Research On Access Mechanism Of Heterogeneous Wireless Network

Recently, as the mobile communication technology develops rapidly, the structureof the communication network system is becoming more and more complex, and theservices provided are also richer and richer. The wireless networks have differentcharacteristics, and the services they provide to users are also different. Merging theseheterogeneous wireless networks, to provide services with full coverage, highbandwidth, seamless mobility and cheap cost, is the focus of the current study. In theheterogeneous network environment, how to ensure users to access to the right networkto get better services and how to reasonably schedule various network resources toachieve greater efficiency, is a problem to be worked out, as well as the focus of thisstudy.After analyzing the existing access mechanism, this paper puts forward aconcurrent access mechanism of multi-service based on UMTS and WLAN integrationenvironment, in order to allow users to share two networks at the same time. First of all,a multi-objective decision algorithm is introduced, and it focuses on thedecision-making multiple parameters and theirs weights; the multi-objective containsnetwork performance, business QoS requirements and user preferences, so that thedecision-making is more comprehensive. Then, a concurrent access mechanism(MC-AS) is proposed. The user’s traffic flows are spitted into several independent flowsaccording different QoS, and each traffic flow is carried by the suitable network decidedby the multi-objective decision algorithm, to satisfy business needs, while sharingnetwork resources.In order to perform multiservice concurrent access mechanism, a simulationsystem is structured using OPNET. And an intelligent multi-mode terminal and CRMare designed, as well as the interaction protocols between them. The simulation resultsshow that the concurrent access methods can be performed well. Based on themulti-objective decision algorithm, each traffic flow can access the most suitablenetwork, improving the network performance.Meanwhile, the access scheme of heterogeneous network is closely related to the resource allocation, and in order to serve more users, expand the network capacity andensure network fairness issues, this paper presents a utility-based joint resourcescheduling algorithm, based on the concurrent access. A utility function is defined, anda unified joint resource allocation model is built based on the referring basic resourceblock. The utility function can overall consider the relationship among rate, priority andfairness. It contains a dynamic fairness adjustment factor, to ensure the fairness of usersbetween different areas. At last, the algorithm is solved by reducing the dimension. Thesimulations show that the scheduling algorithm can guarantee users’ fairness. It, to someextent, makes the users in the single area have a greater probability to get resources. Inaddition, it accommodates more users to access, and enhances the overall performanceof the whole network.