CA1122732A - Apparatus working with pulse code modulation or similar digitizing techniques and according to the time division multiplexing principle for processing the information of a number of telephone channels - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

An apparatus working with pulse-code-modulation or similar digitizing techniques and according to the time-division multiplexing principle for processing the information of a number of telephone channels, wherein 2 number of individual devices designed for automatic operation are switched or connected together for obtaining the aforesaid number of telephone channels, each of the individual devices working with pulse-code-modulation or similar digitizing techniques and in accordance with the time-division multiplexing process. All of the individual devices con-tain the elements or components needed for the independent operation and for processing the information from telephone channels, the number of which is smaller than the required total number of telephone channels. One of the individual devices can be adjusted to function as a master control device which at least produces the base clock pulses and synchronization pulses for all devices, and upon breakdown of said master control device another device assumes the control functions.

Description

~ 1~22732 BACKGROUND OF TIIE NVENTION

¦~ The present irvention relates to a new and improved¦
constxuction oî apparatus ~hich operates ~ith pulse-code- , ¦
modulation or similar digitizing techniques and according to the time-division multiplex principle for processing the information contained in a niumber of telephone channels.

SUMM~RY OF THE INVENTION
., It is a primary object of the present invention to provide such type apparatus which enables a more operationally reliabl,e utilization of more telephone channels than possible with an individually available device.

Now in order to implement this objec,, and others ~hich will become more readilv apparent as the description proceeds, the apparatus of the invention contemplates switching or connecting together a number of individual devices designed for automatic operation in order to obtain such nu.~nber of telephone channels, each of the individual devices operating with pul,e-code-modulation or similar digitizing techniques and according to the time-division multiplex principle. A]l of the devices contain the elements or components needcd for their indepenoent opera~ion and for proc2s~in~ the inforTTIat-iorl o~ i telel?}lorle channe:ls, the riumber o~ whic'n is sm.aller than the 1 !

r~quired total number of telephone channels. One of the indi-vidual devices is adjustable to operate as a master control device which generates at least the base clock pulses and synchronization pulses for all devices. Upon breakdown or drop-out of such master control device another device assumes the control functions.
In accordance with the invention there is provided an apparatus adapted to be operated by pulse-code modulation or similar digitizing techniques and according to the time-division multiplexing principle for processing information froma number of telephone channels, comprising: a plurality of independently operable devices designed for automatic operation and connected together to obtain said number of telephone channels; each individual device being adapted to be operated by pulse-code modulation or similar digitizing techniques and according to the time-division multiplexing principle;
each individual device containing elements required for the independent operation and for processing the information of telephone channels, the number of telephone channels process-able by each individual device being smaller than the requiredtotal number of telephone channels; each of said individual devices having a clock generator connected to a base clock line common for all the devices and having synchronizing means connected to a frame signal line common for alI the devices;
each of said individual devices being settable to generate base clock pulses on said base clock line and synchronizing pulses on said frame signal line, in order to provide a master control device for all of said devices; wherein upon breakdown of one of said devices which initially functions as a master control device, the clock generator and the synchronizing means of any other device are switchable for being operated to provide a new master control device.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
Figure 1 is a perspective view of an individual device working with pulse-code-modulation and according to the time-division multiplex principle;
Figure 2 illuætrates an apparatus composed of a num-ber of the individual devices shown in Figure l; and Figure 3 schematically illustrates a circuit diagram for the construction of the apparatus shown in Figure 2.

