Method and apparatus to maintain connectivity for mobile terminals in wireless and cellular communications systems

Abstract

The present invention is directed to a system and method that allows mobile platforms each supporting any of a variety of call types, and each having differing mobility characteristics, to maintain connectivity to a backbone network in spite of unreliable radio links that occasionally fail. It accomplishes this by using automatic and user-transparent reconnection attempts for appropriate call sessions when an interruption of the link occurs. The network may be supporting a variety of different call types simultaneously. Access to network connectivity resources can be provided according to call session priority based on (for example, call session type, platform mobility, hand-off status, and user class (fee-for-service)) criteria. The technology allows support of suspended sessions and uses repeated reconnection attempts with priority access to network resources. It also provides for hand-offs of suspended sessions to neighboring gateways as mobile terminals move throughout the service area. In a network that uses this technology, for example, voice calls (typical of time-sensitive stream traffic) may preempt resources of time-insensitive data calls causing suspended sessions that do not result in session failures. Priority access for hand-offs of active sessions with respect to new call sessions can be accommodated. Mobile users that have some autonomy or who are perhaps exchanging time-insensitive data with a remote site can continue to function essentially undisturbed by link failures since the connectivity and reconnection procedures are managed by the network in a manner that is transparent to the end users. Mobile computing sessions and delay-insensitive data communications, for example, will be able to continue, largely unaware of link failures.