Call back arrangement

Claim 2

A call back arrangement for common control telephone systems comprising: means for determining when a connection between a calling station and a called station cannot be completed by the common control; means co-operating with the common control and effective upon a determination that a connection cannot be completed for connecting the calling station to means for receiving a signal from the calling station requesting the call be automatically retried, said means for connecting being arranged to transfer the identities of said calling and called stations from the common control to storage in said means for receiving upon connection of said calling station to said means for receiving; means for determining when the called station is free and seizing the called station without signalling the called station; means responsive to the seizure of the called station for ringing the calling station, and means, responsive to the answer of the calling station, for automatically completing the connection between the calling station and the called station and ringing the called station.

Claim 3

In a telephone system: a switching network; common control means responsive to the receipt of a called station number dialed by a calling subscriber station for controlling the establishment of a connection through said switching network between said calling and called stations and including means activated during the servicing of a call for determining when a connection cannot be completed between said stations, and means for determining the class of service of a calling party; storage means, connected to said common control means, responsive to said determining means when a call cannot be completed, for storing the calling and called station identities, if the calling station has a call back class of service, and retry means connected to said calling station by said common control means for receiving a retry signal when a call cannot be completed and effective upon said storage of said station identities, including means for periodically causing the common control to attempt a connection through said network between said called station and said retry means and, if Successful, for seizing said called station without signalling said called station, and means responsive on said seizure for causing the common control to attempt to complete a connection between calling and called stations through said network and retry means.

Claim 4

In a telephone system: a switching network; common control means responsive to the receipt of a called station number dialed by a calling subscriber station for controlling the establishment of a connection through said switching network between said calling and called stations and including means activated during the servicing of a call for determining when a connection cannot be completed between said stations, and means for determining the class of service of a calling party; storage means, connected to said common control means, responsive to said determining means when a call cannot be completed, for storing the calling and called station identities, if the calling station has a call back class of service, and retry means connected to said calling station by said common control means for receiving a retry signal when a call cannot be completed and effective upon said storage of said station identities, including means for periodically causing the common control to attempt a connection through said network between said called station and said retry means and, if Successful, for seizing said called station without signalling said called station, and means responsive on said seizure for causing the common control to attempt to complete a connection between calling and called stations through said network and retry means.

Claim 5

In a common control telephone system: means operable under the control of a calling subscriber for attempting the completion of a connection between a calling station and a called station; means for determining when a connection between the calling and called station cannot be currently completed; means, effective upon such determination, for registering information concerning the identity of the calling and called stations when the calling party has the call back class of service; means for accepting a signal from the calling station, having the call back class of service requesting that the call can be automatically retried; means, responsive to the acceptance of said signal, for determining when the identified called station is free and thereafter seizing the called station without ringing the called station, and means effective upon said seizure of the called party line for automatically retrying the establishment of a connection between the identified calling and called stations.

Claim 6

In a common control telephone system: means operable under the control of a calling subscriber for attempting the completion of a connection between a calling station and a called station; means for determining when a connection between the calling and called station cannot be currently completed; means, effective upon such determination, for registering information concerning the identity of the calling and called stations when the calling party has the call back class of service; means for accepting a signal from the calling station, having the call back class of service requesting that the call can be automatically retried; means, responsive to the acceptance of said signal, for determining when the identified called station is free and thereafter seizing the called station without ringing the called station, and means effective upon said seizure of the called party line for automatically retrying the establishment of a connection between the identified calling and called stations.

Claim 7

A call back arrangement for telephone systems including a switching network and a common control for connecting stations through the network, the common control including circuits for receiving the identity of the station to be connected, for determining the class of service of calling parties and for determining when attempted connections cannot be completed between stations, and a call back arrangement comprising: a plurality of call back trunks, each trunk including a detection circuit for detecting call back signals from stations connected thereto by common control to produce a call back request signal; circuit means, responsive to a determination that a connection requested by a calling station having a call back class of service cannot be currently completed to a called party, for effecting the connection by the common control of a free call back trunk to the calling station; storage circuit means, effective upon the connection of a call back trunk to a calling party, for receiving the identity of the calling and called stations from the common control and storing the identities of the called and calling parties along with the identity of the connected call back trunk; circuit means, responsive to a call back request signal from a call back trunk, for transmitting a called station identity associated with the call back trunk to the common control for effecting a connection between the call back trunk and called station, and circuit means, responsive to the completion of a connection between a call back trunk and the called station, for transmitting the calling station identity associated with the call back trunk to the common control to effect a connection between the call back trunk and the calling party.

Claim 8

A call back arrangement for telephone systems including a switching network and a common control for connecting stations through the network, the common control including circuits for receiving the identity of the station to be connected, for determining the class of service of calling parties and for determining when attempted connections cannot be completed between stations, and a call back arrangement comprising: a plurality of call back trunks, each trunk including a detection circuit for detecting call back signals from stations connected thereto by common control to produce a call back request signal; circuit means, responsive to a determination that a connection requested by a calling station having a call back class of service cannot be currently completed to a called party, for effecting the connection by the common control of a free call back trunk to the calling station; storage circuit means, effective upon the connection of a call back trunk to a calling party, for receiving the identity of the calling and called stations from the common control and storing the identities of the called and calling parties along with the identity of the connected call back trunk; circuit means, responsive to a call back request signal from a call back trunk, for transmitting a called station identity associated with the call back trunk to the common control for effecting a connection between the call back trunk and called station, and circuit means, responsive to the completion of a connection between a call back trunk and the called station, for transmitting the calling station identity associated with the call back trunk to the common control to effect a connection between the call back trunk and the calling party.

