Today's mobile service providers allow their users to receive telecom services when they roam to other countries. However, international roaming is very expensive. In the standard mobile call setup procedure, a call from the visited country to a roaming user in that country results in two international calls. This phenomenon is referred to as the tromboning effect. Several third-party solutions have been proposed to resolve the tromboning problem by replacing two international calls with two local calls. These solutions require one or more gateways for call re-routing. This paper proposes a handset-based solution that does not need to add/modify network nodes in the existing mobile telecom systems. Analytic modeling and simulation experiments indicate that our solution is effective in international trunk elimination and call setup signaling.
- international roaming
- mobile telecom service