KR100610030B1 - A radio communication system and gateways, radio intelligent terminals and radio communication - Google Patents

Abstract

In a communication system for establishing communication between a wireless information terminal and a server through a gateway, it is necessary to smoothly switch when a need arises for switching the gateway to be used for another reason for some reason.

When the switching instruction of the gateway is instructed, the information notification means notifies the wireless information terminal of the occurrence of the switching of the gateway. In the above information, when only switching of the gateway is notified, in addition to the switching, information necessary for the radio information terminal to communicate with the server through the switching gateway may be included, for example, an address of the switching gateway. . When the information is notified to the terminal, the restarting means of the radio information terminal stops the communication with the gateway of the switching source and executes the resumption procedure of communication with the gateway of the switching destination.

Gateway, wireless information terminal, server, information notification means, transaction, information exchange means, capability, switching source, switching destination

Description

A RADIO COMMUNICATION SYSTEM AND GATEWAYS, RADIO INTELLIGENT TERMINALS AND RADIO COMMUNICATION}

1 is a configuration diagram of a wireless network through a public network or a premises network of a gateway sharing a server according to an embodiment of the present invention;

2 is a configuration diagram of a wireless network through a public network or a premises network in which the gateway itself according to an embodiment of the present invention has information;

3 is a configuration diagram of a wireless network through a public network or a premises network of a gateway connected to another server according to an embodiment of the present invention;

4 is a configuration diagram of a wireless network in which the gateway itself according to an embodiment of the present invention does not go through a public or premises network having information;

5 is a configuration diagram of a wireless network via a public network or a premises network in which a gateway sharing a server according to a conventional form is shown.

6 is a configuration diagram of a wireless network in which the gateway itself according to a conventional form does not go through a public or premises network having information;

7 is a diagram illustrating positioning of a session layer protocol and a session layer management entity in a protocol stack of a terminal and a gateway;

FIG. 8 is a conventional gateway switching sequence diagram in the configuration of FIG. 6; FIG.

Fig. 9 is a gateway switching sequence diagram according to the embodiment of the present invention in the configuration of Fig. 1;

Fig. 10 is a gateway switching sequence diagram according to the embodiment of the present invention in the configuration of Fig. 2;

Fig. 11 is a gateway switching sequence diagram according to the embodiment of the present invention in the configuration of Fig. 3;

12 is one embodiment of a gateway switching sequence according to the present invention;

13 is a sequence diagram when there is communication between a terminal and a server during negotiation between gateways;

14 is a sequence diagram showing stop timings of gateways connected to multiple terminals;

15 is a sequence diagram in the case of receiving a switchover rejection by negotiation with a switchover gateway and switching a connection with another gateway;

16 is a sequence diagram when the switching destination gateway has the terminal capacity;

17 is a sequence diagram when displaying a terminal application that is switching gateway.

Fig. 18 is a gateway switching sequence diagram according to the embodiment of the present invention in the configuration of Fig. 1;

19 is one embodiment of a gateway switching sequence according to the present invention;

20 is a retransmission control sequence diagram of a gateway and a terminal according to the present invention;

21 is a sequence diagram of transaction processing that occurs after a gateway change notification;

Fig. 22 is a sequence diagram of a transaction process for not receiving data with respect to a request generated before a gateway change notification.

23 is a sequence diagram of a transaction process for receiving data with respect to a request generated before a gateway change notification;

24 is a diagram illustrating a gateway switching sequence according to the fifth embodiment of the present invention;

25 is a sequence diagram of a transaction process occurring after the gateway change notification by the gateway changeover according to the fifth embodiment according to the present invention;

Fig. 26 is a sequence diagram of transaction processing in which gateway switching according to Embodiment 5 of the present invention does not receive data with respect to a request that occurred before the gateway switching notification;

Fig. 27 is a sequence diagram of a transaction process in which data is received for a request that occurred before the gateway change notification in the gateway changeover according to the fifth embodiment according to the present invention;

* Description of the sign *

1,14,15,17: Wireless terminal 2,10: Wireless base station

3: public network 4,5,16: gateway according to the present invention

6,9: Server 7,8: Information for running terminal applications

11, 12: conventional gateway 13: connection means between gateways

14: connection method between gateway and server

The present invention relates to a wireless communication system, and more particularly, to a method for switching a gateway of a wireless communication system, and a gateway, a wireless information terminal, and a communication system used in the method.

