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US4574164A Expired / Lapsed US ⏱️ 0.0 years remaining

Ringing signal transmission system for radiotelephone system

Assignee: NEC Corp
•
Filing: 1984-09-19
•
Granted: 1986-03-04
•
Expires: 2004-09-19
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Abstract

Abstract A base station (coast station) of such a radiotelephone system as a maritime mobile radiotelephone system is connected to a telephone exchange of a public telecommunication network. A ringing signal from a subscriber's station of the telecommunication network which is connected to the exchange is transmitted to an end station (ship station) of the radiotelephone system by way of the line concentrator and a radio section between the base and end stations. When a false calling tone signal is sent from a tone signal delivery circuit included in the line concentrator to an end station for a predetermined short period of time upon completion of a connection between the exchange and the end station, with no regard to a ringing signal from the exchange, a subscriber's telephone at the end station produces a calling tone. Thereafter, the line concentrator delivers a calling tone signal in synchronism with a ringing signal from the exchange. The telephone at the terminal station, therefore, produces a tone immediately after a connection has been completed, so that the subscriber at the end station is prevented from off-hooking during an interruption time of a calling tone to cause collision of receipt of a call and origination of a call.

Inventors

  • 👤 Hiromi Orikasa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 08:03
CPC Classifications
H; H04; H04W; H04W84/00; H04W84/02; H04W84/04

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 190 words
In a radiotelephone system comprising a telephone switching network which includes a telephone exchange for sending a ringing signal, at least one base station connected to the telephone switching network, and a plurality of end stations each being provided with a telephone, wherein a multi-channel access radio section is set up between the base station and each of the end stations and the telephone at each of the end stations produces a calling tone in synchronism with a ringing signal after the ringing signal from the telephone exchange is transmitted over the radio section, a ringing signal transmission system comprising: trunk circuits connected between the base station and the telephone exchange in correspondence with channels of the radio section; and a tone signal generator circuit called by the telephone exchange to generate a calling tone signal for a predetermined period of time immediately after the completion of a connection of the radio section for a call to be received by one of the end stations, with no regard to a ringing signal to be delivered from the telephone exchange, said calling tone signal being transmitted to said one end station.
Claim 2
Dependent Claim 190 words
In a radiotelephone system comprising a telephone switching network which includes a telephone exchange for sending a ringing signal, at least one base station connected to the telephone switching network, and a plurality of end stations each being provided with a telephone, wherein a multi-channel access radio section is set up between the base station and each of the end stations and the telephone at each of the end stations produces a calling tone in synchronism with a ringing signal after the ringing signal from the telephone exchange is transmitted over the radio section, a ringing signal transmission system comprising: trunk circuits connected between the base station and the telephone exchange in correspondence with channels of the radio section; and a tone signal generator circuit called by the telephone exchange to generate a calling tone signal for a predetermined period of time immediately after the completion of a connection of the radio section for a call to be received by one of the end stations, with no regard to a ringing signal to be delivered from the telephone exchange, said calling tone signal being transmitted to said one end station.
Claim 3
Dependent Claim 34 words
A ringing signal transmission system as claimed in claim 1, in which the trunk circuits constitute trunk circuits of a line concentrator which is interposed between the telephone switching network and the base station.

References Cited (Backward Citations)

US3692952A Cited
US3906166A Cited
US4320265A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-03-03 1989-09-02 1990-03-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-03-03 1993-09-02 1994-03-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-03-03 1997-09-02 1998-03-04 $7700.00 Window Closed / Lapsed

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