B.Balavenkatesh
Abstract— The increasing demand for broadband services is causing the cellular network providers to consider for the integration of Wireless LAN with GPRS. WLAN is having higher data rate but low coverage area but GPRS is having lower data rate but with high coverage area. So integrating these two heterogeneous networks will lead to utilization of advantages of both and can increase the system throughput. The handoff latency is reduced by considering the threshold values of both the networks and anticipating the handoff well before. Especially the packet loss is completely eradicated by multicasting the packets during the handoff period and switch back to normal mode after the handoff. Hence the system throughput obviously increase by certain amount by our procedure of multicasting.
Keywords— Duplicate Packet Detection (DPD), Simplified Multicast Forwarding(SMF),Sequence Number Approach(SMA) Loose Coupling(LC),Mobile Node(MN),Previous Access Router (PAR),Next Access Router(NAR).
I. Introduction
Network selection techniques play a vital role in ensuring quality of service in heterogeneous networks. Handoff is the term which tells about the movement of mobile node from one access point to another.
Voice over IP(VOIP)
VoIP (voice over IP) is an IP telephony term for a set of facilities used to manage the delivery of voice information over the Internet.VoIP involves sending voice information in digital form in discrete packets rather than by using the traditional circuit-committed protocols of the public switched telephone network (PSTN). A major advantage of VoIP and Internet telephony is that it avoids the tolls charged by ordinary telephone service. To improve the Quality Of Service(QoS) of VOIP the handoff latency should be reduced, the packet loss should be reduced or else should be
References: Motorola India Research Labs Bangalore, India ian.chakeres@motorola.com, 1525-3511/08/$25.00 © 2008 IEEE 2) ETSI, “ Requirements and Architectures for Interworking 3) 3GPP, “ Group Services and System Aspects; 3GPP Systems to Wireless Local Area Network (WLAN) Interworking; System Description (Release 6),” TS 23.234, v.6.2.0, Sept. 2004. 4) K. Ahmavaara, H. Haverinen, and R. Pichna, “ interworking Architecture between 3GPP and WLAN Systems,” IEEE Commun. Mag., vol. 41, no. 11, Nov. 2003, pp 8) G. Lampropoulos, N. Passas,L.Merakos, and A. Kaloxylos, “Handover management architectures in integrated WLAN/cellular networks," IEEE Commun. Surveys Tutorials, vol. 7, no. 4, pp. 30-44, 2005. 9) D. Saha, A. Mukherjee, I. S. Misra, and M. Chakraborty, “Mobility support in IP: a survey of related protocols," IEEE Network, vol. 18, no. 6, pp. 34-40, 2004. 10) I. F. Akyildiz, J. Xie, and S. Mohanty, “ A survey of mobility management in next-generation all-IP-based wireless systems," Wireless Commun., vol. 11, no. 4, pp. 16-28, 2004. 13) Feasibility Study on 3GPP System to Wireless Local Area Network (WLAN) Interworking, Sep. 2003. 3GPP TR 22.934. 14) 3GPP System to Wireless Local Area Network (WLAN) Interworking; System Description, Jun. 2005. 3GPP TR 23.234. 15) Requirements and Architectures for Interworking Between HIPERLAN/2 and 3rd Generation Cellular Systems, Aug. 2001. ETSI TR 101 957. 17) A. K. Salkintzis, C. Fors and R. Pazhyannur, “WLAN-GPRS Integration for Next-Generation Mobile Data Networks,” IEEE Wireless Communications Magazine, vol. 9, no. 5, pp. 112-124, Oct. 2002.