Debabrata Sarddar et al. / (IJCSE) International Journal on Computer Science and Engineering Vol. 02, No. 03, 2010, 630-634 Abstract—Next Generation Wireless Systems (NGWS) include co-existence of current wireless technologies such as WLANs, WiMAX, General Packet Radio Service (GPRS) and Universal Mobile Telecommunications System (UMTS). The most important and challenging issue is seamless handoff management in NGWS to ensure the Quality of Service (QoS). In this article, we propose a GPS based handoff technique to improve handoff probability in NGWS. Using GPS we determine the direction of velocity of the MT (Mobile Terminal). In earlier works handoff based on Relative Signal Strength (RSS) of BS (base station) was proposed. But in the case when a MT is moving towards an NBS whose RSS is less than that of its adjacent NBS, to take the decision of handover is quite decisive. But using GPS we can ensure efficient hand-off. The result shows that the proposed approach can solve the problem and helps to take the right decision decreasing false hand-off initiation probability. Index Terms-Next Generation Wireless Systems (NGWS), Handoff, GPS (Global Positioning System), Direction of velocity of MT (Mobile Terminal), Pre-registration. I. INTRODUCTION High capacity wireless access for mobile users is increasing rapidly. In tomorrow's always-on wireless connectivity, users will come to expect a certain level of Quality of Service (QoS) from their network providers. Integration of wireless networking and communication systems such as GSM(Global System for Communication),GPS(Global Positioning System GPRS(General Packet Radio Services), UMTS(Universal Mobile Telecommunication Services) and Wireless LAN (WLAN), Bluetooth for personal area and Satellite networks for Global networking can assure a certain level of Quality of Service (QoS). Two types of handoff can be occurred in NGWS shown in fig 1.  Horizontal handoff: handoff between two BSs of the same system. It can be further classified into  1) Link-layer handoff: Horizontal handoff between two BSs, under same foreign agent (FA), ., .g e the handoff of a MT from BS10 to BS11 in Fig. 1.  2) Intra-system handoff: Horizontal handoff between two BSs that belong to two different FAs and both FAs belongs to the same system and hence to same gateway foreign agent (GFA), ., .g e handoff of MT from BS11 to BS12 in Fig. 1.  Vertical handoff (Inter-System Handoff): Handoff between two BSs, belong to two different systems and two different GFAS, ., .g e the handoff of the MT from BS12 to BS20 in Fig. 1. Fig1 A Handoff Technique to Reduce False-Handoff Probability in Next Generation Wireless Networks Debabrata Sarddar 1 , Kaushik Mandal 1 , Tapas Jana 2 , Utpal Biswas 3 , M.K. Naskar 1 1. Department of Electronics and Telecommunication Engg, Jadavpur University, Kolkata – 700032. 2. Department of Electronics and Communication Engg, Netaji Subhash Engg College, Techno City, Garia, Kolkata – 700152. 3. Department of Computer Science and Engg, University of Kalyani, Nadia, West Bengal, Pin –741235. ISSN : 0975-3397 630