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

DETAILED DESCRIPTION An embodiment of the present invention provides a method for locating a particular or desirable communications service provider in an environment having a plurality of service providers.
After power-up, a mobile communications device such as a cellular telephone, checks the most recently used control channel to determine whether an optimal service provider is available on that channel.
If an optimal service provider is not available or if that channel is not available, the mobile communication device performs a search through frequency spectrum in a pre-determined order until an optimal or acceptable service provider is located.
In another embodiment of the invention, the frequency spectrum is searched in a pre-determined order that changes based on information entered by a mobile communication device distributor or mobile communication device user.
In yet another embodiment of the invention, the pre-determined order for searching the spectrum for service providers is updated by over the air programming.
In still another embodiment of the present invention, the pre-determined order for searching is based on the mobile communication device's operational history.
In yet another embodiment of the invention, the communications device registers with a less preferred service provider in a first frequency band.
While remaining registered with the less preferred service provider, the device examines several frequency bands in the order specified by the frequency band search schedule.
A frequency band is examined by dividing the frequency band into many sub-bands, and by locating the strongest signal above a threshold within the sub-band being examined.
The examination continues until a second frequency band having a more preferred service provider is located.
The communication device then registers with the more preferred service provider.