BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention is directed generally to a method and apparatus for the acquisition of a cellular system and, more particularly, to using position location to accelerate the acquisition of a preferred cellular system by a portable communication device.

[0004] 2. Description of the Background

[0005] When mobile station equipment or mobile communication devices, such as portable telephones, are powered on, i.e. are activated, the mobile communication devices search for signals from base stations. The mobile communication device must register with a suitable base station in order to provide service to the user. At a given time, an activated portable communication device 10 may find signals from several different base stations 20 , 30 , 40 , 50 , some of which are home 20 and some of which are roam 30 , 40 , 50 , and some of which are preferred 20 , 40 and some of which are not 30 , 50 , as shown in FIG. 1 . For example, in the case of IS-95 CDMA systems, the mobile communication device uses an IS-683-A roaming list to search for base stations.

[0006] The activated mobile communication device may receive signals from base stations that are part of the home system for that device, part of a competitor's system, or part of a competitor's system that has a usage agreement with the home system, for example. The base station that is part of the home system is the most preferred system for the activated mobile communication device to send and receive signals to and from, because the user is typically already paying for the use of that home system. A less preferred system may be a base station that is part of a competitor's system that has a usage or roam agreement with the home system. According to the terms of the roam agreement, the user may incur additional, but discounted, fees for usage, when using the competitor's system with a usage or roam agreement. The least preferred system may be, for example, a base station that is part of a competitor's system that does not have a usage or roam agreement with the home system. Thus, the user, or the home system, may incur substantial additional fees for usage of the base station that is part of the competitor's system, which will frequently require roaming to use the competitor's system without an agreement to the contrary.

[0007] Thus, an activated mobile communication device uses one of several methods to identify the most preferred system for the user. In the case of IS-95 CDMA based systems, for example, the phone will use the IS-683-A standard roaming list that lists the systems that can be used arranged by preference and geographic regions. A typical layout of such a roaming list information is shown below in Table 1. 1

[0008] The locations of activated portable communication devices are specific geographic regions, according to protocols such as IS-683-A. These specific geographic regions group together various mobile communication systems in the same geographic region. Thus, systems in the same geographic region are differentiated from other cellular systems in another geographic region. For example, the first system in a geographic region is identified as the first new geographic region, and subsequent systems in the same geographic region are identified as being in the same geographic region but and as being in the first new geographic region. If the subsequent cellular system is in a different geographic region, the system is identified as in the second new geographic region.

[0009] Within a specific geographic region, the system identifier (SID), and the network identifier (NID), identify the system. For example, the system and network may be ‘Airtouch®’, or ‘Sprint®.’ The roaming indicator then indicates if the system, such as ‘Sprint’, is a home system or a roam system. For example, if the home system is ‘Sprint’, then any system that is ‘Sprint’ will be identified as the home system with roam indicator reading “Off,” but non-Sprint systems will be identified as a roam system with the roam indicator reading “On.”

[0010] The block or channel number in Table I indicates the frequency of transmission of a base station. The Preference column of Table I indicates whether a system is preferred or negative. Preferred systems will be acquired, but negative systems will not be acquired except in the case of emergency calls. Desirability indicates whether a first cellular system is more desirable than a subsequent cellular system. For example, in the first geographic region, the first system (SID 101 , NID 1 ) is not more desirable than the second system (SID 102 , NID 2 ). However, the second system (SID 102 , NID 2 ) is more desirable than the third system (SID 103 , NID 300 ).

[0011] Mobile communication devices typically have large roaming areas that span several geographic regions, due to the prevalence of communication networks world-wide and the service provider's desire to provide preferred service for the users wherever they travel. Each geographic region may have several SIDs in it. Mobile communication devices preferably have the capability to remember the last geographic region, or SID, that the particular device was connected to the last time the particular device was powered off, and the capability to quickly and efficiently search that appropriate region when the device is powered on the next time. However, if the user is traveling, and the device is powered on in a new geographic region not overlapping the prior appropriate region, the device will then have to search sequentially for every entry in each geographic region in order to find the preferred service. This search process is inconvenient for the user in that it can take a long time, sometimes as long as several minutes.

[0012] Algorithms available currently take an “educated guess” at the correct geographic region by looking at an acquired SID, but such algorithms work properly only if the mobile communication devices acquires a known system (i.e. a system with the SID in the roaming list). If the phone does not acquire a known system, an “educated guess” system may take an exceedingly long time to find the most preferred system, particularly if the geographic regions are large.

[0013] Therefore, the need exists for a mobile communication device and system that allows a system to be quickly acquired, based on the location of a user, without the need to search all available geographic locations and systems until a preferred system is located.

BRIEF SUMMARY OF THE INVENTION

[0014] The present invention is directed to a mobile communication device. The mobile communication device includes a signal sender, a signal receiver, and a processor and memory. The processor and memory include a static table, and are in communication with the signal sender and the signal receiver. The processor and memory match a location of the device directly to at least one preferred system. The mobile communication device may additionally include a location converter to convert a location from a locator into a position range for comparison in the static table. The position locator is a receiver contained in the mobile communication device. The static table preferably includes at least one roaming list and at least one lookup table.

[0015] The present invention is also directed to a mobile communication system. The mobile communication system includes at least one base station and at least one mobile communication device. The mobile communication device includes a signal sender, a signal receiver, and a processor. In a preferred embodiment, each mobile station includes a position locator, and the locator locates the mobile communication device and sends that geographic location to the location converter. The location converter converts the location generated by the locator into a geographic region in a static table.

[0016] Additionally, the present invention is directed to a method of connecting a mobile device to a preferred communication system. The method includes the step of locating the position of the mobile communications device, via a locator function, the step of converting the location generated into a position range, the step of matching the position range to at least one preferred SID index for the position range using a lookup table, the step of selecting the preferred SID from a roaming list, wherein the preferred SID is correspondent to the at least one preferred SID index, and the step of connecting the mobile device to a channel correspondent to the preferred SID. In an embodiment wherein at least two preferred SID indexes match the position range, the method further includes sequentially searching, according to an order of preference, at least two channels correspondent to the at least two preferred SID indexes before the step of selecting.

[0017] The present invention is further directed to a mobile communication device having a processor therein, which processor may include a memory, and which processor is communicatively connected to the device, and which processor includes thereon computer software that performs the step of converting a location of the mobile device to a position range, the step of matching the position range to at least one preferred SID index for the position range using a lookup table, wherein the lookup table is stored in the memory, the step of selecting the preferred SID from a roaming list, wherein the preferred SID is correspondent to the at least one preferred SID index, wherein the roaming list is stored in the memory, and the step of connecting the mobile device to a channel correspondent to the preferred SID.

[0018] The present invention solves problems experienced with the prior art because it provides a portable communication device and system that allows a system to be quickly acquired, based on the location of a user, without the need to search all available geographic locations and systems until a preferred system is located. Those and other advantages and benefits of the present invention will become apparent from the detailed description of the invention hereinbelow.