Network Selection And Resource Allocation Based On Preference Value In Heterogeneous Wireless Networks

With the development of wireless communication technology, the trend of future wireless network is heterogeneous networks convergence, which combines various access technologies to provide service to user together. These radio access technologies have their own advantages in coverage, mobility and service type, which shows they can complement each other in a specific way and provide high quality communication access to users wherever and whenever. As one of the key technologies in heterogeneous network convergence, network selection algorithms are the research hotspot. Such algorithms study how to select the most suitable network according to users’service requirement and other parameters by some certain selection strategy among several coexisting access technologies. Besides, with the development of communication service, the requirement of users on bandwidth and data rate becomes higher and more urgent. It has become an important issue in heterogeneous wireless network that how to make full use of existing spectrum resource to satisfy the growing requirement and increase the capacity of the system, namely, provide users with the most suitable resource by some specific allocation strategy, and improve the efficiency of wireless resource, so as to ensure the service quality.The main work of this dissertation is to study the network selection and resource allocation based on preference value in heterogeneous network. The details are as follows:First, a network selection algorithm based on preference value is proposed. By analyzing users’service requirement and other parameters, calculating the preference value by a weighting way, and then, performing the network selection according to the preference value, the algorithm can reach the payload balance. The simulation result shows that the algorithm can distribute services into various networks and realize load balancing.Second, a based resource allocation algorithm based on preference value is proposed. The algorithm ranks the users according to users’ requirement after all the users have completed the network selection, and then allocate the resource recursively until matching users’requirement. The main process of the algorithm is that, the user gets the channel gain information and noise information through detecting and reports this information with other necessary parameters to the network. The network allocates the resource unit to user according to user’s preference value and detected channel information. The resource unit is a single carrier and each round user can be allocated with a most suitable sub-carrier. The network allocates the resource one by one until every user has been allocated with enough resource. Simulation result shows that the algorithm can improve the spectrum efficiency as well as guarantee users’ fairness.Finally, a NS2-based heterogeneous network platform is built, which realize related modules of the radio resource management and mobility management. The platform concludes the WCDMA-based network and GPRS-based network. This thesis implements the functions of IMSI attach/detach location update, authentication and ciphering and radio resource allocation.