Abstract :
Cognitive Radio (CR) technology enables Dynamic Spectrum Access (DSA) to
improve the eciency of under-utilized licensed bands and overcrowded unlicensed bands.
However, providing an acceptable service for cognitive users requires more sophisticated
approaches due to the existence of Primary Users (PU) with high priority over licensed
bands. Additionally, it is of paramount importance that interference with PUs be reduced
so that they can communicate without interruption. In order to meet requirements of users
as much as possible and reduce interference with PUs, a new Class-based Multi-path Ondemand
Routing protocol for Cognitive radio networks (CMORC) is proposed. CMORC
is a multipath routing protocol, which de nes two classes of routing to make delay or
interference optimum. To the best of our knowledge, it is the rst multipath protocol
that takes into consideration both route discovery and rate allocation. CMORC nds the
optimum sending rates for each path by solving an optimization problem for each routing
class. Since solving these optimization problems is shown to be easy, CMORC is an ecient
and practical solution for radio equipment with limited hardware. The simulation results
reveal that CMORC outperforms the other recent multipath routing protocol, D2CARP,
in terms of interference, delay and packet delivery ratio depending on class type.
