The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 01, 1986
Filed:
Sep. 24, 1984
Michael R Williamson, Dallas, TX (US);
VMX, Inc., Richardson, TX (US);
Abstract
Method and apparatus for determining the integrity of a communications channel includes a first communications system connected to a communications channel with a receiving communications system attached to the other end of the chennel. The first communications system generates a discrete frequency at the low end of the bandwidth for reception by the receiving system. The receiving system measures the frequency and the power level of the first tone. The first communications system then inhibits transmission for a predetermined duration of time during which the receiving system measures the noise floor of the communications channel. A second tone is then generated at the high end of the channel bandwidth for reception by the receiving system. The receiving system then compares the measured power levels of the first and second tone and the noise floor with predetermined criteria and determines the integrity of the communications channel from this comparison. If the integrity meets a prescribed level, voice messages are transmitted from the first communications system to the receiving communications system.