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The Spectrum Shortage Problem: Channel Assignment and Cognitive Networks

In recent years there has been a huge proliferation of wireless
applications and services
which has conducted to the so-called spectrum shortage problem.

In this talk, we illustrate this problem and we propose solutions in
order to improve the usage of unlicensed channels as well as to
opportunistically use licensed channels.
Initially, we introduce a joint channel assignment and routing
algorithm for multi-radio multi-channel mesh networks,
then we move our focus on cognitive networks (CNs) which are seen as
the most promising technology to solve the spectrum shortage problem.
In fact, although the channels usage is improved by channel assignment
techniques, unlicensed channels are still overcrowded.
With the aim to solve the channel overcrowding problem, the Federal
Communications Commission conducted careful analysis on the frequency
spectrum.
These analysis show that most of the licensed channels are
surprisingly underutilized by legitimate users and hence they can be
used by unlicensed users in CNs.

We propose four algorithms focusing on different features of CNs.
Three of these algorithm use a game theoretic approach and are based
on the new IEEE 802.22 standard.
They address the self-coexistence problem as a channel assignment
problem where devices acquire channels in a dynamic and distributed
way.
The fourth algorithm, instead, handles describe the issues of
implementing cognitive mesh networks.


Dal 30/03/2011-11.00 al 30/03/2011-11.00 , Aula A32 (vicino alla biblioteca)

Responsabile: Paolo Santi

Attività: Algoritmica per reti wireless