US 3852538 A
A concentration type matrix is more efficiently combined with trunks in a single frame, by assigning the trunks on an individual frame basis and pre-wiring a given pattern of trunks into the first or A stage of the matrix and using a standard wiring pattern between the A and B, and B and C stages.
Claims available in
Description (OCR text may contain errors)
United States Patent [1 1 Mila [111 3,852,538 1 Dec. 3, 1974 1 ARRANGEMENT AND METHOD OF COMBINING TRUNKS AND A MATRIX INTO A SINGLE FRAME  Inventor: Truman R. Mila, Batavia, Ill.
73 Assignee: GTE Automatic Electric Laboratories, Incorporated, Northlake, 111.
22 Filed: Sept. 14, 1973 21 1 Appl. No.: 397,546
 US. Cl. 179/91 R, 317/99  Int. Cl. H04q l/04, H02b 15/04  Field of Search, 179/18 FC, 91 R, 22;
 References Cited UNITED STATES PATENTS 1,861,224 5/1932 Neir et a1. 179/91 R 2,773,940 12/1956 Lebedinsky v. 179/91 R 3,394,287 7/1968 v Zitzmann et a1...
3,465,291 9/1969 De Witt. Jr. 317/99 3,539,873 11/1970 v Rosenberg et a1. 317/99 Primary Examiner--Thomas A. Robinson 5 7 ABSTRACT A concentration type matrix is more efficiently combined with trunks in a single frame, by assigning the trunks on an individual frame basis and pre-wiring a given pattern of trunks into the first or A stage of the matrix and using a standard wiring pattern between the A and B, and B and C stages.
1 Claim, 4 Drawing Figures Fuse PANEL a0 PATENTh 55B 74 SHEET 2 BF 3 m- MJE Y ARRANGEMENT AND METHOD OF COMBINING TRUNKS AND A MATRIX INTO A SINGLE FRAME and between the latter and the trunks. This results in a high degreeof installer cabling and cross-connecting at a high manpower cost.
In theherei nafter briefly described centralized automatic message accounting system, the switching network or matrix therein is not a switching matrix in the true sense of the term in that it is not held during [the] an entire conversation. It is rather an access matrix, being used only during the processing of a call and then released at the end 'of the call setup, leaving only the trunk to be-held during the entire conversation. For this reason, the matrix is of the concentration type, that is, it. has a large number or high percentageof inlets compared to outletsi In accordance with the present invention, such a matrix can be more efficiently combined with the trunks in a single frame, by carefully assigning the trunks on an individual frame basis and pre-wiring a given pattern of trunks into the first of A stage of the matrix and using a standard wiringpattern between the A and B,- and B and C stages. Being a concentration type matrix,
the A stage performs a reduction of inlets to outlets, by a factor of four in the illustrated system. The B stage fu'rtherreducesby a factor of to 4. By mounting both the A stage andthe B. stage of the matrix within the same frame as the trunks, it is possible to machine wire all trunks to A stage connections, and A to B stage connections. Furthermore, the number of wires which have to be cabled from the frame including the trunks and the A andB stages of the matrix to the C stage matrix frame is reduced by a factor of 5. Using this arrangement, a compact, trunk and matrix' unit is provided, with one frame containing either 40'or 80 trunks, the associated A and B stages of the matrix and the electronic access and-control for both the trunks and the matrix. f h v I It further can be seen that such an ar'rangem'en t creates a convenient, orderly package .for expansion of an office. lnaddition, it'enhances'the maintenance'aspects of the officeas the only required maintenance records of frame numbers are those'which show the interconnect from the outside plan-t to'the'trunk frame on the entrance or main distribution frame. All otherpath s are wired withinthe-office using a fixed'pattern which we cludes additional frame maintenance records andexpedites trouble shooting-of a-' fault within the matrix.
Accordingly, it is an object to provide an improved arrangement and method forcombining trunks and a concentration type matrix into a single frame.
The invention accordingly comprises the several bodying features of construction, combination of elements and arrangement of parts which are adapted to effect such steps, all as exemplified in thefollowing detailed disclosure, and the scope of the invention will be indicated in the claims.
For a fuller understanding of the nature andiobjects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:
FIG. 1 is a block diagram schematic of the centralized automatic message accounting system;
FIG. 2 is a partialfront elevation of one of the frames with the system; I
FIG. 3 is a side view of the frame of FIG. 2; and
FIG. 4 is a rear view of the frame of FIGS. 2 and 3.
Similar reference characters refer to similar parts throughout the several views of the drawings.
DESCRIPTION OF THE INVENTION Referring now to the drawings, in FIG. 1 the centralized automatic message accounting system is illustrated in block diagram, and the'functions of the principal consistsof three stages of matrix switching equipment I between its inlets and outlets. A suitable distribution of links between matrices .are provided :to insure that every inlet hasfull access to every outlet for any given size of the switching network. The three stages, which consist ofA, B and C crosspoint matrices, are interconnected byAB and BC links. The network-provides a minimum of 80 inlets, up to a maximum of 2,000 inlets and 80 outlets. Each inlet extends into an A matrix and is definedby an inlet address. Eachoutlet extends from a C matrix to a terminal and is def ned'by an outlet address.
