Research On The Key Technologies For Vertical Handover Decision In Heterogeneous Wireless Networks

The next generation wireless communication system is composed of multiple radio access technologies. They differ in terms of coverage, access capability, Qo S guarantee and so on. Not a single network can be in the bandwidth, latency, coverage range to satisfy all the end user demands. In order to take full advantage of network resources and achieve seamless roaming in heterogeneous wireless networks, it must adopt high-performance vertical handover scheme. In the vertical handover, the handover decision is a very critical factor. Therefore, this paper focuses on the investigation of the vertical handover decision.Firstly, this article describes the background knowledge of the current mobile communication network, summarizes the characteristics of heterogeneous wireless networks, and introduce the existing vertical handover decision as important.Secondly, in order to satisfy personalized vertical handover for end-user, this paper proposed a vertical handover decision algorithm consist of user preferences and fuzzy logic(UP-FLHO), defined network acceptance value(NAV) and network satisfaction value(NSV). Through situational awareness of context information to classify variety of network attributes and use the utility function to get the NSV, the network who with the largest NSV is the target network. This method not only provides "ABC", but also supports the "ABS". The simulation results show that proposed method can always keep the most satisfactory network connection.Thirdly, for the proposed algorithm, this paper presents a new method to calculate the weight. It consists of two parts, one of which by weight of the objective is to get the different conditions of the network itself, based on the information entropy. On the other hand, it is the user’s preference for users of each attribute, which is a combination of two weights on the weight of the final act, so that the final weight not only reflect itself in the case of network properties, but also reflect the preferences of the user-specific network properties.Finally, this paper presents a terminal system architecture to support the proposed handover decision algorithms.