Patent Publication Number: US-9900373-B2

Title: System for providing a service, such as a communication service

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Application is a Section 371 National Stage Application of International Application No. PCT/FR2010/050522, filed Mar. 23, 2010 and published as WO 2010/109128 on Sep. 30, 2010, not in English. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     None. 
     THE NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT 
     None. 
     FIELD OF THE DISCLOSURE 
     The present disclosure relates to a system for providing a service, such as a communication service. In particular, the disclosure relates to a system for telemonitoring, in particular via the Internet. 
     BACKGROUND OF THE DISCLOSURE 
     Today&#39;s communications networks are supporting ever more numerous services using in particular the Internet and relying especially on an architecture called Client-Server. 
     This Client-Server architecture designates a mode of communication between several nodes of a communication network which distinguishes one or more terminal nodes (computers, IP telephones, IP camera, IP sensors, etc.) from a server node (service platform, contents server, etc.). This architecture is based on the fact that each terminal node comprises a client for dispatching requests to a server and that the server is initially passive while listening to the client terminal nodes. Depending on the applications, the server is optionally specialized as an applications server, file server, terminal server, electronic messaging server, videomonitoring platform. 
     In this case, the client sends requests to a server, which may be a Web server or http server, the name of the communication protocol used at the level of the application network layer. The role of the server is to ensure the processing of the request and to return the response to this request. The dialog between client and server is often carried by a transport network layer, such as the TCP layer, the name of a communication protocol: the TCP protocol. The TCP protocol is a reliable transport protocol according to RFC 793. 
     Thus, the respective Client and Server modes of operation of the nodes apply the transport and application network layers as a whole, which correspond, for example, to the respective TCP and HTTP protocols: the client of a service is also the client in terms of connection, the server of a service is also the server in terms of connection (The transport layers of the client and of the Server need to be connected to allow the service). 
     In the case of a TCP connection in a network architecture, the server operates in passive opening mode, that is to say that a point of access to a TCP connection is open, namely that it is made available to a TPC connection, and the server places itself on passive standby awaiting connection requests. The client, for its part, effects active opening, namely that it establishes a connection with the server by dispatching a request for connection to the server comprising its client initial sequence number, that the server responds thereto by an acknowledgment of receipt of the client request with its server initial sequence number and the incremented client initial sequence number and that the client acknowledges receipt with the incremented server sequence number and client sequence number incremented again. 
     Ever more terminals are being installed in private communications networks or LANs (Local Area Networks). These private networks are linked to the public communication network to which the servers generally belong or to the public network ensuring the hookup between the LAN and the network environment hosting the servers by way of access device also called access gateway. The access gateway permits the accessibility of the communication terminals of the private networks of private communication remotely through a public communication network such as an open and/or shared network, in particular of Internet type. For this purpose, the access gateway ensures the interconnection between the private network hosting these terminals and the public communication network. In particular, the gateway implements functions for network address translation and functions for filtering the incoming communications entering the private communication network. 
     The network address translation functions (NAT or else NAT/PAT for network address to port address translation) have made it possible to limit the number of public IP addresses required in order to individually reach the various terminals connected to this network by establishing a correspondence between network addresses and port addresses. Thus, when such address translation functions are implemented, a terminal of a private communication network placed behind the access gateway is not accessible from the public communication network as long as the translation functions are not configured in the access gateway for this terminal. 
     In certain services, such as a telemonitoring or video monitoring service, it may be useful for the server to be able at any moment to command a video stream upload or control the motion of a camera. And, if this camera&#39;s address translation functions are not configured in the access gateway placed in front of this camera, the telemonitoring server can do nothing. 
     Moreover, the filtering functions implemented at the level of the access gateways making it possible to secure the private communication network in relation to the public communication network are here again in order to limit the outside accesses entering the private communication network. Therefore if these filtering functions are not configured, the telemonitoring server does not have access to the cameras allowing it to operate the monitoring. 
