Handoff vertical entre réseau UMTS et WLAN

Abstract

One of the major challenges for next génération for the wireless communication Systems is to use the limited resources of communication networks effectively to provide quality and capacity that are sufficient for the growing need of bandwidth and the ability to provide ail sorts of value added services. The bandwidth requirements of users hâve increased due to new applications such as video and Internet browsing. This as enabled many emerging technologies that are constantly improving to meet the needs of users. This is particularly the case of heterogeneous networks used to interconnect varions networks such as WiFi, GSM/UMTS and Satellite. Thèse networks will help meet user's needs by offering them cheaper bandwidth, higher mobility, and more reliable networks. The objective of this Master thesis is to study and combine techniques of mobility management to exploit the advantages of both networks: cellular (UMTS) and wireless LAN (WLAN) and can integrate thèse two technologies so that the change in technology is transparent. The first part of this thesis, particular aspects of mobility management will be discussed. Heterogeneous UMTS/WLAN network can be intercormected in three différent ways; two particular architectures will be discussed. Furthermore, différent hand-off algorithms will be discussed, such as RSS algorithm, SNR and SINR. Most contributions in this context take into account just the maximization of throughput across both UMTS and WLAN networks, but not much research was donc on minimizing the number of handoffs during a call or data transfers. This plays an important rôle to avoid unnecessary handoffs and eliminate the ping-pong effect which dégrades the quality of service. Hence, in the second part of the thesis, a new integrated strategy for achieving vertical handoffs is proposed for mobile users between the two networks while minimizing the number of handoffs. This solufion will lower the packets lost in the network. It will also achieve greater throughput and transfer rates, while the cost remains lower. In this context we présent and we test several handoff algorithms, and we compare thèse algorithms with our proposed solution. AU algorithms hâve been validated and evaluated by simulafions.

Date	6 May 2010
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Michel Kadoch (Supervisor)