PERFORMANCE EVALUATION FOR THE VoIP MOBILITY IN IP/CELLULAR NETWORK INTERNETWORKING

Abstract

The success of new services largely depends on the ability to blend with existing technologies. H.323 gateways provide an interconnection between IP network and Circuit Switched Networks. Cellular systems are been connected to the H.323 gateways only through the existing PSTN lines, which carry data at a rate 64 Kbps; very less as ? compared to the 1.5 Mbps IP lines. Presently, H.323 has no provision for the direct interconnection to the ellular networks. IC Here, performance evaluation of calls has been done for a proposed method of direct connection between the H.323 gateways and the Cellular networks without the PSTN coming in picture and without making any modifications in the present H.323 protocol structure. Further, a new method has been proposed to take care of the blocked calls by subdividing the existing channels into emergency channels and ordinary channels. By using the above two methods, a mobile user can directly connect to the IP, and with a very less probability of call blocking. A simulation is performed to find the blocking probability and the handoff probability of calls for a time of 24 hours. The performance is compared with the presently existing system where, firstly connection between the MSC and the gateway is through the PSTN and secondly no channels are reserved as emergency channels.