Method and apparatus for providing fault tolerance in frequency reuse wireless communication systems

• US 6,178,327 B1
• Filed: 05/08/1998
• Issued: 01/23/2001
• Est. Priority Date: 05/08/1998
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Gomez, Susan Lorraine
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): BEAMER, TEMICA M
• Application Number:
  US09/074,750
• Time in Patent Office: 991 Days
• Field of Search: 455/8, 455/9, 455/447, 455/67.1, 455/437, 455/561, 455/434, 455/515, 455/560, 455/423, 455/424, 455/425, 455/436-439, 455/445
• US Class Current: 455/445
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 48/10 using broadcasted information

Abstract

A base station (106) is connected to several communication servers (114, 116, 118) by a corresponding number of communication links (128). Should one or more of the connections fail, the base station comprises a base mobile radio (210) for scanning one or more neighbor cells (108-113) to determine their current service status. The neighbor cells have overlapping coverage with serving cell, but on different frequencies. The base station broadcasts a fault message along with the updated neighbor cell information to mobile stations (102), allowing the mobile stations to choose the most appropriate cell for the desired communication activity.

Claims

1. A method of providing fault tolerance in a frequency reuse wireless communication system, comprising the steps of:

detecting a fault between a base station and a communications server, the base station for providing a plurality of communication services;

scanning for at least one neighbor cell capable of providing the communication service in which the fault was detected, performed by a base mobile radio located at the base station;

updating a neighbor cell list at the base station while performing the step of scanning;

broadcasting a fault detection message indicating in which communications services a fault was detected;

broadcasting the neighbor cell list in a serving cell, performed by the base station after performing the step of updating;

receiving the neighbor cell list;

selecting a neighbor cell from the neighbor cell list; and

connecting to the neighbor cell selected in the step of selecting;

wherein the steps of receiving, selecting, and connecting are performed sequentially by a mobile station in the serving cell.

2. A method of providing fault tolerance as defined in claim 1, wherein the step of detecting is performed by an access controller gateway located at the base station.

3. A method of providing fault tolerance as defined in claim 1, wherein the step of detecting comprises detecting the fault in a telephone interconnect circuit between the base station and the communications server.

4. A method of providing fault tolerance as defined in claim 1, wherein the step of detecting comprises detecting the fault in a dispatch circuit between the base station and the communications server.

5. A method of providing fault tolerance as defined in claim 1, wherein the step of detecting comprises detecting the fault in a packet data circuit between the base station and the communications server.

6. A method of providing fault tolerance as defined in claim 1, wherein the step of detecting comprises detecting the fault in a circuit data circuit between the base station and the communications server.

7. A method for a mobile station to avoid a compromised serving cell, the serving cell established around a base station, the base station for providing a plurality of communication services, the base station having updated a neighbor cell list to include current service information for each one of a plurality of neighbor cells by scanning the neighbor cells from the base station, the method comprising the steps of:

detecting a fault in one of the plurality of communications services;

broadcasting a fault detection message, indicating in which communications service the fault has been detected, and a neighbor cell list, performed by the base station;

receiving the neighbor cell list;

selecting a neighbor cell from the neighbor cell list; and

connecting to the neighbor cell selected in the step of selecting;

wherein the steps of receiving, selecting, and connecting are performed sequentially by the mobile station in the serving cell.

8. A method for a mobile station to avoid a compromised serving cell as defined in claim 7, wherein the base station provides a plurality of communication services, the step of broadcasting comprises broadcasting the service status of the serving cell.