In recent years, with the rapid spread of so-called Internet services such as the World Wide Web (WWW), expansion of computer networks and diversification of connection types have been progressing.

In accordance with this, gateways for network connection of information terminals, servers, and the like are also required to have improved processing capacity and increased functions.

An example of the diversification of connection types is the use of mobile communication networks, such as cellular telephone networks, by adding wireless communication capabilities to information terminals, and wireless networks, so-called mobile computing, which can be used when not directly connected to a mobile or computer network. Can be.

5 and 6 are conceptual diagrams showing a communication mode using the wireless network.

5 shows a configuration of a wireless network using a public network or a premises network.

When a user wants to execute an application of the terminal 1, the terminal 1 is connected to the server 6 via the radio base station 2, the network 3 and the gateway 11 or the gateway 12. It is connected to the server and communicates with this server to execute the application.

FIG. 6 shows a form of a wireless network having a server function in the gateway itself, for example, in an office, and not through a network operating in a narrower range than in FIG. 5. That is, the terminal 1 and the gateway 11 or the gateway 12 communicate with each other via the radio base station 2 and execute an application.

In the above wireless network, it is necessary to temporarily stop the operation of the gateway in order to expand the function of the gateway according to the change of the network or to perform regular maintenance. In order to continue network operation even when the gateway is stopped in this way, as shown in Figs. 5 and 6, a plurality of gateways are prepared. For example, when one gateway 11 is stopped, the other gateway 12 The gateway connection switching function, which enables the terminal and the server to communicate with each other, is required in the network.

Here, the outline of the communication protocol between the terminal and the gateway will be described with reference to FIG.

The application 71 on the terminal side is a program that the user directly operates, such as a WWW browser, for example, and the example of the application 75 on the gateway side (here, shown in FIG. 6 in which the server function is built into the gateway) is used as an example. ) Is a program for exchanging information with a terminal-side application such as WWW server software.

The session layer protocol means 72 is a protocol for providing various applications 71 and 75 with a common transfer control function, for example, a transfer of data in a short-circuit unit and a transfer process in a short-circuit unit. In addition, the session layer management entity 73 manages system resources (e.g., memory) used by a plurality of session processes and the like generated by data communication between the terminal and the server, and manages the system-wide processing (e.g., notification of gateway switching timing). Program). The lower protocol 74 is a program and an apparatus for communication control.

Fig. 8 shows a communication sequence of the communication mode of Fig. 6.

The session layer protocol means 802 of the terminal 1 is in communication 803 with the session layer protocol means 804 of the gateway 11 because it executes the application 801. At this time, when an instruction 808 for gateway switching is issued from the operator to the management entity 805 of the gateway 11, the management entity 805 passes through the session layer protocol means 804 and performs a session of the terminal 1. A cutting notification 809 is issued to the layer protocol means 802. As a result, the session layer protocol means 802 of the terminal 1 may or may not display the cut-off display 810 on the application 801, and the application 801 stops executing.

When the gateway 11 issues the cutting notification 809, the gateway 11 is stopped by the operator's operation or the function of the gateway 11. Next, the terminal 1 requests the session layer protocol means 802 to reconnect 811 to the gateway 12 based on the information held therein in order to execute the suspended application 801 again.

After the session 812 is established between the session layer protocol means 802 and the session layer protocol means 806 of the gateway 12, the communication 813 is established and the execution of the suspended application 801 is resumed. This becomes possible.

In the above-described conventional technique, when switching the gateway connection by stopping the gateway, there is a problem that the terminal must terminate the application currently being executed, reconnect to another gateway, and then re-execute the application from the beginning.

