVs.

- Every address block that use head or tail compression can refer to one 
of these addresses instead of explicitly including the prefix in the 
bytestream.

Both head and tail compression of addresses call for a 1 byte length 
field to define the split between header-, tail- and mid-parts.

Because of the limited address length of 16 bytes these length fields 
only contain numbers between 1 and 15.

My idea is to reuse the "free" four bits of the length field to allow 
the address block to refer to one of the stored addresses or the 
originator of the message.

I think this could be a major help for IPv6 MANETs.

I am still thinking about how to include this idea for the originator 
address.

Example Schema:
---------------
...
Address 1: 10.0.0.0

Uncompressed address block:
----------------------------
3 addresses (10.0.0.1, 10.0.0.2, 10.0.0.3), three byte header (10.0.0.), 
no prefix

# <num-addr>
03

# <addr-flags> = ahashead
80

# <head-length> <head>
03 0A 00 00

# <mid>*
01 02 03

Example for compressed address blocks:
--------------------------------------

3 addresses (10.0.0.1, 10.0.0.2, 10.0.0.3), three byte header (10.0.0.), 
no prefix

# <num-addr>
03

# <addr-flags> = ahashead
80

# <head-length>, refer to schema address 1 for head bytes
13

# <mid>*
01 02 03

Henning Rogge
-- 
Diplom-Informatiker Henning Rogge , Fraunhofer-Institut für
Kommunikation, Informationsverarbeitung und Ergonomie FKIE
Kommunikationssysteme (KOM)
Fraunhofer Straße 20, 53343 Wachtberg, Germany
Telefon +49 228 9435-961,   Fax +49 228 9435 685
mailto:[email-masked] http://www.fkie.fraunhofer.de