Systems and methods for mobility management in overlaid mobile communications systems

Abstract

Communications of a mobile station with a satellite mobile communications system and a terrestrial mobile communications system are coordinated. The mobile station is registered with the terrestrial mobile communications system and, responsive to the registration of the mobile station with the terrestrial mobile communications system, the mobile station is concurrently registered with the satellite mobile communications system. The concurrent registration may include implicitly registering the mobile station with the satellite mobile communications system, e.g., by storing information identifying the mobile station may be stored in a location register of the satellite mobile communications system responsive to the registration of the mobile station with the terrestrial mobile communications system, and maintaining synchronization between the two registrations. Authentication tokens may be pre-generated for quick re-registration with a satellite mobile communications system.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of provisional Application No. 60 / 505,526, filed Sep. 23, 2003, entitled Mobility Management for Hybrid Terrestrial-Satellite Networks, the disclosure of which is hereby incorporated herein by reference in its entirety as if set forth fully herein.BACKGROUND OF THE INVENTION [0002] The present invention relates to wireless communications systems and methods, and more particularly, to mobility management systems and methods for wireless communications. [0003] An aim of hybrid terrestrial-satellite networks may be for the satellite network to provide a ubiquitous coverage overlay for the terrestrial network. However, this may give rise to a number of mobility management challenges that may not be optimally handled by the current state of the art. [0004]FIG. 1 shows a satellite overlay for a terrestrial network. Three types of regions are identified. A region A is the planned coverage area of the cellular...

AI Technical Summary

Benefits of technology

[0012] In further embodiments of the present invention, concurrent registration of the mobile station with the satellite mobile communications system may include explicitly registering the mobile station with the satellite mobile communications system responsive to the registration of the mobile station with the terrestrial mobile communications system. For example, explicit registration of the mobile station with the satellite mobile communications system may include initiating a registration request from the mobile station to the satellite mobile communications system responsive to the registration of the mobile station with the terrestrial mobile communications system without detecting a loss of communications between the mobile station and the terrestrial mobile communications system.

Problems solved by technology

However, this may give rise to a number of mobility management challenges that may not be optimally handled by the current state of the art.

The holes exist mainly in suburban areas and in corridors between urban areas where the population density may not be sufficient for the cellular operator to prioritize the deployment of more base station towers.

This could create a huge and unnecessary burden on the satellite resources of power and bandwidth, which may be unnecessary, as most of the MS's may not need to use the satellite network.

Call dropping is generally considered a very negative user experience in cellular services and, if the user has been told that there is a satellite coverage-overlay, he may expect the same seamless service as in cellular.

As the mobile re-entered the cellular network it would typically roam back again to the cellular network, which again could involve a significant period of service unavailability for the user.

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