     Now, hitherto the procedures for configuring the address translation and filtering functions remain dependent on the implementations of the various gateway providers: they are therefore APIs or methods implemented in the form of proprietary computer programs. This results in difficulties, or indeed impossibilities for the service provider server to configure gateways of heterogeneous origin. The gateways can also be configured manually. However, the problematic issue of modifying the configuration of these gateways is nonetheless not solved. 
     Furthermore, the correspondences between the network addresses and the port addresses and the filtering are activated only in a temporary manner in most cases, the traffic stream reinitializing the temporary activation timer. This temporary activation is incompatible with certain services, in particular monitoring services, which require the server to search repeatedly (whenever, at any moment, periodically, etc.) for elements at terminals placed behind such access gateways after a long period of traffic inactivity that has caused the deactivation of the correspondences. 
     Mechanisms such as the heartbeat (or keepalive) mechanism make it possible maintain the crossing of the NATs and therefore the connection between the server and the client. These mechanisms are based on periodic messages exchanged between the server and the client on the initiative of the server when the service requires a permanent connection. These mechanisms pose problems of scalability, that is to say problems of dimensioning when the server dialogs for this service with a large number of clients since the server must then manage the monitoring and the maintaining of as many connections as clients. 
     The right to configure the translation and filtering functions of an access gateway can also be legally or contractually prohibited to the service provider, in particular when the service provider is not the owner and/or operator of the access gateway. This limits the provision of certain services only to the clients of the same access provider. 
     SUMMARY 
     A subject of an exemplary embodiment of the invention is a terminal device of a communication network comprising: 
     means for establishing a connection with a service provider device through at least said communication network, and 
     application server means able to receive a service request from said service provider device on said connection. 
     Thus, the terminal device can make itself accessible to a service provider device as soon as it is put into service. Furthermore, the fact that the terminal device is at the initiative of the connection for a service secures access to the data of the terminal device relating to this service. 
     Advantageously, said communication network is a private communication network comprising an access device allowing the means for establishing a connection to establish said connection between said terminal device and said service provider device through the private and public communication networks. 
     Thus, the connection being an outgoing connection, it is not filtered by the access device and the terminal device can always be accessed by the service provider device to respond to a service request. In addition, the access device continues to play its role of securing the private communication network. 
     Furthermore, this connection allows, advantageously, bidirectional traffic between the terminal device and the service provider device. 
     The subject of an embodiment of the invention is also a service provider device of a communication network comprising: 
     connection means to allow a terminal device to establish a connection with said service provider device through at least said communication network, and 
     means for sending a service request on said connection to application server means of the terminal device. 
     The subject of an embodiment of the invention is also a method for the putting into service of application server means of a terminal device of a communication network comprising the establishment of a connection by said terminal device with said service provider device through said communication network, said connection allowing said service provider device to send a service request to said application server means of said terminal device. 
     Advantageously, the connection establishment is renewed after each dropout of said connection between said terminal device and said service provider device. 
     Thus, the service provider device can always access the terminal device even after a reinitialization of the terminal device, a network dropout etc. 
     Advantageously, said connection is a connection in permanent mode. 
     Thus, if the service requires exchanges interspersed with significant silence time slots causing a connection dropout in the case of standard connection, the terminal device restores the connection with the service provider device less frequently. 
     Advantageously, said connection is an encrypted connection. 
     Thus, the data exchanged on the connection are readable only by the terminal device and by the service provider device. 
     Another subject of an embodiment of the invention is a computer program comprising program code instructions for the execution of the steps of the method for the putting into service of application server means of a terminal device when said program executed by a processor. 
     The subject of an embodiment of the invention is also a system for providing a service in a communication network comprising at least this terminal device and this service provider device. 
