Abstract:
A method and a system opens a network connection using solicitation triggers. A terminal device that is connecting to a communication network sends a network connection request to a mobile network communication device and forms a connection between the terminal device and the mobile network communication device. The terminal device sends a network initialization signal in order to connect to the desired network. The mobile network communication device uses a pre-configured network connection for forwarding the network initialization signal to the desired network. The desired network will respond by returning necessary network information that is forwarded to the terminal device.

Description:
FIELD OF THE INVENTION 
     The invention relates to data communication. The invention relates especially to opening and terminating a network link on demand. 
     BACKGROUND OF THE INVENTION 
     Modern network connectivity includes a plurality of transmission schemes. There are several transmission protocols that can be transferred on different transmission mediums. Portable devices, such as a laptop PC, are typically connected to the Internet by using IPv4 protocol. The most efficient way is to connect by using a regular Ethernet connection or Wireless Local Area Network. However, these technologies are not always available. Thus, there is a need for a connection arranged over a mobile telecommunication network. 
     Typically the connection over a mobile telecommunication network is implemented as a dial up connection. This is supported by modern operating systems. The dial up connection dials to the number of the selected internet service provider and uses the connection for data transfer needs. Typically the dial up connection obtains a dynamic IP-address that is assigned to the terminal device using the dial up connection. 
     In the case of IPv6 protocol, in the establishment of a connection to a router a neighbor discovery protocol for IPv6 is used. Further details of the protocol are disclosed in RFC 1970 (Request for Comments) dated on August 1996 published by Internet Engineering Task Force. Automatic IPv6 Stateless Address Autoconfiguration is disclosed in RFC 1971 dated on August 1996 published by Internet Engineering Task Force. These documents have been revised and replaced by RFC 2461 and RFC 2462, dated on December 1998. 
     Drawbacks of the prior art is that the dial up connection needs to be implemented to support different connection protocols. For example, it is possible that the operating system supports IPv4 and IPv6 protocols but only IPv4 is available for dial up connections. This is a major drawback as there are several benefits in using IPv6 protocol. Typically this problem has been solved by tunneling a protocol over an other protocol. However, this solution is not as efficient as native support without tunneling. 
     Thus, there is a need for a solution allowing for opening and terminating a network link that allows using different transmission mediums with the desired transmission protocol. 
     SUMMARY OF THE INVENTION 
     The invention discloses a method and a system for opening a network connection using solicitation triggers. According to the invention a terminal device that is connecting to a network sends a network connection request to a network connectivity device and establishes a connection between the terminal device and the network connectivity device. Typically the network communication device is a separate mobile device or an internal mobile device or component with network connectivity capabilities. Then the terminal device sends a network initialization signal in order to connect to the desired network. The network connectivity device uses a pre-configured network connection for forwarding the network initialization signal to the desired network. The desired network will respond by returning necessary network information that is forwarded to the terminal device. 
     According to the invention a following method is used. As a first step a connection between the terminal device and the network connectivity device is opened. This could be for example a cable connection, a bluetooth connection or other connection that is known to a person skilled in the art. The second step comprises configuring the network connection by sending a network initialization signal from the terminal device to the network connectivity device. After receiving the network initialization signal, the network connectivity device opens a pre-configured network connection to the network. The network initialization signal will be then sent from the network connectivity device to the network using the pre-configured connection. The network connectivity information will be received as a response from the network to the network connectivity device. The network connectivity information is forwarded to the terminal device. 
     In an embodiment the invention is implemented as software that is executed in the network connectivity device. The network connectivity device is configured to listen the terminal device for possible connection requests. When a connection request is received, the software will start an opening procedure that comprises receiving the actual network initialization signal. The network connectivity device then forwards the network initialization signal by using a pre-configured network connection and waits for response that is forwarded to the terminal device. In a further embodiment the connection is terminated after a predetermined time of inactivity. The activity may be requested before terminating the connection. 
     In an embodiment of the invention several terminal devices are connected to one network connectivity device. In the case of inactivity the connection will be terminated if all connected terminal devices are detected inactive. 
     The benefit of the invention is that it allows different types of terminal devices to use different types of networks easily. The terminal device may use any network connection solicitation that it is capable of using, and the network connectivity device may be configured to establish and route the connection. It is simpler to implement this kind of functionality to the network connectivity device than to a terminal device that would require changes in network connectivity layers and in even in standards. A further benefit of the invention is that the user does not need to make any configurations to the terminal device but he/she can request the needed configuration information from the network. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and constitute a part of this specification, illustrate embodiments of the invention and together with the description help to explain the principles of the invention. In the drawings: 
         FIG. 1  is a block diagram of an example embodiment of the present invention, 
         FIG. 2  is a signaling chart of an example implementation presented in  FIG. 1 , 
         FIG. 3  is a signaling chart of an example implementation presented in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
     In  FIG. 1  a block diagram of an example embodiment of the present invention is disclosed. The example embodiment comprises a workstation  10 , a mobile device  11 , a mobile network  12 , a serving node  13  and a target network  17 . The workstation is connected to the mobile device by available connectivity means  14 . These can be for example a wireless connection or a wired connection. Typically the workstation is a portable computer and the mobile device is a data communications enabled mobile telephone, but it is obvious to a person skilled in the art that also different types of terminals may be used. Typically the connectivity means  14  are enabled only when needed as there might be expenses for keeping the connection opened, or there might be bandwidth limitations that require terminating the connection for allowing others to have the best possible quality of service. The mobile device  11  is arranged to function as a network connectivity device. 
