Document Type : Article
Department of Computer Engineering, Sharif University of Technology, Tehran, Iran
Cognitive Radio (CR) technology enables Dynamic Spectrum Access (DSA) to ameliorate 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, reducing interference with PUs so that they can communicate without interruption is of paramount importance. In order to meet requirements of users as much as possible and reduce interference with PUs, a new Class-based Multi-path On-demand Routing protocol for Cognitive radio networks (CMORC) is proposed. CMORC is a multipath routing protocol which denes 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 finds optimum sending rates for each path by solving an optimization problem for each routing class. Since it is shown to be easy to solve these optimization problems, 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 the class type.