     The subject of an embodiment of the invention is also a telemonitoring system comprising at least one video camera comprising this terminal device and a videomonitoring service platform comprising this service provider device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The characteristics and advantages will be more clearly apparent on reading the description, given by way of example, and the figures pertaining thereto which represent: 
         FIG. 1 , a block diagram of a terminal device, 
         FIG. 2 , a block diagram of a service platform, 
         FIG. 3 , an architecture diagram of a service provision system in a public communication network, 
         FIG. 4 , an architecture diagram of a service provision system with at least one terminal device placed behind an access device, 
         FIG. 5 , a diagram of the exchanges in particular during the putting into service of the application server means of a terminal device. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     An embodiment of the invention will be more particularly described within the framework of a videomonitoring application. Generally, it applies in any field of application where a terminal operates by exchanging data with a remote item of equipment on a service. Other applications such as remote home-automation services, security services, etc. will also be able to use an embodiment of the invention. 
     An embodiment of the invention proposes to provide a new structure of the devices, seen from the Client-Server architectures in terms of connectivity and application. 
       FIG. 1  illustrates an exemplary terminal device  1 , in particular an IP terminal (the abbreviation standing for Internet Protocol). The terminal device operates in “server” mode at the application level by virtue of the application server  12 . Thus, it is possible to dispatch a service request to the terminal device  1 , in particular to its application server  12 . The application server  12  of the terminal  1 , once reached, responds the service request received. 
     In order to make provision to reach the application server  12  remotely and at any moment realizing the role of server of the application server  12 , the terminal device  1  establishes a connection  31  by virtue of a device for establishing a connection  11  with a remote service provider device (not illustrated in  FIG. 1 ). 
     To establish this connection, the terminal device  1  knows, prior to the establishment of the connection  31 , the service provider device  2  with which it desires to establish this link, for example having previously identified it by its address. In the case of a videomonitoring application, the terminal device  1  can either receive this identification by manual input, or by direct transmission or via a network during registration with the videomonitoring service, etc. 
     The terminal device  1  then mixes the roles of “client” and of “server” according to the application level: 
     from an application service point of view (at least protocols and services, in particular http service), the terminal device  1  is in “server” mode. It comprises application servers  12  and  17 , such as at least one WEB or http server  12  and, if appropriate, a streaming server  17  or any other type of application in particular Internet service such as an FTP server (not illustrated). 
     From a connectivity point of view, in particular TCP connectivity, the terminal device  1  is positioned in “client” mode. For this purpose, the terminal device  1  comprises a device for establishing a connection  11  which is coupled to the input/output means  13 . In this case, the device for establishing a connection  11  of the terminal device  1  is at the initiative of the connection  31  of the terminal device  1 . 
     Within the framework of the videomonitoring application, the terminal device  1  is a camera comprising capture device  16 , optionally a storage device  15  for storing the captured images and a displacement device  14 . Thus the application server  12  can receive requests for services such as: 
     video stream send requests 
     camera displacement commands, in particular for cameras of PTZ type, 
     requests for a previously recorded video file 
     etc. 
     In the case of a video stream send request, the application server  12  can, in particular, either take responsibility for transmitting the video stream originating from the capture device  16  via the input/output device  13  and the connection  31 , or order streaming-server  17  to perform this transmission of the video stream originating from the capture device  16  via the input/output device  13  and the connection  31 . 
     In the case of a camera displacement command, the application server  12  can, in particular, transmit a command cmd to the displacement device  14  so as to orient the camera  1  with respect to the object to be filmed. Thus, the camera can constantly be controlled remotely by virtue of an embodiment of the invention. 
     In the case of a request for a video file, the application server  12  can, in particular, search the database  15  either for images to form a video file corresponding for example to a time slot, or for a stored video file so as to transmit it via the connection  31 . 
       FIG. 2  illustrates a service provider device  2 , constituting for example, the service provider device with which the terminal device of  FIG. 1  dialogs via a connection  31 . 
     The service provider device  2  comprises connection device  21  connected to the input/output device  23  able to receive a connection establishment request and allow the establishment of the connection  31 . 
     The service provider device  2  furthermore comprises a transmitter for sending a service request  22  by virtue of the input/output device  23  via a connection  31  to a terminal device. 
     In the case where the service provider device  2  constitutes a videomonitoring service, the transmitter  22  are able to send service requests such as 
     video stream send requests 
     camera displacement commands, in particular for cameras of PTZ type, 
     requests for a previously recorded video file 
     etc. 
