FR2505123A1 - TELECOMMUNICATIONS SYSTEM WITH INTEGRATION OF SERVICES BY INTERCONNECTING SWITCHES AND SPECIALIZED NETWORKS - Google Patents

Abstract

TELECOMMUNICATIONS SWITCHING SYSTEM USING A SPECIALIZED CENTRAL SWITCH, FOR EXAMPLE A PRIVATE TELEPHONE PABX, AND IN WHICH DIFFERENT SERVICES ARE INTEGRATED WITHOUT MODIFICATION OF THIS SWITCH. THE INTEGRATION OF SPEECH, DATA, TEXT AND IMAGE COMMUNICATIONS IS ACHIEVED BY INTERCONNECTING THE EXISTING PABX 1 WITH ONE OR MORE LOCAL NETWORKS IN RING 5, 30 VIA DISTRIBUTED DIGITAL SWITCHES 6, 35 PROVIDING THE FUNCTIONS OF 'INTERFACE REQUIRED ACCORDING TO THE TYPES OF TERMINALS AND PABX. DATA TRANSMISSION TERMINALS 8 AND DATA AND SPEECH TERMINALS 9 ARE FOR EXAMPLE CONNECTED TO A FIRST RING 5 BY CORRESPONDING INTERFACES 6. VIDEO PHONES 31 AND MULTIFUNCTIONAL TERMINALS 32 ARE CONNECTED TO A SECOND TO THE BAND 30 , CERTAIN INTERFACES 36 OF THIS SECOND RING GIVING ACCESS TO THE FIRST AND CERTAIN INTERFACES 6, 35 OF THE TWO RINGS GIVING DIRECT ACCESS TO PABX 1. A RING 5 CAN BE CONNECTED TO A PUBLIC OR PRIVATE DATA NETWORK 13 BY A SPECIAL INTERFACE 12 APPLICATION TO THE REALIZATION OF COMMUNICATION NETWORKS WITH INTEGRATION OF SERVICES, IN PARTICULAR FOR OFFICE OR PUBLIC NETWORKS OF SUBSCRIBER LINES.

Description

The present invention relates to a telecommunications system serving

  a certain number of terminals of different types, in particular for

  telephone, data and text communications.

  A recent trend has been the provision of a number of non-voice services to subscribers in a telephone network. These non-voice terminals, some of which may have voice capabilities, include multifunctional voice / data / text / picture terminals, videophone terminals (included). in the "non-telephone" category because of the large bandwidth they require), and computer terminals The central to which additional faculties need to be added may not be a telephone exchange So it could be a

Central Telegraph.

  In most cases if such terminals are desired it is necessary to add them to an existing system. Economical considerations can avoid the replacement of this existing system, and therefore one of the objects of the system. invention is to allow the provision of new faculties for the proportion

  generally low subscribers who want them.

  Another object of the invention is to make it possible to produce a central office which, conceived initially for a single type of traffic, for example the flow of telephone communications, can be extended later on by the addition of equipment for

to dispose of another type of traffic.

  According to the present invention there is provided an automatic telecommunications switching system, which comprises a central switch to which the subscriber lines served by this switch are connected, and an additional switching device which serves a number of terminals other than said lines. of subscribers, characterized in that the additional switching device comprises at least one distribution circuit which interconnects a plurality of said

  other system terminals, each of these terminals -

  being connected to the respective distribution circuit via an interface; that the central switch can be connected to a telecommunications network and the distribution circuit to another telecommunications network, or to said network; and that at least some of the interfaces connected to the distribution circuit

  are also connected to the central switch.

  In the systems that will be described here the central switch is a telephone switch, for example a PBX, but it will be noted that the invention can be applied to a switching center of a public network In one or the 'other case

  the invention allows maximum use of the installation

  and, especially when relatively modern, some of these control devices may also

  local having a ring structure.

  As will be seen in the following, two or more rings may be used, at least one of which may be a

  Incomplete ring (that is, not closed).

