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.
April 19, 1999
Date of Patent:
July 23, 2002
Christopher J. Hall, Clay S. Turner, Jimmy C. Ray
Abstract: A display having as a light source thereof an electron tube. The electron tube has disposed in an evacuated envelope thereof a plurality of cathode means, each one thereof adapted to emit electrons in response to a control signal. A plurality of sets of at least one cathodoluminescent stripe is disposed within the envelope. Each one of said sets is associated with a corresponding one of the cathode means and adapted to emit light with a predetermined one of a set of primary colors in response to electrons emitted by the corresponding cathode means striking such stripe. An anode for collecting electrons emitted by said cathode is also disposed within the evacuated envelope.