FR2859589A1 - Surveillance zone remote surveillance method having zone/centre digital word interface links with bridge assembly links virtual circuit/platform connected detecting digital word transmission loss - Google Patents

Abstract

The remote surveillance system has a subscriber network (10) and a packet switching network (12). There are two control platforms (18) forming a digital word communications interface between the surveillance zone and the remote surveillance area. Virtual networks relay frames using the X25 protocol. There is an assembly of bridge links connected between the virtual circuit and the platform, detecting the loss of digital word transmission.

Description

Installation and method for transmitting data between

  monitored premises and one or more remote remote monitoring systems.

  The present invention relates to an installation and a method for transmitting data between two remote sites and more particularly relates to an installation and a method for transmitting data between monitored premises and one or more remote remote monitoring systems.

  Conventionally, in order to receive alarm signals from sensors fitted to the monitored premises, such as fire detectors, intrusion detectors, movement detectors, etc., the remote surveillance systems or installations communicate with the premises. monitored using an analog phone line.

  As it is conceived, the proper functioning of such a remote monitoring system is linked to the integrity of the link established between the monitored sites and the central remote monitoring installation.

  Also, if the telephone line, support for transmission of alarm information, is no longer operational, for example in the event of malicious cut by a burglar, or in case of disturbance or work, the alarm system installed in the monitored sites becomes isolated from the monitoring center and no more information can be exchanged, so that the telemonitoring company is no longer able to provide its service.

  To overcome this drawback, telemonitoring companies offer to verify the proper functioning of the telephone line. Different techniques can be used for this purpose.

  According to a first technique, the remote remote monitoring installation periodically calls the monitored site. If this is not answered, an on-site intervention can be triggered. This technique is relatively uncommon, insofar as it generates unacceptable costs for the remote monitoring company which must periodically call all subscribers to the proposed remote monitoring service.

  According to another technique, the monitored sites are responsible for periodically calling the remote monitoring installation. An intervention on site is then triggered in the absence of such calls. Costs relating to the establishment of the telephone link are then borne by the subscribers.

  These techniques, however, have a major drawback, insofar as they generate significant network traffic between the monitored sites and the centralized remote monitoring facility. The remote monitoring company must therefore have substantial material resources, and must in particular be equipped with sufficient telephone connections to absorb the traffic generated.

  In addition, fraud remains possible, since it is relatively easy to connect a network simulator on the line of a monitored premises and to program it to work in luring. Such a decoy is also more effective when the establishment of the call line is made by an on-hook call.

  Moreover, even when the call is made on the initiative of the subscriber to the remote monitoring service, the cost in communication is relatively important. In fact, a call made every fifteen minutes corresponds to 2880 monthly communications, the cost of which is reflected on the subscriber's telephone bill.

  An attempt has been made to overcome these various disadvantages by using a mobile type telephone network for establishing communications between the monitored sites and the remote remote monitoring installation. However, this technique is not widespread because, on the one hand, it has a relatively high cost and its reliability is insufficient because of the risk of absence or poor radio reception, due to interference, poor radio reception , or a congestion of the network.

  An alternative to these different techniques is to create a specific communication channel on the telephone line of each subscriber, in a specific frequency range. To this end, telephony surveillance hubs (CTS), installed on the fixed telephony network and to which the remote monitoring facilities are connected, constantly monitor the customer's line and warn the monitoring companies when a change in state is detected.

  However, this technique requires a specific concentrator for monitoring the line, so that certain geographical areas can not be affected by this supervision technique. In addition, this type of technique generates a relatively high network operating cost.

  In view of the above, the object of the invention is to overcome the disadvantages of telemonitoring systems according to the state of the art by permitting permanent monitoring of the proper operation of the telephone lines connecting the sites monitored to the remote monitoring installation without using a specific concentrator for connecting the various elements of the remote monitoring system.

  The invention therefore relates to a data transmission facility between monitored premises and one or more remote remote monitoring systems, via a digital ISDN subscriber network, an X25 packet-switched network, and a frame relay network.

