Affiliations: Department of Electronic Systems Engineering,
University of Essex, Colchester, UK
Note: [] Corresponding author. University of Essex, ESE Department,
Wivenhoe Park, Colchester CO4 3SQ, UK. Tel.: +44 (0)1206 87 4247; Fax: +44
(0)1206 87 2900; E-mail: antonio.liotta@ieee.org
Abstract: With an ever increasing penetration of Internet Protocol (IP)
technologies, the wireless industry is evolving the mobile core network towards
all-IP network. The IP Multimedia Subsystem (IMS) is a standardised Next
Generation Network (NGN) architectural framework defined by
the 3rd Generation Partnership Project (3GPP) to bridge
the gap between circuit-switched and packet-switched networks and consolidate
both sides into on single all-IP network for all services. In this paper, we
provide an insight into the limitation of the presence service, one of the
fundamental building blocks of the IMS. Our prototype-based study is unique of
its kind and helps identifying the factors which limit the scalability of the
current version of the presence service (3GPP TS 23.141 version 7.2.0 Release
7 [1]), which will in turn dramatically limit the performance of advanced
IMS services. We argue that the client-server paradigm behind the current IMS
architecture does not suite the requirements of the IMS system, which defies
the very purpose of its introduction. We finally elaborate on possible avenues
for addressing this problem.