Each full size network is divided into a maximum of 25 trunk grids on the inlet side of the networkand a service grid with a maximum of 16 arrays on'theoutlet side of the. network. The trunk grids and service grid within the networks are interconnected by the, BC link sets of 16 links per set. Each MF trunk v grid is provided for 80 inlets. Each DP.trunk grid is provided for 40 inlets. T-'he service grid is provided for a maximum of 80 outlets. A BC link is defined as the interconnection of an outlet of a B matrix in a trunk grid and an inlet of a C matrix in theservice grid.
trated frame-includes the usual side frame members i i 71 and 72 which are vertically disposed and which .have
a number of horizontally disposed shelves, such as the shelves 73-77, secured between themt-for supporting andseparating the various components of the system,
contained within the-particular frame. The frame 70 also has a fusepanel which is secured in a horizonsteps and the relation of one or more of such steps with respect to' each of the others and the apparatusemequipment of the system. i q
tally disposed fashionbetween the side frame members i 71 and 72, which fuse panel effects a physicalseparation between the electronic and electromechanical In the illustrated embodiment, the trunk circuits It) fice using a fixed pattern which precludes additional are mounted low, below the fuse panel 80. These trunk circuits are formed on cards in the conventional manner, and the cards and the shelves76 and 77 are both arranged to permit the cards to be affixed within the frame 70 in side-by-side relationship.
The A and B stages of the matrix and the electronic access and control for both the trunks and the matrix likewise are formed on cards or as cards which can be affixed within the frame 70 in side-by-side relationship on the shelves located above the fuse panel 80, thereby effecting a physical separation between the electromechanical trunks and the electronic equipment. Itmay be noted that the cabling such as the cables 85-86 for the electronic equipment, that is, the A and B stages and the access and control for the matrix and the trunks is cabled across the front of the frame 70 and, as can be seen in FIG. 4, the cabling suchas the cabling 89 which fans out to and between the shelves for the electromechanical equipment or trunks is cabled across the rear of the frame. Cabling in this fashion preserves the electrical integrity to prevent noise from passing from one type of equipment to thev other, as more fully described in copending application, Ser. No. 397,569 filed Sept. 19, 1973, by Truman R. Mila.
Asindicated above, a much higher degreeof efficiency than normally available in othersystems can be obtained by combining the matrices and the trunks into a single frame and by carefully assigning'the trunks on anindividual frame basis and prewiring a given pattern of trunks into the first or Astage of the matrix and using a standard wiring pattern between the A and B stages, as generally illustrated in the drawings. One
frame .is now capable of containing either 40, or 80 trunks, the associated A and B stages of matrix and the access and control for both the trunks and the matrix. Assuming that that frame contains 80 trunks, theA stage performs a reduction of inlets to outlets by a factor of 4, or, 20 outlets. The. B stage further reducesthe number or inlets to outlets by a factor of 5 to 4, or from outlets to .l6 outlets. Hence, thisreduces the nummatrix frame by a'factor of 5, thatis, from 80 to 16.
As further indicated above, this wiring scheme also enhances the maintenance aspects of the office as the only required maintenance records of frame numbers are those which show the interconnect from the outside plant tothe trunk frame on the entrance-or main distributionframe. All other-paths are wiring within the of- -ber of wires to be cabled from this frame to the C stage frame maintenance records and expedites trouble shooting of a fault within the matrix.
All of the cards in a frame generally are removable and replaceable, the cards having printed wiring contacts on them which establish electrical contact with plug-in type connectors secured to the shelves of the frame. These electrical connectors each have a plurality of contacts or pins, such as the pins 90, 91 and 92 (FIG. 3) on them, and are wired in the manner de scribed above. With the cabling on the front freeing the backplane of the frame, much of this wiring can be machine wired rather than installed or hand wired, so that substantial savings also are realized from this aspect of the wiring scheme.
It will thus be seen that the objects set forth above among those made apparent from the preceding description, are efficiently attained and certain changes may be made in carrying out the above method and in the construction set forth. Accordingly it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in'a limiting sense.
Now that the invention has been described, what is claimed as new and desired to be secured by Letters Patent is: r v 1. In a common'control communication switching system including a pluralityof trunks connectable through a matrix including A, B and C stages to any one of a plurality of service-circuits, said trunks being machine'wired to said .A stage and said service circuits being connected to said- C stage, a plurality 'of links connecting said A and B stag'esand a'pl'urality'o'f links connecting said Band C stages,said matrix being a concentration type matrix which is used only during the processingof a call and then released at the end of the call setup, the improvement comprising a frame, said trunks and said A and B stages being contained within said frame, said A stage performing a reduction of inlets to outlets and said B stage performinga further re duction of inlets to outlets, whereby the number of wires which have to be cabled tof'said C. stage ,matrix frame is reduced, said trunks being assigned on an individual frame basis and a given pattern of said trunks being wired into said A stage, a standardwiring pattern