Terrestrial and satellite cellular network interoperability
First Claim
1. A method for automatic handoff of a subscriber unit telephone call, wherein said subscriber unit is operable with a terrestrial based cellular system and a satellite based cellular system, comprising the steps of:
- (a) sending a handoff request from a subscriber unit to a base station of said terrestrial based cellular system, said subscriber unit being operable with said terrestrial based cellular system and said satellite based cellular system;
(b) said base station forwarding said handoff request to a mobile switching center of said terrestrial based cellular system;
(c) forwarding said handoff request to a gateway of said satellite based cellular system;
(d) said gateway determining at least one of said satellites of said satellite based cellular systems to be used by said subscriber unit;
(e) transferring synchronizing messages between said at least one of said satellites and said subscriber unit; and
(f) establishing a communications channel between said subscriber unit and said at least one of said satellites, wherein handoff from said terrestrial based cellular system and said satellite based cellular system is performed by the interaction between said subscriber unit, said base station, said mobile switching center and said gateway and not primarily by said subscriber unit interacting independently with said base station, said mobile switching center and said gateway.
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Accused Products
Abstract
Interoperability between terrestrial cellular systems and satellite based cellular systems allows handoffs between different cellular systems. A call in progress by a subscriber unit (101) over a terrestrial based cellular system (100) which includes a mobile switching center (MSC) (105a) and a plurality of base stations (103a-d) is handed off to a satellite based cellular system (1000) comprising a satellite network (100a, 1001b), a regional gateway (1007) and an interface gateway (1005). A call in progress by subscriber unit (101) over satellite based cellular system (1000) is also handed off to terrestrial based cellular system (100). A dual mode subscriber unit (400) provides switching functionality (409) to switch between transmit modes.
190 Citations
10 Claims
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1. A method for automatic handoff of a subscriber unit telephone call, wherein said subscriber unit is operable with a terrestrial based cellular system and a satellite based cellular system, comprising the steps of:
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(a) sending a handoff request from a subscriber unit to a base station of said terrestrial based cellular system, said subscriber unit being operable with said terrestrial based cellular system and said satellite based cellular system; (b) said base station forwarding said handoff request to a mobile switching center of said terrestrial based cellular system; (c) forwarding said handoff request to a gateway of said satellite based cellular system; (d) said gateway determining at least one of said satellites of said satellite based cellular systems to be used by said subscriber unit; (e) transferring synchronizing messages between said at least one of said satellites and said subscriber unit; and (f) establishing a communications channel between said subscriber unit and said at least one of said satellites, wherein handoff from said terrestrial based cellular system and said satellite based cellular system is performed by the interaction between said subscriber unit, said base station, said mobile switching center and said gateway and not primarily by said subscriber unit interacting independently with said base station, said mobile switching center and said gateway. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A system for automatic handoff of a subscriber unit telephone call, wherein said subscriber unit is operable with a terrestrial based cellular system and a satellite based cellular system, said satellite based cellular system having a plurality of satellites associated therewith, comprising:
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a subscriber unit being interoperable with said terrestrial based cellular system and said satellite based cellular system; a base station within said terrestrial based cellular system, said subscriber unit sending a handoff request to said base station; a mobile switching center within said terrestrial based cellular system, said base station forwarding said handoff request to said mobile switching center; a gateway of said satellite based cellular system, said mobile switching center forwarding said handoff request to said gateway, said gateway determining at least one of said plurality of satellites of said satellite based cellular systems that is to be used by said subscriber unit for use in establishing a communication between said subscriber unit and said at least one of said plurality of satellites, wherein handoff from said terrestrial based cellular system and said satellite based cellular system is performed by the interaction between said subscriber unit, said base station, said mobile switching center and said gateway and not primarily by said subscriber unit interacting independently with said base station, said mobile switching center and said gateway. - View Dependent Claims (9, 10)
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Specification