FR2569507A1 - INSTALLATION FOR THE TRANSMISSION OF INFORMATION GENERALLY ACCESSIBLE TO USERS - Google Patents

Abstract

FACILITY FOR THE TRANSMISSION OF INFORMATION CONTAINING DIFFERENT PROGRAMS (SUCH AS STEREO BROADCASTING PROGRAMS, FOR EXAMPLE), FROM A CENTER AND TO A PLURALITY OF SUBSCRIBERS. THIS CENTER INCLUDES MULTIPLEX EQUIPMENT THROUGH WHICH INFORMATION IS APPLIED TO A PROGRAM BUS ACCORDING TO A TIME MULTIPLEXING MODE, EACH PROGRAM BEING ASSIGNED TO A FIXED TIME INTERVAL IN A TIME INTERVAL FRAME. A PLURALITY OF TIME STAGES 45A, B ARE CONNECTED TO PROGRAM BUS 44. A SECOND PROGRAM BUS 46 IS CONNECTED TO THE OUTPUT OF EACH TIME STAGE 45A, B AND A PLURALITY OF SUBSCRIBERS ARE CONNECTED TO EACH OF THE SECOND PROGRAM BUSES 46, A FIXED TIME INTERVAL IS ALLOCATED TO EACH. EACH SUBSCRIBER IS ALSO CONNECTED TO THE CENTER BY A FEEDBACK 7. A CONTROL UNIT 13 ASSOCIATE THE TIME INTERVALS ON THE SECOND PROGRAM BUS 46 WITH THE TIME INTERVAL ON THE FIRST PROGRAM BUS 44 ACCORDING TO THE PROGRAM REQUESTED BY THE SUBSCRIBERS 3 .

Description

! 2569507

  The present invention relates to an installation for the transmission of information generally accessible to users and containing different programs (such as broadcast programs

  stereophonic, for example), in accordance with the preamble of the claim

  main tion. An installation of this nature was described in 1983 in

  the flight. 36 of NTZ (N 7, pages 428 to 433) by K. Kneisel in the

  ticle entitled 'Bigfon-Vergleich der verschiedenen firmenindividuel-

  len Systemlosungen ". The column titled 'SEL' in Table 3 indicates the specifications of a system in which information is transmitted from a center to a plurality of subscribers who

  fifteen programs are linked by two ISDN channels to its stereopho-

  two TV channels per subscriber. The fifteen channels with stereophonic sound are initially applied to a program bus according to a time multiplexing mode, each program being assigned to a fixed time interval in a frame of intervals of

  time defined on the program bus. The information that

  are then combined in a multiple frame with information flows from other services (ISDN, television) and

  they are transmitted in this way to the subscriber.

  Since no subscriber would listen to 15 stereo programs simultaneously, this system no doubt transmits

  more information than necessary. As on the one hand it is

  sible to transmit an unlimited volume of information, even with advanced technologies and that on the other hand the introduction of a

  extreme variety of services is very strongly desired, an approach

  che of this nature is not economical. We should therefore provide

  each subscribes only the volume of information of which it has real-

  ment need. The same article presents, in the column entitled "Siemens", a system allowing the subscriber to use a communication channel.

  back to select up to four programs provided

  nis by means of a switching installation. Contrary to

  telephone switching facilities it is impossible to sup-

  in the case of switching installations for programs,

  radio or television, etc., that only part of the subscribers

2 2569507

  connections will use them at some point. On the contrary, the installation

  switching equipment must be equipped in such a way that each subscriber can be connected to any program source to

  any time. This requires a switching matrix

  plex. The object of the invention is to provide an improvement in

  installation for the transmission of information generally ac-

transferable to users.

  In accordance with the present invention, this object is achieved by means of an installation for the transmission of information generally accessible to users and containing different programs (such as stereophonic broadcasting programs, for example), from a center and towards a plurality subscribers attached to it, this center comprising multiplex equipment through which information is applied to a

  program bus in a time multiplexing mode, each program

  gram being assigned to a fixed time interval in a time slot frame defined on the program bus, characterized in that a plurality of time stages are connected to the program bus in that a second program bus is connected to the output of each time stage, in that a plurality of subscribers are connected to each of the second program buses in that at least one fixed time interval in each frame on the corresponding second program bus is allocated to each subscriber, in that each subscriber is connected to the center by a return channel, in that each time stage is connected to a control unit which associates the time intervals on each of the second program buses with the time intervals on the first program bus according to the program desired by the subscribers requested by transmission on the return channel, and in that only the programs selected by each subscriber are transmitted to the latter by a channel go According to the invention, there is also a service multiplexer in the center for each subscriber, which combines the generally accessible information selected