  The invention will be better understood when reading

  of the following detailed description, made as a

  non-limiting example with reference to the accompanying figures which show: Figure 1, a system embodying the invention and comprising a private branch exchange and a closed ring network; FIG. 2, an interface connecting a terminal of the system to a closed ring such as that of FIG. 1; Figure 3, a system similar to that of Figure 1, but with another ring formed by a broadband transmission channel; Figure 4, a system similar to that of Figure 1, but with a transmission channel formed by an incomplete ring, and also an additional mesh network; FIG. 5, an embodiment of the invention in which the central switch is a telex central, the terminals connected to the ring being other digital devices, FIG. 6, an embodiment of the invention, the central switch is a message switch, the devices connected to the ring including

voice terminals.

  In some of the systems that will be described here, there is a telephone switch with one or more distributed bus or line systems arranged concentrically around the switch serving various terminals whose traffic is routed to the switch or either to the appropriate distribution system depending on the nature of the service, faculty or communication medium (eg voice, data, image or text) required It should be noted that the main feature of the system is that distinct capabilities may be provided by the systems. distribution, which are different from

  those provided by the exchange, or even incompat-

with them.

  The central switch, in the devices of FIGS. 1 to 4, is a private branch exchange for telephony; it can be of any known type, for example analog, digital, step-by-step or centrally controlled and may have either a centralized or distributed architecture. As already mentioned, the invention is also applicable to a public central office The first distribution system comprises a number of nodes interconnected to form a network interposed between some or all of the user terminals and the central switch can be interposed other systems of this type between said first system and some or all of the user terminals Depending on their operational requirements, terminals may be connected to one or more of

  these concentric communication networks.

  Such a system, when the exchange is an existing exchange, provides the addition of different services or means of communication in an integrated manner. These services or means may have different switching, interface or transmission requirements, such as for example the speed of transmission. transmission or speed of connection and may even be incompatible with the switching systems provided for one or more of the other services or means of communication Any terminal may have access to one or more of said services or means of communication depending on the systems to which it is connected Each switching system can be given independent dimensions depending on the number of terminals to access the service or

appropriate means of communication.

  In the system represented by FIG. 1, telephone sets providing only the transmission of speech are connected directly to a private branch exchange 1 in the conventional manner, and this central office is connected to a public telephone network by one or more trunks (trunk lines). 'subscribers' as indicated by the arrow 2 Private telephone lines served by the central office 1 are represented by voice-only terminals 3, 4, only two of which have been represented Data transmitting equipment such as computers, data buses and the computer terminals are connected to a ring bus system consisting of interconnected ring interface units such as the ring as depicted with separate buses for the two transmission directions. use a network

unidirectional to a single bus.

  The ring system can be centrally located in the same location as the PBX to use the local line distribution of the existing star network and common bearer capabilities or can be fully or partially distributed by having interfaces in the terminals. whether they serve or

2505 1 23

  proximity to these Terminals that provide both voice and non-voice services are connected to ring switching interfaces that also provide access to the private branch exchange Non-voice terminals, for example processing of information are represented by small square boxes such as 8, and voice / non-voice terminals by circles such as 9 voice, non-voice and control signals from any terminal or group terminals can share a common circuit or line to the appropriate interface in any conventional manner including digital or analog techniques or a combination of both, but preferably by a frame-wise digital multiplexing system. interfaces are connected to the private branch exchange 1, including interfaces such as to which no terminal

user is not connected yet.

  The ring 5 is connected via another interface 12 to a public or private data network, as shown by the arrow 13. This connection can be of any type suitable for transmission.

of data.

  FIG. 2 represents a digital ring network switching interface that can be used in the system of FIG. 1. This unit transmits and receives digital signals on the line-coming from the terminal at 80 kebps. line through the interface of

  line 20 are demultiplexed into a multiplexer-

  demultiplexer 21 and transmitted on a voice channel 22 to 64 keb / s permanently connected to an interface 23 (I the private branch switch through which it is connected to the private branch exchange, and a channel

  24 to 16 keb / s which is connected to a signaling unit

  25 for data processing on this channel.

  The signaling unit 25 extracts control messages from the channel 16 keb / s, which it passes either to the interface 23 of the private branch exchange or to the interface 27 of the ring according to the content or the label

of each message.

  Packets of data or other messages in the 16 keb / s channel 24 are routed by the signaling unit 25 to the interface 27 which places them in the appropriate format and transmits them to the ring system, which may be any known type In the reverse direction, the data and other messages coming from the ring and the control signals coming from the PBX are combined in the format appropriate to the signaling unit and multiplexed in the multiplexer 21 with the speech signals. at 64 keb / s to form a transmission channel at 80 keb / s which is sent to the line via

of the line interface 20.

