ABSTRACT
In the Multiple-Operability Mobile Systems, mobile users (MUs) will be able to move across various heterogeneous networks
while using their mobile terminals (MTs) to communicate. It has been proven that this global roaming freedom significantly
increases the network-signaling traffic. Several schemes have been recently proposed to reduce such a traffic. This paper
presents an efficient approach which uses a special gateway called Wireless INterworking Gateway (WING) to facilitate
interoperability between heterogeneous subsystems of the NG wireless systems. Results reveal that such an approach
significantly improves the network performance, in terms of generated signaling traffic and response time during the global
roaming process.
Keywords: - Global Roaming, Multiple-Operability Mobile Systems, heterogeneous networks, Service portability, Location
management.