Z569507

  by the subscriber with other information (for example, telephone, television,

  sion) intended for this subscriber for transmission by time division multiplexing, and in that there is a service demultiplexer, at each subscriber, which separates the information intended for this subscriber from one another. The different objects and characteristics of the invention

  will now be detailed in the description which follows, made

  by way of nonlimiting example, with reference to the appended figures which represent: - Figure 1, part of an integrated broadband service system comprising a device according to the invention for the transmission of stereo broadcasting programs; - Figure 2, a frame of time intervals for the system according to Figure 1, - Figure 3, the center detail for a system according to Figure 1, - Figure 4, the time sequence of information in three points of the center in accordance with Figure 3, - Figure 5, details of. center according to figure 3, - figures 6 to 8, modifications of the embodiment

in accordance with Figures 3 to 5.

  The entire integrated service broadband system will now be described briefly from Figure 1. The system includes a center 1, a plurality of transmission systems 2 and

a plurality of subscribers 3.

  The center 1 contains n sources of stereophonic sounds lla 3 lln, which can emit for example broadcasting programs

4 2569507

  radio, local studio broadcast programs or cable stereo programs received, as well as

  monophonic broadcasting programs. These stereo- sound sources

  Phones lia to lin which emit an analog output signal are followed by an analog-digital converter 12a to 12m. In the case of stereophonic sound sources that already emit digitized output signals, it may be necessary to replace the analog-to-digital converter with a code converter. The digital or digital information streams coming from the stereophonic sound sources 11a to lin are applied to a stereophonic sound distribution and switching installation 4. In addition, additional information, for example the identification of

  transmitter and station for broadcast programs from

  from stereophonic sound sources 11, arrive at the installation

  distribution of stereophonic sounds and switching 4 by

  additional inputs 41. In addition the distribution system

  tion of stereophonic and switching sounds 4 comprises a control input 42 which is connected to the output of a control unit 13. A service multiplexer 5 is provided in the center 1 for each subscriber 3 in the center 1. A separate output of the installation

  distribution of stereophonic sounds and switching 4 is displayed

  assigned to each service multiplexer 5. Other inputs of each service multiplexer 5 are connected to the outputs of other installations 51, through which the different subscribers are

  attached to other services. Other installations 51 are con-

  connected by a command line 131 to a return channel 7 coming

  of subscriber 3 via control unit 13.

  The transmission system 2 comprises a forward channel and the

  return channel 7, mentioned above, for each subscriber 3.

  Each subscriber has a service demultiplexer 31 which separates from one another the signals belonging to the different

  services, which have been combined with each other in the multi-

  service plexer 5 corresponding in the center 1. Two conver-

  digital-analog weavers 32a and 32b, as well as other ins-

  tallations 34 for other services are attached to the exits of the

  service demultiplexer 31. The outputs of digital converters

  Analogicals 32a and 32b are connected to the inputs of stereophonic sound reproduction units 33a and 33b. The stereophonic sound programs to be reproduced are selected by signaling on the return channel 7. Other installations 34 are also

connected to the return channel 7.

  The time slot frame formed in each service multiplexer 5 by the information flows arriving at its

  inputs will now be described briefly from Figure 2. This-

  first of all, attention should be drawn to the fact that the term "multiplexer" can have a narrow and a broad meaning. In the narrow sense it is a component allowing any input selected from a plurality of inputs to be switched to the single output. In the broad sense, the multiplexer further comprises components which serve, for example, for buffering

  input information, to reclassify this information and to order.

  The same is valid by analogy for the term

  demultiplexer ". The multiplexers and demultiplexers that generate

  rent and then process the time interval frames of the type shown in FIG. 2, respectively, are units of more complex design. As an example of the different uses of these two terms, reference should be made to an article published on pages 251

  to 258 from "Elektrisches Nachrichtenwesen" in 1983 (Vol. 57, N 3).

  The time interval frame according to Figure 2 includes

  takes sixteen identical time intervals, represented as

  lines in Figure 2. Four consecutive time intervals consist of

  kill a subframe. Each time slot contains sixty-eight words of sequential data. In the figure these words are represented under

  form of columns and they will be designated by this term subsequently.

