FR2583943A1 - Network for transmission of information between computer hardware - Google Patents

Abstract

The physical transmission media are arranged in the working location as an at least partial quadrilateral grid forming rows and columns, each of the stations S being connected both to a column medium 2, 4, 6, 8 and to a row medium 1, 3, 5. At least one point of each column or row medium is linked to the main processing centre (CTP).

Description

 The invention relates to a network for transmitting information between computer equipment comprising receiving and receiving stations, distributed within at least one activity site, linked together and possibly to one or more main processing centers by physical transmission media.

 data processing whatever it is, increasingly calls for solutions using computer hardware.

 As a result of this evolution, the transmitters and the users of data are no longer grouped in "Data center" but distributed and the transmissions of the data are carried out by means of computer networks which must allow an exchange of messages comprising all the guarantees of speed, reliability.

 When the distance, separating two extreme posts which must correspond together, does not exceed ten kilometers, what is known as a local area network is established. longer-distance communications generally use networks managed by the administration, such as telephone and radiotelephone networks.

 networks are made up of electronic equipment specific to transmission such as interfaces, communication controllers, couplers, etc., and transmission media such as coaxial cable, telephone pair, optical fibers, etc.

The quantitative and qualitative importance of the data passing through such networks requires very high quality transmissions quality and reliability. the quality and reliability criteria aim to guarantee: the physical possibility of message routing by reliability and availability of the network itself, that is to say the continuity of the service; protection against the consequences of aggression caused by the environment, for example radio interference, temperature, humidity, etc., and protection against accidental events such as mechanical risks, or malicious acts such as sabotage, fraud, etc .;
the integrity of the messages themselves by protecting the content of the messages against errors, jamming, eavesdropping, unauthorized transmission, and the certain identification of the senders and recipients.

 All the network equipment offered on the market includes communication and transmission control protocols making it possible to verify the correct routing of messages, but this is only possible insofar as the network elements in service offer the physical possibility. .

 The topology or architecture of the network must be adapted to the level of reliability and security sought. the most common architectures are the star, the loop, the ring, the tree and the bus. Each of these architectures has advantages and disadvantages which are well known. To improve the level of security in the event of a break in the physical link serving transmitting and receiving stations, the break being caused either by physical destruction or by failure of an active element necessary for transmission, we place in parallel on the service transmission support a second emergency support of the same nature (telephone pair, coaxial target, bus, etc.).

 This solution Although it increases technical reliability compared to a single-support solution, it does not however provide additional protection against environmental damage, mechanical accidents, malicious acts, etc. since the path of the two supports must remain essentially identical in principle.

Binvention offers a network for the transmission of information, in an activity site, whose architecture is based on an arrangement of the physical transmission media according to columns and lines, each transmitting and / or receiving station being connected to at least a column support and at least one row support,
The description and figures given below by way of example will make it possible to understand how the invention can be implemented.

FIG. 1 represents the block diagram of an example of topology of a network in accordance with the invention0
Figure 2 is the block diagram of another example of topology.

 FIG. 3 is a diagram of a connection of a station to a physical support of the network.

FIG. 1 represents the block diagram of an example of a network for transmitting information between computer hardware,
computer equipment, to be linked and called stations, are on the one hand, acquisition machines ensuring local functions and information gathering and on the other hand, computer assemblies (centers or treatment stations) providing central processing and processing of the data received.

 the S stations to be linked are distributed across an activity site. The site can be limited, for example, to one or more floors of a building or on the contrary extend to a set of buildings located within a radius of several kilometers.

 physical transmission media? to 8 are arranged in the site according to an at least partial grid.

the supports, for example: telephone pairs, coaxial cables, fiber optic cables etc, form in the plane of the figure columns 2, 4, 6, 8 ... and lines 1, 3 5
In order to distinguish the supports forming this grid, they will be designated by the terms column supports 2, 4, 6, 8 and row supports 1, 3, 5.

 Each station S is connected to both a column support and a row support.

 According to the example of network shown, at least one end of the row supports and of the column supports is connected to the main processing center CTP by head ends TR, located in the processing center and connected to the computer equipment of the latter by a primary network RP formed of two distinct physical supports.

Given the limited length of this network, it is easy to take all the necessary care for its security in order to minimize the risks due to physical aggressions and electrical parasites.

 The column and line supports to which the stations are connected form a secondary RS network in which the physical transmission security is ensured by the connection of each station to two column and line supports having different paths.

According to another embodiment of the network, at least part of the row and / or column supports form loops, one point of which is connected to the primary network by a network head,
The configuration is that shown for example in Figure i by the lines 9, 10 in broken lines, one of the two TR network heads being deleted.
This loop formed on two column supports 6, 8 can be produced on one or more groups of two column or row supports. the loops thus formed are in the plane of Figure lo
According to the exemplary embodiment shown in FIG. 2, at least part of the loops determines planes distinct from that defined by at least part of the column and row supports arranged substantially in a plane as shown in FIG. 1. column and / or row supports form a side of a loop which extends in a plane approximately perpendicular to the plane containing the supports 1 to 8. This gives at least partially a three-dimensional network defined by vertical and horizontal loops corresponding respectively to column supports and row supports.

 One point of each loop is connected via the head ends TR to the main processing center CTP.

 Depending on the activity site to be served, a network according to the invention may comprise a part of a secondary two-dimensional network and a part of three dimensions, the network part or the two-dimensional network being able to itself comprise loops formed by two supports columns or neighboring rows corm represented in FIG. 1 by the loop 6, 8, 9, 10.

