Automatic channel switching system

Claim 2

Apparatus for initiating the substitution of a protection channel for any one of a plurality of regular channels comprising: a protection network including a plurality of channel associated circuit segments each of which is associated with a different channel, said segments being connected in series and providing a means for transmitting an enabling signal from segment to segment; and control means responsive to said enabling signal for initiating the substitution of said protection channel for a failed regular channel.

Claim 3

Apparatus in accordance with claim 1 in which said circuit segments form a closed loop.

Claim 4

Transmission terminal apparatus responsive to a plurality of regular channels and to a first protection channel comprising: a first protection network including a plurality of first channel associated circuit segments each of which is associated with a different channel, said segments being connected in series to form a first closed loop and providing a means for circulating an enabling signal around said first loop from segment to segment; means for enabling said protection network in response to the failure of a regular channel, the enabling of said protection network resulting in initiating the circulation of said enabling signal; and control means responsive to said regular channel failure for initiating the substitution of said first protection channel for said failed regular channel when an enabling signal is present within the circuit segment associated with said failed regular channel.

Claim 5

Transmission terminal apparatus responsive to a plurality of regular channels and to a first protection channel comprising: a first protection network including a plurality of first channel associated circuit segments each of which is associated with a different channel, said segments being connected in series to form a first closed loop and providing a means for circulating an enabling signal around said first loop from segment to segment; means for enabling said protection network in response to the failure of a regular channel, the enabling of said protection network resulting in initiating the circulation of said enabling signal; and control means responsive to said regular channel failure for initiating the substitution of said first protection channel for said failed regular channel when an enabling signal is present within the circuit segment associated with said failed regular channel.

Claim 6

Apparatus in accordance with claim 3 in which each of said first circuit segments associated with said regular channels includes means responsive to said control means for stopping said enabling signal from circulating to subsequent circuit segments upon initiation of the substitution of said protection channel for the regular channel associated with the segment.

Claim 7

Apparatus in accordance with claim 3 further including means responsive to the failure of said protection channel for disabling said enabling means.

Claim 8

Apparatus in accordance with claim 3 which is responsive to a second protection channel and which further includes a second protection network associated with said second protection channel, said second protection network including a plurality of second channel associated circuit segments each of which is associated with a different channel, said segments being connected in series to form a second closed loop and providing a means for transmitting an enabling signal around said second loop from segment to segment, and means for enabling said second protection network when the enabling signal generated by said first protection network is stopped from circulating.

Claim 9

Apparatus in accordance with claim 6 in which said means for enabling said second protection network initiates the circulation of an enabling signal within said second network.

Claim 10

Apparatus in accordance with claim 7 in which said control means acts to initiate substitution of said first protection channel for a failed regular channel in response to the presence of an enabling signal within the first circuit segment associated with the failed regular channel and in which said control means acts to initiate substitution of said second protection channel for a failed regular channel in response to the presence of an enabling signal within the second circuit segment associated with the failed regular channel.

Claim 11

Apparatus in accordance with claim 7 in which said control means includes inhibiting means for preventing the substitution of said second protection channel for a particular failed regular channel from being initiated once substitution of said first protection channel for said particular regular channel has been initiated.

Claim 12

Automatic switching system apparatus responsive to a plurality of regular channels and to a first protection channel, said regular channels and said first protection channel linking a transmitter terminal and a receiver terminal of a communications system, including: detecting means for reporting the failure of any one of said channels; a first sequential pulsing circuit comprising a first plurality of first sequential pulsing circuit segments which are serially connected to form a first closed loop, said first circuit segments providing a means for sequentially circulating a first enabling pulse from segment to segment around said first loop upon said first sequential pulsing circuit being started; a first protection channel section associated with said first protection channel comprising one of said first segments and a first activation means for causing said first segment included in the section to start said first sequential pulsing circuit in response to reports from said detecting means of the failure of any one of a first group of selected ones of said regular channels; a plurality of regular channel sections each associated with a different one of said regular channels, each of said sections including a different one of said first segments and a first assignment means for assigning the regular channel associated with the section to said first protection channel in response to reports from said detecting means of the failure of said associated regular channel and to the presence of said first enabling pulse within said first segment included in the section; and means responsive to the first assignment means of each of said regular channel sections for initiating the substitution of said first protection channel for the particular regular channel which has been assigned to said first protection channel.

Claim 13

Automatic switching system apparatus responsive to a plurality of regular channels and to a first protection channel, said regular channels and said first protection channel linking a transmitter terminal and a receiver terminal of a communications system, including: detecting means for reporting the failure of any one of said channels; a first sequential pulsing circuit comprising a first plurality of first sequential pulsing circuit segments which are serially connected to form a first closed loop, said first circuit segments providing a means for sequentially circulating a first enabling pulse from segment to segment around said first loop upon said first sequential pulsing circuit being started; a first protection channel section associated with said first protection channel comprising one of said first segments and a first activation means for causing said first segment included in the section to start said first sequential pulsing circuit in response to reports from said detecting means of the failure of any one of a first group of selected ones of said regular channels; a plurality of regular channel sections each associated with a different one of said regular channels, each of said sections including a different one of said first segments and a first assignment means for assigning the regular channel associated with the section to said first protection channel in response to reports from said detecting means of the failure of said associated regular channel and to the presence of said first enabling pulse within said first segment included in the section; and means responsive to the first assignment means of each of said regular channel sections for initiating the substitution of said first protection channel for the particular regular channel which has been assigned to said first protection channel.