  Columns 3 to 17, 20 to 34, 37 to 51 and 54 to 68 are reserved for the

  transmission of a television channel. Columns 18 and 19 contain-

  2 related sound programs are produced, each in stereo. Columns 35 and 36 are reserved for the transmission of stereophonic sound programs from the sound broadcasting installation

  stereophonic and switching 4. Columns 52 and 53 are re

6 2569507

  used for the transmission of information flows from a system

  teme PCM 30. The transmission of 8 ISDN channels, ISDN 1 to ISDN 8, is possible in columns 1 and 2, on which the data words are also transmitted for the synchronization of frames, Si, for the synchronization of sub-frames , S2, for a service channel, SC,

  as well as for additional information regarding the trans-

  mission of images, AIP, and for additional information

  concerning the transmission of stereophonic sounds, AR1 and AR2.

  The installation for broadcasting stereophonic sounds and

  switching 4 will now be described in more detail from fig.

  gure 3, which represents the installation and the converts-

  analog-digital sisters 12a to 12m mentioned above, the control unit

  command 13, the service multiplexer 5, the other installations 51,

  the forward channel 6 and the return channel 7. Each analog converter

  digital-digital 12a to 12m, as well as stereophonic sound sources

  nics llm + l to l1n with digital output not illustrated, is followed by a multiplexer 43a to 43n, which makes it possible to add additional information by the aforementioned additional inputs 41. The

  outputs of multiplexers 43a to 43n lead to the inputs of a multiple-

  program fixer 40. In addition the outputs of the multiplexers 43a to

  43n are also connected to the inputs of a first synchronizer 471.

  This first synchronizer identifies the beginnings of data words at

  outputs of each of the multiplexers 43a to 43n and can thus influence

  cer the program multiplexer 40 by a frame generator 472

  and a program control unit 401 contained in the multiple-

  xer of programs. The output of the program multiplexer 40 is connected with a first program bus 44. All the programs

  from the stereophonic sound sources lla to lin are trans-

  put on the first program bus 44 by time multiplexing, each source of stereophonic sounds lla has 11n, and therefore

  each program, being assigned a fixed time interval.

  Multiplexers 43a to 43n, the program multiplexer

  with its 401 program control unit, the first synchro-

  niser 471 and frame generator 472 are each shown

  as an individual unit; these units cooperate very closely-

  so that another distribution is easily possible.

  A plurality of time stages 45 is attached to the first

  mier program bus 44. FIG. 3 represents only one of these

  time stages 45a with its connections. Another time stage 45b is represented by dotted lines. Other time stages

  are indicated by other lines coming out of the first program bus

  mes 44. In addition, a second synchronizer 473 is attached to the first

  program bus 44. The control unit 13 is thus synchronized

  set by means of the second synchronizer 473 and controls the time stages 45 which are attached to it according to the programs that

  the connected subscribers request via their return channels 7. A se-

  cond program bus 46 is attached to the output of each floor

  temporal 45. A plurality of subscribers is connected to each of the se-

  program bus conds 46 by means of service multiplexers 5

  mentioned above, allocated to subscribers.

  Two fixed time intervals are allocated to each subscriber connected to each second program bus 46. This is why each time stage 45 converts the time intervals allocated to the programs on the first program bus 44 into intervals of

  times allocated to subscribers on the second corresponding program bus

  dant 46. The number of time intervals on the first pro- bus

  grams 44 is completely independent of the number of intervals of

  time on the second program bus 46, since on the one hand more

  subscribers can listen to the same program simultaneously and that

  on the other hand the different programs do not need to be selected

  by any of the attached subscribers. Thus very great flexibility is guaranteed. It is also possible to assign each time stage 45 its own second synchronizer 473 and its own control unit 13 or to combine the time stages by groups. It is therefore also possible to create a relatively large separation in space between the different time stages, between the time stages 45 and the program multiplexer.

  , and therefore also between stereophonic sound sources 11.

  The time stages 45 can for example be arranged on the level

  lower calf of a public network of integrated services, while the

8 2569507

  program multiplexer 40 is arranged at a higher level. Following the reclassification, according to subscribers, of the time intervals to

  the time stage 45 between the first program bus 44 and the multiple

  service tiplexer 5 allocated to subscribers, the selection of pro-

  desired grams require only a minimum of complexity of the service multiplexer 5. For this purpose, a fixed address assigned to subscribers is stipulated for each service multiplexer 5 by the

  address entries 52, the address representing the location of the information

  corresponding time intervals of the second program bus 46. Owing to the interposed time stage 45, it is unnecessary to provide individually for each subscriber the installations required for

program selection.

  The flow of information to different locations in the center 1

  will now be described according to FIG. 4. The first line represented

  sense the information flow to an input of a program multiplexer 40. In principle, the information flows to the other inputs are identical. Besides their different content, information flows differ in that there are mutual time lags between them. Each of these information flows

  includes a sequence of stereophonic sound data words 81.

