US 5,442,806 AGranted

Preferred carrier selection method for selecting any available cellular carrier frequency when neither home nor preferred cellular carrier frequencies are available

AssigneeOki Telecom, Inc.

InventorsClifton J. Barber, Stephen T. Hardin

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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.

Claims38

Dependent claims

A method for selecting a cellular carrier frequency for accessing cellular airtime services, said method comprising the steps of:

defining at least one predefined home system identification code (SID) and at least one predefined preferred SID;
monitoring a plurality of frequencies to detect any SID corresponding to any frequency of the plurality of frequencies, including steps of
monitoring a plurality of primary carrier frequencies to detect any SID corresponding to any frequency of the plurality of primary carrier frequencies, and
monitoring a plurality of secondary carrier frequencies to detect any SID corresponding to any frequency of the plurality of secondary carrier frequencies;
selecting a frequency, for calls to ordinary telephone numbers, corresponding to a SID matching said predefined home SID if the SID matching said predefined home SID is detected, including steps of
selecting a primary carrier frequency corresponding to the SID matching said predefined home SID if the SID matching said predefined home SID is detected upon the primary carrier frequency, and
selecting a secondary carrier frequency corresponding to the SID matching said predefined home SID if the SID matching said predefined home SID is detected upon the secondary carrier frequency and the SID matching said predefined home SID is not detected upon any primary carrier frequency;
selecting a frequency, for-calls to ordinary telephone numbers, corresponding to a SID matching said predefined preferred SID if
the SID matching said predefined preferred SID is detected and
no SID matching said predefined home SID is detected;
and
selecting a frequency, for calls to ordinary telephone numbers, corresponding to a SID not matching either said predefined home SID or said predefined preferred SID if
the SID not matching either said predefined home SID or said predefined preferred SID is detected and
no SID matching either said predefined home SID or said predefined preferred SID is detected.

11 more elements

A cellular carrier frequency selection apparatus comprising:

detecting means for monitoring a plurality of frequencies to detect any system identification code (SID) corresponding to any frequency of said plurality of frequencies, wherein said detecting means includes, at least,
primary means for monitoring a plurality of primary carrier frequencies to detect any SID corresponding to any frequency of said plurality of primary carrier frequencies, and
secondary means for monitoring a plurality of secondary carrier frequencies to detect any SID corresponding to any frequency of said plurality of secondary carrier frequencies;
and
analyzing means associated with said detecting means for analyzing any SID detected by said detecting means and for selecting a frequency for use with calls, said analyzing means including, at least,
memory means for defining at least one predefined home SID and at least one predefined preferred SID,
home selecting means for selecting a frequency, for calls to ordinary telephone numbers, corresponding to a SID matching said predefined home SID if the SID matching said predefined home SID is detected, wherein said home selecting means includes, at least,
primary home selecting means for selecting a primary carrier frequency corresponding to the SID matching said predefined home SID if the SID matching said predefined home SID is detected upon the primary carrier frequency, and
secondary home selecting means for selecting a secondary carrier frequency corresponding to the SID matching said predefined home SID if the SID matching said predefined home SID is detected upon the secondary carrier frequency and the SID matching a predefined home SID is not detected upon any primary carrier frequency,
preferred selecting means for selecting a frequency, for calls to ordinary telephone numbers, corresponding to a SID matching said predefined preferred SID if
the SID matching said predefined preferred SID is detected and
no SID matching said predefined home SID is detected, and
remainder selecting means for selecting a frequency, for calls to ordinary telephone numbers, corresponding to a SID not matching either said predefined home SID or said predefined preferred SID if
the SID not matching either said predefined home SID or said predefined preferred SID is detected and
no SID matching either said predefined home SID or said predefined preferred SID is detected.

12 more elements

A method for selecting a cellular carrier frequency for accessing cellular airtime services, said method comprising the steps of:

defining at least one predefined home system identification code (SID) and at least one predefined preferred SID;
monitoring a plurality of frequencies to detect any SID corresponding to any frequency of the plurality of frequencies, including steps of
designating a plurality of carrier frequencies as primary carrier frequencies by determining a carrier type of a SID stored in an initial number assignment module,
designating a remaining plurality of carrier frequencies as secondary carrier frequencies in response to the step of designating the plurality of carrier frequencies as primary carrier frequencies,
monitoring the plurality of primary carrier-frequencies to detect any SID corresponding to any frequency of the plurality of primary carrier frequencies, and
monitoring the plurality of secondary carrier frequencies to detect any SID corresponding to any frequency of the plurality of secondary carrier frequencies;
selecting a frequency, for calls to ordinary telephone numbers, corresponding to a SID matching said predefined home SID if the SID matching said predefined home SID is detected;
selecting a frequency, for calls to ordinary telephone numbers, corresponding to a SID matching said predefined preferred SID if
the SID matching said predefined preferred SID is detected and
no SID matching said predefined home SID is detected;
and
selecting a frequency, for calls to ordinary telephone numbers, corresponding to a SID not matching either said predefined home SID or said predefined preferred SID if
the SID not matching either said predefined home SID or said predefined preferred SID is detected and
no SID matching either said predefined home SID or said predefined preferred SID is detected.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/073,947Filed 8 Jun 1993
Granted: 15 Aug 1995
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

H04W 72/02
Local resource management: selection of wireless resources by user or terminal
H04W 48/18
Access restriction ; Network selection; Access point selection: selecting a network or a communication service
H04W 4/00
Services specially adapted for wireless communication networks
H04W 4/90
Services specially adapted for wireless communication networks; Facilities therefor: services for handling of emergency or hazardous situations,…