In addition, as described above, in order to change the gateway and re-execute the application, it is necessary to store address information of a plurality of gateways to be changed in advance in the terminal, but information necessary only when changing the connection of the gateway is always present in the terminal. The use of verbose resources to remember is a problem for terminals requiring small multi-functions.

In addition, whenever there is a change in the network configuration such as the addition or deletion of a server or a gateway, there is a problem that the address information of the tactical gateway of the terminal must be updated. In addition, when the connection is changed to another gateway, information such as port number, address, and capability of the terminal needs to be negotiated between the terminal and the gateway of the switching destination, and this negotiation takes time. Another problem is that it takes longer to rerun.

If, as a result of the negotiation between the terminal and the gateway of the switching destination, the gateway does not have the capacity or resources to accommodate the communication capability (capability) of the terminal, the connection with the gateway is terminated and the capability of the terminal is terminated. Another problem is that an extremely poor work efficiency situation may occur in which an attempt is made to connect to a separate gateway until an acceptable gateway is found.

SUMMARY OF THE INVENTION The present invention has been made to solve and improve the above-mentioned problems, and it is not necessary for the terminal to always maintain information of a plurality of gateways by changing the connection destination gateway without ending application execution in the terminal, and even if the network configuration changes. It is an object of the present invention to provide a method and apparatus for dynamically switching a gateway, which enables a terminal to easily cope with it and shortens the negotiation time of the connection between the terminal and the gateway, thereby enabling the terminal to be connected to a gateway having the capability or resources to accommodate the terminal at one time. It is done.

In order to achieve the above object, the present invention employs the following configurations.

First, the present invention is applied to a communication system for establishing communication between a wireless information terminal and a server through a gateway, when the communication system needs to change the gateway to be used to another gateway for some reason.

First, in the present invention, the information notification means notifies the occurrence of gateway switching to the radio information terminal when the switching instruction of the gateway is given.

In the above information, when only switching of the gateway is notified, in addition to the switching, information necessary for the wireless information terminal to communicate with the server through the switching gateway may be included, for example, the address of the switching gateway. .

When the terminal is informed of the information necessary to communicate with the server through the gateway of the switching destination, the restarting means of the wireless information terminal stops communication with the gateway of the switching source and resumes communication with the gateway of the switching destination. Run the procedure. On the other hand, when the wireless information terminal is not receiving a service from the server, there is a case where the switching notification is received at the gateway of the switching source. At this time, the communication start means of the radio information terminal activates communication with the server via the gateway of the switching destination.

When changing the above-mentioned gateway, the gateway of the switching source in advance informs the gateway of the switching destination of information necessary for communication with the radio information terminal by means of the information exchange means and confirms that it may start communication from the gateway of the switching destination. Can be placed

In the case of having information exchange means between the gateways, the capability of the wireless switching terminal can be notified from the gateway of the switching source to the gateway of the switching destination together with the address of the radio information terminal. As a result, when the switching destination gateway is inferior in its own capability, the switching destination notifies the gateway of the switching source.

The gateway of the switching source notifies the radio information terminal of the capping capability of the upper limit, and the radio information terminal resumes communication through the gateway of the switching destination with this capping capability. However, when communication with the upper limit capability cannot be performed, communication is stopped by the determining means of the switching source or the determining means of the radio information terminal.

There may be an incomplete transaction remaining in the interruption process.

If the information exchange means is not provided, the gateway of the switching source notifies the server corresponding to the switching destination gateway of the address of the response destination (wireless information terminal) before restarting the radio information terminal. You can complete the transaction. In the case of having information exchange means, the incomplete transaction can be completed at the time of resumption by notifying the gateway of the switching destination from the switching gateway.

Before and after the information exchange, there is a change in the communication state between the wireless information terminal and the server. In this case, the resumption order status is notified to the gateway of the switching destination in the resumption order.

Here, the above-mentioned term becomes as follows in the following description and drawings.