Claim 9

A call back arrangement as defined in claim 4 wherein: each of said plurality of call back trunks include a busy tone circuit for applying a busy tone to a calling party when initially connected thereto in response to a determination that a requested call cannot be completed, and circuit means for terminating the busy tone is response to the detection of a call back request signal by said detection circuit.

Claim 10

A call back arrangement as defined in claim 5 wherein: each of said plurality of call back trunks includes a first ringing circuit for applying ringing signals to the calling station when the calling station is connected to a call back trunk that was previously connected to a called station, and a second ringing circuit for applying ringing signals to the called station after the calling party answers.

Claim 11

A call back arrangement defined in claim 6 wherein: each of said plurality of call back trunks includes a second tone circuit for applying a call waiting tone to said called station when connected to a call back trunk until the answer of the calling party.

Claim 12

A call back arrangement as defined in claim 4 wherein said call back trunks are connected to one side of said switching network and connection through said switching network of said called and calling station is effected to the other side of said switching network.

Claim 13

A call back arrangement as defined in claim 8 wherein said circuit means for effecting a connection between the call back trunk and called station include means for providing a premature ring trip signal to the called station.

Claim 14

A call back arrangement as defined in claim 9 wherein said circuit means for effecting a connection between the call back trunk and calling party include means for providing a premature ring trip signal to the calling station.

Claim 15

A call back arrangement as defined in claim 10 wherein said plurality of call back trunks include means to connect the calling station to the called station through individual ones of said call back trunks.

Claim 16

A call back arrangement as defined in claim 11 wherein said storage circuit means includes a plurality of memory addresses and means to write into a memory address, synchronously with said common control, the identity of the calling station and subsequently to write into the same memory address the identity of the called station.

Claim 17

A call back arrangement as defined in claim 12 wherein said address written into depends upon the particular call back trunk requesting service, whereby a unique address in said storage means is associated with each of said call back trunks.

Claim 18

A call back arrangement as defined in claim 13 wherein said storage means includes means for detecting the presence of said identities in said memory addresses and for producing an output when the coincidence of a call back trunk request and the detection of identities in the associated memory address occurs.

Claim 19

A call back arrangement as defined in claim 14 wherein each of said call back trunks include means, connected to said presence detecting means, effective upon detecting an output therefrom to reserve the call back trunk associated with the memory address where the presence of an identity was found and to generate an identity detected signal unique to said address.

Claim 20

A call back arrangement as defined in claim 15 wherein said storage means includes attempt means adapted to read identities stored in said addresses and to communicate said identities stored in said storage means both to said means for effecting a connection between the call back trunk anc called station and to said means for effecting a connection between the call back trunks and calling party.

Claim 21

A call back arrangement as defined in claim 16 wherein said storage means includes scanning means arranged to be enabled periodically, to scan said memory addresses sequentially for a stored identity pair and to enable a said attempt means connected to said common control when a said identity is found and the associated identity detected signal has been generated.

Claim 22

A call back arrangement as defined in claim 17 wherein said attempt means includes counting means for counting each attempt until a preset number is reached and thereupon terminating said identity detected signal.

Claim 23

A call back arrangement for a common control telephone system including a plurality of subscriber line circuits connectable by the common control through a switchable line link network to a plurality of ringing circuits and to a plurality of local junctors, wherein the plurality of local junctors and ringing circuits are further connectable by said common control through a switchable trunk link network to each other, thereby defining connecting paths between said line circuits, said call back arrangement comprising: at least one of a plurality of call back trunks for establishing a call back path between two of said line circuits through the trunk link network; call back control means connected to said common control and to said plurality of call back trunks for controlling the connection between said line circuits and for communicating supervisory signals to said common control and to said subscriber lines, and call back storage means for receiving the identities of said two line circuits from said common control and for storing said identities, said call back storage means being adapted to periodically release said identities, under the supervision of said call back control means, to the common control to attempt a termination between said two line subscribers.

Claim 24

A call back arrangement for a common control telephone system including a plurality of subscriber line circuits connectable by the common control through a switchable line link network to a plurality of ringing circuits and to a plurality of local junctors, wherein the plurality of local junctors and ringing circuits are further connectable by said common control through a switchable trunk link network to each other, thereby defining connecting paths between said line circuits, said call back arrangement comprising: at least one of a plurality of call back trunks for establishing a call back path between two of said line circuits through the trunk link network; call back control means connected to said common control and to said plurality of call back trunks for controlling the connection between said line circuits and for communicating supervisory signals to said common control and to said subscriber lines, and call back storage means for receiving the identities of said two line circuits from said common control and for storing said identities, said call back storage means being adapted to periodically release said identities, under the supervision of said call back control means, to the common control to attempt a termination between said two line subscribers.