Performance estimation of UMTS release 5 IM-subsystem elements

Universal Mobile Telecommunications System (UMTS) is the third generation (3G) mobile communications systems specified by European Telecommunications Standards Institute (ETSI) and the world-wide 3G Partnership Project (3GPP) within the framework defined by the International Telecommunication Union (ITU) and known as International Mobile Telecommunications-2000 (IMT-2000). ETSI and 3GPP are introducing UMTS in phases and annual releases. UMTS is a 3G GSM successor standard using the GSM Phase 2+ enhanced core networks. Currently, there is an evolution from GSM Phase 2+ core network towards UMTS Release 5 multiservice packet network. This process is characterized by creating of Internet Protocol (IP) Multimedia Core Network Subsystem (IMsubsystem), which includes elements necessary to support IM services in UMTS. Traffic patterns generated by IM services are different from traditional Poisson models used for circuit switched voice traffic. As a result, the network parameters can be underestimated. Therefore, the UMTS network planning problem arises. For successful solution of the problem it is necessary to estimate a performance of IM-subsystem elements. In this paper we have analyzed the performance of Gateway GPRS Support Node (GGSN) on a base of FBM/D/1/W queueing system (FBM Fractional Brownian Motion). Submitted results may be applied for estimation of parameters of UMTS Rel’5 IM-subsystem elements.