Systems and methods for mobility management in overlaid mobile communications systems
View Patent ↗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.
1. A method of coordinating communications of a mobile station with a satellite mobile communications system, the method comprising:
generating respective copies of a set of authentication tokens at respective ones of the mobile station and the satellite mobile communications system; and then
performing successive registrations of the mobile station with the satellite mobile communications system using successive ones of the authentication tokens;
wherein performing successive registrations of the mobile station with the satellite mobile communications system using successive ones of the authentication tokens comprises:
registering the mobile station with the satellite mobile communications system using a first one of the authentication tokens;
establishing communications between the mobile station and a terrestrial mobile communications system;
re-establishing communications between the mobile station and the satellite mobile communications system; and
re-registering the mobile station with the satellite mobile communications system using a second one of the authentication tokens;
the method further comprising:
communicating security data for the mobile station from the terrestrial mobile communications system to the satellite mobile communications system, and wherein generating respective copies of a set of authentication tokens at respective ones of the mobile station and the satellite mobile communications system comprises generating the respective copies of the set of authentication tokens at respective ones of the mobile station and the satellite mobile communications system from the communicated security data;
communicating new security data from the terrestrial mobile communications system to the satellite mobile communications system responsive to detecting that a predetermined number of the previously generated authentication tokens have been used; and
generating respective copies of a new authentication token at respective ones of the mobile station and the satellite mobile communications system from the communicated new security data.
2. A method according to claim 1 , wherein each of the successive registrations of the mobile station with the satellite mobile communications system comprises:
communicating an authentication token from the mobile station to the satellite mobile communications system; and
determining whether the communicated authentication token matches an authentication token generated by the satellite mobile communications system.
3. A method according to claim 1 , wherein re-registering the mobile station with the satellite mobile communications system using a second one of authentication tokens comprises re-registering the mobile station with the satellite mobile communications system without retrieving additional security data from the terrestrial mobile communications system.
4. A method according to claim 1 , wherein the communicated security data comprises a plurality of triplets, each including a random number, an encrypted value generated from the random number according to a key associated with a subscriber, and a cipher key, and wherein generating respective copies of a set of authentication tokens at respective ones of the mobile station and the satellite mobile communications system from the communicated security data comprises:
communicating the random numbers from the satellite mobile communications system to the mobile station; and
generating matching triplets at the mobile station from the communicated random numbers.
5. A mobile communications system, comprising:
a satellite mobile communications system that supports generation of respective copies of a set of authentication tokens at respective ones of a mobile station and the satellite mobile communications system and that is further operative to subsequently accept successive registrations of the mobile station with the satellite mobile communications system using successive ones of the authentication tokens;
wherein the satellite mobile communications system is operative to receive security data for the mobile station from a terrestrial mobile communications system and to generate the copy of the set of authentication tokens from the received security data; and
wherein the satellite mobile communications system is further operative to receive new security data from the terrestrial mobile communications system responsive to detecting that a predetermined number of the previously generated authentication tokens have been used and to generate a copy of a new authentication token from the received new security data.
6. A system according to claim 5 , wherein the satellite mobile communications system is further operative to transfer at least a portion of the received security data to the mobile terminal to support generation of the copy of the set of authentication tokens at the mobile station.
7. A system according to claim 5 , wherein the satellite mobile communications system is operative to re-register the mobile station therewith out retrieving additional security data from the terrestrial mobile communications system.
8. A system according to claim 5 , wherein the received security data comprises a plurality of triplets, each including a random number, an encrypted value generated from the random number according to a key associated with a subscriber, and a cipher key.
9. A system according to claim 5 , wherein the satellite mobile communications system is further operative to transfer at least a portion of the received new security data to the mobile terminal to support generation of a copy of the new authentication token at the mobile station.
10. A method performed by a mobile station to coordinate communications of the mobile station with a satellite mobile communications system, the method comprising:
providing a set of authentication tokens; and then
performing successive registrations of the mobile station with the satellite mobile communications system using successive ones of the authentication tokens;
wherein performing successive registrations of the mobile station with the satellite mobile communications system using successive ones of the authentication tokens comprises:
registering the mobile station with the satellite mobile communications system using a first one of the authentication tokens;
establishing communications between the mobile station and a terrestrial mobile communications system;
re-establishing communications between the mobile station and the satellite mobile communications system; and
re-registering the mobile station with the satellite mobile communications system using a second one of the authentication tokens;
the method further comprising:
receiving security data for the mobile station from the satellite mobile communications system, and wherein providing a set of authentication tokens comprises generating the set of authentication tokens at the mobile station from the communicated security data;
receiving new security data for the mobile station responsive to detecting that a predetermined number of the previously generated authentication tokens have been used; and
generating a new authentication token at the mobile station from the communicated new security data.
11. A method according to claim 10 , wherein each of the successive registrations of the mobile station with the satellite mobile communications system comprises:
communicating an authentication token from the mobile station to the satellite mobile communications system; and
determining whether the communicated authentication token matches an authentication token generated by the satellite mobile communications system.
12. A method performed by a satellite mobile communications system to coordinate communications of a mobile station with the satellite mobile communications system, the method comprising:
generating a set of authentication tokens at the satellite mobile communications system; and then
performing successive registrations of the mobile station with the satellite mobile communications system using successive ones of the authentication tokens;
wherein performing successive registrations of the mobile station with the satellite mobile communications system using successive ones of the authentication tokens comprises:
registering the mobile station with the satellite mobile communications system using a first one of the authentication tokens; and
re-registering the mobile station with the satellite mobile communications system using a second one of the authentication tokens;
the method further comprising:
receiving security data for the mobile station from the terrestrial mobile communications system at the satellite mobile communications system, and wherein generating a set of authentication tokens at the satellite mobile communications system comprises generating the set of authentication tokens at the satellite mobile communications system from the communicated security data;
receiving new security data from the terrestrial mobile communications system at the satellite mobile communications system responsive to detecting that a predetermined number of the previously generated authentication tokens have been used; and
generating a new authentication token at the satellite mobile communications system from the communicated new security data.
13. A method according to claim 12 , wherein each of the successive registrations of the mobile station with the satellite mobile communications system comprises:
receiving an authentication token from the mobile station at the satellite mobile communications system; and
determining whether the communicated authentication token matches an authentication token generated by the satellite mobile communications system.
14. A mobile communications device, comprising:
a mobile station that includes a set of authentication tokens and that is operative to successively register with the satellite mobile communications system using successive ones of the authentication tokens from the set of authentication tokens;
wherein the mobile station is operative to receive security data from a terrestrial mobile communications system and to generate the copy of the set of authentication tokens from the received security data; and
wherein the mobile station is further operative to receive new security data from the terrestrial mobile communications system responsive to detecting that a predetermined number of the previously generated authentication tokens have been used and to generate a copy of a new authentication token from the received new security data.
15. A device according to claim 14 , wherein the mobile station is further operative to receive security data from the satellite mobile communications system and to generate the set of authentication tokens at the mobile station from the security data.
16. A device according to claim 15 , wherein the security data comprises a plurality of triplets, each including a random number, an encrypted value generated from the random number according to a key associated with a subscriber, and a cipher key.