  This installation comprises at least one pair of control platforms forming a communication interface through which data is transmitted between the monitored premises and the remote monitoring system via dedicated transmission channels, virtual circuit establishment means. in the frame-relay network between the packet-switched network and the control platforms, means for establishing virtual circuits according to the X25 protocol between the monitored premises and the control platforms and between the systems monitoring platforms and control platforms, and a set of gateways providing the transfer of data conveyed between the virtual circuits established according to the X25 protocol and the permanent virtual circuits pre-established in the frame relay network, the platforms control devices being adapted to detect cuts in the transmission channels data session.

  It is thus possible to monitor the state of the link between the monitored sites and the remote monitoring system by using the hardware means of the network, without periodic calls.

  According to another characteristic of the invention, the installation comprises a pair of platforms comprising a main control platform used during the normal operation of the installation, and a backup control platform used in case of malfunction of the installation.

  In addition, each monitored premises has a main data channel, and a backup channel used in case of failure of the main channel.

  In this case, in one embodiment, the main channel is a virtual circuit established according to the X25 protocol in the D-channel of the ISDN network and the spare channel is a virtual circuit established according to the X25 protocol in the B-channel of the ISDN network. .

  Each platform can be connected to the frame relay network by at least two separate connection links.

  In an advantageous embodiment of the installation, each monitored premises is equipped with a connection interface (TCT) of a remote monitoring equipment which communicates with the X.25 packet-switched network via a remote control device. a permanent logical link established in the ISDN digital subscriber network and each remote monitoring system is provided with a remote monitoring interface (FTS) by which it is connected to the X.25 packet-switched network.

  In this case, to connect a monitored premises and the remote monitoring system, each connection interface (TCT) includes, stored in memory, a list of X.25 addresses of permanent virtual circuits that can be used to establish a X.25 communication by means of the corresponding permanent virtual circuit between said room and the platform.

  For example, each connection interface includes, stored in memory, a list of at least two X.25 addresses of permanent virtual circuits connecting a switch of the X.25 packet-based packet exchange network with which to communicate. , via the main channel, the connection interface and the main control platform and a list of at least two X.25 permanent permanent virtual circuit addresses connecting said packet access point and the platform backup control.

  In addition, according to another characteristic of the invention, each connection interface includes, stored in memory, a list of at least two X.25 permanent permanent virtual circuit addresses connecting a second switch of the X packet network. .25 other than said packet access point switch and with which the back-up channel, the connection interface and the master control platform communicate, and a list of at least two X.25 addresses permanent virtual circuits of emergency connecting said second switch and the backup control platform.

  In an advantageous embodiment, each connection interface and each control platform comprise the same authentication algorithm for authentication of the connection interface.

  In addition, the platforms may each be connected to a center for managing the platforms and operating a remote monitoring service implemented by the installation.

  According to the invention, there is also provided a method for transmitting data between monitored premises and one or more remote remote monitoring systems, via a digital ISDN subscriber network, a packet-switched network. X.25 and a frame relay network implemented by means of an installation as defined above.

  According to this method, for each connection interface connected to a remote monitoring equipment, permanent virtual circuits are established between the connection interface and the platforms; establishing a main data transmission channel between the connection interface and a main platform using one of the previously established permanent virtual circuits; the proper functioning of the main channel is monitored; and in the event of a break in the main transmission channel, a backup transmission channel is established using another permanent virtual circuit.

  According to one embodiment, permanent logical links are established between the connection interface and a switch of the X.25 packet-switched network and virtual circuits according to the X.25 protocol on the permanent logical links and on a network. frame relay network between the packet network and the platforms.

  For example, the virtual circuits according to the X.25 protocol are established from a pre-established permanent virtual circuit addressing, from virtual circuit numbers previously downloaded in the connection interface (TCT).

  Advantageously, the main data transmission channel is established using the D-channel of the ISDN digital user network, the backup channel used in the event of a malfunction being established in the B-channel of the ISDN network.

  According to another characteristic of the method according to the invention, in case of rupture of a main transmission channel, a backup transmission channel leading to either the main platform or to an emergency platform is used.