- 3a -l~lZ2~32 ~DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, the device or apparatus l illustrated by way of example in Figure 1 will be understood to correspond in construction and mode of operation to the equipment described in the copending, commonly assigned Swiss patent No. 611 093, and entitled "Apparatus Working with Pulse-Code-Modula~ion Or Similar Digitizing Techniques and According to Time-Division Multiplexing Principles for Processing Information From a Number of Telephone Channels", to which reference may be readily had. The device or apparatus 1 processes the information from a maximum of 8 telephone channels in standard fashion according to the pulse-code-modulation technique or a similar digitizing process and according to the time-division multiplexing principle. The illustrated device 1 contains all of the elements or compon-ents needed for the automatic operation and such components or elements are housed internally of a housing 2, as has been shown and described in the afore-mentioned Swiss patent. At the front plate 3 of the housing 2 there are ar-ranged the operating elements, terminals and indicator or display lamps.
The front plate 3 possesses a control or operating panel 4 having a number of operating or control elements 5 to 15, ., - llZZ732 each o, wh ch coacts witll a schematica].ly and not particularly referenced scale. This control panel can be covered by means of a cover 16. The ope.rating el~ents 5 to 15 can be actuate~d by ¦I means of a not particularly illustrated key which is secured ¦ to the CGver mernber or cover 16.

I¦ By means of the operating or control elements 5 to 15, ¦~ each of which is associated wit~ a telephone channel, there can be adjusted in each channel, independent of the other channeis, one of a number of operating conditions or states.

By means of the operating element 13 there is adjusted or set the number of the device within the connected or switched together group of devices. The device with the device number 1 assumes the function of a master control device in a manner still ' to be described hereinafter.

By means of the operati.ng element 14 there is set or adjusted the number of used channels. The operating element 15 enables setting the bit rate per channel~ With the illustrated apparatus the bit rate per channel can be adjusted to, for instance, 16 k bit/s, 32 k bit/s or 64 ]c bit/s.

Furthermore, at the front plate 3 there are arranged different control lamps 11 and schematicall~ illustrated terminals 18 ~o 23 ar which there can he connected the cables _ 5 _ ~ ~lZZ732 'j best seen by referring to Fig~re 2, at the terM1nnl or connecti.on 18 there i.s connected a terminal box 2~ by means o a cable 25. At this terminal or connection box 24 there are con-nected the telephone lines 26 which are coupled with not particularly illustrated telephone installations. By means of this~
connection 18 there is accomplished the input and output of analogue signals which are produced by the telephone installations, and delivered to the telephone installations, respectively.

As also best seen by referring to Figure 2 with the devices J.a, lb, lc and ld connected or switched together, in each ¦
case the terminal or connection 19 of the one device is connected ' by means o~ a ca~le 27 with the terminal or connection 20 of the next following device. The terminal l9 of the last device ld is connected by means ol a cable 28 with a microwave or similar transmission device 29. In the event that the transmission is accompiished by a cable, instead of by means of microwaves, then C I the ter~.ina]. ~ of the last device ld is connected with such transmission cable.
I
At the terminal 21 there is connected a direct-current ¦ voltage source, wherea~ the terminal 22 is connected with an ~ alterllating-current vo].tage source. q~he devices l are designed ¦¦ such that upon breakdown of the alternating-current voltage ¦¦ supply there is automatically accomplished a switch-over to the direct-current voltage suppl~. ~,t the term.inal 23 there i~ I

i! ' .

1~22~3~ ' ~can bc connected a buzz^r or other suitable or equivalent d~vice.

By means of the switch 30 both of the voltage sources can be cut-in or cut-off. The lamp 31 illuminates when the voltage sources are turned-on. Further, two fuses 32 and 33 are provided for ~he direct-current voltage source and the alterllatln~
current voltage source respectively.

Now in Figure 2 there is shown an apparatus wheLe for increasing the total number of telephone channe]s there are switched or connected together a number of similar devices, in the embodiment under discussion four similar devices la, lb, lc and ld. E~ch of these devices la, lb, lc and ld is of the same construction or design as the individual device shown in Figure 1.
Since each individual device la, lb, lc and ld possesses a maximum of eight channels, with the apparatus of Figure 2 the ¦maximum possible nllmber of channels is increased to 32.

