Time division switching system conference circuit

Claim 2

In a time division switching system having a plurality of communication paths wherein each path has a signal storage device associated therewith and wherein a plurality of time slots occur in repetitive cycles, a circuit for conferencing more than two communication paths comprising means for defining a first group of successive time slots, means for assigning a pair of conference path storage devices to each of said first group of successive time slots, means operative in each of said first group of successive time slots comprising means responsive to the signals in each of the conference path storage devices assigned to the occurring one of said first group of successive time slots for generating a signal corresponding to the difference between the signals from said assigned conference storage devices, means responsive to the generated signals in said first group of successive time slots for forming a signal corresponding to the sum of said generated signals, means for defining a second group of successive time slots, means for associating a pair of conference storage devices with each of said second group of successive time slots, means operative in the occurring one of said second group of successive time slots comprising means for producing a first signal corresponding to the difference between said formed signal and the signal in one of the associated conference storage devices, means for applying said first signal to said associated one conference storage device, means for producing a second signal corresponding to the difference between said formed signal and the signal on the other of said associated conference storage devices, and means for applying said second signal to said other associated conference storage device.

Claim 3

In a time division switching system having a plurality of communication paths wherein each path has a signal storage device associated therewith and wherein a plurality of time slots occur in repetitive cycles, a circuit for conferencing more than two communication paths according to claim 1 wherein said signal forming means comprises storing means and means operative in each of said first group of successive time slots for applying said generated signal to said storing means.

Claim 4

In a time division switching system having a plurality of communication paths wherein each path has a signal storage device associated therewith and wherein a plurality of time slots occur in repetitive cycles, a circuit for conferencing more than two communication paths according to claim 2 wherein said first signal applying means comprises means responsive to said first signal for producing a first pulse having a duration corresponding to said first signal, and means connected between said first pulse producing means and said one associated conference storage device for applying a first constant current signal to said one associated conference storage device for the duration of said produced first pulse, and said second signal applying means comprises means responsive to said second signal for producing a second pulse having a duration corresponding to said signal, and means connected betweeN said second pulse producing means and said other associated conference storage device for applying a second constant current signal to said other associated conference storage device for the duration of said produced second pulse.

Claim 5

In a time division switching system wherein a plurality of time slots occur in repetitive cycles, the combination comprising first and second groups of communication paths, each communication path having an associated signal storage device, and a circuit for conferencing more than two of said first and second group communication paths, said conferencing circuit comprising means for defining a first plurality of successive time slots, means for assigning a first group storage device to be conferenced and a second group storage device to be conferenced to each of said first plurality of successive time slots, means operative in each of said first plurality of successive time slots responsive to the signals in the first group storage device and the second group storage device assigned to the occuring one of said first plurality of successive time slots for generating a signal corresponding to the difference between the signal in the assigned first group storage device and the signal in the assigned second group storage device, means responsive to the generated signal in each of said first plurality of successive time slots for forming a signal corresponding to the sum of said generated signals, means for defining a second plurality of successive time slots, means for associating one first group storage device to be conferenced and one second group storage device to be conferenced with each of said second plurality of successive time slots, means operative in each of said second plurality of successive time slots comprising means responsive to said formed signal and the signal in the associated first group storage device for producing a first signal corresponding to the difference between said formed signal and the signal in the associated first group storage device, means for applying said first signal to said associated first group storage device, and means responsive to said formed signal and the signal on the associated second group storage device for producing a second signal corresponding to the difference between said formed signal and said associated second group storage device, and means for applying said second signal to said associated second group storage device.

Claim 6

In a time division switching system wherein a plurality of time slots occur in repetitive cycles, the combination comprising first and second groups of communication paths, each communication path having an associated signal storage device, and a circuit for conferencing more than two of said first and second group communication paths, said conferencing circuit comprising means for defining a first plurality of successive time slots, means for assigning a first group storage device to be conferenced and a second group storage device to be conferenced to each of said first plurality of successive time slots, means operative in each of said first plurality of successive time slots responsive to the signals in the first group storage device and the second group storage device assigned to the occuring one of said first plurality of successive time slots for generating a signal corresponding to the difference between the signal in the assigned first group storage device and the signal in the assigned second group storage device, means responsive to the generated signal in each of said first plurality of successive time slots for forming a signal corresponding to the sum of said generated signals, means for defining a second plurality of successive time slots, means for associating one first group storage device to be conferenced and one second group storage device to be conferenced with each of said second plurality of successive time slots, means operative in each of said second plurality of successive time slots comprising means responsive to said formed signal and the signal in the associated first group storage device for producing a first signal corresponding to the difference between said formed signal and the signal in the associated first group storage device, means for applying said first signal to said associated first group storage device, and means responsive to said formed signal and the signal on the associated second group storage device for producing a second signal corresponding to the difference between said formed signal and said associated second group storage device, and means for applying said second signal to said associated second group storage device.