  Other objects, features and advantages of the invention will become apparent on reading the following description, given solely by way of nonlimiting example, and with reference to the appended drawings in the figures: FIG. 1 is a block diagram illustrating the general architecture of a data transmission installation according to the invention, for transmitting information between a monitored premises and a remote monitoring installation; FIG. 2 is a block diagram illustrating the mode of data transmission between a monitored premises and a remote monitoring installation; and FIG. 3 is a detailed diagram illustrating the architecture of the data transmission installation according to the invention.

  In Figure 1, there is shown the general architecture of a data transmission installation according to the invention.

  This installation is intended to use the fixed telephony network of a telecommunications operator in order to establish a communication channel between monitored premises, each equipped with an alarm system provided with all the sensors necessary for carrying out surveillance effective monitoring of the premises, such as a fire detector, intrusion, movement, ... and a central remote monitoring system or installation.

  Thus, by using such a communication channel, in the event of an intrusion or, generally, in the event of an incident being detected, the alarm system of the monitored premises transmits alarm information to the remote monitoring system so that an operator can identify the nature of the incident and dispatch a response team to the scene.

  In addition, the data transmission installation is intended to continuously check the state of the telephone line supporting the communication channel and, in the event of a break in the channel, to inform the centralized remote monitoring installation of a such dysfunction.

  The purpose of this installation is also to enable data transmission from the remote surveillance installation to the monitored sites in order to offer them additional functionalities, such as archiving and subscriber authentication functions. , an optimized pricing function, ...

  As can be seen in FIG. 1, the installation according to the invention essentially uses software and hardware resources of a telecommunications operator for the transmission of data between the monitored sites, on the one hand, and the installation or installations of remote monitoring, on the other hand.

  Thus, as can be seen in FIG. 1, the data transmission installation according to the invention uses the digital subscriber network 10 as well as the packet-switching network 12 of the telecommunication operator to establish a link between a TCT (Customer Telefication Transmitter) connection interface 14 serving to connect an alarm system placed in each monitored premises and a remote monitoring interface 16 through which the remote monitoring installation of a surveillance provider connects packet switched network 12.

  More particularly, the data transmission installation according to the invention uses the ISDN integrated services digital network 10 of the telecommunications operator, with which the connection interfaces communicate.

  The ISDN network consists of a telecommunications network well known to those skilled in the art. It will not be described in detail later. Note however that this network uses different types of channels to convey data, including a D-channel, which operates in message mode, which is shared between all terminals connected to the ISDN network in a multi-point configuration, and which is particularly suitable for transporting low-rate data, such as alarm signals, and a B-channel, which is a circuit-switched channel, i.e., a channel assigned to a terminal and a single channel for any the duration of a communication, and which can be used to carry any type of information.

  The installation uses the ISDN network D-channel to form a main data channel and ISDN network B-channel as a backup channel, used in the event of a main channel failure, as will be described in detail by the after.

  As is known, the ISDN network makes it possible, via the D channel, to establish permanent logical links LLP between the interface of the TCT connection 14 of the monitored premises and, for example, with regard to the French territory, a point PAP packet accesses of the X.25 packet-switched network, via an ACT frame concentrator router.

  With regard to the packet-switched network, it is constituted by a network according to the X.25 protocol, which provides an interface between the remote monitoring interface 16 and the ISDN network 10. Such a network is also known from the person skilled in the art and will not be further described later. However, it will be noted that it allows the establishment of virtual circuits according to the X.25 protocol to the remote monitoring interfaces and comprises, as will be described later, a set of PSX switches, in which are placed the points of PAP packet access.

  It can be seen in FIG. 1 that the installation is also provided with a set of control platforms, such as 18, which constitute communication interfaces through which the connection interfaces 14 and the remote monitoring interfaces 16 communicate. These control platforms 18 are connected in a local network and operate under the supervision of management centers of the platforms 20. Each management center 20 communicates, via an intranet network of the operator 22, with a system 23, which is owned by the operator and manages all the resources used for the development of permanent logical links and billing resources and for the provision of supplementary services to subscribers, such as, for example, example, billing management services.

