Cordless key telephone system capable of quickly answering incoming calls
First Claim
1. In a cordless key telephone system having a plurality of access units divided into groups corresponding respectively to service areas for broadcasting radio signals on a two-way control channel or on an assigned two-way speech channel, a plurality of cordless stations, and a main controller coupled to a switched telephone network for selecting one of the access units for each of said service areas in response to an incoming call from said network and transmitting a first alert signal to the selected access units, a method comprising the steps of:
- a) receiving said first alert signal and, in response thereto, broadcasting from the selected access units a recurrent sequence of second alert signals over the control channel, the second alert signals respectively identifying standby cordless stations;
b) receiving the second alert signal and, in response thereto, transmitting an acknowledgment signal over the control channel from each cordless station if the received second alert signal identifies;
c) receiving the acknowledgement signal and, in response thereto, transmitting a copy thereof from each of the selected access units to said main controller;
d) receiving said copy of the acknowledgement signal from the selected access units and, in response thereto, transmitting a proceed-to-assign signal from said main controller to said selected access units if the number of the received copies of the acknowledgement signals is equal to the number of all standby cordless stations;
e) receiving said proceed-to-assign signal and, in response thereto, broadcasting a channel assignment signal over the control channel from said selected access units, said channel assignment signal identifying said assigned speech channel;
f) receiving said channel assignment signal and, in response thereto, transmitting an end-of-switching signal over the assigned channel from one of the cordless station which are located in each of said areas;
g) receiving said end-of-switching signal and, in response thereto, broadcasting from each of the selected access units ringing signals over the assigned speech channel, the ringing signals identifying the cordless stations, which have transmitted said acknowledgment signals;
h) receiving the ringing signal and, in response thereto, generating a ringing tone in each cordless station if the received signal identifies the cordless station and allowing an off-hook signal to be transmitted over the assigned speech channel from a replying cordless station;
i) receiving the off-hook signal and, in response thereto, transmitting a copy thereof from one of the selected access units to said main controller;
j) returning a turn-on signal from the main controller as a response to said copy of the off-hook signal, said turn-on signal identifying the replying cordless station;
k) receiving said turn-on signal and, in response thereto, broadcasting a copy thereof from said access unit; and
1) causing said replying cordless station to receive said copy of the turn-on signal and establish a speech circuit thereof.
2 Assignments
0 Petitions
Accused Products
Abstract
In a cordless key telephone system, access units are located in groups corresponding to service areas for broadcasting radio signals on a control channel or on an assigned speech channel to cordless stations. A main controller selects one of the access units for each service area in response to an incoming call from the switched telephone network and sends a first alert signal to the selected access units to cause them to broadcast a recurrent sequence of second alert signals containing the identifiers of standby cordless stations. The second alert signal is received by each standby cordless station and an ACK signal is transmitted if the received signal contains its identifier. The ACK signal is copied by each access unit for transmission to the main controller, whereupon it returns a proceed-to-assign signal if the number of the received copies of the ACK signals is equal to the number of all standby stations. The proceed-to-assign signal is received by the selected access units and a channel assignment signal is broadcast indicating the assigned channel. On receiving it, each station is switched to the assigned channel and one of the stations in each area transmits an end-of-switching signal to cause the access units to broadcast ringing signals containing the identifiers of the alerted stations. In response to a given cordless station going off hook, an off-hook signal is sent from it and copied by the associated access unit for transmission to the main controller, which returns a turn-on signal to allow the given station to activate its speech circuit.
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Citations
6 Claims
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1. In a cordless key telephone system having a plurality of access units divided into groups corresponding respectively to service areas for broadcasting radio signals on a two-way control channel or on an assigned two-way speech channel, a plurality of cordless stations, and a main controller coupled to a switched telephone network for selecting one of the access units for each of said service areas in response to an incoming call from said network and transmitting a first alert signal to the selected access units, a method comprising the steps of:
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a) receiving said first alert signal and, in response thereto, broadcasting from the selected access units a recurrent sequence of second alert signals over the control channel, the second alert signals respectively identifying standby cordless stations; b) receiving the second alert signal and, in response thereto, transmitting an acknowledgment signal over the control channel from each cordless station if the received second alert signal identifies; c) receiving the acknowledgement signal and, in response thereto, transmitting a copy thereof from each of the selected access units to said main controller; d) receiving said copy of the acknowledgement signal from the selected access units and, in response thereto, transmitting a proceed-to-assign signal from said main controller to said selected access units if the number of the received copies of the acknowledgement signals is equal to the number of all standby cordless stations; e) receiving said proceed-to-assign signal and, in response thereto, broadcasting a channel assignment signal over the control channel from said selected access units, said channel assignment signal identifying said assigned speech channel; f) receiving said channel assignment signal and, in response thereto, transmitting an end-of-switching signal over the assigned channel from one of the cordless station which are located in each of said areas; g) receiving said end-of-switching signal and, in response thereto, broadcasting from each of the selected access units ringing signals over the assigned speech channel, the ringing signals identifying the cordless stations, which have transmitted said acknowledgment signals; h) receiving the ringing signal and, in response thereto, generating a ringing tone in each cordless station if the received signal identifies the cordless station and allowing an off-hook signal to be transmitted over the assigned speech channel from a replying cordless station; i) receiving the off-hook signal and, in response thereto, transmitting a copy thereof from one of the selected access units to said main controller; j) returning a turn-on signal from the main controller as a response to said copy of the off-hook signal, said turn-on signal identifying the replying cordless station; k) receiving said turn-on signal and, in response thereto, broadcasting a copy thereof from said access unit; and 1) causing said replying cordless station to receive said copy of the turn-on signal and establish a speech circuit thereof. - View Dependent Claims (2, 3)
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4. A cordless key telephone system for covering a plurality of service areas in which cordless stations are located, comprising:
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a plurality of access units divided into groups corresponding respectively to said service areas, the access units of each group being located in the corresponding service area for broadcasting signals on a two-way control channel or on an assigned two-way speech channel; a main controller coupled to a switched telephone network for selecting one of the access units for each of said service areas in response to an incoming call from said network and transmitting a first alert signal to the selected access units; each of said access units being responsive to said first alert signal for broadcasting over the control channel a recurrent sequence of second alert signals respectively identifying standby cordless stations, responsive to receipt of an acknowledgement signal from the cordless stations for transmitting a copy of the acknowledgement signal to said main controller, responsive to receipt of a proceed-to-assign signal from said main controller for broadcasting over the control channel a channel assignment signal identifying an assigned speech channel, responsive to receipt of an end-of-switching signal from the cordless stations for sequentially broadcasting over the assigned speech channel ringing signals respectively identifying the cordless stations which returned said acknowledgement signals, responsive to an off-hook signal from a replying cordless station for transmitting a copy of the off-hook signal to said main controller, and responsive to receipt of a turn-on signal from said main controller identifying the replying cordless station for broadcasting over the assigned speech channel a copy of said turn-on signal, said main controller transmitting said proceed-to-assign signal if the number of the copies of the acknowledgement signals from said selected access units is equal to the number of all standby cordless stations, and transmitting said turn-on signal to one of the selected access units if said copy of the off-hook signal is received therefrom, and each of said cordless stations responsive to the second alert signal identifying the cordless station for transmitting over the control channel said acknowledgement signal, responsive to the channel assignment signal for transmitting over the assigned speech channel said end-of-switching signal, transmitting over the assigned speech channel said off-hook signal when the cordless station goes off hook in response to the ringing signal identifying the cordless station, and establishing a speech circuit in response to the copy of said turn-on signal identifying the cordless station. - View Dependent Claims (5, 6)
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Specification