Information notification means: The switch instruction is from the operator of the gateway to the gateway of the switch source. The management entity of the switchover gateway receives the above instruction, edits the notification content to the radio information terminal, and notifies the terminal of its meaning through the session layer protocol. Therefore, the information notification means is constituted by the management entity of the gateway and the session layer protocol.

Information exchange means: Both the switching source gateway and the switching destination gateway are provided to exchange information such as the address of the wireless information terminal between the two management entities. Since the management entity is naturally edited by the management entity, the information exchange means is also configured by the management entity. In the figure, information is exchanged between management entities, but information exchange may be performed from the management entity via the session layer protocol.

Resume start means: The session layer protocol of the wireless information terminal receives information such as the address of the switching source gateway, performs an interruption process with the gateway of the switching source, and executes a restart procedure. Therefore, the restart start means is constituted by the session layer protocol. On the other hand, the communication start means differs from the restart start means in that the interrupt processing is not performed. In this case, the restart layer means also constitutes the session layer protocol.

Determination means: As described above, the capability of the radio information terminal and the switchover gateway are compared to determine whether communication between the radio information terminal and the switchover gateway is possible. There may be a case where the terminal is provided in the wireless information terminal and a case where the switching one gateway is provided. In either case, the management entity will determine.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described.

Embodiment 1

Fig. 1 shows the configuration of a wireless network via a public network of gateways sharing a server according to an embodiment of the present invention.

The radio information terminal (hereinafter referred to as a terminal) 1 is a radio information terminal such as a notebook PC connected to a cellular phone, and the base station 2 is, for example, a cellular phone base station, and the network 3 is, for example, a cellular phone. It is a telephone public network.

The gateways 4 and 5 share the server 6 and connect the network 3 and the server 6. The gateways 4 and 5 are also provided with information exchange means for negotiating between the gateways according to the present invention. This information exchange means includes, for example, a wired or wireless connection means 13 enabling direct communication of the gateways 4 and 5, or a connection means of the gateways 4 and 5 and the server 6 ( 14) or a connection via the network 3 may be used.

The terminal 1 is connected to the server 6 via the base station 2, the network 3, and the gateway 4 or 5, and uses the information 7 of the server 6 to execute an application. Run

FIG. 9 shows a sequence in which the gateway 4 stops while the terminal 1 is connected to the server 6 via the gateway 4 and switches the gateway 4 to the gateway 5. .

The session layer protocol means 902 of the terminal 1 communicates with the application 911 of the server 6 via the gateway 4 to execute the application 901.

At this time, the communication protocol used as the communication 903 between the session layer protocol means 902 of the terminal 1 and the session layer protocol means 904 of the gateway 4 and the session layer protocol means 904 of the gateway 4. Since the communication protocol used in the communication 907 between the server and the server 6 is different, the protocol conversion is performed by the protocol conversion means 905 of the gateway 4. That is, the communication protocol used for the communication 903 is converted into the communication protocol used in the communication 907 between the gateway 4 and the server 6 by the above-described protocol conversion means 905, and thereby the terminal. (1) and the server 6 can be communicated.

Some applications do not require protocol conversion means, and in this case, protocol conversion at the gateway is not performed.

Here, if the server switching instruction 912 is issued from the operator while the terminal 1 and the server 6 are communicating, the management entity 906 of the gateway 4 communicates the communication of the terminal 1 with the gateway. In order to change from (4) to the gateway 5, negotiation with the management entity 910 of the gateway 5 is carried out.

In other words, the management entity 906 of the gateway 4 notifies the management entity 910 of the gateway 5 of the session switch request 913. At this time, the selection of the switching destination gateway (in this case, the gateway 5) in which the gateway 4 notifies the session switching request is performed according to the information of another gateway that the gateway 4 stores in advance or from the operator. It is also possible according to the designation of. In addition to the session switching request 913, the management entity 910 of the gateway 5 is informed of information such as the address, the session ID, the maximum data length, the window size, and the like of the currently connected terminal.

