[Nrg-l] Kave Salamatian: 2pm Tuesday IN MCS 135

Mark Crovella crovella at cs.bu.edu
Mon Dec 13 20:54:51 EST 2004


A reminder: Kave Salamatian's talk is at 2pm tomorrow.

We will MOVE THE TALK TO MCS 135 due to the strong interest.

Mark

--
Title: A network coding based approach for Communication in AdHoc/sensor
networks

Wireless networks consist of senders, receivers and intermediate nodes that
collaborate (more or less) to communicate with each others. Most of the
researches in the domain of wireless network have focused on routing based
approaches where the wireless network is reduced as a dynamic graph and a
minimum cost routing mechanism is applied. These approaches have lead to
several routing mechanisms as OLSR (Optimized Link State Routing Protocol),
AODV (Ad hoc On Demand Distance Vector). 
However the fundamental nature of wireless network is broadcast, meaning
that every transmission is potentially received by all tuned receivers.
This basic property is not well captured by graph based approaches where
packets follow a single path from sender to receiver. Using the multipath
approaches have been very attractive, however Optimal MultiPath routing have
shown to be NP-Complete and on the other extreme packet flooding approaches
that also use all the available capacity in the wireless network are very
wasteful of energy.  

In this presentation we will present an approach that tries to benefit from
the overall capacity inside the network without flooding it with redundant
packets. The proposed approach is rooted in Information theory. It is based
on collaboration of intermediate relays at network layer to forward useful
side information in place of dumbly forwarding packets. We will show in this
paper the information theoretic bounds and show that they are achievable
using practical codes. The practical coding scheme is presented for the
general case of multiple intermediate nodes. The proposed coding scheme is
simulated in realistic scenarios and the obtained results show a remarkable
improvement in throughput and relay load compared to network using classical
routing approach.



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