Claim 7

In a time division switching system, the combination in accordance with claim 4 wherein said signal forming means comprises storing means, and means responsive to the generated signal in each of said first plurality of successive time slots for applying said generated signal to said storing means.

Claim 8

In a time division switching system wherein a plurality of time slots occur in repetitive cycles, the combination in accordance with claim 5 further comprising a first common bus selectively connectible to said first group of storage devices, a second common bus selectively connectible to said second group of storage devices, means for connecting the assigned first group storage device to said first common bus and for connecting the assigned second group storage device to said second common bus in each of said first plurality of successive time slots, and means for connecting said first common bus and said second common bus to said signal generating means in each of said first plurality of successive time slots.

Claim 9

In a time division switching system wherein a plurality of time slots occur in repetitive cycles, the combination according to claim 6 wherein said first signal applying means comprises means responsive to said first signal for producing a first pulse having a duration corresponding to said first signal, means connected between said first pulse producing means and said first common bus responsive to said produced first pulse for generating a first constant current signal having the same duration as said produced first pulse, and means for applying said first constant current Signal to said associated first group storage device via said first common bus, and wherein said second signal applying means comprises means responsive to said second signal for producing a second pulse having a duration corresponding to said second signal, means connected between said second pulse producing means and said second common bus responsive to said produced second pulse for generating a second constant current signal having the same duration as said produced second pulse, and means for applying said second constant current signal to the associated second group storage device via said second common bus.

Claim 10

In a time division switching system wherein a plurality of time slots occur in repetitive cycles, the combination comprising first and second groups of communication paths to be conferenced, each communication path having an associated storage device, first and second common buses, storing means, means for defining a first plurality of successive time slots, means for assigning a first group conference storage device and a second group conference storage device to each of said first plurality of successive time slots, apparatus operative in each of said first plurality of successive time slots comprising means for connecting the assigned first group conference storage device to said first bus and for connecting the assigned second group conference storage device to said second bus, means connected to said first and second buses for receiving a signal from said assigned first group conference storage device and a signal from said assigned second group conference storage device, and means connected to said receiving means for generating a signal corresponding to the difference between the signal from said assigned first group conference storage device and the signal from said assigned second group conference storage device and means for applying said generated signal to said storing means, said storing means being operative to accumulate the sum of said applied generated signals, means for defining a second plurality of successive time slots, means for associating a first group conference storage device and a second group conference storage device with each of said second plurality of successive time slots, and apparatus operative in each of said second plurality of successive time slots comprising means for connecting the associated first group conference storage device to said first bus, means for connecting the associated second group conference storage device to said second bus, means connected to said storing means and said first common bus for producing a first signal corresponding to the difference between the sum of said generated signals in said storing means and the signal in the associated first group conference storage device, means connected to said first bus responsive to said produced first signal for applying said produced first signal to the associated first group conference storage device via said first bus, means connected to said storing means and said second bus for producing a second signal corresponding to the difference between the sum of said generated signals in said storing means and the signal in said associated second group conference storage device, and means connected to said second bus responsive to said produced second signal for applying said second signal to said associated second group conference storage device via said second bus.

Claim 11

In a time division switching system wherein a plurality of time slots occur in repetitive cycles, the combination comprising first and second groups of communication paths to be conferenced, each communication path having an associated storage device, first and second common buses, storing means, means for defining a first plurality of successive time slots, means for assigning a first group conference storage device and a second group conference storage device to each of said first plurality of successive time slots, apparatus operative in each of said first plurality of successive time slots comprising means for connecting the assigned first group conference storage device to said first bus and for connecting the assigned second group conference storage device to said second bus, means connected to said first and second buses for receiving a signal from said assigned first group conference storage device and a signal from said assigned second group conference storage device, and means connected to said receiving means for generating a signal corresponding to the difference between the signal from said assigned first group conference storage device and the signal from said assigned second group conference storage device and means for applying said generated signal to said storing means, said storing means being operative to accumulate the sum of said applied generated signals, means for defining a second plurality of successive time slots, means for associating a first group conference storage device and a second group conference storage device with each of said second plurality of successive time slots, and apparatus operative in each of said second plurality of successive time slots comprising means for connecting the associated first group conference storage device to said first bus, means for connecting the associated second group conference storage device to said second bus, means connected to said storing means and said first common bus for producing a first signal corresponding to the difference between the sum of said generated signals in said storing means and the signal in the associated first group conference storage device, means connected to said first bus responsive to said produced first signal for applying said produced first signal to the associated first group conference storage device via said first bus, means connected to said storing means and said second bus for producing a second signal corresponding to the difference between the sum of said generated signals in said storing means and the signal in said associated second group conference storage device, and means connected to said second bus responsive to said produced second signal for applying said second signal to said associated second group conference storage device via said second bus.

