Automated testing for cellular telephone system including emergency positioning

• US 6,714,779 B2
• Filed: 05/20/2002
• Issued: 03/30/2004
• Est. Priority Date: 04/19/1999
• Status: Active Grant

• Current Assignee: Christopher J. Hall, Clay S. Turner, Jimmy C. Ray
• Original Assignee: Christopher J. Hall, Clay S. Turner, Jimmy C. Ray
• Inventors: Hall, Christopher J., Ray, Jimmy C., Turner, Clay S.
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): Milord, Marceau
• Application Number:
  US10/151,521
• Publication Number:
  US 20020147007A1
• Time in Patent Office: 680 Days
• Field of Search: 455/423, 455/67.1, 455/456, 455/226.1, 455/560, 455/62.4, 455/404, 455/436, 455/439, 455/437, 455/424, 455/67.14, 455/456.2, 455/226.2, 455/404.2, 455/405
• US Class Current: 455/423
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic

Abstract

A method for automatically testing cellular telephone equipment includes a method for determining a geographic location of a mobile unit. The system includes monitoring sites located, e.g., at high elevations, so that each monitoring site electronically covers a geographical area including several cellular telephone base stations. Locations of mobile cellular stations, especially of such stations placing emergency 911 calls, are determined by comparing signal time-of-reception and other observable signal parameters at a combination of three cell sites and/or monitoring sites. Testing functions include transmitting gradually increasing power levels on a frequency assigned to a particular base station to determine the power level required to acquire service from that base station. Periodic repetitions are monitored over time to indicate any changes or degradation in performance. A scanner scans a designated group of control-channel frequencies, selecting active channels for measurement of transmission parameters and detection of anomalous transmission characteristics on any particular channel.

Claims

1. A method for automatically testing to monitor performance of cellular telephone equipment by a combination of passive signal monitoring and active signal testing, comprising the following steps:

locating a plurality of cellular facilities for transmitting signals to and/or receiving signals from a mobile telephone station, wherein a portion of the radio coverage area of at least one of said plurality of cellular facilities overlaps a portion of the radio coverage area of at least one other of said plurality of cellular facilities, and wherein the plurality of cellular facilities are selected from among a cellular base station and a fixed active monitoring station having a radio coverage area comprising a plurality of cellular base station coverage areas or portions thereof,

accessing a cellular facility via an RF link,

testing, via one or more cellular facilities, operational parameters of transmissions from cellular mobile stations and cellular base stations,

controlling said testing with a test and measurement control computer, and

reporting from said cellular facilities variations in said signal quality parameters outside predetermined limits.

2. The method as described in claim 1, wherein said cellular facility includes on-site test equipment at a cellular telephone base station.

3. The method of claim 1 further comprising:

transmitting a signal from an active monitoring station to a cellular base station having an overlapping base station coverage area, wherein the signal causes the active monitoring station to acquire service with the cellular base station,

modifying the power level of the signal, and

determining the power level at which service is acquired.

4. The method of claim 1 further comprising:

transmitting a signal from a first and a second monitoring station to a cellular base station having an overlapping radio coverage area with both the first and the second monitoring stations,

decreasing the signal level of the signal transmitted from the first monitoring station,

increasing the signal level of the signal transmitted from the second monitoring station,

determining the signal level of both the first and the second signals that would cause a call to be switched from the first monitoring station to the second monitoring station.