Lossless network junctor for pcm digital switching systems

Claim 2

In a common control switching network of a pulse code modulated digital switching system particularly useful in switching communication paths between calling and called transmission highways carrying digitally coded informational signals presented in a fractional coding frame format, a network junctor comprising first memory means for simultaneously storing said informational signals from selected paths of said transmission highways during a preselected one of reoccurring divisional time slots of one time frame and transmitting said informational signals to call-related pairs of transmission highways during call-related divisional time slots of an immediately following time frame, second memory means for storing common control instructions and controlling in a predetermined sequence in accordance with said instructions the connections of said first memory means with said selected pairs and with said call-related pairs of transmission highways, and third memory means for storing other common control instructions for causing said first memory means to store and transmit said informational signals in said predetermined sequence, said first memory means being connectible to said selected pairs and to said call-related pairs of transmission highways through at least two pairs of access lines, said first memory means including a pair of memory devices and each memory device being alternately connectible to saiD two pairs of access lines during two adjacent time frames, respectively, for both storing and transmitting said informational signals from said selected pairs of the transmission highways during one time frame and both storing and transmitting said informational signals from said call-related trnasmission highways during said immediately following time frame.

Claim 3

A network junctor as claimed in claim 1 wherein said second memory means comprises at least two memory devices for providing a second-type memory device in association with each of said two access line pairs, one of said second memory devices selectively connecting its associated pair of said two pairs of access lines with said selected pairs of transmission highways and the other of said second memory devices selectively connecting its associated pair of said two pairs of access lines with said call-related pairs of transmission highways.

Claim 4

A combined space and time switching system for completing communication paths along transmission highways having pairs of originating and terminating trunk lines carrying time division digital informational signals, said switching system comprising (a) x number of pairs of access lines connectible to said pairs of trunk lines for carrying said informational signals, and (a) x/2 number of switching junctors, each of said junctors connected to at least two pair of said access lines and including a pair of data transfer memory devices having a plurality of memory stores and being (alternately) connected to said two pairs of access lines alternately in adjacent time frames for selectively receiving from and transferring thereto said informational signals, (a pair) x number of line switching memory devices, each thereof having a plurality of memory stores and each (for) selectively (connecting) activating the connection of selected pairs of said trunk lines to an associated pair of said two pairs of access lines (with selected pairs of said trunk lines, each of said line switching memory devices having a plurality of memory stores), (a) x/2 number of channel switching memory devices, each having a plurality of memory stores which (for) selectively address(ing) in alternate time frames (said) the memory stores of alternate ones of said data transfer memory devices (and having a plurality of memory stores), said memory stores for said data transfer memory devices, said line switching memory devices and said channel switching memory devices all being at least equal to the number of distinct informational signals presented within a single time frame.

Claim 5

A combined space and time switching system for completing communication paths along transmission highways having pairs of originating and terminating trunk lines carrying time division digital informational signals, said switching system comprising (a) x number of pairs of access lines connectible to said pairs of trunk lines for carrying said informational signals, and (a) x/2 number of switching junctors, each of said junctors connected to at least two pair of said access lines and including a pair of data transfer memory devices having a plurality of memory stores and being (alternately) connected to said two pairs of access lines alternately in adjacent time frames for selectively receiving from and transferring thereto said informational signals, (a pair) x number of line switching memory devices, each thereof having a plurality of memory stores and each (for) selectively (connecting) activating the connection of selected pairs of said trunk lines to an associated pair of said two pairs of access lines (with selected pairs of said trunk lines, each of said line switching memory devices having a plurality of memory stores), (a) x/2 number of channel switching memory devices, each having a plurality of memory stores which (for) selectively address(ing) in alternate time frames (said) the memory stores of alternate ones of said data transfer memory devices (and having a plurality of memory stores), said memory stores for said data transfer memory devices, said line switching memory devices and said channel switching memory devices all being at least equal to the number of distinct informational signals presented within a single time frame.

Claim 6

A switching system as claimed in claim 3 wherein some of said originating and terminating trunk lines comprise communication paths for one associated set of transmission highways and others of said originating and terminating trunk lines comprise communication paths for another associated set of transmission highways, and one of said line switching memory devices is used to connect one of said associated pair of access lines to selected pairs of trunk lines of said one set of transmission highways and the other said line switching memory devices is used to connect the other of said associated pair of access lines to selected pairs of trunk lines of said other set of transmission highways.