  The root of each stereophonic sound data word 81 is the stereophonic sound data part 811 itself, which originates in the corresponding analog-to-digital converter.

  12a to 12m or in the stereo sound sources llm + l to lin.

  In the case of the present invention, it does not matter how the content of the two stereophonic sound channels is understood in the

  part of stereophonic sound data. A portion of additional data

  812 is attached to each part of stereo sound data

  811 reophonics, and each part of stereophonic sound data

  811 is preceded by a word synchronization part 813. The as-

  appearance of a stereophonic sound data word 81 from the stereophonic sound data part 811, the additional data part 812 and the word synchronization part

  813 takes place in the corresponding multiplixer 43a to 43n. The se-

  conde line of figure 4 represents the flow of information on the

  first program bus 44, where the data words of stereo sound

  phonic 81 assigned to different stereophonic sound programs

  picnics are grouped in frames. The start of a frame is mar-

  qué by a frame synchronization word 821, followed by words of data of stereophonic sounds 822a to 822n, the contents of which coincide with the words of data of stereophonic sounds 81. Thus a

  fixed time slot is assigned to each program internally

  laughing of the frame. The third line represents the information flow

  the second program bus 46. The also each frame includes

  begins with a frame synchronization word 831, the content of which coincides with the frame synchronization word 821. Next comes a series of pairs of stereophonic data words 832, the quantity of which coincides with the number of connected or connectable subscribers. to the second program bus 46. The first pair of data words 832, la and 832, 1b, which contains the data of the second and fifth programs, another pair of data words 832, ia and 832, ib, which contains the data of the umpteenth and twenty-fifth programs, and the last pair of data words 832, ka and 832, kb, which contains the data of the fifth and third programs, are shown here. The two stereophonic data words of a pair of data words are assigned to the stereophonic sound reproduction units 33a and 33b of the respective subscriber 3. Depending on the wishes of the connected subscribers, individual data words can

  be present several times on the second program bus 46.

  The design and function of the stereophonic sound input unit of a service multiplexer 5 will now be described from FIG. 5. The input of a third synchronizer 53

  which, like the first synchronizer 471, responds to the syn-

  word chronization 813 contained in the stereophonic data word

  is connected to the second program bus 46. This third synchronizer 53 is followed by a frequency divider 54 which divides by a number equal to that of the stereophonic sound programs

  that a subscriber can receive, that is to say in pairs in this example.

  The output of the frequency divider 54 is connected to the clock input.

  accommodates a counter. The 3 zero reset inputs of counter 55 and

2569507

  frequency divider 54 are connected to the output of a fourth synchronizer 56 which emits an output pulse at the start of a frame on the second program bus 46. Therefore the counter 55

  counts 832 st & reophonic data word pairs.

  teur 57 compares the counting of the counter 55 with the fixed address of the subscriber assigned to the respective service multiplexer 5 which is at its address inputs 52. The frequency divider 54 can be considered as the last part of the counter 55 which is not included in the comparison. If the counting of the counter 55 and the address at the address inputs 52 coincide, the output signal from the comparator 57 opens a door 58 and thus connects the second program bus 46 with the data input from a memory 59 comprising

  two cells 59a and 59b. At the same time the output signal from the compa-

  erator 57 validates the memory 59 by an validation input EN, so that the precise pair of stereophonic data words 832

  provided for the connected subscriber is stored in memory 59. The procedure

  registration time itself is triggered by the clock pulse

  lodge T of the system. The passage between the memory cells 59a and

  59b is triggered by the output pulse of the third synchronization

  53, while the memory 59 returns to its rest position under the action of an output signal from the fourth synchronizer 56, so that the stereophonic sound data becomes available for further processing in the service multiplexer

  5. The word synchronization part contained in each data word

  stereophonic data is not stored in memory 59.

  Figures 6 to 8 show a variant of the embodiment described according to Figures 3 to 5. This embodiment

  differs from the one just described by the way in which the differences

  rents floors are synchronized with each other. In the example

  ple described above, the required clock pulses are generated by the information flow itself where it is needed. AT

  this effect the information flow contains parts of synchronization

  tion of words 813, frame synchronization words 821 and frame synchronization words 831. In the present example in

  otherwise the necessary clock pulse signals are applied

he

ques by different ways.