  Other services or communication means incompatible with this first ring distribution system such as a video service that requires a wider transmission band can be realized by another ring formed by a concentric channel 30 as shown in Figure 3 The terminals connected to the ring 30 comprise at least one videophone terminal 31, connected to the ring 30 by an interface 35 and multifunctional voice / data / video terminals such as 32, 33, which are connected to the ring 30 by Such interfaces may be connected, as shown in the figure, to the internal ring and / or the private branch exchange 1 The type of network used for each distribution system may be

  the most appropriate type of service.

  The example of FIG. 4 represents a four-level concentric system in which two rings

  and a mesh network surround a single central switch.

  There is indeed a private branch exchange 50, which can be of any desired type. According to the current mode, it can be spoken of as a central exchange, especially if it is a central exchange. number of voice-only terminals, ie extensions

2505 1 23

  The first ring system is similar to the ring of FIG. 1, and serves non-voice terminals such as 53 and voice / non-voice terminals such as 54. The second ring, which in this case is in the form of an "arc-of-circle" channel concentric with the first ring, provides a number of services, and is connected via its interfaces 57 to interfaces located on the ring 51, and also to the private switch 50 Note that this channel 56, as shown, has access to the public data network via the ring

51 and appropriate interfaces.

  In addition to the ring 51 and the non-closed channel 56 there is a mesh network 58 which serves a number of multifunctional terminals. This network 58 is connected to interfaces on the other two ring systems 51 and 56, and also to the automatic switch 50

  through the appropriate interfaces.

  In the device of Figure 5, the central switch is a telex central or a message changer, which serves teleprinters such as 61, 62, generally operating at 75 eb / s Other data processing devices operate at speeds The devices connected to the ring 63 may comprise variable speed printers such as 64, databases such as 65 and consoles. For such devices that can transmit or receive at more than one speed through the associated speed matching circuitry, ring system switching and interface units are provided to provide access to the lines. omnibus ring and / or central switch, depending on the destination and

the nature of the traffic.

  In FIG. 6, the central switch 70 is a message switch 70 to which a teleprinter or other data transmission equipment such as 71 is connected, while the ring 72 serves terminals.

  teletex 73, 74, videotex or telex

  such as 75, 76 can share lines of teletypewriter, said telephones can use a fixed time sector rather than operating in packet mode In addition, there may be telephone sets such as 77 which are connected only Such a system is useful when the nature of the activity requires the exchange of written messages, with

  only occasional voice traffic.

  It is obvious that the description which

  precedes has been made only as a non-limitative example and that other variants can be envisaged without

  to go beyond the scope of the invention.

Claims (4)

CLAIMS l Automatic telecommunication switching system, comprising a central switch to which the subscriber lines served by this switch are connected, and an additional switching device which serves a number of terminals of the system other than said subscriber lines. , characterized in that said additional switching device comprises at least one distribution circuit (5 or 30) which interconnects a plurality of said other terminals of the system (8, 9, 31 to 33), each of these terminals being connected to its distribution circuit (5 or 30) via an interface (6 or 35, 36), that the central switch (1) can be connected to a telecommunication network (2) and that the distribution circuit (5) can be connected to another telecommunications network (13) or the same network (2), and that at least some of the interfaces (6); connected to the distribution circuit (5) are also connected to the central switch (1).   System according to Claim 1, characterized in that the distribution circuit (5) is a closed ring-type circuit which interconnects a number of interface circuits (6), at least one of said interfaces ( 12) provides access to one of said telecommunications networks (13), that at least some of said interfaces provide access to the respective interfaces of said other terminals (8, 9), and that at least one of said   these interfaces have access to the central switch (1).   System according to Claim 2, characterized in that the closed ring circuit has two transmission paths, one for clockwise transmission and the other for   the transmission in the opposite direction.   4 System complying with any of the   1, 2 or 3, characterized by the fact that   includes a number of other   connected to provide a mesh network (58), which mesh network is coupled to one or more of said plurality of   distribution (51,56) as well as audit central switch (50).   6 System according to any of the   1 to 5, characterized in that the   Central switch (1.50) is a telephone switch.