Claim 7

A switching system as claimed in claim 3 wherein said digital informational signals are arranged in a repeating time frame format and during any single time frame of said format, one of said data transfer memory devices is connected to one pair of said two pairs of access lines and the other of said data transfer memories is connected to the other pair of said two pairs of access lines, and during an immediately following time frame, said one data transfer memory device is connected to said other pair of access lines and said other data transfer memory device is connected to said one pair of access lines for transferring information received over one pair of access lines during one time frame to the other pair of access lines during the subsequent time frame.

Claim 8

A switching system as claimed in claim 5 wherein during any two adjacent time frames of said repeating time frame format, said channel switching memory device is connected during the entire first time frame to one of of said data transfer memory devices and during the entire second time frame is connected to the other of said data transfer memory devices for selectively addressing the memory stores of said two data transfer memory devices in separate time frames.

Claim 9

A switching system as claimed in claim 6 wherein said single time frame is comprised of a plurality of time slots within which to provide voice informational samples, said time slots corresponding in number to the plurality of memory stores for each of said two data transfer memory devices for providing the storage of two separate informational signals and the transmittal of two separate informational signals in a selected single time slot of said single time frame.

Claim 10

A switching system as claimed in claim 7 wherein some of said trunk lines comprise a first set of trunk lines and others of said trunk lines comprise a second set of trunk lines, a first time slot of a single time frame communicated over a predetermined one of said trunk lines of said first set thereof has a correspondingly numbered memory store in each of said data transfer memory devices, a selected one of said two memory stores receiving said informational sample from said first time slot, a second time slot of a single time frame communicated over a predetermined one of said trunk lines of said second set thereof has a correspondingly numbered memory store in each of said data transfer memory devices, a selected one of said two memory stores receiving said informational sample from said second time slot, and when said informational sample within said first time slot of said one trunk line of said first set thereof is to be inputted to said second time slot of said one trunk line of said second set thereof and vice versa, said correspondingly numbered memory stores in each of said data transfer memory devices provide a first selectable communications path through said junctor extending from said one access line pair to said other access line pair and a second selectable communications path through said junctor extending from said other access line pair to said one access line pair whereby there is provided two potential communication paths through said junctor for each time slot of each time frame.

Claim 11

A switching system as claimed in claim 8 wherein when said selected one of said two memory stores which receives said informational sample from said first time slot is within one data transfer memory device, the selected one of said two memory stores which receives said informational sample from said second time slot is within the other data transfer memory device.

Claim 12

In a time division multiplexing pulse code modulating communication system having a number of group multiplexer/demultiplexer units for providing digital informational signals arranged in a repeating time frame format, a combination space and time switching system comprising a number of pairs of originating and terminating trunk lines for carrying said informational signals and being connectible to said group units, respectively, at least two other pair of originating and terminating trunk lines for carrying said informational signals and being connectible to said first-mentioned pairs of trunk lines to define a grid-like crosspoint matrix arrangement, and at least one switching junctor including a pair of data transfer memory devices, each having a plurality of memory stores (selectively) and being alternately connected in successive time frames to said first-mentioned pairs and said other pairs of trunk lines for both receiving said informational signals from and transferring said informational signals thereto (to said other pairs of trunk lines), respectively, a pair of line switchiNg memory devices each having a plurality of memory stores and selectively connecting an associated one of said data transfer memory devices (other pairs of trunk lines) with selected ones of said firstmentioned pairs and said other pairs of trunk lines at the crosspoints of said matrix arrangement, a channel switching memory device having a plurality of memory stores, said channel switching memory device alternately (selectively) addressing the (said) memory stores of said data transfer memory devices within (any given two adjacent) successive time frames of said repeating time frame format, said memory stores for said data transfer memory devices, said line switching memory devices and said channel switching memory device all being at least to the number of distinct informational signals presented within one time frame of said repeating time frame format.

