Method, system and mobile station for handing off communications from a cellular radio access network to an unlicensed mobile access network

• US 20060094431A1
• Filed: 11/01/2004
• Published: 05/04/2006
• Est. Priority Date: 11/01/2004
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Zheng, Haihong, Saifullah, Yousuf
• Granted Patent: US 7,565,144 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 36/0066 of control information between different types of networks in order to establish a new radio link in the target network
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/1446 wherein at least one of the networks is unlicensed

Abstract

A method, system and mobile station for handing off communications from a cellular radio access network, such as a code division multiple access (CDMA) radio access network, to an unlicensed mobile access network (UMAN) are provided. The handoff may be effected by a signaling sequence between the mobile station, an unlicensed network controller of the UMAN, a base station controller of the cellular radio access network and the core network. In this signaling sequence, the UMAN may be identified in various manners, such as by means of an otherwise unassigned pilot PN offset or by means of a band class and an invalid frequency.

Claims

1. A method of handing off communications with a mobile station from a cellular radio access network to an unlicensed mobile access network (UMAN), wherein the method comprises:

registering the mobile station with the UMAN including identifying an unlicensed network controller of the UMAN to the mobile station, wherein identifying the unlicensed network controller comprises assigning a band class and a frequency outside of the frequency range of the respective band class to the unlicensed network controller;

transmitting a message from the mobile station to the cellular radio access network directing a handoff of communications from the cellular radio access network to the UMAN; and

handing off communications from the cellular radio access network to the UMAN such that the mobile station is thereafter in communication with the unlicensed network controller of the UMAN.

2. A method according to claim 1 wherein directing the handoff of communications comprises transmitting pilot strengths for a plurality of pilot pseudo noise (PN) offsets that are less than a predefined value.

3. A method according to claim 2 further comprising transmitting a message including the frequency assigned to the unlicensed network controller to the mobile station.

4. A method of handing off communications with a mobile station from a cellular radio access network to an unlicensed mobile access network (UMAN) comprising:

registering the mobile station with the UMAN including identifying an unlicensed network controller of the UMAN to the mobile station, wherein identifying the unlicensed network controller comprises assigning a pilot pseudo noise (PN) offset to the unlicensed network controller, wherein the pilot PN offset that is assigned to the unlicensed network controller is otherwise unassigned;

transmitting a message from the mobile station to the cellular radio access network directing a handoff of communications from the cellular radio access network to the UMAN; and

handing off communications from the cellular radio access network to the UMAN such that the mobile station is thereafter in communication with the unlicensed network controller of the UMAN.

5. A method according to claim 4 further comprising associating the pilot PN offset that is assigned to the unlicensed network controller with a cell global identifier (CGI) of the unlicensed network controller and providing the association to the cellular radio access network.

6. A method according to claim 4 wherein directing the handoff of communications comprises transmitting a message from the mobile station to the cellular radio access network that assigns a greater pilot strength to the pilot PN offset assigned to the unlicensed network controller than to any other pilot PN offset.

7. A method of handing off communications with a mobile station from a code division multiple access (CDMA) radio access network to an unlicensed mobile access network (UMAN) comprising:

registering the mobile station with the UMAN including identifying an unlicensed network controller of the UMAN to the mobile station;

transmitting a message from the mobile station to the CDMA radio access network directing a handoff of communications from the CDMA radio access network to the UMAN; and

handing off communications from the CDMA radio access network to the UMAN such that the mobile station is thereafter in communication with the unlicensed network controller of the UMAN.

8. A method according to claim 7 wherein identifying the unlicensed network controller comprises assigning a pilot pseudo noise (PN) offset to the unlicensed network controller, wherein the pilot PN offset that is assigned to the unlicensed network controller is otherwise unassigned.

9. A method according to claim 8 further comprising associating the pilot PN offset that is assigned to the unlicensed network controller with a cell global identifier (CGI) of the unlicensed network controller and providing the association to the CDMA radio access network.

10. A method according to claim 8 wherein directing the handoff of communications comprises transmitting a message from the mobile station to the CDMA radio access network that assigns a greater pilot strength to the pilot PN offset assigned to the unlicensed network controller than to any other pilot PN offset.

11. A method according to claim 7 wherein a plurality of band classes define respective frequency ranges, and wherein identifying the unlicensed network controller comprises assigning a band class and a frequency outside of the frequency range of the respective band class to the unlicensed network controller.

12. A method according to claim 11 wherein directing the handoff of communications comprises transmitting pilot strengths for a plurality of pilot pseudo noise (PN) offsets that are less than a predefined value.

13. A method according to claim 12 further comprising transmitting a message including the frequency assigned to the unlicensed network controller to the mobile station.

14. A system for handing off communications from a mobile station, the system comprising:

an unlicensed network controller of an unlicensed mobile access network (UMAN), wherein said unlicensed network controller is capable of being identified to the mobile station during registration of the mobile station with the UMAN; and

a base station controller of a code division multiple access (CDMA) radio access network for supporting communications with the mobile station and for receiving a message from the mobile station directing a handoff of communications to the UMAN,

wherein said unlicensed network controller and said base station controller are further capable of cooperating to hand off communications from the CDMA radio access network to the UMAN such that the mobile station is thereafter in communication with said unlicensed network controller of the UMAN.

