Network Coding

Efficient and Simple Multicasting

In traditional communication systems, nodes exchange data in packets, through relaying by intermediate nodes without modification of their content (routing). Seminal work from Ahlswede, Cai, Li and Yeung in has introduced the idea of network coding, whereby intermediate nodes are mixing information from different flows (different bits or different packets), for instance performing "exclusive or" between packets, before retransmitting them.

Since the introduction of the concept, many results have blossomed including methods for coding, evaluation of its performance, algorithms, mecanisms, proof of concept implementations, ...

The Hipercom team is studying network coding specifically for MANET networks. It is mostly used as an efficient multicast/broadcast method (limiting the number of transmissions), and also as a reliable flooding mecanism. Hipercom has proven some theoretical results: the optimality of network coding for asymptotically large and dense wireless networks, and also its advantage over non-coding.

Work is ongoing to adjust this theoretic asymptotic result to practice: we are developing dynamic adaptative algorithms, that are resilient to loss and mobility, while they attempt to approach the optimality. The theoretic capacity of network coding in smaller instances of wireless networks is also explored.

T. Clausen and U. Herberg at IEEE-NSS 2010 in Melbourne, Australia, September 1-3
They will present the paper "Router and Link Admittance Control in the Optimized Link State Routing Protocol version 2 (OLSRv2))". Part of the OLSRv2 Security series of publications documenting efforts on providing secure, OLSRv2-based networks, this paper studies the use and performance of "fine-grained signatures".

Here's some more OLSRv2-security-related information on the Hipercom@LIX website:
Securing OLSRv2
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T. Clausen and U. Herberg at IEEE-iTAP 2010 in Wuhan, China, August 21-23
They will present the paper "Digital Signatures for Admittance Control in the Optimized Link State Routing Protocol version 2". Part of the OLSRv2 Security series of publications documenting efforts on providing secure, OLSRv2-based networks, this paper emphasizes the use and performance of ECC for admittance control in OLSRv2-based networks.

Here's some more OLSRv2-security-related information on the Hipercom@LIX website:
Securing OLSRv2
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IETF in Maastricht
Before and during the IETF in Maastricht, July 25-30 2010 a new slew of I-Ds happened, from the quills of Hipercom@LIX:

NHDP was updated after AD review, and IESG evaluation started - hopefully, this is the second-to-last document in the core OLSRv2 protocol suite.

The OLSRv2 mib document also was updated as was the NHDP mib document and the the PacketBB-SEC document -- the latter of which now is a working group document (yay!).

A new I-D, YAAP was published, detailing one current ad hoc address autoconfiguration protocol.

In the Wireless Sensor Networking area, two new documents were published: a p2p (sensor-to-sensor) extension to RPL and a performance study hereof.
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