Enhancement to PLMN selection process while roaming

Patent metadata

Field	Value
Publication number	US-9277492-B2
Application number	US-201213560929-A
Country	US
Kind code	B2
Filing date	Jul 27, 2012
Priority date	Jul 27, 2012
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

A method and apparatus for a mobile wireless device configured to adaptively scan for a preferred wireless network while roaming is described. In one embodiment, at least a portion of a database including characteristic information regarding wireless networks can be stored within the mobile wireless device. Network characteristic information can include mobile country codes, mobile network codes, location area codes and cell-IDs. When the mobile wireless device is connected to a network that is not a preferred network, the mobile wireless device can use the database information in conjunction with characteristics from a connected wireless network to determine when to scan for the preferred wireless network.

First claim

What is claimed is:

1. A method of network selection by a mobile wireless device while roaming on a visited wireless network, the method of network selection comprising:
storing, at least in part in the mobile wireless device, network adjacency information, comprising a first database and a second database, for wireless networks, while the mobile wireless device is connected to a home wireless network;
roaming from the home wireless network to the visited wireless network;
connecting the mobile wireless device to the visited wireless network;
determining from the first database that a country code of the visited wireless network matches a country code of the home wireless network or that the visited wireless network is adjacent to the home wireless network;
searching the second database to determine whether the home wireless network is adjacent to the visited wireless network; and
scanning for the home wireless network when the home wireless network is adjacent to the visited wireless network based on the search of the second database.

2. The method of claim 1 , wherein the first database comprises country code information for wireless networks, and the second database comprises location area code, mobile network code and cell-ID information for wireless networks.

3. The method of claim 1 further comprising:
updating the second database based on data obtained from a location server, while the mobile wireless device is roaming on the visited wireless network.

4. The method of claim 2 , further comprising:
performing a limited high priority network search when the country code information for the visited wireless network is not included in the first database.

5. The method of claim 4 , wherein the limited high priority network search is performed for a particular public land mobile network (PLMN) network in accordance with a priority specified in a user controlled PLMN list or in an operator controlled PLMN list.

6. A method for adaptively scanning for a home wireless network, by a mobile wireless device while roaming on a visited wireless network, the method for adaptively scanning for the home wireless network comprising:
prior to roaming on the visited wireless network, storing a first database and a second database of network adjacency information correlating country code information and network identifiers at least in part in the mobile wireless device;
roaming on the visited wireless network;
determining from the first database of network adjacency information that a country code of the visited wireless network matches a country code of the home wireless network or that the visited wireless network is adjacent to the home wireless network; and
scanning for the home wireless network, while roaming on the visited wireless network when the mobile wireless device determines based on the second database that the home wireless network is adjacent to the visited wireless network.

7. The method of claim 6 , wherein the second database of network adjacency information includes location area code, mobile network code and cell-ID information of wireless networks.

8. The method of claim 7 , further comprising updating the second database of network adjacency information when an identifier of the visited wireless network is not included in the second database of network adjacency information.

9. The method of claim 8 , further comprising updating the second database of network adjacency information when a data connection exists between the mobile wireless device and a wireless network.

10. The method of claim 9 , further comprising:
locating the home wireless network; and
notifying a user of the mobile wireless device that the home wireless network is available when the mobile wireless device is configured to manually connect to a network.

11. The method of claim 9 , further comprising;
locating the home wireless network; and
automatically connecting to the home wireless network when the mobile wireless device is configured to automatically connect to a network.

12. A mobile wireless device, configured to roam on a non-preferred wireless network, comprising:
a transceiver for transmitting data to and receiving data from wireless networks;
a memory for storing data and processor instructions; and
a processor configured to determine when a preferred wireless network is proximate to a currently connected non-preferred wireless network by:
connecting to the non-preferred wireless network,
storing network adjacency information comprising a first database and a second database for wireless networks at least in part in the mobile wireless device, and
determining from the first database that a country code of the non-preferred wireless network matches a country code of the preferred wireless network or that the non-preferred wireless network is adjacent to the preferred wireless network; and
scanning for the preferred wireless network, while roaming on the non-preferred wireless network when the mobile wireless device determines based on the second database that the preferred wireless network is adjacent to the non-preferred wireless network.

13. The mobile wireless device of claim 12 , wherein the processor is further configured to scan for the preferred wireless network when the processor determines based on the network adjacency information whether the preferred wireless network is adjacent to the non-preferred wireless network .

14. The mobile wireless device of claim 12 , wherein the processor is further configured to connect the mobile wireless device to the preferred wireless network when the preferred wireless network is located during the scanning and the mobile wireless device is configured to automatically connect to a network.

15. The mobile wireless device of claim 12 , wherein the processor is further configured to notify a user of the mobile wireless device when the preferred wireless network is located during the scanning.

16. The mobile wireless device of claim 12 , wherein the processor is further configured to query a location server to update the network adjacency information stored at least in part in the mobile wireless device.

17. A method for adaptively scanning for a home public land mobile network (HPLMN) by a mobile wireless device, while roaming on a visited public land mobile network (VPLMN), the method for adaptively scanning comprising:
prior to operating the mobile wireless device away from the HPLMN, storing network adjacency information comprising a first database and a second database at least in part in the mobile wireless device;
connecting to the VPLMN;
determining from the first database that a country code of the VPLMN matches a country code of the HPLMN or that the VPLMN is adjacent to the HPLMN;
scanning for the HPLMN, while roaming on the VPLMN, when the mobile wireless device determines that the HPLMN is adjacent to the VPLMN based on a search of the second database; and
performing a limited high priority network search when the mobile wireless device determines that the HPLMN is not adjacent to the VPLMN based on the search of the second database.

18. The method of claim 17 , further comprising periodically updating network adjacency information stored in the mobile wireless device.

19. The method of claim 18 , wherein updates to the network adjacency information is provided by a location server.

20. The method of claim 17 , further comprising:
notifying a user of the mobile wireless device when the HPLMN is found during the scanning and the mobile wir

Assignees

• Juang Ben-Heng
• Zhang Qin
• Ayyappan Ravi
• Apple Inc

Inventors

• Juang Ben-Heng
• Zhang Qin
• Ayyappan Ravi

Classifications

• H04W8/12

  between location registers or mobility servers · CPC title

• H04W8/10

  between location register and external networks · CPC title

• H04W8/18

  Processing of user or subscriber data, e.g. subscribed services, user preferences or user profiles; Transfer of user or subscriber data · CPC title

• H04W48/18 Primary

  Selecting a network or a communication service · CPC title

• H04W8/02

  Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks · CPC title