Cellular carrier selection system incorporating a preferred list of system identification codes (SIDs) corresponding to preferred cellular carriers

• US 6,405,038 B1
• Filed: 05/17/1995
• Issued: 06/11/2002
• Est. Priority Date: 06/08/1993
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: OKI Telecom, Inc. (OKI Electric Industry Company Limited)
• Inventors: Hardin, Stephen T., Barber, Clifton J.
• Primary Examiner(s): LE, THANH C
• Application Number:
  US08/442,883
• Time in Patent Office: 2,582 Days
• Field of Search: 455/33.1, 455/33.2, 455/33.4, 455/34.1, 455/34.2, 455/53.1, 455/54.1, 455/56.1, 455/62, 455/63, 455/166.1, 455/166.2, 455/166.3, 455/434, 455/435, 455/445, 455/450, 455/452, 379/59, 379/60
• US Class Current: 455/434
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 4/00 Services specially adapted for wireless communication networks; Facilities therefor
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 74/00 Wireless channel access
• CPC Class Codes: H04W 76/50 for emergency connections
• CPC Class Codes: H04W 8/183 Processing at user equipment or user record carrier
• CPC Class Codes: H04W 8/22 Processing or transfer of terminal data, e.g. status or physical capabilities
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems

Abstract

A method and an apparatus for selecting a cellular carrier frequency for accessing cellular airtime services based upon a list of preferred system identification codes (SIDs). A cellular telephone is programmed to accept into memory a list of preferred SIDs corresponding to carriers through which service is preferred. While any SID remains in a preferred list, the standard A/B system selection function is replaced by a substitute system selection function which includes only three carrier selection modes including the Home Only mode, the SID Only mode, and a Roam Saver mode. With the Roam Saver carrier selection mode, the cellular telephone first prefers service through a home carrier and then through a carrier broadcasting a SID matching a SID on the preferred list, but never denies service to emergency or non-emergency destinations if any SID is detected. Status indicators are used to, among other purposes, differentiate between no service being available, service being available through a carrier broadcasting a home SID, a preferred SID, or a non-preferred available SID. Also, in addition to multiple number assignment modules (NAMs) being included to support subscriptions to services from multiple carriers, the user is provided the option of manually selecting which NAM is used or enabling the cellular telephone, through an auto-NAM function, to automatically select and use the NAM of any home carrier detected by the cellular telephone.

Claims

1. A method for selecting a cellular carrier corresponding to a home SID for accessing cellular airtime services, said method comprising steps of:

defining a plurality of home system identification codes (SIDs);

monitoring cellular carrier signals to detect SIDs corresponding to cellular carriers; and

automatically selecting, as a home carrier, the cellular carrier corresponding to the detected SID matching any home SID of the plurality of home SIDs.

2. The method of claim 1, wherein the automatically selecting step includes automatically selecting the carrier corresponding to the first detected SID matching any home SID of the plurality of home SIDs.

3. The method of claim 1, wherein the automatically selecting step is responsive to selective user enablement.

4. The method of claim 1, wherein the monitoring step includes monitoring primary carrier signals and secondary carrier signals.

5. The method of claim 1, further including steps of

defining a plurality of preferred SIDs;

selecting a cellular carrier corresponding to a SID matching one of the plurality of preferred SIDs if

the SID matching one of the plurality of preferred SIDs is detected and

no SID matching one of the plurality of home SIDs is detected; and

selecting a cellular carrier corresponding to a SID not matching one of the home SIDs and not matching one of the plurality of preferred SIDs if

the SID not matching one of the home SIDs and not matching one of the plurality of preferred SIDs is detected and

no SID matching one of the plurality of home SIDs or one of the plurality of preferred SIDs is detected.

6. An apparatus for selecting a cellular carrier corresponding to a home SID for accessing cellular airtime services, comprising:

means for defining a plurality of home system identification codes (SIDs);

means for monitoring cellular carrier signals to detect SIDs corresponding to cellular carriers; and

means for automatically selecting a cellular carrier corresponding to a detected SID matching any home SID of the plurality of home SIDs.

7. The apparatus as claimed in claim 6, wherein said automatically selecting means includes means for automatically selecting the cellular carrier for processing calls to conventional telephone numbers.

8. The apparatus as claimed in claim 6, further comprising means for defining a plurality of preferred SIDs;

means for automatically selecting a cellular carrier corresponding to a detected SID matching any preferred SID of the plurality of preferred SIDs responsive to detecting no SIDS matching any home SID of the plurality of home SIDs; and

means for automatically selecting a cellular carrier corresponding to a detected SID not matching any preferred SID of the plurality of preferred SIDs or home SID of the plurality of home SIDs responsive to detecting no SID matching any home SID of the plurality of home SIDs and no SID matching any preferred SID of the plurality of preferred SIDs.