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:
Mar. 16, 1982
Filed:
Dec. 21, 1979
Giancarlo Biggiogera, Milan, IT;
Manlio Saba, Milan, IT;
Societa Italina Telecomunicazioni Siemens S.p.A., Milan, IT;
Abstract
A telephone exchange communicates with a number of scattered local stations via radio links extending from a central terminal to respective peripheral installations each comprising a radio transceiver coupled via a repeater to the line loop of an associated local station. The repeater includes a constant-current generator, combined with a polarity inverter, which is controlled via a logic network in response to signals from the exchange and from the local station (detected by a sensor in the line loop) to reverse the flow of direct current for the transmission of binary pulses to the local station. In the case of a private subscriber, these pulses may be an intermittent square wave generating a ringing signal; in the case of a public pay station they may constitute commands for the collection of tokens or coins.