Claim 12

In a time division switching system wherein a plurality of time slots occur in repetitive cycles, the combination according to claim 8 wherein each first group communication path comprises a station and a bidirectional two-wire line for coupling said station to the corresponding first group storage device, and each second group communication path comprises a trunk connected to the corresponding second group storage device.

Claim 13

In a time division switching system wherein a plurality of time slots occur in repetitive cycles, the combination comprising a plurality of communication lines each having a signaL storage device associated therewith, and a circuit for establishing a conference hookup among said plurality of lines, said conference circuit comprising storing means, means for defining a first group of successive time slots, means for assigning a pair of the plurality of line storage devices to each of said first group of successive time slots, apparatus operative in each of said first group of successive time slots comprising means for sampling the signals on the assigned pair of storage devices, means for linearly combining the sampled signals from said assigned pair of storage devices in each of said first group of time slots and means connected to said linearly combining means for applying a signal corresponding to said linearly combined sampled signals to said storing means, said storing means being operative to sum the signals from said linearly combining means, means for defining a second group of successive time slots, means for associating a pair of storage devices with each of said second group of successive time slots, and apparatus operative in each of a second group of successive time slots comprising means for sampling the signal on each of said associated pair of said plurality of storage devices, first means jointly responsive to the sum signal from said storing means and the sampled signal from one of said pair of storage devices for generating a first signal and means for applying said first signal to said one associated storage device, and second means jointly responsive to the sum signal from said storing means and the sampled signal from the other associated storage device for generating a second signal and means for applying said second signal to said other associated storage device.

Claim 14

In a time division switching system wherein a plurality of time slots occur in repetitive cycles, the combination comprising a plurality of communication lines each having a signaL storage device associated therewith, and a circuit for establishing a conference hookup among said plurality of lines, said conference circuit comprising storing means, means for defining a first group of successive time slots, means for assigning a pair of the plurality of line storage devices to each of said first group of successive time slots, apparatus operative in each of said first group of successive time slots comprising means for sampling the signals on the assigned pair of storage devices, means for linearly combining the sampled signals from said assigned pair of storage devices in each of said first group of time slots and means connected to said linearly combining means for applying a signal corresponding to said linearly combined sampled signals to said storing means, said storing means being operative to sum the signals from said linearly combining means, means for defining a second group of successive time slots, means for associating a pair of storage devices with each of said second group of successive time slots, and apparatus operative in each of a second group of successive time slots comprising means for sampling the signal on each of said associated pair of said plurality of storage devices, first means jointly responsive to the sum signal from said storing means and the sampled signal from one of said pair of storage devices for generating a first signal and means for applying said first signal to said one associated storage device, and second means jointly responsive to the sum signal from said storing means and the sampled signal from the other associated storage device for generating a second signal and means for applying said second signal to said other associated storage device.

Claim 15

In a time division switching system, the combination according to claim 10 wherein each storage device comprises a storage capacitor, said linearly combining means comprises means for forming a signal corresponding to the difference between the sampled signals from said assigned pair of said plurality of storage capacitors in each of said first group of time slots.

Claim 16

In a time division switching system, the combination according to claim 11 wherein said first means comprises means for generating a first pulse having a duration corresponding to the difference between the sum signal for said storing means and the sampled signal from said one associated storage capacitor, and means responsive to said generated first pulse for generating and applying a first constant current signal to said one associated storage capacitor for the duration of said first pulse, and wherein said second means comprises means for generating a second pulse having a duration corresponding to the difference between the sum signal from said storing means and the sampled signal from the other associated capacitor, and means responsive to said generated second pulse for generating and applying a second constant current signal to said other associated storage capacitor for the duration of said second pulse.