Patent · US Expired

System and method for the verification of authentic telephone numbers in a wireless telephone system

US5999807A · kind A · utility

17Cited by
55References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 28, 1997
Grant dateDec 7, 1999
Priority date
Expiry dateFeb 28, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M1/725
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A system for the authorization of wireless telephone communications establishes two sets of authorized telephone numbers. A first set of authorized telephone numbers are supplied by the customer, and the second set of authorized numbers are derived from customer bills paid by the customer. The system analyzes transmission characteristics from an unauthenticated cellular telephone and attempts to verify its authenticity based on the transmission characteristic by analyzing the transmission characteristic with respect to stored reference waveforms for the authentic wireless telephone. However, the results of this signature analysis if negative may be overridden if the telephone number dialed by the unauthenticated cellular telephone matches a telephone number in either the first or second sets of authorized telephone numbers. The system also includes a technique for modifying the reference waveforms to compensate for changes in the transmission characteristic. The system will only consider the inclusion of transmission characteristics from the present communication if the dialed digits for the present communication match one of the telephone numbers in either the first or second sets…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.