  As seen in FIG. 2, the control platforms 18 constitute a relay between the connection interfaces 14 and the remote monitoring interfaces 16 through which the messages exchanged between the interfaces 14 and 16 transit. Indeed, the messages between the connection interface of each monitored premises and the remote monitoring interface pass through the control platform 18 (F1 arrow). Furthermore, as will be further described later, the platform continuously monitors the state of the link by which it communicates with the connection interface 14 (Arrow F2) and transmits indications of malfunction. transmission channel in the event of detected fault (Arrow F3).

  In other words, to reach a provider, a connection interface 14 must address a control platform 18. Similarly, to join the connection interface 14 of a subscriber, the remote monitoring installation must address a control platform 18, which routes the information received to their recipient according to a dedicated protocol.

  As can be seen in FIG. 3, the control platforms 18 are connected to the X.25 packet-switched network via a frame relay network 24, also called a Frame Relay (FR) network. More particularly, each platform is connected to the frame relay network by at least two separate connection links. Such a network is also widely known. It will be noted that, because of its properties, this frame relay network is particularly suitable for X.25 data transmission, and gateways, constituted by the PSX switches of the X25 packet-switched network, are provided between the X25 packet-switched network and the Frame Relay 24 network. It should also be noted that the installation supports the Frame Relay standard to establish permanent virtual circuits according to this Frame Relay standard, which connect the control platforms to different PSX switches.

  Thus, by virtue of the use of permanent logical links LLP, X.25 packet switched network 12, and frame relay network 24, the control platforms 18 are able to control the integrity of the channels of X.25 virtual circuits and Frame Relay permanent virtual circuits, and to detect any breakage by exploiting link break or connection information that is transmitted to in accordance with the standards that describe the X25 protocols and the Frame Relay standard protocols.

  Referring to FIG. 3, it can be seen that in order to be able to connect the service providers as well as the subscribers to the control platforms 18 by permanently established X.25 CV virtual circuits, these virtual circuits X25 must borrow virtual circuits. These virtual circuits 26 are addressable by means of X.25 numbers and can therefore be selected for the establishment of the frame relay network 18 and the packet-switched network. a transmission channel between the interfaces 14 and 16 and the platforms 18 PST1 and PST2. In FIG. 3 only the PSX switches of the X.25 network serving to connect two TCT1 and TCT2 connection interfaces and also forming X25 network / Frame Relay network gateways have been represented, the FTS1 remote monitoring interface connection switches. , FTS2, FTS3 of the remote monitoring system not shown, With regard to the remote monitoring interfaces 16, each of them is connected to all the platforms 18 on which they have subscribers declared by at least two circuits virtual X.25 CVs.

  Each connection interface 14 is declared with a pair of platforms 18. One of the platforms 18 of "this pair is declared normal PST and is used during the normal operation of the installation, the other flat -form 18 being declared as a backup PST, used in the event of a malfunction of the normal PST, More particularly, each connection interface 14 TCT1 or TCT2 includes, stored in memory, a first list of X.25 addresses of permanent virtual circuits. used during the normal operation of the installation, that is to say in the absence of malfunctions and which therefore correspond to a transmission channel established in the D-channel of the ISDN network, and a second list of addresses X .25 permanent virtual circuits 26 used in the event of a malfunction, and which correspond to the establishment of a transmission channel in the B-channel of the ISDN network.

  The first address list contains the X.25 numbers of at least four permanent virtual circuits 26 connecting the access point of PAP packets with which the connection interface 14 communicates to the two platforms PST1 and PST2 of the corresponding pair. In other words, this address list contains the X.25 addresses of the permanent virtual circuits 26 for accessing the normal platform and the standby platform from the PSX switch of the X packet network. .25 with which communicates, via the channel D of the ISDN network, the connection interface 14 TCT1 or TCT2.

  The second address list contains permanent X.25 address numbers of permanent virtual circuits 26 connecting a PSX switch of the X.25 packet-switched network, other than the switch having the dot function of packet access for the corresponding connection interface 14, to both platforms PST1 and PST2. This list thus contains two X.25 access addresses to the normal platform 18, and two X.25 access addresses to the so-called backup platform 18.

  Furthermore, each interface 14 connecting the remote monitoring equipment installed in a subscriber is connected by a permanent logical link to its connection packet access point (PAP). The permanent logical link is established in the D-channel of the ISDN network via an ISDN network subscriber attachment (AAC) switch, a frame concentrator router (ACT) located in a transit center from the switched network, and then to the PAP packet access point.

