1
Ronald S Rudokas, John A Storch, David L Daniels: Mehtod and apparatus for fraud control in cellular telephone systems utilizing RF signature comparison. AirTouch Communications, Merchant Gould Smith Edell Welter & Schmidt, May 30, 1995: US05420910 (169 worldwide citation)

A method and apparatus for fraud control in cellular telephone systems. Call records from a switch are scanned to identify a fraudulent cellular phone based on its behavior. An identifier, e.g., a radio frequency (RF) signature, representative of the fraudulent phone is stored in a control channel e ...


2
William J Kaminsky: Method and apparatus for exchanging RF signatures between cellular telephone systems. AirTouch Communications, Gates & Cooper, February 8, 2000: US06023619 (153 worldwide citation)

A method for reducing roaming fraud in mobile phone systems includes the exchange of an RF signature of a roaming mobile phone between the foreign and home service areas. Thereafter, the analysis of the RF signature can be performed either at the foreign or home service area.


3
Ronald S Rudokas, John A Storch, David L Daniels: Method and apparatus for fraud control in cellular telephone systems. AirTouch Communications, Merchant Gould Smith Edell Welter & Schmidt, September 10, 1996: US05555551 (96 worldwide citation)

A method and apparatus for fraud control in cellular telephone systems. Call records from a switch are scanned to identify a fraudulent cellular phone based on its behavior. An identifier, e.g., a radio frequency (RF) signature, representative of the fraudulent phone is stored in a control channel e ...


4
William Chien Yeh Lee, F Craig Farrill: Location-ruled radio-integrated network. AirTouch Communications, Merchant Gould Smith Edell Welter & Schmidt, September 22, 1998: US05812522 (86 worldwide citation)

An integrated radio frequency communication system, known as a Location-Ruled Radio-Integrated Network (LORRAINE) system, provides integrated voice, data and location services. The radio frequency communications system combines time division multiplexing (TDM) techniques with optional time division ...


5
William Chien Yeh Lee, F Craig Farrill: Method and apparatus for eliminating intermodulation interference in cellular telephone systems. AirTouch Communications, Gates & Cooper, November 2, 1999: US05978362 (73 worldwide citation)

The invention describes method and apparatus for reducing intermodulation interference caused by reception of undesired signals in wireless receivers. The apparatus comprises an antenna for receiving the desired signal, a low noise amplifier for amplifying this signal, an adjustable attenuator, and ...


6
David Leighton Daniels: Cellular fraud prevention using selective roaming. AirTouch Communications, Gates & Cooper, May 2, 2000: US06058301 (61 worldwide citation)

A method of preventing roaming fraud in cellular telephone systems using different levels of roaming privileges for individual subscribers. When the subscriber initiates a call in a foreign service area that exceeds their roaming privileges, an authentication method is used to verify the identity of ...


7
William C Y Lee: CDMA transmission delay method and apparatus. AirTouch Communications of California, Merchant Gould Smith Edell Welter & Schmidt, December 26, 1995: US05479397 (58 worldwide citation)

A cellular telephone system is described of the type wherein a plurality of contiguous cells, each having an assigned set of identification codes, are arranged with means for maintaining continuous communication with mobile telephones moving from cell to cell. The system allows multiple access by in ...


8
William C Lee: Microcells for digital cellular telephone systems. AirTouch Communications of California, Merchant Gould Smith Edell Welter & Schmidt, April 2, 1996: US05504936 (53 worldwide citation)

A cellular telephone system is described of the type wherein a plurality of contiguous cells, each having an assigned set of identification codes, are arranged with means for maintaining continuous communication with mobile telephones moving from cell to cell. The system allows multiple access by in ...


9
William C Lee: Inbuilding telephone communication system. AirTouch Communications, Merchant Gould Smith Edell Welter & Schmidt, September 20, 1994: US05349631 (45 worldwide citation)

An Inbuilding Communications System for providing telephone communication to a first set of portable telephones located in a first area and to a second set of portable telephones located in a second area; the first set of portable telephones transmit and receive a first set of radio signals having a ...


10
William J Kaminsky, Jeffrey G Sanpore, David L Daniels, Mary H Kennedy: Method and apparatus for fraud control in cellular telephone systems. AirTouch Communications, Gates & Cooper, September 7, 1999: US05950121 (41 worldwide citation)

A method and apparatus for fraud control in cellular telephone systems. The invention identifies relative fraud probabilities for call records from the cellular telephone system, associates the call records with radio frequency (RF) signatures, and identifies the radio frequency signatures as being ...