Reconfigurable multiple-point wired in-house network for simultaneous and/or alternative distribution of several types of signals, notably baseband images, and method for the configuration of a system such as this

• US 5,130,793 A
• Filed: 07/20/1989
• Issued: 07/14/1992
• Est. Priority Date: 07/22/1988
• Status: Expired due to Fees

• Current Assignee: Etat Francais, Telediffusion De France SA
• Original Assignee: Etat Francais, Telediffusion De France SA
• Inventors: Bottin, Daniel, Bordry, Herve, Pace, Daniel
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Urban, Edward
• Application Number:
  US07/383,173
• Time in Patent Office: 1,090 Days
• Field of Search: 455/3, 455/5, 455/6, 358/86, 333/18, 333/26 R, 375/12, 375/14
• US Class Current: 725/78
• CPC Class Codes: H04N 7/10 Adaptations for transmission by electrical cable H04N7/12 takes precedence
• CPC Class Codes: H04N 7/106 for domestic distribution
• CPC Class Codes: H04N 7/108 the cable being constituted by a pair of wires
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

A transmission line formed by a twisted pair of conductors with at least one input point for connection to a device for injection of a signal into the pair of conductors, and several output points for connection to devices for tapping of the signal transmitted on the pair of conductors. Each of the points has means for symmetrical tapping of the signal on the two wires of the pair. The tapping means has a high impedance with respect to the impedance of the pair of conductors, and is compatible with a multiple tapping of the signal on the pair of conductors. This transmission line permits the transmission of signals emitted in wideband, such as baseband video signals over distances of several hundreds of meters, with multiple tapping of a signal on one and the same line of the network, without causing any mismatching phenomena.

Claims

1. A reconfigurable in-house multiplepoint wired network for the simultaneous and/or alternative distribution of several types of data including, notably, audio-visual signals comprising, amongst others, baseband image signals, among sets of devices, each comprising at least one unit for the injection of signals into the network and at least one unit for the reception of said signals, each said unit capable of being connected, without distinction, at different connection points of the network,

a network of the type formed by at least one line for the transmission of said signals provided with connection points of said units to the network, distributed over the length of said line,

wherein each transmission line is formed by a twisted pair of conductors comprising at least one input point for the connection of a unit for the injection of a signal into said pair of conductors;

and several output points for the connection of units for tapping said signal transmitted on the pair of conductors,

where each of said at least one input point comprises means for the symmetrical injection of the signal on the two wires of said pair of conductors, said means for the injection having a high impedance with respect to the impedance of said pair,

and wherein each of said output points comprises means for the symmetrical tapping of the signal on the two wires of said pair,

said means for the tapping having a high impedance with respect to the impedance of said pair of conductors, compatible with a multiple tapping of the signal on the pair of conductors.

2. A network according to claim 1, wherein at least one of said connection points is an input/output point comprising, at the same time, firstly, means for the injection of a signal into said pair of conductors and, secondly, means for the tapping of the signal transmitted at low level on said pair of conductors, as well as means for the selection of the operation mode of said connection point, in injection and/or in reception.

3. A network according to claim 1, wherein each of said output points of the network comprises adjustable means for equalization of the level of the signal received with respect to the signal injected into the network, as a function of the electrical distance between said output point and the injection point of the signal in said pair of wires, said means for equalization comprising means for determining said electrical distance.

4. A network according to claim 3, wherein said equalization means comprise means for the memorization, at each connection point, of its electrical distance with reference to a single reference point on said pair of conductors, and means for the computation of the electrical distance between two connection points of said pair of conductors by algebraic substraction of their respective distance from said reference point.

5. A network according to claim 3, wherein said equalization means comprise:

means for the temporary short-circuiting of a line at a first of said injection connection points;

means for measuring the electrical resistance of said short-circuited line, seen from the second of said connection points, which is representative of said electrical distance;

means for selection of an adjusted value of equalization as a function of said measured electrical resistance.

6. A network according to claim 3, wherein said equalization means comprise distinct, selectively switchable, equalization cells, alone or in combination, as a function of said electrical distance, namely electrical resistance measured respectively.

7. A network according to claim 1, comprising:

a bunch of lines formed, firstly, by several twisted pairs of conductors for the transmission of useful signals and, secondly, by at least one signalling line,

a set of connection sockets with multiple contacts, each connection contact of which is connected to a pair of conductors of said bunch;

a set of multiple-contact connectors for the connection of said units, each having connection elements dedicated to the transmission/reception of a specific signal per type of unit;

a set of switching matrices, each matrix being interposed between a connection socket and an associated connector for the selective and reconfigurable making of contact of each connection element of the unit connector with the connection contact of the socket connected with the pair of conductors carrying the corresponding signal to said dedicated connection elements;

means for the control of each of said switching matrices, for setting up and breaking off each unit connection with the network, comprising, firstly, means to emit control signals on said signalling line and, secondly, a control element specific to each switching matrix connected to said signalling line.

8. A network according to claim 7, formed by at least two bunches of twisted pairs of conductors connected by repeater.

9. A network according to claim 7, wherein said signalling line is formed by at least one twisted pair of conductors.

10. A network according to claim 7, wherein said means for the emission of control signals are formed by an emitter connectable to any point of the network, of a videotex terminal type.

11. A network according to claim 7, wherein said means for the emission of control signals include a piece of supervision equipment capable of creating automatic connections.

12. A method for the configuration of a network according to claim 7, wherein a logic address is attributed to each device connected to a connection point of the network, said logic address being formed by two distinct fields:

a first field identifying the type of device and, hence, the locating of the position of each of the connection elements dedicated to the connector of said device;

a second field specifically identifying said device in an individualized way.

13. A method according to claim 12, wherein said second field is formed by an alphanumeric code comprising an order number and/or a mnemonic identifier chosen by the user.

14. A method according to claim 12, comprising an iterative procedure for the assigning, to each device newly connected to the network, of an individual identification number, said procedure consisting in:

emitting, at least once on the signalling line, a test message containing a first candidate number value;

testing a new candidate number at each rejection of the current candidate number, by a device already connected to the network and/or by a piece of supervisory equipment of said network;

assigning said candidate number to said device when there is no rejection.

15. A method according to claim 12, wherein a list of connected devices is memorized, each article of said list corresponding to a separate device, and comprising said first and second fields of the logic address of the device, as well as a piece of information on the status, whether active or idle, of the link of said device with the network.

16. A method according to claim 12, comprising a procedure for requesting the setting up of a connection between an emitter and a receiver on said network, consisting in:

emitting a connection request comprising the logic address of the emitter and the logic address of the receiver;

obtaining, from each of the connection points of said emitter and receiver, a piece of information on the existence of pairs of conductors which are either already carriers of signals implicated by the connection requested or available in sufficient number to establish said connection requested;

setting up or aborting said connection requested as a function of the value of said information on existence.

17. A method according to claim 12, wherein a priority level is assigned to each device, and wherein the procedures for setting up connection, in the event of saturation of the network, favor the connections made as a function of the level of priority of the device with the highest priority of each connection.

18. A method for the configuration of a network according to claim 7, notably for the transmission of image signals in Peritelevision, wherein the so-called slow switching information of said image signals is broadcast on said signalling line.

19. A method for the configuration of a network according to claim 7, wherein items of remote control information of an emitter are transmitted in the network in said signalling line.