Il ~
' The total number of channels is adjusted at each ¦device la, lb, lc and ld bv means of the operating or control ¦elemerlt 14. The de~rice number associated with each individual ¦device is adjusted or set at each device la, lb, lc and ld b~ i ~Imeans of the operating element 13. The device with the device ,'nl~lber 7 assumes the master control function. Since llall devices la, lb, lç and ld are of the same construction, ' llZZ732 ¦¦ basical:Ly each l.ndiv.i~ual device can functj.on as the master ¦¦contro]. device.

Now in F.igure 3 there i~ schematica].ly illustrated the construction of the interconnected indi.vidual devices la, la, lc ¦and l.d, the device lc having been omitted and as to each such device which has ~een illustrated there have onl~ been showll the most important components or elements thexeof.

Each device la, lb, lc and ld possesses a transmitter po~tion o.r transmi.ter and a receiver portion or receiver which t is independent of the transmitter~ The transmitter of each individual device, among other things, possesses a clock generator~.
35 which is connected with a quartz oscillator 34. This clock genexator 35 is operatively connected b~ means of a driving or driver circuit 36 at a base clock line or conductor 37 which is common for all of the devices. Moreover, each device possesses a multiplexer 38 to which there are delivexed the digital pulses f !
leach channel A, B ... N. To simplify the sho~ing of the drawing ¦not all of the channels have been illustrated. Now in each channel¦
¦~, B, ... N there is provided a structural group or assembly 39 ¦~7hich encompasses all of the components or elements which are ¦re~uired for converting the incoming analogue signals into digital pulses according to the pu'se-code-modulati.on or a ~¦simila.. technique.

,' t 1, ~'Z~32 The multiplexer 38 receives its clock pulses from the clock generator 35. The multiplexer 38 is connected at the output side thereof by means of a driver circuit 40 with a comnnon data line 41 at which there are delivered the digital information pulses which are interleaved according to the time-division multiplex technique. The bit cycle output of the multiplexer 38 is connected by a driver circuit 42 with a bit cycle line 43. The input and output of the multiplexer 38 for the frame signal FT is connected by means of a driver circuit 44 with a frame signal line 45.
The data line 41 and the bit cycle line 43 are connected with a conventional and thus not particularly shown transmission device.
The device assigned the number 1, for instance the device la, functions, as already mentioned, as the master control device. This control device la produces the clock pulses for all of the devices la, lb, lc and ld. The pulses are delivered by means of the clock 37 to all of the other devices lb, lc, and ld. Now from the clock pulses there are derived in each device all of the internally required cycles and pulses. The master control device la furthermore produces a frame signal FT which is transmitted by means of the frame signal line 45 to the other devices lb, lc and ld. The frame signal FT ensures for synchronous operation of all of the devices la, lb, lc and ld.

g _ llZZ73Z

~1 In the even~ that there is required in the transmissi.on device ¦ a bit cvcle ~ hen thi.s bit cycle li.~;ewise is onJ.y produced by the master con~rol device la and delivered to the bit cycle line 43.

Since all of t~e ~evices la, ib, lc and ld are con-~i c ,;~v~es trolled by the same base~c~el_ BT and synchronized with the frame signal FT, thus, as with a sing].e device, the channel~ of all connected together devices la, lb, lc and ld, can be connected ¦ with one another in the following manner: Fixst of all all of the channels of the devi.ce No. 1~ then all of the channels or the device No. 2, then all of the channels of the device No. 3 and ¦ so forth. It is immaterial in this regard in which se~luence the devices are numbered. What is important is that one device can be ¦
¦set or adjusted to carry out the functions of a master control t ¦¦device.

¦ The reoeiver of each dev~ce la, lb, lc and ld, a~.ong other things, possesses a quartz oscillator 46, a clock generator i 47 connected therewith and a demultiplexer 48. The clock generator !
47 is connected by means of a respecti.ve driver or driving circuit 49 and 50 on the one hand with the bit cycle line Sl coming ~ om the transmission device and, on the other hand, with a i base c~e~ line 52. The output side of the c'ock generator 47 additionaJ.ly is oonnected ~-ith the demultiplexer 48.

