Systems, methods and computer program products for mobility management in hybrid satellite/terrestrial wireless communications systems

Abstract

Apparatus, methods and computer program products that support inter-PLMN coordination in registration and handover operations are provided. Hysteresis is introduced in registration of radioterminals in a hybrid terrestrial / satellite mobile communications environment. Inter-PLMN handover techniques are provided, including techniques for coordination of communication of timing information and traffic channel controls.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the priority of U.S. Provisional Application Ser. No. 60 / 725,813; filed Oct. 12, 2005, incorporated by reference herein in its entirety.FIELD OF THE INVENTION [0002] This invention relates to wireless communications systems and methods, and more particularly to hybrid satellite and terrestrial wireless communications systems and methods. BACKGROUND OF THE INVENTION [0003] Satellite radiotelephone communications systems and methods are widely used for radiotelephone communications. Satellite radiotelephone communications systems and methods generally employ at least one space-based component, such as one or more satellites, that is / are configured to wirelessly communicate with a plurality of satellite radiotelephones. [0004] A satellite radiotelephone communications system or method may utilize a single satellite antenna pattern (beam or cell) covering an entire service region served by the system. Alternatively, o...

AI Technical Summary

Benefits of technology

[0017] In some embodiments, determining a duration of the degradation of coverage may include determining a signal strength for communications between the radioterminal and the first one of the satellite wireless communications network and the terrestrial wireless communications network. Determining whether to register the radioterminal with a second one of the satellite wireless communications network and the terrestrial wireless communications network responsive to whether the determined duration meets a predetermined criterion may include registering the radioterminal with the second one of the satellite wireless communications network and the terrestrial wireless communications network responsive to the signal strength meeting a predetermined level criterion for a predetermined time interval.

[0018] In some embodiments, a potential degradation of coverage for the radioterminal while registered with the terrestrial wireless communications network is detected. A duration of the degradation of coverage is determined responsive to detecting the potential degradation of coverage while remaining registered with the terrestrial wireless communications network. The radioterminal may be registered with the satellite wireless communications network responsive to the signal strength meeting a first predetermined level criterion for a first predetermined time interval. Subsequently, a potential improvement of coverage by the terrestrial wireless communications network for the radioterminal is detected while registered with the satellite wireless communications network. A duration of the potential improvement of coverage is determined. The radioter

Problems solved by technology

But only uplink (from MT to gateway) may be impacted by the post synchronization issue.

If the first RR Handover Access message is not received correctly by the satellite BSC BSC-B, the ACK may be delayed by additional rounds of handshake delays until the new path is truly open.

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