  Figure 6, which largely corresponds to Figure 3, shows

  first of all feels analog-digital converters 12a to 12m, multiplexers 43 'to 43'n with additional inputs 41', a program multiplexer 40 'with a program control unit 401', a first bus of programs 44 ', a time stage' a, a control unit 13 ', a second program bus 46', a service multiplexer 5 'with other installations 51 and

  address entries 52, as well as a forward channel 6 and a return channel

  tower 7. These installations fully correspond (number

  identical reference ros) or for the most part (prime reference numbers) to the corresponding installations in FIG. 3. There are also clock lines of words 121a to 121m which lead

  from analog to digital converters 12a to 12m at the control unit

  program control 401 'and word clock lines 121m + l to 121n, which lead digital stereo sound sources 11m + l to lin to the program control unit 401' and which apply the clock pulses of words belonging to the different stereophonic sound programs to the program control unit 401 '. A first word clock bus 44a and a first frame clock bus 44b are allocated to the first program bus 44 '. A second word clock bus 46a and a second frame clock bus 46b

  are allocated to the second program bus 46 '.

  FIG. 7 represents the information flows, which are different from those represented by FIG. 4. Each stereophonic data word 81 ′ here comprises only a part

  811 stereo sound data and some additional data

  812. Instead of the word synchronization part 813, a separate word clock signal 814 is transmitted here on

  the corresponding word clock line 12i. Instead of the word syn-

  frame timing 821, a frame clock signal 823 is here transmitted on the first frame clock bus 44b, in addition to its transmission to the first program bus 44 '. The word clock signal distributed over the first word clock bus 44a is not shown. Similarly, a frame clock signal

- 12- 2569507

  833 is distributed on the second frame clock bus 46b instead of

  of the frame synchronization word 831. While the time signals

  frame boxes 823 and 833 have the same time sequence they

  may have a phase shift relative to each other.

  -5 When the word clock pulse and the clock pulse-

  frame boxes are applied by the corresponding buses, it is

  tooth, as shown in Figure 8, that third synchronizers

  53 or fourth synchronizers 56 are useless for multi-

  service plexers 5. Furthermore, they are of identical design to that of the service multiplexers described above according to the

figure 5.

  It is also possible to provide for a mixed application of the two types of synchronization described according to FIGS. 3 to 5 on the one hand, and 6 to 8 on the other. The synchronization of the time stages 45 with the program multiplexer 40 can be carried out for example in accordance with the first embodiment, especially if they are distant

  each other in space. The synchronization between a temporary stage

  porel 45'a and the 5 'service multiplexers attached to it can be carried out independently, in accordance with the second mode

of achievement.

13 2569507

Claims (5)

  1. Installation for the transmission of information generally accessible to users and containing different programs (such as stereophonic broadcasting programs, for example), from a center and to a plurality of subscribers who are attached to it, this center comprising multiplex equipment through which information is applied to a   program bus in a time multiplexing mode, each program   gram being assigned to a fixed time interval in a time interval frame defined on the program bus, characterized in that a plurality of time stages (45a, b) are connected to the program bus (44), in that a second program bus (46) is connected to the output of each time stage (45a, b), in that a plurality of subscribers are connected to each of the second program buses (46), that at least one fixed time interval in each frame on the second corresponding program bus (46) is allocated to each subscriber (3), in that each subscriber is connected to the center by a return channel (7), in that each time stage (45a, b) is connected to a control unit (13) which associates the time intervals on each of the second program buses (46) with the time intervals on the first program bus (44) according to the program desired by the subscribers (3) requested by transmission on the return channel (7), and in that only the progra ms selected by each subscriber (3) are transmitted to the latter by a channel go (6).   2. Installation according to claim 1 characterized in that there is a service multiplexer (5) in the center (1) for each subscriber (3), which combines the generally accessible information selected   by subscriber (3) with other information (for example, telephone, television,   sion) intended for this subscriber (3) for transmission by time division multiplexing, and in that there is a service demultiplexer (31), at each subscriber (3), which separates the information for then to this subscriber.   3. Installation according to claim 2, characterized in that the service multiplexer (5) comprerdun counter (54, 55), which counts the time intervals in the time interval frames distributed on the second program bus ( 46) and in that the service multiplexer (5) also comprises a comparator (57), which identifies a count value assigned to the subscriber (3) and causes the acceptance by a memory (59) of the content of the 'corresponding time interval (word 832 stereophonic data).   4. Installation according to any one of the claims   1 to 3, characterized in that units (43, 471, 472, 473, 53, 56) are provided, for adding synchronization characters (813, 821, 831) to the individual information and to the time interval frames, or who identify them.   5. Installation according to any one of the claims   1 to 4, characterized in that the center (1) comprises trans-   additional missions (121, 44a, 44b, 46a, 46b) which are used to transmit   synchronization characters (814, 823, 833).