Claim 14

Apparatus in accordance with claim 10 in which the first segment of each of said regular channel sections includes means for stopping said first enabling pulse from circulating around said first loop in response to an assignment by the first assignment means included in the section of the regular channel associated with the section to said first protection channel.

Claim 15

Apparatus in accordance with claim 10 in wHich said first protection channel section includes means responsive to reports from said detecting means of the failure of said first protection channel for preventing said first segment included in said first protection channel section from starting said first sequential pulsing circuit.

Claim 16

Apparatus in accordance with claim 10 which is responsive to a second protection channel, said second protection channel also linking said terminals, and which includes: a second sequential pulsing circuit comprising a second plurality of second sequential pulsing circuit segments which are serially connected to form a second closed loop, said second segments providing a means for circulating a second enabling pulse from segment to segment around said second loop upon said second sequential pulsing circuit being started; a second protection channel section associated with said second protection channel including one of said second segments and a second activation means for causing said second segment included in said section to start said second sequential pulsing circuit in response to reports from said detecting means of the failure of any one of a second group of selected ones of said regular channels; and in which each of said regular channel sections includes: a different one of said second segments and a second assignment means for assigning the regular channel associated with the section to said second protection channel in response to reports from said detecting means of a failure of said associated regular channel and to the presence of said second enabling pulse within said second segment included in the section; and in which said means for initiating is responsive to the second assignment means of each of said regular channel sections and acts to initiate the substitution of said second protection channel for the regular channel which has been assigned to said second protection channel.

Claim 17

Apparatus in accordance with claim 13 in which said first protection channel section includes means for causing said second activation means to start said second sequential pulsing circuit in response to an assignment being made by any one of said first assignment means and in which said second protection channel includes means for causing said first activation means to start said first sequential pulsing circuit in response to an assignment being made by anyone of said second assignment means.

Claim 18

Apparatus in accordance with claim 14 in which said first group of regular channels is different from said second group of regular channels.

Claim 19

Apparatus in accordance with claim 10 in which: said first segment included in said protection channel section comprises a series connection of first, second and third logic circuits; and the first segment included in each regular channel section comprises fourth and fifth serially connected logic circuits and sixth and seventh serially connected logic circuits, said series connection of sixth and seventh logic circuits being connected in parallel with said fourth logic circuit.

Claim 20

Apparatus in accordance with claim 16 in which: said first logic circuit is connected to the input of said second logic circuit and said second logic circuit is connected to the input of said third logic circuit; the output of said fifth logic circuit of the segment of said first loop immediately preceding the segment included in the first protection channel section is connected to the input of said first logic circuit and the output of the third logic circuit is connected to the input of the fourth logic circuit of the segment of said first loop immediately following said segment included in the first protection channel section; and the output of the fifth logic circuit of each of the other segments of said first loop is connected to the input of the fourth logic circuit of the immediately following segment of said first loop.

Claim 21

Apparatus in accordance with claim 17 in which said first logic circuit is rEsponsive to said first activation means and causes said first sequential pulsing circuit to start and in which said started first sequential pulsing circuit causes said first enabling pulse to appear sequentially at the outputs of said seventh logic circuits.

Claim 22

Apparatus in accordance with claim 17 in which each of said first, second, third, fourth, fifth, sixth and seventh logic circuits is a NAND gate.

Claim 23

Apparatus in accordance with claim 3 which both receives and transmits transmission channels.

Claim 24

Apparatus in accordance with claim 10 which includes means responsive to said initiating means for performing the substitution initiated thereby.

Claim 25

In a communications system comprising a transmitter terminal, a receiver terminal, a plurality of regular channels linking said terminals, a protection channel also linking said terminals and means for substituting said protection for any one of said regular channels, a protection network for enabling said substitution means, said protection network including a plurality of channel associated circuit segments each of which is associated with a different channel, said segments being connected in series and providing a means for transmitting an enabling signal from segment to segment, and control means responsive to said enabling signal for initiating operation of said substitution means to substitute said protection channel for a failed regular channel.

Claim 26

In a communications system comprising a transmitter terminal, a receiver terminal, a plurality of regular channels linking said terminals, a protection channel also linking said terminals and means for substituting said protection for any one of said regular channels, a protection network for enabling said substitution means, said protection network including a plurality of channel associated circuit segments each of which is associated with a different channel, said segments being connected in series and providing a means for transmitting an enabling signal from segment to segment, and control means responsive to said enabling signal for initiating operation of said substitution means to substitute said protection channel for a failed regular channel.