Method for selecting a preferable wireless communications service provider in a multi-service provider environment

• US 8,081,973 B2
• Filed: 03/18/2008
• Issued: 12/20/2011
• Est. Priority Date: 12/12/1995
• Status: Expired due to Fees

• Current Assignee: AT&T Wireless Services Incorporated (AT&T, Inc.)
• Original Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Inventors: Bamburak, Michael D., Lawrence, Christopher Gregory, Prise, Michael Edward, Raffel, Michael Allen, Daly, John J.
• Primary Examiner(s): Vuong, Quochien B
• Application Number:
  US12/050,810
• Publication Number:
  US 20080160982A1
• Time in Patent Office: 1,372 Days
• Field of Search: 455/62, 455/67.11, 455/161.1, 455/166.2, 455/168.1, 455/432.1, 455/435.1, 455/435.2, 455/435.3, 455/455, 455/524, 455/525, 455/550.1, 455/552.1
• US Class Current: 455/434
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service

Abstract

A communication device locates a preferable wireless service provider in a multi-service provider environment using a frequency or frequency band search schedule. Initially, the communication device registers with a less preferred service provider in a first frequency. While remaining registered with the less preferred service provider, the device examines several frequencies in the order specified by the frequency search schedule. The device determines whether the last frequency used by the communication device has a more preferred service provider. If the last frequency used does not have a more preferred service provider, the device examines each of the plurality of frequencies in the predetermined order in the search schedule. The examination continues until another frequency band having a more preferred service provider is located. The communication device then registers with the more preferred service provider.

Claims

1. A method performed by a wireless communication device comprising a list of frequency bands in an order, each frequency band comprising a plurality of frequencies, the plurality of frequencies being used to transmit a plurality of signals, the method comprising:

registering the wireless communication device with a non-optimal service provider associated with one of the plurality of signals transmitted on one of the plurality of frequencies of one of the frequency bands; and

searching the frequency bands in accordance with the order of the list until the wireless communication device is registered with an optimal service provider or a last frequency band of the list of frequency bands has been searched, the searching of the frequency bands comprising;

selecting a frequency band from the list of frequency bands in accordance with the order in the list;

identifying a signal of the plurality of signals transmitted using the plurality of frequencies of the frequency band that is selected, the signal that is identified having a received signal strength that is greater than a respective received signal strength of any other of the plurality of signals transmitted on the plurality of frequencies of the frequency band that is selected;

determining a service provider code based on the signal that is identified;

determining whether the service provider code is associated with the optimal service provider; and

if the service provider code is associated with the optimal service provider, terminating the searching the frequency bands and registering with the optimal service provider.

2. The method of claim 1, wherein before the searching the frequency bands, a signal associated with the non-optimal service provider with which the wireless communication device is registered is a control channel, and the wireless communication device is in an idle state in which communications functions of the wireless communication device are limited to monitoring the control channel for information.

3. The method of claim 2, further comprising:

before the searching the frequency bands and while the wireless communication device is in the idle state, starting a timer having a predetermined duration; and

waiting until an expiration of the predetermined duration before transitioning out of the idle state and searching the frequency bands.

4. The method of claim 2, wherein the searching the frequency bands further comprises:

before the selecting the frequency band from the list of frequency bands in accordance with the order in the list, waiting until a predetermined time period expires before transitioning out of the idle state; and

after the determining whether the service provider code is associated with the optimal service provider, returning the wireless communication device to the idle state.

5. The method of claim 1, wherein the searching the frequency bands further comprises:

determining whether the signal that is identified is valid by determining whether the signal that is identified conforms with a cellular communication standard.

6. The method of claim 1, wherein the searching the frequency bands further comprises:

determining whether the signal that is identified is a digital traffic channel; and

if the signal that is identified is the digital traffic channel;

using the digital traffic channel to obtain a digital channel locator,

using the digital channel locator to locate a digital control channel associated with the digital traffic channel,

determining a received signal strength of a signal transmitted on the digital control channel, and

if the received signal strength of the signal transmitted on the digital control channel is greater than a received signal strength of any other signal of the plurality of signals transmitted on the plurality of frequencies of the frequency band that is selected, replacing the signal that is identified with the signal transmitted on the digital control channel.

7. A computer-readable medium having instructions that when executed by a processor perform the method of claim 1.

8. A method performed by a wireless communication device comprising a list of frequency bands in an order, each frequency band comprising a plurality of control channels, the wireless communication device being registered with a service provider associated with one of the plurality of control channels of one of the frequency bands, the wireless communication device being configured to communicate on the one control channel associated with the service provider, the wireless communication device operating in an idle state, wherein the wireless communication device monitors the one control channel associated with the service provider, the method comprising:

transitioning out of the idle state;

determining whether the service provider with which the wireless communication device is registered is optimal; and

when the service provider is non-optimal;

selecting a next frequency band from the list of frequency bands,

identifying a control channel of the plurality of control channels of the next frequency band that is selected having a strongest received signal strength at the wireless communication device, the control channel carrying a service provider code,

determining whether the service provider code is associated with an optimal service provider,

when the service provider code is associated with the optimal service provider, registering the wireless communication device with the optimal service provider, and

returning the wireless communication device to the idle state.

9. The method of claim 8, further comprising:

excluding the frequency band comprising the control channel associated with the service provider with which the wireless communication device is registered from the list of frequency bands.