-- :L O -- I

i t ' l~Z2732 The demultiplexer 48 is connected at its input side by means of a driver or driving circuit 53 with a d~ta line 54 which is coupled with the transmission device and which delivers to the demultiplexer 48 the digital data pulses transmitted by the transmitter. Each demultiplexer 48 is connected by means of a driver circuit 55 with a frame signal line 56.
At the output side there are connected with the demultiplexer 48 the individual channels A', B' ... N'. Each channel possesses a channel structural group or assembly 57 analagous to the transmitter, and which contains all of the components or elements needed for converting the digital pulses into analogue signals, in order to obtain an analogue output signal which corresponds to the corresponding analogue input signal at the transmitter side.
The device la which operates as~the guidance or control device produces, in accordance with the bit cycle TR
received by the transmitter side, the base cycle BR for all devices la, lb, lc and ld. The clock pulses are transmitted by means of the clock line 52 to the other devices lb, lc, ld. Out of the digital pulses appearing at the data line 54 each device la, lb, lc and ld seeks synchroni~ation pulses, places into operation its receiver frame and after having obtained synchronous running delivers a frame signal FR to the frame signal line 56. In the event that synchronism is not established then there is not produced any frame signal.

1~2Z732 ~1 .
I

¦~ A]l ol the de~ices la, lb, lc and ld receive this frame ¦~s~gllal FR and are re~ulated to a synchronous operation based upon ¦

! such frame siynal. If the synchronization device breaks down at a device, then this does not have any influence upon the re-maining functjons, since this clevice then wili be synchronized from another dev.ice.

All~of~the d~ ultiplexers 4~ operate on the basis OL
the same base~eye~æ BR and are synchronized to one another by means of the frame signal line 56. The information pulses app~aring at the data line 54 are distribu.ed, analogous to multiplexir.g at the transmitter side as for a single device, pro~erly at the individual channe]s A', B' ... N'.

Since, as mentioned, each device la, lb, lc and ld possesses all of the elements or components needed for the automatic operation and with the illustrated st~c~ operation of a nurnber of devices only the master control device carries out all fv.nctions, certain of the components of the devices which are .lOt employed as the master control device are not or only incompletely utilized. Nonetheless, it is readily possible at any time ¦to have anotller one of the devices fulfil the control functions ¦in the event that the master control de~ice has partially or completely broken down. As mentioned, such adaptation of the system can be readily accomplished by ~¦ fiimply switchin~ the o~erating e]ement 13. It is also Il !
.

llZ2732 ' .

conceiva~le to cons~-.ruc~ the devices such that such switching operation is accomplished automatically.

: ~ While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be ¦
otherwise variously embodied and practiced within the scope OI
the following claims. ACCORDINGLY.
.

li 13 _ '., , , ~

Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An apparatus adapted to be operated by pulse-code modulation or similar digitizing techniques and according to the time-division multiplexing principle for processing informa-tion from a number of telephone channels, comprising: a plural-ity of independently operable devices designed for automatic operation and connected together to obtain said number of telephone channels; each individual device being adapted to be operated by pulse-code modulation or similar digitizing techniques and according to the time-division multiplexing principle; each individual device containing elements required for the independent operation and for processing the information of telephone channels, the number of telephone channels processable by each individual device being smaller than the required total number of telephone channels; each of said individual devices having a clock generator connected to a base clock line common for all the devices and having synchroni-zing means connected to a frame signal line common for all the devices; each of said individual devices being settable to generate base clock pulses on said base clock line and synchroni-zing pulses on said frame signal line, in order to provide a master control device for all of said devices; wherein upon breakdown of one of said devices which initially functions as a master control device, the clock generator and the synchroniz-ing means of any other device are switchable for being operated to provide a new master control device.

2. The apparatus as defined in claim 1 wherein each individual device has a switching element settable to a plural-ity of positions each corresponding to a number between 1 and the maximum number of devices being connectable, the switching element being arranged to operate the clock generator of the respective device, when set on the position corresponding to the number 1 thus defining the device which assumes the master control function.