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EP0136167A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Ringing signal transmission system for radiotelephone system

Assignee: NEC Corp
•
Filing: 1984-09-25
•
Granted: —
•
Expires: 2004-09-25
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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 subsrciber'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 C/O Nec Corporation Orikasa

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-03 23:07
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.

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