Safco Corporation

Other

Kurt T Lemke

Kenneth D Wruk

Charles Marth

Joseph A Schifferdecker

Daryl J Chymyck

Zhu Shenzhong

A system for deterring fraudulent cloning by a reader station of valid call-origination message parameters assigned to authorized mobile radiotelephone stations operating within a cell or other area of a cellular radiotelephone system in which valid call origination messages are initiated between the mobile stations and a fixed cell-site radiotransceiver station for that cell or area. A database containing a plurality of valid call-origination message parameter combinations assigned to the authorized mobile stations is established in the radiotelephone system. An auxiliary fraud-deterrent transmitter station transmits call origination messages containing invalid parameters in such cell or area the cellular radiotelephone system. These invalid parameters are not verifiable at the database. The reader station receives both the valid and invalid call origination messages with an inability to discern with certainty between the valid and the invalid call origination messages.

Cellular fraud deterrent system

A manually-movable, portable, cellular-system signal-strength analyzer for measuring, recording and displaying geographically-located, downlink, cellular-communication-channel signal strengths in non-vehicular pedestrian areas and also inside buildings. The analyzer has a cellular-telephone scanning receiver housed within a backpack that is worn by a human operator who traverses the areas to be analyzed. A height-adjustable antenna mast formed from a set of telescoping tubes is fixed to the exterior of the backpack. This mast supports a self-resonant antenna of fixed length whose elevation height may be varied to determine signal-strengths at different pedestrian heights. The backpack also houses a controller. A laser rangefinder which has a built-in compass inputs data to the controller concerning the geographic locations of various points traversed by the analyzer. An arm-held computer is also connected to the controller. The computer has a display and a 'pen' for manual writing on the display to input data and instructions to the analyzer. The computer records and displays the signal strengths of the selected cellular-communication channels for various geographically located points throughout the areas traversed.

Cellular-system signal-strength analyzer

A cellular system access monitor for monitoring and reporting information relating to the operation of cellular telephone systems. The monitor features a cellular telephone of current design, responding to the expanded spectrum of 832 channels. The cellular telephone communicates with a controller using a self-clocking data transmission scheme to improve the reporting and displaying of cellular system parameters, such as cellsite control-channel identification numbers and textual cellsite identification information. Additionally, the monitor employes a calibration feature for measuring and displaying accurately signal strength in decibels. System parameters are shown on a bit-mapped display.

Growing community of inventors

Palatine, IL, United States of America

Kurt T Lemke