Topology verification process for controlling a personal communication services system

• US 5,862,477 A
• Filed: 06/13/1996
• Issued: 01/19/1999
• Est. Priority Date: 08/31/1995
• Status: Expired due to Fees

• Current Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: Wellard, Ronald George, Onsy, Sammy John, Papineau, Mario Rosaire Joseph, Hamel, Pierre-Antoine Bertrand Nicolas
• Primary Examiner(s): Bost, Dwayne D.
• Assistant Examiner(s): WYCHE, MYRON
• Application Number:
  US08/662,965
• Time in Patent Office: 950 Days
• Field of Search: 455/403, 455/422, 455/423, 455/446, 455/450, 455/424, 455/67.1
• US Class Current: 455/423
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

A topology verification process for controlling a Personal Communication Services (PCS) system which includes a plurality of Cordless Fixed Parts (CFP)s. The process includes mapping the spatial relationships of the CFPs utilizing Received Signal Strength Indication (RSSI) vectors resulting from test signals transmitted between the CFPs, to establish the topology of the system; repeating the mapping process after any disruption of power to the system, and comparing the results. Any significant change in the results, would be highly indicative of a potential change in the geographic area of operation of the system, and can be used to initiate disablement of the system operation. Additional confirmation that the system has not been reconfigured (and hence moved), may be had by matching a unique identifier for each CFP against a stored set of identifiers which specify the particular port that the CFP was connected to immediately prior to any disruption in power to the system.

Claims

1. A method for controlling a Personal Communication Services system, which includes a plurality of base stations that communicate with a plurality of portable handsets, the method comprising the steps of:

a) measuring and recording the received signal strengths of test signals transmitted in turn by each base station, that are received by the other base stations;

b) repeating the measuring and recording step in response to a system restart;

c) comparing the earlier recorded received signal strengths with the most recent recorded received signal strengths;

d) disabling operation of the Personal Communications Services system when predetermined differences in the recorded received signal strengths are detected;

e) recording a unique identifier from each base station together with an identifier of the port to which that base station is connected in the system during initialization of the system;

f) if the system is not disabled in step d) after the system restart, comparing the current identifiers against the recorded identifiers; and

g) disabling operation of the Personal Communications Services system whenever any of the compared identifiers differ.

2. A method for controlling a Personal Communication Services system as defined in claim 1, which forms part of a stand alone key telephone system having a plurality of wireline sets, further comprising the steps of:

h) recording a unique identifier from each wireline set together with an identifier of the port to which that wireline set is connected in the key telephone system during initialization of the system;

i) if the system is not disabled in step d) after the system restart, comparing all the identifiers against those recorded during initialization; and

j) disabling operation of the adjunct Personal Communications Services system, whenever any of the compared identifiers differ.

3. A method for controlling a Personal Communication Services system as defined in claim 2, further comprising the steps of:

k) dynamically updating the recorded identifiers whenever there are any changes to the base stations, wireline sets or the ports to which the stations and sets are connected, while the system is enabled.

4. A method for controlling a Personal Communication Services system, which includes a plurality of base stations that communicate with a plurality of portable handsets, comprising the steps of:

a) disabling operation of the Personal Communications Services system after a system restart, if the signal strengths of test signals received from a plurality of base stations by other base stations in the system, differ from signal strengths of the test signals recorded during initialization of the system; and

b) if the system is not disabled in step a), disabling operation of the Personal Communications Services system after the system restart, if either one of i) an identifier of the port in the system to which each base station is connected or ii) a unique identifier of that base station, differ from those recorded during initialization of the system.