Method and apparatus for performing preferred system selection

• US 5,870,674 A
• Filed: 03/27/1996
• Issued: 02/09/1999
• Est. Priority Date: 03/27/1996
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: English, Sean
• Primary Examiner(s): VO, NGUYEN THANH
• Application Number:
  US08/626,743
• Time in Patent Office: 1,049 Days
• Field of Search: 455/33.1, 455/33.2, 455/33.4, 455/34.1, 455/34.2, 455/54.1, 455/56.1, 455/422, 455/426, 455/432, 455/434, 455/435, 455/436, 455/448, 455/552-553, 455/561 , 455/440-444, 455/524-525, 455/551, 455/186.1, 455/456, 379/59, 379/60
• US Class Current: 455/432.2
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 8/183 Processing at user equipment or user record carrier

Abstract

A method and apparatus for selecting a communication system in accordance with geographic region of the subscriber station. The subscriber station first attempts to determine its geographic region. It does so by attempting to acquire a system which covers the region. Once the subscriber station has determined its geographic region, the subscriber station then determines whether the acquired system is the most desirable system for use in the geographical region. If it is the most desirable system for use in the geographical region, the subscriber station registers with the acquired system. If it is not the most desirable system for use in the geographical region, the subscriber station attempts to acquire a more desirable system.

Claims

1. A method for system acquisition in a subscriber station comprising the steps of:

providing a system table containing an entry for each communication system known to the subscriber station, each entry containing a system identification corresponding to each communication system, each entry further containing aquisition parameters used to acquire the communication system, said entries within said system table being organized by geographic region and including entries for each of a plurality of geographic regions, each geographic region containing information regarding the relative desirability of each communication system within that geographic region;

storing said system table within the subscriber station;

determining a first geographical region hypothesis in accordance with a geographical region of a most recently used system;

performing, in accordance with said first geographical region hypothesis, a first geographical region hypothesis search of said system table for a first communication system;

extracting, from said system table, aquisition parameters corresponding to said first communication system, and attempting to acquire said first communication system using said extracted acqisition parameters;

receiving a system identification from an acquired communication system, said received system identification corresponding to one of the system identifications listed in said system table;

determining from said system table an actual geographical region based on said received system identification; and

performing an actual geographical region search of said system table for a second communication system in accordance with said actual geographic region and said desirability information.

2. The method of claim 1 further comprising the steps of in

determining a second geographical region hypothesis in accordance with a set of representative acquisition parameters if said first geographical region hypothesis search is unsuccessful;

and

performing a second geographical region hypothesis search in accordance with said second geographical region hypothesis.

3. The method of claim 2 further comprising the steps of

determining a third geographical region hypothesis in accordance with a set of remaining preferred systems if said second geographical region hypothesis search is unsuccessful;

and

performing a third geographical region hypothesis search in accordance with said third geographical region hypothesis.

4. The method of claim 1 wherein said system identification comprises a message indicating geographic location.