Performance Evaluation Of Sip Based Services In Umts

"With ever increasing penetration of IP technologies and the tremendous growth in wireless data traffic, the wireless industry is evolving the mobile core networks towards IP technology. The 3rd Generation Partnership Project (3GPP) is specifying an IP Multimedia Core Network Sub-System (IMS) in UMTS Release 5 and Release 6, which is adjunct to the UMTS GPRS core network. This IP-based network will allow mobile operators to provide commonly used Internet applications to wireless user. The UMTS IMS uses the Internet Engineering Task Force (IETF) defined text based Session Initiation Protocol (SIP), to control a wide range of anticipated IP-based services such as Voice over IP, Multimedia calls, etc. Moreover, its capabilities have made SIP suitable to provide new applications and services. Text based protocols are easier to develop than bit-wise representations and likely to be more expediently taken to market, as they allow operators/vendors to open the application space to a much broader development community. This is likely to result in new services offering such as wireless multimedia calls, chat, presence and messaging services. However, initial indications as to the signalling delays associated with packet call control using SIP have concerned operators about the viability of such services over the UMTS air interface. This has led UMTS vendors/operators to invest in the standardisation of ways to wireless by enable the efficient use of SIP with such measures such as protocol compression. This study provides insight into the performance that can be expected from the broad range of UMTS services. Several types of services, with different QoS characteristics are analysed. A UMTS packet-switched voice service is studied and then compared with the UMTS circuit-switched voice service. Moreover new offered services, such as Instant Messaging with presence capabilities are studied providing a broader view of UMTS system capabilities."