  Once the permanent logical link is established, an X.25 protocol communication can be performed between the interface 14 and one of the control platforms 18 of the pair on which the subscriber is declared.

  It will be noted that this X.25 link can be established either on the initiative of the platform 18 or on the initiative of the interface of the connection 14.

  In the case where the X.25 communication is established on the initiative of the platform 18, the call request must be made in PCV (PerCeSee), that is to say to the called user, in using one of the permanent virtual circuits 26 created to reach the PAP packet access points for connection to the interface 14, or, failing that, another PAP packet access point. The destination number is the X.25 address of this connection interface 14. In the event of failure, the platform 18 attempts to establish the connection via another permanent virtual circuit connected to the access point. connecting PAP packets of the aforementioned interface 14, until a link can be established, or until all X.25 addresses have been used.

  In the case where the connection interface 14 establishes the communication, the destination number of the call request is initialized with the first address of the address list corresponding to the channel D. In case of failure of the establishment communication, a call is again attempted with the following address taken from the list. In case of a new failure, the connection interface 14 uses the following address, until the connection can be established or until the list is exhausted. In the case where all the addresses have been tried without success, the connection interface 14 implements a delay before starting a new cycle of attempts and attempts to connect to a platform 18, namely the same platform. normal form or standby platform, using ISDN B-channel in order to guard against a failure of all X.25 network / Frame Relay network gateways from its PAP packet access point.

  Note that once an X.25 communication of the main channel is established, it is maintained permanently.

  As previously indicated, in the event of a platform connection 18 being lost via the D-channel of the ISDN network, that is to say in case of loss of the permanent logical link LLP, the connection interface 14 has B-channel ISDN network to connect to either the normal platform or the back-up platform. For this purpose, the interface 14 establishes a circuit mode communication in

  using synchronous standardized input (EBS) of the X.25 packet switched network. Such an entry allows the establishment of a connection according to the X.25 protocol, even in the absence of a specific subscription.

  Once the circuit mode connection is established, the connection interface 14 is invited to issue a call request according to the X.25 protocol. Such a request is made in PCV. The destination number of the call request is initialized with the first address of the list called channel B. In case of failure, the connection interface 14 attempts to establish a connection with the next address taken in the list. In case of a new failure, the interface 14 uses the next address and so on until the X.25 circuit is established or until the list is exhausted.

  Once the X.25 communication is established, by the main channel or by the backup channel, authentication is performed, on the initiative of the platform 18, so as to identify the connection interface. This authentication is for example carried out using authentication software means shared between the platforms 18 and the connection interfaces 14. For example, to carry out this authentication, secret authentication mechanisms are used. According to such mechanisms, each connection interface 14 has the same authentication algorithm and a secret key, which are known to the platform 18. The platform 18 transmits to each connection interface 14 a number generated randomly. The interface then performs a calculation from the number received from the platform, the authentication algorithm and its secret key and then transmits the result of the control platform calculation. In parallel, the platform performs the same calculation, an identity between the result from these parallel calculations allowing authentication of the subscriber.

  After establishing the link according to the B-channel and transmitting data, the link is released.

  It will be noted that, during the normal operation of the installation, that is to say in the absence of malfunction, the platforms 18 deal with the state of the data traffic conveyed normally on the permanent virtual circuits, as is known per se and control the entire transmission channel. A break in the transmission channel can thus be detected. This information is then transmitted to the remote monitoring service provider so that the latter is informed of the situation.