Claim 13

In a time division multiplexing pulse code modulating communication system having a number of group multiplexer/demultiplexer units for providing digital informational signals arranged in a repeating time frame format, a combination space and time switching system comprising a number of pairs of originating and terminating trunk lines for carrying said informational signals and being connectible to said group units, respectively, at least two other pair of originating and terminating trunk lines for carrying said informational signals and being connectible to said first-mentioned pairs of trunk lines to define a grid-like crosspoint matrix arrangement, and at least one switching junctor including a pair of data transfer memory devices, each having a plurality of memory stores (selectively) and being alternately connected in successive time frames to said first-mentioned pairs and said other pairs of trunk lines for both receiving said informational signals from and transferring said informational signals thereto (to said other pairs of trunk lines), respectively, a pair of line switchiNg memory devices each having a plurality of memory stores and selectively connecting an associated one of said data transfer memory devices (other pairs of trunk lines) with selected ones of said firstmentioned pairs and said other pairs of trunk lines at the crosspoints of said matrix arrangement, a channel switching memory device having a plurality of memory stores, said channel switching memory device alternately (selectively) addressing the (said) memory stores of said data transfer memory devices within (any given two adjacent) successive time frames of said repeating time frame format, said memory stores for said data transfer memory devices, said line switching memory devices and said channel switching memory device all being at least to the number of distinct informational signals presented within one time frame of said repeating time frame format.

Claim 14

In a common control switching network of a pulse code modulated digital switching system particularly useful in switching communication paths between calling and called transmission highways carrying digitally called information signals presented in a fractional coding frame format of reoccurring divisional time slots arranged in repeating time frames, a network junctor comprising first and second memory means including, respectively, a plurality of separate memory stores equal in number to twice the number of informational time slots of a single time frame and provided as first and second groupings of memory stores, each grouping thereof equal in number to the number of time slots of a single time frame, said first grouping of said first memory means being connectible during a predetermined time slot of a selected time frame to a calling and a called transmission highway for simultaneously storing said informational signals carried thereon and further being connectible to call-related called and calling transmission highways, respectively, during a call-related time slot of an immediately subsequently occurring time frame for simultaneously transmitting said stored signals thereto, said second grouping of said first memory means being connectible during said predetermined time slot of said selected time frame to said call-related called and calling highways for simultaneously storing said transmitted signals carried thereon and further being connectible to said calling and called highways during said call-related time slot of said subsequently occurring time frame for simultaneously transmitting said stored signals thereto, said first and second groupings of said second memory means having memory stores corresponding to said selected memory stores of said first and second groupings of said first memory means, respectively, said corresponding memory stores sotring therein common control instructions relating to the connection patterns of said selected memory stores and alternately activating in accordance with said instructions the connections of said first and second groupings of said first memory means to said calling and called highways and to said call-related called and calling highways, respectively, and third memory means having a plurality of memory stores equal in number to the number of separate signals of a time frame, selected ones of said memory stores being associated with said selected memory stores of said first and second groupings of said first memory means and containing therein stored common control instructions providing for the read out of said selected memory stores of said first and second groupings of said first memory means alternately in successive time frames.

Claim 15

In a common control switching network of a pulse code modulated digital switching system particularly useful in switching communication paths between calling and called transmission highways carrying digitally called information signals presented in a fractional coding frame format of reoccurring divisional time slots arranged in repeating time frames, a network junctor comprising first and second memory means including, respectively, a plurality of separate memory stores equal in number to twice the number of informational time slots of a single time frame and provided as first and second groupings of memory stores, each grouping thereof equal in number to the number of time slots of a single time frame, said first grouping of said first memory means being connectible during a predetermined time slot of a selected time frame to a calling and a called transmission highway for simultaneously storing said informational signals carried thereon and further being connectible to call-related called and calling transmission highways, respectively, during a call-related time slot of an immediately subsequently occurring time frame for simultaneously transmitting said stored signals thereto, said second grouping of said first memory means being connectible during said predetermined time slot of said selected time frame to said call-related called and calling highways for simultaneously storing said transmitted signals carried thereon and further being connectible to said calling and called highways during said call-related time slot of said subsequently occurring time frame for simultaneously transmitting said stored signals thereto, said first and second groupings of said second memory means having memory stores corresponding to said selected memory stores of said first and second groupings of said first memory means, respectively, said corresponding memory stores sotring therein common control instructions relating to the connection patterns of said selected memory stores and alternately activating in accordance with said instructions the connections of said first and second groupings of said first memory means to said calling and called highways and to said call-related called and calling highways, respectively, and third memory means having a plurality of memory stores equal in number to the number of separate signals of a time frame, selected ones of said memory stores being associated with said selected memory stores of said first and second groupings of said first memory means and containing therein stored common control instructions providing for the read out of said selected memory stores of said first and second groupings of said first memory means alternately in successive time frames.