     Optionally, the service request transmitter  22  also constitutes a receiver for receiving a response to said service requests. 
     For example, in the case of a video stream send request, the service request transmitter  22  are able to receive the requested video stream sent by the application server  13  or  17  of the terminal device  1  via the connection  31 . 
     If appropriate, the service provider device furthermore comprises a processor connected to the service request transmitter  22  so as to receive data to be processed as a function of the responses to said service requests. The processor  28  utilizes the resources of the cameras and can comprise means for processing the image, means for searching the image for specific data, archiving means, etc. 
       FIG. 3  illustrates an architecture of a service provision system in a public communication network  3 . 
     The service provider architecture comprises: 
     A terminal device  1  consisting of various layers: a physical layer  19   1 , a level 2 network layer  19   2 , a level 3 network layer  19   3 , a “client” mode connection layer comprising the device for establishing a connection  11 , a “server” mode application layer comprising at least application server  12 . Within the framework of the video monitoring application, the terminal device  1  comprises sensor  16 . 
     A service provider device  2  consisting of an item of equipment of the public network  3  (or shared network) remote in this network from the terminal device  1  and constituting a service platform. This service provider device  2  likewise consists of various layers: a physical layer  29   1 , a level 2 network layer  29   2 , a level 3 network layer  29   3 , a “server” mode connection layer comprising connection means  21 , a “client” mode application layer comprising at least means for sending a service request  22 . 
     The device for establishing a connection  11  of the connection layer, in particular TCP client, of the terminal device  1  sends a connection request req 1  to the connection means  21  of the connection layer, in particular TCP server, of the service provider device  2  (previously identified). This request req 1  triggers the establishment of the connection  31 , in particular permanent TCP connection, of the terminal device  1  with the service provider device  2  through the network  3 . 
     A TCP permanent connection implements, in particular, a mechanism such as the “keepalive” mechanism so as to allow permanent accessibility from the remote service provider device  2 . 
     The permanence of the connection is at the initiative of the application server  12  for the services requiring such a connection. Thus, it is the connection establishment device  11  of the terminal device which implement the mechanisms such as “keepalive” by monitoring the connection and by regularly or periodically exchanging messages with the connection means  21  of the service provider device  2 . The permanence mechanism being the responsibility of the terminal device  1 , no dimensioning problem arises. 
     By way of this connection  31 , the service provider device  2  is then able to contact the terminal device  1  at any moment in respect of a service request req 2  sent by its service request sending means  22  to the application server  12  of the terminal device. As connection  31  is bidirectional, it allows the application server  12  to respond to the service request req 2 . 
       FIG. 4  illustrates an architecture of a service provision system with at least one terminal device placed behind an access device. 
     Here again the service provider architecture comprises: 
     A terminal device  1  consisting of various layers: a physical layer  19   1 , a level 2 network layer  19   2 , a level 3 network layer  19   3 , a “client” mode connection layer comprising a device for establishing a connection  11 , a “server” mode application layer comprising at least application server  12 . Within the framework of the video monitoring application, the terminal device  1  comprises a sensor  16 . 
     A service provider device  2  consisting of an item of equipment of the public network  3  (or shared network) remote in this network from the terminal device  1  and constituting a service platform. This service provider device  2  likewise consists of various layers: a physical layer  29   1 , a level 2 network layer  29   2 , a level 3 network layer  29   3 , a “server” mode connection layer comprising connection means  21 , a “client” mode application layer comprising at least means for sending a service request  22 . 
     The device for establishing a connection  11  of the connection layer, in particular TCP client, of the terminal device  1  send a connection request req 1  to the connection means  21  of the connection layer, in particular TCP server, of the service provider device  2  (previously identified) via an access device such as a gateway (in particular an ADSL gateway such as a Box)  5  which filters the incoming information entering the local network  4  or private network or LAN (for Local Access Network). This request req 1  triggers the establishment of the connection  31 , in particular permanent TCP connection, of the terminal device  1  with the service provider device  2  through the network  3 . As request req 1  is an outgoing request, it is not filtered by the access device and thus allows the systematic establishment of the connection  31  which would not be the case if the connection establishment request originated from the service provider device  2 . 