Claims (16)

  1. Installation for the transmission of data between monitored premises and one or more remote remote monitoring systems, via a digital ISDN subscriber network (10), an X.25 packet network (12) ) and a frame relay network, characterized in that it comprises at least one pair of communication interface control platforms (18) through which data is transmitted between the monitored premises and the control room. remote monitoring system by dedicated transmission channels, permanent virtual circuit establishment means in the frame relay network between the packet-switched network (12) and the control platforms (18), means for X.25 virtual circuit establishment between monitored premises and control platforms and between remote monitoring systems and control platforms, and a set of gateways (PSX) providing the transfer of data conveyed between the virtual circuits established according to the X.25 protocol and the virtual circuits pre-established in the frame relay network, the control platforms (18) being adapted to detect cuts in the data transmission channels.   2. Installation according to claim 1, characterized in that it comprises at least one pair of platforms comprising a main control platform (PST1) used during normal operation of the installation and a control platform. (PST2) used in case of malfunction of the installation.   3. Installation according to one of claims 1 and 2, characterized in that each monitored premises has a main channel for data transmission and a backup channel used in case of failure of the main channel.   4. Installation according to claim 3, characterized in that the main channel is constituted by a virtual circuit established according to the X.25 protocol in the D-channel of the ISDN network and in that the spare channel is constituted by a permanent virtual circuit established according to the X.25 protocol in the B-channel of the ISDN network.   5. Installation according to any one of claims 1 to 4, characterized in that each platform is connected to the frame relay network (24) by at least two separate connection links (27).   6. Installation according to any one of claims 1 to 5, characterized in that each monitored premises is equipped with a connection interface (14) of a remote monitoring equipment which communicates with the X.25 packet-switched network. via a permanent logical link established in the ISDN digital subscriber network and in that each remote monitoring system is provided with a remote monitoring interface (16) by which it is connected to the X-switched network. .25.   7. Installation according to claim 6, characterized in that each connection interface (14) comprises, stored in memory, a list of X.25 permanent virtual circuit addresses (26) used for the establishment of a communication X .25 by means of the corresponding permanent virtual circuit between said room and the platform.   8. Installation according to claim 7, characterized in that each connection interface comprises, stored in memory, a list of at least two X.25 addresses of permanent virtual circuits (26) connecting a switch of the X packet network .25 forming a packet access point with which the main channel communicates the connection interface and the main control platform and a list of at least two X.25 addresses of permanent virtual circuits back-up connecting said packet access point and the backup control platform.   9. Installation according to one of claims 7 and 8, characterized in that each connection interface comprises, stored in memory, a list of at least two X.25 addresses of permanent virtual circuits (26) backup connecting a second an X.25 packet-switched network switch other than said packet access point switch and with which the spare channel, the connection interface and the main control platform communicate, and a list of at least two X.25 permanent permanent virtual circuit addresses connecting said second switch and the backup control platform.   10. Installation according to any one of claims 6 to 9, characterized in that each connection interface (14) and each control platform comprise the same authentication algorithm for authentication of the connection interface.   11. Installation according to any one of claims 1 to 10, characterized in that the platforms are each connected to a center (20) for managing the platforms and operating a remote monitoring service implemented by the installation.   12. A method of transmitting data between monitored premises and one or more remote remote monitoring systems via a digital ISDN subscriber network, an X.25 packet network and a network frame relay, implemented by means of an installation according to any one of claims 1 to 11, characterized in that it comprises the steps of, for each connection interface (TCT) connected to an equipment of remote monitoring: establishing permanent virtual circuits (26) between the connection interface and the platforms (18); establishing a main data transmission channel between the connection interface and a main platform by using one of the permanent virtual circuits previously established; - monitor the proper functioning of the main channel; and - in the event of a break in the main transmission channel, establish a backup transmission channel using another permanent virtual circuit.   The method as claimed in claim 12, characterized in that permanent logical links are established between the connection interface (14) and a switch (PSX) of the X.25 packet-switched network and virtual circuits according to the X.25 protocol over permanent logical links and over a frame relay network (24) between the packet network and the platforms.   14. Method according to claim 13, characterized in that the virtual circuits according to the X.25 protocol are established from a pre-established permanent virtual circuit addressing, from virtual circuit numbers previously downloaded into the interface. connection (TCT).   15. Method according to any one of claims 12 to 14, characterized in that the main data transmission channel is established using the D-channel of the ISDN digital user network (10), the backup channel used. in case of malfunction being established in the B-channel of the ISDN network.   16. Method according to any one of claims 12 to 15, characterized in that in the event of rupture of a main transmission channel, a backup transmission channel leading to either the main platform or to a main transmission channel is used. rescue platform.