Research And Simulations On Load Balancing Algorithms In Heterogeneous Wireless Networks

With the wireless mobile communication technology to flourish, the third generation mobile communication technology has become the mainstream of the global mobile communications.Existing commercial wireless mobile communication technologies includes the second-generation networks (such as GSM),2.5-generation (such as GPRS and EDGE technology) and the third-generation mobile communication technology (such as WCDMA, CDMA2000 and TD-SCDMA technology).Next-generation mobile communications network will be a heterogeneous interworking architecture of various wireless access technologies. The load balancing algorithms of the single access technology cannot suit the future heterogeneous wireless networks,which needs to design a novel, effective load balancing algorithm.To solve the load balancing problem for heterogeneous wireless networks, a load balancing algorithm, named AMLB,which is based on analytic hierarchy process and multi-attribute decision making is proposed. This algorithm guides the system's call admission controlling and vertical handoff decision by the calls'importance values which is acquired by analyzing the calls'various attributes. But AMLB algorithm is still not enough incompetent for improving the performance of new calls.To solve this problem, an algorithm named BP-AMLB,which is based on BP artificial neural network and former AMLB algorithm is proposed. BP-AMLB algorithm uses the BP neural network's ability of non-linear function approximation to obtain the mapping between sample input and output. Then BP-AMLB algorithm dynamically adjusts the lower load threshold of a cell to access new calls as much as possible according to that mapping, so that it can improve the call blocking probability in AMLB algorithm.For validating and evaluating the capability of the proposed algorithms, a simulation platform is designed in MATLAB R2008a. Compared with traditional STLB algorithms, AMLB algorithm effectively reduces HCDP, and guaranteed the QoS of superior users. BP-AMLB algorithm is based on AMLB algorithm and improves NCBP.