     By way of this connection  31 , the service provider device  2  is then able to contact the terminal device  1  at any moment in respect of a service request req 2  sent by its service request sending transmitter  22  to the application server  12  of the terminal device. Indeed, once the connection  31  with the service provider device  2  is established, the incoming requests originating from the service provider device  2  via this connection  31  are automatically authorized to enter the local network  4  by the access device  5 . 
     The use of an access device  5  allows global filtering, for example NAT, of the incoming requests entering the private communication network  4  and limits the risks of intrusion, in particular by deploying a process for identifying the remote service provider device  2  (process prior to the establishment of a connection  31  such as envisaged in the literature in respect of the crossing of the NATs during TCP connection establishment). 
     The establishment of the connection  31  on the initiative of the terminal device  1  makes it possible to configure a correspondence table or IP address mapping in accordance with the general operating principles of the NATs in the access device  5 . This mapping retains the benefit of using only a single IP address, the public IP address of the access device  5 , to reach the terminal. Thus, within the framework of our application, the addressing of the cameras is conditioned by the use of a single public IP address, in this instance that of the access device  5 : the ADSL gateway. The solution is compatible whatever the access device. 
     The use of a connection  31  made secure by encryption, in particular encrypted TCP connection SSL and associated protocols (TLS, DTLS), makes it possible to strengthen the security of the transmission, in particular to guarantee the confidentiality of the videos, while using the same principle of an embodiment of the invention of server client inversion between the connection layer ( 11  on the terminal device side and  21  on the service provider device side) and the application layer ( 12  on the terminal device side and  22  on the service provider device side). 
       FIG. 5  illustrates exchanges, in particular during the putting into service of the application server  12  of a terminal device  1 . During the putting into service of the application server  12  which takes place, for example, during the putting into service of the terminal device  1 , during the reinitialization of the terminal device  1 , after a network dropout, etc., the device for establishing a connection  11  of the terminal device transmit via the access device  5  on the network  3  to a previously identified service provider device  2  a connection establishment request req 1  c. As means of connection  21  of the service provider device  21  are in passive opening O, they are listening to such a request and respond thereto ack 1  s. Subsequent to the response ack 1  c of the connection establishment device  11  of the terminal device to the response of the service provider device  2 , the connection is established represented in the figure by the tunnel between the connection layers  11  of the terminal device  1  and  21  of the service provider device  2 . 
     By this connection, the service provider device  2  by its service request sending transmitter  22  can transmit requests for services to the application server  12  of the terminal device  1 , such as: 
     displacement commands for the camera constituting the terminal device  1  req 2  cmd (14, R30°) (here, command for translation by 14 units and for rotation to the right by 30°) to which the application server  12  can respond, for example, by transmitting the stream of the displaced camera f/cmd; 
     requests for a previously recorded video file req 2  fic(d,h) to which the application server  12  respond by transmitting the requested file fic(d,h); 
     video stream send requests req 2  f to which the application server  12  respond by transmitting the requested stream f 2  (an end-of-stream request req 2  stop f of the service request sending transmitter  22  making it possible to end the transmission of the stream); 
     etc. 
     The principle used by an embodiment of the invention to make the terminal device establish the connection so as thereafter to receive service requests from a service provider device make it possible to establish, for this identified service provider device, permanent and secure accessibility to the terminal device via in particular an open (Internet) or shared network. Furthermore, the proposed solution is independent of the gateways and transparent to the latter and scalable. 
     In the case of terminal devices belonging to private communications networks and placed behind access devices, an embodiment of the invention affords, within the framework of service provision calling upon such terminals, a universal response to the problematic issue of crossing of the NATs. 
     Although the present disclosure has been described with reference to one or more examples, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the disclosure and/or the appended claims.