 A network constituted according to one of the preceding embodiments and working according to a suitable access protocol ensures: security and redundancy of the transport of information; direct dialogue between all stations, guaranteed exchange time, transparent communications, the possibility of configuration modification by intervention in the application program, automatic reconfiguration in the event of a network interruption; and continuity of service, the breakdown of one of the stations does not hamper the smooth running of the whole.

According to an exemplary embodiment of a network according to the invention, the physical media for transmitting information from one station to another have been chosen from two types: coaxial cable, which has a small footprint, immunity to interference, a high mechanical resistance and which is easy to install, constitutes the primary network and the essential of the links between stations;
- optical fiber, used on certain sections requiring a high transmission rate, which has perfect immunity to electrical and electromagnetic disturbances and particular physical qualities such as lightness and flexibility.

 the coaxial target is connected to the optical fiber by means of optoelectronic couplers integrated and supplied in self-protected cabinets of stations connected to the network.

 the connection between the stations and the coaxial cable is made using communicators and front ends.

 COM communicators (Figure 3) are made up of electronic circuits ensuring the connection of the station's internal BUS bus connected to the CATV coaxial cable via a physical UPR connection unit. A communicator manages a buffer memory MT by a microprogrammed processor PM, the buffer memory MT also being accessible by the processor of the station. the physical connection unit UPR is connected to the processor through an AC adapter which contains the transmit and receive amplifiers.

Protections are made on the "input and" output connections of the UPR against any voluntary or accidental overvoltage appearing on the network,
Specific software manages the dual-access memory ME between the application and the communicator commands.

 the front ends provide connection with larger stations such as central stations by synchronous type links.

 The network can receive several front ends in order to increase the reliability of the system.

the connection between the primary dual network and a secondary network is ensured by a network head E which is responsible for specific tasks of monitoring the network to which it is attached such as monitoring of bit rates and transmission times, message plausibility, and network testing. A network head comprises "communicators'l logic which manages access to the secondary network and to the dual primary network, a central processing unit CPU which controls the whole operation of the network tette, memories necessary for operation, and a physical UPR connection unit,
I1 is provided a power supply and individual protection of the headend.

the network operating mode is described belowO
For each transmission to another station, a station has the choice between two paths, that consisting of column supports and that constituted by row supports. These paths should respectively be called column network and line network.

 In normal operation, the transmission is done on each network alternately. In degraded operation, the defective network is inhibited and transmission is made only on the other network, the communicator of the defective network remaining ready for reception.

 In the event that transmission over a network is unsuccessful, the data packet is retransmitted during the next transmission authorization. If the transmission still does not succeed, or if it is impossible to transmit, the degraded operation is triggered, an alarm message is transmitted via the second network to the centers and treatment stations in charge of the functions of 'e exploitation. The return to normal operation takes place on the order of the main processing center, from which a forced transition to degraded operation can also be ordered.

The transmission on the primary / secondary network of the data received on the secondary / primary network is ensured by the network tettes0
In the case of a transmission from the secondary network, the network text has the choice between the two primary dispatch networks.

In the case of normal operation, transmission takes place on each alternating network. # Degraded operation is identical to that described previously for stations
In the example of application described, the transfer from a secondary network to another secondary network is carried out via the head ends and the primary network.

 A generalization of the transmission system consists in using all or part of the stations as transmission nodes allowing the direct transfer of information between column networks and secondary lines. The corresponding network diagram will then be limited to a grid of independent lines and columns.

 the number of primary and secondary networks is limited only by the possibility of addressing the type of network used.

 Networks conforming to the invention provide access protocols to transmission media using dynamic reservation of the "token" type or a random access policy CSt # of the Ethernet type.

Claims (8)

 1. Network for transmitting information between computer equipment comprising transmitting and / or receiving stations, distributed within at least one activity site, linked together and possibly to one or more main processing centers by physical transmission supports, characterized in that the physical supports are arranged in the activity site according to an at least partial grid forming columns and lines, each of the stations (S) being connected at the same time to a column support (2 , 4, 6, 8) and to a line support (i, 3, 5).  2. Network according to claim 1, characterized in that one or more groups of two column or row supports form one or more loops (6, 8, 9, 10).  3. Network according to claim 1 or 2, characterized in that at least part of the column and / or row supports (2, 4, 6 ...; 1, 3, 5) form loops (B1, B2, 33) which extend in separate planes from that or those defined by at least part of the column and / or row supports.  4. Network according to one of claims 1 to 3, characterized in that at least one point of each column or row support is connected to the main processing center (CT P).  5. Network according to one of claims 1 to 4, characterized in that it consists of a primary network (RP) formed of two physical media having approximately the same path connected to the principle processing center (CTP) of networks secondary formed by supports and / or column and row loops (2, 4, 6; 1, 3, 5 ...; Bi, 132, 133, B4 ...) of which one of their ends is connected to the primary network by network tettes (TR), and stations (S) connected between a column support and a line support, said support possibly belonging to a column loop and a line loop.  6. Network according to one of the preceding claims, characterized in that the stations (S) are connected to a physical transmission medium by a physical connection unit (UPR) via a communicator (COM) connected to the internal bus (BUS) of the station (S).  7. Network according to one of the preceding claims, characterized in that, when normal, transmissions from one station to another and to the main processing center (CTP) and vice-versa take place alternately on the supports and / or the loops. columns and rows.  8. Network according to claim 7, characterized in that in degraded operation, the transmissions are made only on the undisturbed network or networks.