Method and system for handoffs between public and private wireless networks

• US 8,335,188 B1
• Filed: 05/19/2008
• Issued: 12/18/2012
• Est. Priority Date: 05/19/2008
• Status: Active Grant

• Current Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Original Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Inventors: Harris, David L., Rausch, Walter F.
• Primary Examiner(s): TRAN, PHUC H
• Application Number:
  US12/123,010
• Time in Patent Office: 1,674 Days
• Field of Search: 370331-334, 455/434
• US Class Current: 370/331
• CPC Class Codes: H04W 12/03 Protecting confidentiality, e.g. by encryption
• CPC Class Codes: H04W 36/0061 of neighbour cell information
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00

Abstract

A mobile station receives a neighbor list from a base station in an area of a public wireless network that borders a private wireless network. The neighbor list includes encrypted channel identifiers corresponding to private network channels transmitted by the private wireless network and unencrypted channel identifiers corresponding to public network channels transmitted by the public wireless network. If the mobile station does not subscribe to the private wireless network, the mobile station does not recognize the encrypted channel identifiers and simply ignores them. However, if the mobile station subscribes to the private wireless network, the mobile station decrypts the encrypted channel identifiers and determines whether it is able to initiate a handoff to any of the corresponding private network channels.

Claims

1. A method for a mobile station that subscribes to both a private wireless network and a public wireless network, said method comprising:

while being served by said public wireless network, said mobile station receiving a neighbor list, said neighbor list including at least one private network channel identifier corresponding to at least one private network channel transmitted by said private wireless network and at least one public network channel identifier corresponding to at least one public network channel transmitted by said public wireless network, wherein said at least one private network channel identifier is encrypted; and

after receiving said neighbor list;

(a) said mobile station decrypting said at least one private network channel identifier;

(b) said mobile station determining whether said at least one private network channel satisfies a private network handoff criterion; and

(c) if said private network handoff criterion is satisfied, said mobile station initiating a handoff to said at least one private network channel without regard to said at least one public network channel.

2. The method of claim 1, further comprising:

if said private network handoff criterion is not satisfied, said mobile station determining whether said at least one public network channel satisfies a public network handoff criterion.

3. The method of claim 2, wherein said private network handoff criterion differs from said public network handoff criterion.

4. The method of claim 1, further comprising:

said mobile station periodically determining whether said at least one private network channel satisfies said private network handoff criterion.

5. The method of claim 1, wherein said mobile station determining whether said at least one private network channel satisfies a private network handoff criterion comprises:

said mobile station measuring a signal strength of said at least one private network channel; and

said mobile station comparing said signal strength to a predetermined threshold value.

6. The method of claim 1, wherein said neighbor list is an IEEE 802.16 neighbor advertisement message or a CDMA neighbor list message.

7. A mobile station that subscribes to both a private wireless network and a public wireless network, said mobile station comprising:

at least one transceiver for wireless communication with said private wireless network and said public wireless network;

a processor;

data storage;

a plurality of program instructions stored in said data storage and executable by said processor to perform functions comprising;

(a) receiving a neighbor list, said neighbor list including a plurality of channel identifiers, said plurality of channel identifiers including at least one encrypted channel identifier that corresponds to at least one private network channel transmitted by said private wireless network and at least one unencrypted channel identifier that corresponds to at least one public network channel transmitted by said public wireless network;

(b) decrypting said at least one encrypted channel identifier;

(c) determining whether said at least one private network channel satisfies a private network handoff criterion; and

(d) if said private network handoff criterion is satisfied, initiating a handoff to said at least one private network channel.

8. The mobile station of claim 7, wherein said plurality of program instructions are executable by said processor to perform functions comprising:

(e) if said private network handoff criterion is not satisfied, determining whether said at least one public network channel satisfies a public network handoff criterion.

9. The mobile station of claim 7, wherein said plurality of program instructions are executable by said processor to perform functions (c) and (d) periodically.

10. The mobile station of claim 9, wherein said public network handoff criterion differs from said private network handoff criterion.

11. The mobile station of claim 7, wherein said neighbor list is an IEEE 802.16 neighbor advertisement message or a CDMA neighbor list message.

12. The mobile station of claim 7, wherein determining whether said at least one private network channel satisfies a private network handoff criterion comprises:

measuring a signal strength of said at least one private network channel; and

comparing said signal strength to a predetermined threshold value.