15. A system according to claim 14 wherein the unlicensed network controller is capable of being identified by a pilot pseudo noise (PN) offset that is otherwise unassigned.

16. A system according to claim 15 wherein said base station controller is capable of storing an association between the pilot PN offset that is assigned to the unlicensed network controller and a cell global identifier (CGI) of the unlicensed network controller.

17. A system according to claim 15 wherein said base station controller is capable of receiving a message from the mobile station that assigns a greater pilot strength to the pilot PN offset assigned to the unlicensed network controller than to any other pilot PN offset in order to direct the handoff of communications to the UMAN.

18. A system according to claim 14 wherein a plurality of band classes define respective frequency ranges, and wherein the unlicensed network controller is capable of being identified by a band class and a frequency outside of the frequency range of the respective band class.

19. A system according to claim 18 wherein said base station controller is capable of receiving a message from the mobile station defining pilot strengths for a plurality of pilot pseudo noise (PN) offsets to be less than a predefined value in order to direct the handoff of communications to the UMAN.

20. A system according to claim 19 wherein the base station controller is further capable of transmitting a message including the frequency assigned to the unlicensed network controller to the mobile station.

21. A dual mode mobile station capable of communicating via a cellular radio access network and an unlicensed mobile access network (UMAN), wherein the mobile station comprises:

a memory for storing an identification of an unlicensed network controller of the UMAN, wherein said memory is capable of storing a band class and a frequency outside of the frequency range of the respective band class that identify the unlicensed network controller; and

a controller for registering the mobile station with the UMAN including obtaining the identification of the unlicensed network controller of the UMAN, said controller also capable of transmitting a message to the cellular radio access network directing a handoff of communications from the cellular radio access network to the UMAN such that the mobile station is thereafter in communication with the unlicensed network controller of the UMAN following hand off of communications from the cellular radio access network to the UMAN.

22. A mobile station according to claim 21 wherein said controller is capable of transmitting a message to the cellular radio access network that defines pilot strengths for a plurality of pilot pseudo noise (PN) offsets to be less than a predefined value in order to direct the handoff of communications to the UMAN.

23. A mobile station according to claim 21 wherein the controller is further capable of receiving a message from the cellular radio access network including the frequency assigned to the unlicensed network controller.

24. A dual mode mobile station capable of communicating via a cellular radio access network and an unlicensed mobile access network (UMAN), the mobile station comprising:

a memory for storing an identification of an unlicensed network controller of the UMAN, wherein said memory is capable of storing a pilot pseudo noise (PN) offset that identifies the unlicensed network controller and is otherwise unassigned; and

a controller for registering the mobile station with the UMAN including obtaining the identification of the unlicensed network controller of the UMAN, said controller also capable of transmitting a message to the cellular radio access network directing a handoff of communications from the cellular radio access network to the UMAN such that the mobile station is thereafter in communication with the unlicensed network controller of the UMAN following hand off of communications from the cellular radio access network to the UMAN.

25. A mobile station according to claim 24 wherein said controller is capable of transmitting a message to the cellular radio access network that assigns a greater pilot strength to the pilot PN offset assigned to the unlicensed network controller than to any other pilot PN offset in order to direct the handoff of communications to the UMAN.

26. A dual mode mobile station capable of communicating via a code division multiple access (CDMA) radio access network and an unlicensed mobile access network (UMAN), the mobile station comprising:

a memory for storing an identification of an unlicensed network controller of the UMAN; and

a controller for registering the mobile station with the UMAN including obtaining the identification of the unlicensed network controller of the UMAN, said controller also capable of transmitting a message to the CDMA radio access network directing a handoff of communications from the CDMA radio access network to the UMAN such that the mobile station is thereafter in communication with the unlicensed network controller of the UMAN following hand off of communications from the CDMA radio access network to the UMAN.

27. A mobile station according to claim 26 wherein said memory is capable of storing a pilot pseudo noise (PN) offset that identifies the unlicensed network controller and is otherwise unassigned.

28. A mobile station according to claim 27 wherein said controller is capable of transmitting a message to the CDMA radio access network that assigns a greater pilot strength to the pilot PN offset assigned to the unlicensed network controller than to any other pilot PN offset in order to direct the handoff of communications to the UMAN.

29. A mobile station according to claim 26 wherein a plurality of band classes define respective frequency ranges, and wherein said memory is capable of storing a band class and a frequency outside of the frequency range of the respective band class that identify the unlicensed network controller.

30. A mobile station according to claim 29 wherein said controller is capable of transmitting a message to the CDMA radio access network that defines pilot strengths for a plurality of pilot pseudo noise (PN) offsets to be less than a predefined value in order to direct the handoff of communications to the UMAN.

31. A mobile station according to claim 30 wherein the controller is further capable of receiving a message from the CDMA radio access network including the frequency assigned to the unlicensed network controller.