10. The method of claim 8, further comprising:

repeating the method of claim 8 until the wireless communication device is registered with the optimal service provider or all of the frequency bands have been selected from the list of frequency bands.

11. The method of claim 8, further comprising when the service provider is non-optimal:

determining whether the control channel that is identified is valid by determining whether the control channel that is identified conforms with a cellular communication standard, the determining of whether the service provider code is associated with the optimal service provider being performed only if the control channel that is identified is valid.

12. A computer-readable medium having instructions that when executed by a processor perform the method of claim 8.

13. A method performed by a wireless communication device, the method comprising:

obtaining a master search schedule identifying a plurality of frequency bands in a predetermined order, each of the plurality of frequency bands comprising a plurality of control signals each being transmitted using a frequency of a respective frequency band;

searching each of the plurality of frequency bands one at a time in accordance with the master search schedule, to identify a first control signal, the first control signal being associated with a preferred service provider and having a received signal strength that is the stronger than a received signal strength of any of the other of the plurality of control signals within a same frequency band as the first control signal;

registering with the preferred service provider;

determining the wireless communication device is not registered with an optimal service provider;

after determining the wireless communication device is not registered with the optimal service provider, conducting a search of each of at least a portion of the plurality of frequency bands identified by the master search schedule, the search terminating when the plurality of frequency bands have been searched by the search or the wireless communication device is registered with the optimal service provider, for each frequency band identified by the master search schedule, the periodic search comprising;

identifying a second control signal of the plurality of control signals of a next frequency band associated with a service provider and having a received signal strength that is the stronger than a received signal strength of any of the other of the plurality of control signals within the next frequency band;

determining whether the service provider associated with the second control signal is the optimal service provider; and

when the service provider associated with the second control signal is the optimal service provider, registering with the optimal service provider.

14. The method of claim 13, further comprising:

before the conducting the ordered search, removing the frequency band of the first control signal from the plurality of frequency bands identified by the master search schedule.

15. The method of claim 13, further comprising:

before the searching each of the plurality of frequency bands one at a time in accordance with the master search schedule, inserting a frequency band associated with a home service provider of the wireless communication device in the plurality of frequency bands as a first frequency band in the predetermined order of the plurality of frequency bands.

16. The method of claim 13, further comprising:

after the registering with the preferred service provider and after the determining the wireless communication device is not registered with the optimal service provider, transitioning to an idle state; and

while in the idle state, waiting until a predetermined time period has elapsed.

17. The method of claim 13, wherein the search further comprises:

after the determining whether the service provider associated with the second control signal is the optimal service provider, transitioning to an idle state.

18. The method of claim 13, wherein the wireless communication device comprises a data structure storing a plurality of service provider codes, each service provider code associated with a service provider, the data structure further comprising for each service provider, an indicator indicating whether the service provider is optimal, and

determining whether the service provider associated with the second control signal is the optimal service provider comprises extracting a service provider code from the second control signal and comparing the service provider code that is extracted with the plurality of service provider codes stored in the data structure to identify the service provider associated with the service provider code that is extracted, and determining the service provider that is identified as the optimal service provider if the indicator associated with the indicator service provider indicates the service provider is the optimal service provider.

19. The method of claim 13, wherein the wireless communication device comprises a data structure storing a plurality of service provider codes, each service provider code associated with a service provider, the data structure further comprising for each service provider, an indicator indicating whether the service provider is optimal, preferred, or non-preferred, the data structure further comprises a ranking of the service providers, the method further comprising:

searching each of at least a portion of the plurality of frequency bands one at a time in accordance with the master search schedule, wherein the searching comprises;

identifying a control signal having a received signal strength that is stronger than a received signal strength of any of the other of the plurality of control signals within one of the frequency bands;

extracting a service provider code from the control signal that is identified;

comparing the service provider code that is extracted with the plurality of service provider codes stored in the data structure to identify the service provider associated with the service provider code that is extracted; and

when the indicator indicates the service provider that is identified is a preferred service provider, storing the frequency used to transmit the control signal and the service provider code that is extracted, and

identifying a first control signal by selecting the control signal transmitted on one of the stored frequencies that is associated with the highest ranking service provider in accordance with the ranking stored by the data structure.

20. The method of claim 13, further comprising before the obtaining the master search schedule:

powering up the wireless communication device following a powering down thereof;

identifying a service provider with which the wireless communication device was registered before the powering down; and

inserting a frequency band comprising the frequency associated with the service provider that is identified in the plurality of frequency bands of the master search schedule as a first frequency band in the predetermined order of the plurality of frequency bands.

21. The method of claim 20, further comprising:

if the frequency band comprising the frequency associated with the service provider that is identified is one of the plurality of frequency bands identified in the master search schedule and has an original location within the predetermined order of the plurality of frequency bands before the frequency band is inserted into the predetermined order of the plurality of frequency bands as the first frequency band, removing the frequency band from its original location within the predetermined order of the plurality of frequency bands.

22. The method of claim 13, wherein the search further comprises:

determining whether the second control signal is valid by determining whether the second control signal conforms with a cellular communication standard, the determining of whether the service provider associated with the second control signal is the optimal service provider being performed only if the second control signal is valid.

23. A computer-readable medium having instructions that when executed by a processor perform the method of claim 13.