     The mobile device  11  is connected to the mobile network  12  by the connection  15 . The type of the connection depends on the type of the mobile device. Typically the connection  15  is a pre-configured network connection. Thus, there is no need to choose connectivity parameters. However, the invention does not limit the type of the connection. Thus, it is possible to use for example a packet switched wireless local area network or a circuit switched data call. In case there is no pre-configured connection available, the user may choose the connection type. The mobile device includes means for receiving, transmitting and forwarding data communication. Thus, the mobile device is able to receive connection requests and network initialization signals and able to act accordingly to fulfill the requests. 
     The further connection  16  that is arranged to connect the mobile network to the target network  17  can be any available network known to a person skilled in the art. In the example of  FIG. 1  there is the separate serving node  13 , which is the case for example in the GPRS (General Packet Radio System). 
       FIG. 2  discloses a signaling chart of an example implementation presented in  FIG. 1 , wherein a workstation  20 , a mobile device  21 , a mobile network  22  and a serving node  23  correspond to those of  FIG. 1 . In  FIG. 2  the network initialization signal is an IPv6 router solicitation According to the example the workstation  20  is initializing a network connection. The workstation  20  connects to the network via the mobile device  21 , signal  24 . After establishing the connection between the workstation and the mobile device, a router solicitation message is sent, signal  25 . This signal is typically an IPv6 router solicitation. When the mobile device receives the router solicitation, it establishes a pre-configured connection to the mobile network, signal  26 . Using the pre-configured connection, the mobile device forwards the router solicitation to the serving node, signal  27 . 
     The serving node establishes the connection and informs the mobile node with a router advertisement, signal  28 . The router advertisement is forwarded to the workstation, signal  29 . After receiving the advertisement, the workstation is connected to the network and may start the communication with other devices, signal  210 . If the signal  29  is not received, the mobile device may use a local address, such as IPv6 link-local address. 
     In another embodiment the network connection is already opened by the mobile device. For example, if two workstations desire to share the connection or the connection is always open, the connection from the mobile device to the mobile network needs not to be established twice. The end user does not notice any difference if the connection has been already opened. It is possible to arrange a network address translation service to the mobile device. The network address translation is typically used when communicating with target network instead of one link. Thus, the mobile device is able to serve several workstations that have their own addresses even if the used protocol would not support it. However, if the user does no want to use network address translation, further signaling is required for obtaining a proper network address and connection. 
       FIG. 3  discloses a signaling chart of an example implementation presented in  FIG. 1 , wherein a workstation  30 , a mobile device  31 , a mobile network  32  and a serving node  33  correspond to those of FIG.  1 . The signaling chart of  FIG. 3  discloses terminating the connection that was opened in the signaling chart of  FIG. 2 . If the communication represented by signal  34  is not active during pre-determined timeout, the mobile device sends a neighbor solicitation, signal  35 . In the example of  FIG. 3  the workstation first responds to the solicitation by sending an activity indication, signal  36 . After a second timeout the mobile device sends again the neighbor solicitation, signal  37 . The workstation does not respond to the solicitation and the mobile device terminates the network connection, signal  38 . 
     In another embodiment of the invention the mobile device is arranged to send an inactivity indication to indicate that it does not need the network connection anymore. If the mobile device serves a plurality of workstations, the connection is terminated when there are no active workstations left. 
     In another embodiment, the invention is implemented as a computer program that is executed in the mobile device. In accordance with  FIG. 2  and the embodiment, the mobile device  21  is configured to expect a connection establishment request  24  and a router solicitation  25  from the workstation  20 . In the embodiment the mobile device  21  opens a pre-configured network connection  26  and forwards the router solicitation  27 . After forwarding the router solicitation  27  the mobile device  21  is arranged to expect a router advertisement  28  that is forwarded back to the workstation  20 . When the workstation  20  has received the router advertisement  29 , the network connection has been set up. In accordance with  FIG. 3  and the embodiment, the mobile device  31  is arranged to check the activity of the workstation  30  if the communication represented by signal  34  is active during a pre-determined timeout. If the workstation  30  is still active, the connection is maintained. Otherwise the communication is terminated. In case there are several workstations connected to the mobile device  31 , the mobile device  31  terminates the connection when there are no active workstations left. 
     It is obvious to a person skilled in the art that with the advancement of technology, the basic idea of the invention may be implemented in various ways. The invention and its embodiments are thus not limited to the examples described above; instead they may vary within the scope of the claims.