According to the FCC (Federal Communications Commission) [11], the utilization of the spectrum has been increasing rapidly over a wide range of frequency bands. There are various reasons that cause this dynamic growth. One reason is increase in network capacity. Another reason is increase in mobile services needed to carry over the spectrum. In order to overcome the shortage of spectrum due to increased usage, Cognitive Radio (CR) technology has been introduced. Cognitive Radios can utilize idle spectrum holes that are not occupied by the Primary Users (PUs) for performing temporary wireless communication tasks. PUs are licensed users which own and have access to certain spectrum bands. Challenging issues that need to be addressed by the CRs are spectrum sensing, spectrum sharing, spectrum management and spectrum mobility.

The main contribution of this thesis is to design a new MAC layer protocol in order to determine the behavior of Secondary Users (SUs) based on PUs transmission history while taking into account both PUs and SUs. SUs are non licensed users which transmit only on those spectrum bands that are unutilized by the PUs. SUs usually observe the activity of PUs on spectrum bands. This new protocol allows the CR nodes to sense, share and manage access of the nodes to the spectrum. This protocol prevents any damage caused by SUs to the PUs transmission. Also, the new MAC protocol will negotiate the spectrum by assisting the CRs to identify the underutilized spectrum based on channel conditions such as channel throughput, channel data rate, channel score, channel utilization and packet error rate (PER). The Intelli MAC layer protocol measures transmission time among PUs and reduces channel sensing time for SUs. For managing the entire network, this protocol uses the concept of Harmonious Channel (HC). This protocol uses multiple half duplex transceivers for carrying data communication among users.

Library of Congress Subject Headings

Wireless communication systems--Access control; Ad hoc networks (Computer networks)--Access control; Wireless LANs--Access control; Computer network protocols

Publication Date


Document Type


Student Type


Degree Name

Computer Engineering (MS)

Department, Program, or Center

Computer Engineering (KGCOE)


Andres Kwasinski


Physical copy available from RIT's Wallace Library at TK5103.2 .P384 2009


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