Fuzzy Logic Based Access Selection Algorithm In Heterogeneous Wireless Networks

With the development of wireless communication technology and IT industry, theexisting single network such as:2G/3G, WLAN, WCDMA will may be have no way tomeet the demand for personalized diversity business. Users with multi-mode terminal needthe network provide seamless connectivity at any location, thereby contributing to theaccess networks with different technologies must compensate each other on the serviceprovider, network performance, fused into the heterogeneous wireless network.Users demand varies network service, it makes every wireless network has the space ofsurvival and development. Therefore in a heterogeneous network environment, users can getservice with lower cost and higher degree of satisfaction through multi-access control. Multi-access select as the important technology of the radio resource management, has beenconfirmed through dynamic control the access of users, effectively improve the utilization ofradio resources, such as bandwidth, and avoid congestion of the network, save the capitalcost of the network.Due to the characteristics of the heterogeneous network: variety of network access,variety of techniques, variety of network factors, makes the network model complex and noteasy to establish. Fuzzy logic through the way to simulate the human brain thinking, do notneed modeling accurate model of the system, combined with previous research experience toconduct a analysis of the current status and parameters of the network, to arrive at the finalchoice results, solve the bottleneck of access selection, has been become a hot issue.In this paper, based on the study of existing access selection method, proposed anaccess selection algorithm based on fuzzy logic for heterogeneous wireless networks, thealgorithm consider the factors of network, let the average signal power, available bandwidthof the network, communication cost, network delay as the judgment target, first use the ideaof fuzzy logic, contrast the importance of every elements associated, construct fuzzyconsistent matrix, and assignment the compared results with a0.1-0.9scale, establishmentthe fuzzy judgment matrix, using the method of least squares to fuzzy judgment matrix,obtained weight values of various factors. And then use the gray correlation algorithmnormalized the factors that complex and difficult to determined, solve the gray correlationcoefficient of the normalized decision factors. Finally, obtain the gray relevance rankingfunction combined the fuzzy weight, the users select the highest level of the network access.The end of this article uses the C programming to build a simulation environment,parameter the assignment of the proposed algorithm, analysis the simulation and modeling ofthe proposed algorithm, the compared algorithm is the Analytic Hierarchy Process andMASVH algorithm, the result of simulation show that: The performance of the access selection algorithm based on fuzzy logic for heterogeneous wireless networks is moresuperior than the Analytic Hierarchy Process and MASVH algorithm, have achieve thedesired effect and has practicality.