(Enabling) Roaming management in GPRS and WLAN networks based on SIP

Wireless networks technologies put focus on mobility management and transparent connectivity when user roams. These technologies must be integrated in a single environment based on All‐IP networks. Thus, mobile users could be able to visit and connect any heterogeneous networks technologies. Unfortunately, technical issues and the lack of roaming agreements between the different networks operators avoid the transparent interoperability. Our work is based on compare and analyze two roaming approaches in order to integrate communication and session control between two different networks technologies. We examine solutions based on loose coupled integration and IP mobility, which provide mobile applications (multimedia IP) and mobile services (AAA functions and user profiles). The approaches are based on the classification for service composition of the SAHARA project [39]: 1) Cooperative Model and 2) Brokered Model. Both models depend on the Service Level Agreements (SLAs), which represent a low cost and fast time‐to‐market [14]. The main goal consists to compare both models in the Next Generation Networks (NGN) that enable roaming management and session control from GPRS to WLAN, using SIP signaling and following the same principles, conditions and assumptions.