ZAP: a distributed channel assignment algorithm for cognitive radio networks

Paulo Roberto Walenga Junior,Mauro Fonseca,Artur Ziviani,Aline Carneiro Viana,Anelise Munaretto

doi:10.1186/1687-1499-2011-27

Abstract

AbstractWe propose ZAP, an algorithm for the distributed channel assignment in cognitive radio (CR) networks. CRs are capable of identifying underutilized licensed bands of the spectrum, allowing their reuse by secondary users without interfering with primary users. In this context, efficient channel assignment is challenging as ideally it must be simple, incur acceptable communication overhead, provide timely response, and be adaptive to accommodate frequent changes in the network. Another challenge is the optimization of network capacity through interference minimization. In contrast to related work, ZAP addresses these challenges with a fully distributed approach based only on local (neighborhood) knowledge, while significantly reducing computational costs and the number of messages required for channel assignment. Simulations confirm the efficiency of ZAP in terms of (i) the performance tradeoff between different metrics and (ii) the fast achievement of a suitable assignment solution regardless of network size and density.

Highlights

The unlicensed portion of the spectrum becomes increasingly overloaded because of the growing number of wireless nodes and mobile users
In the case of cognitive radio networks (CRNs), the main and the first issue to care about is to not to interfere with the communication of the primary users (PUs) [15]. This condition suggests that the set of available channels is time variant according to the behavior of PUs
We evaluate the performance of channel assignment by analyzing the percentage of removed interference achieved by the three considered strategies: Centralized Tabu-Based Algorithm (CTBA), ZAP, and random channel attribution method (RANDOM)

Summary

Introduction

The unlicensed portion of the spectrum becomes increasingly overloaded because of the growing number of wireless nodes and mobile users. In the case of CRNs, the main and the first issue to care about is to not to interfere with the communication of the PUs [15] This condition suggests that the set of available channels is time variant according to the behavior of PUs. As a consequence, the communication network formed by SUs varies according to the behavior of the PUs. the use of a distributed approach is suitable as messages are only exchanged by nodes affected by the change in the network. Once the stopping stage of the channel assignment is reached, nodes tune their radio interfaces permanently used for data communication, to the channels dictated by ZAP In this way, the proposed ZAP protocol aims at mitigating interferences by providing a suitable channel distribution among neighbor nodes. This channel is assigned to link in AssignedList

State 3

Findings

Conclusion