ANSWER: Adaptive Network Selection in WLAN/UMTS Environment

• Main Authors: Wei-Chieh Chi, 紀緯傑
• Other Authors: Cheng-Fu Chou
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/23625667015221277771

碩士 === 國立臺灣大學 === 資訊工程學研究所 === 94 === The objective of next generation wireless network is to provide users with anywhere, any- time connectivity, high bandwidth and novel data service. People demanding for this kind of service cause cellular network provider to consider the integration of 3G cellular systems and wireless LAN, since WLAN has the advantages of high data rates and unlicensed spec- trum. Therefore, network selection technique plays a vital role in ensuring quality of service in heterogeneous networks. To improve system performance, we propose a novel network selection algorithm that guarantees making o® to the other access network is pro‾table, which means mobile users is always-best-connected(ABC). In our selection approach, in order to decide the optimum network for mobile users, available bandwidths of all usable networks are estimated. User''s location, moving direction is used to avoid frequent hando®s. This new approach is aimed at improving performances with regard to total throughput/goodput and number of hando®s which deteriorates service quality in mobile host''s life time. We evaluate the performance of our scheme via simulations and the results agree with our goals.