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Asynchronous Quorum-based Channel Hopping MAC Protocols for Cognitive Radio Networks
Thesis

Asynchronous Quorum-based Channel Hopping MAC Protocols for Cognitive Radio Networks

Su, Chih-Wei
Masters, 國立清華大學, 通訊工程研究所
2012

Abstract

跳頻 無線感知網路 媒介存取控制 參數系統 Channel hopping Cognitive radio networks Macao Quorum system
In cognitive radio networks (CRNs), users must rendezvous their neighbors in order to establish the communication between each other. Generally, using common control channel is the simplest way to establish rendezvous process. However, when unlicensed users, such as secondary users (cognitive users), try to access licensed spectrum, it should avoid interference with licensed users (primary users, PUs). A special common control channel may cause the PU long-time blocking problem, and in a high density environment of nodes or traffic may cause the control channel saturation problem. Ideally, SUs should try to rendezvous each other on all licensed channels to maximize the possibility of transmission. Channel hopping (CH) have been proposed to avoid the problems of a single control channel. In this thesis, we use quorum-based system to establish a novel CH protocols and analyzing its performance with the four metrics: 1) Maximum time to rendezvous, 2) Channel loading, 3) Degree of rendezvous, and 4) Maximum conditional time to rendezvous. Furthermore, we will dynamically change the number of hopping channels in different periods when PUs occupy some channels for a long time. By skipping some unavailable channels, the period of rendezvous for SUs can be decreased and the performance can be improved.

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