The management entity 910 of the gateway 5 passes the information received in conjunction with the session switching request 913 to the session layer protocol means 908, and the contents of the information received by the session layer protocol means 908. When confirming, the session switching is possible, and the management entity 910 of the gateway 5 notifies the management entity 906 of the gateway 4 of the session switching confirmation 914.

The management entity 906 of the gateway 4 notifies the session layer protocol means 904 of the switch instruction 922 when it receives the session switch confirmation 914. The session layer protocol means 904 which has received this switching instruction 922 notifies the session layer protocol means 902 of the terminal 1 with the switching notification 915.

As a result, the terminal 1 knows the address information of the gateway 5 which is the switching destination gateway by the switching notification 915.

When the session layer protocol means 902 of the terminal 1 receives the switch notification 915 together with the address information, when the running application 901 is not communicating with the application 911 of the server 6 For example, at a convenient timing for stopping the session, the stop notification 916 is sent to the session layer protocol means 904 of the gateway 4.

The session layer protocol means 904 of the gateway 4 sends the receipt of the interruption notification 916 to the management entity 906, so that the management entity 906 indicates the interruption to the session layer protocol means 904 923. Notify. As a result, the session layer protocol means 904 sends the suspension confirmation notification 917 to the session layer protocol means 902 of the terminal 1, after which the session of the terminal 1 is suspended.

Only the terminal 1 sends the stop notification 916 to the session layer protocol means 904 of the gateway 4, and the server connection switching sequence can continue regardless of the state of the gateway 4.

Therefore, the procedure of the abort instruction 923 and the abort acknowledgment 917 may be omitted, and the session layer protocol means 904 autonomously transmits the abort acknowledgment 917 to the session of the terminal 1 without the abort instruction 923. It may be sent to the layer protocol means 902. In addition, depending on the type of the gateway 4, there is a case where only the interrupt instruction 923 is provided and there is no interruption confirmation notification 917. In any case, if there is no interruption confirmation notification 917, the session of the terminal 1 stops after sending the interruption notification 916.

Further, when the session layer protocol means 902 of the terminal 1 receives the switch notification 915, it instructs the application 901 to display the switch of the gateway, and according to the function of the application 901 or the user's instruction. The session layer protocol means 902 of the terminal 1 may send the interruption notification 916 to the session layer protocol means 904 of the gateway 4.

Subsequently, the session layer protocol means 902 of the terminal 1 sends a resumption notification 918 including information such as the address of the terminal to the session layer protocol means 908 of the gateway 5. Here, the session layer protocol means 908 of the gateway 5 prepares to start a session by the session switch request 913 and the session switch confirmation 914 with the gateway 4 described above. Upon receipt of the resume notification 918 from the session layer protocol means 902 of the terminal 1, the resume confirmation notification 919 is immediately sent to the terminal.

By the resumption confirmation notification 919 from the session layer protocol means 908 of the gateway 5, the session of the suspended terminal 1 is immediately resumed, whereby the session layer protocol means of the terminal 1 902 communicates with the application 911 of the server 6 via the protocol conversion means 909 of the gateway 5 so as to execute the application 901.

Fig. 18 is a sequence showing a case where cutting is used instead of interruption and resumption instead of the interruption.

The switch notification 2515 in Fig. 18 corresponds to the switch notification 915 in the sequence in Fig. 9, and the procedure up to that point is the same sequence in both drawings, and thus description thereof is omitted. Thereafter, the session layer protocol means 2502 of the terminal 1 disconnects the session by notifying the disconnection 2516.

Subsequently, in accordance with the switching destination gateway address notified to the terminal 1 together with the above-mentioned switching notification 2515, the session layer protocol means 2502 of the terminal 1 is the session layer protocol means 2508 of the gateway 5. To the connection 2518. The session protocol 2508 of the gateway 5 processes as a new session, and the session layer protocol 2508 of the gateway 5 checks the connection layer 2519 for the session layer protocol means 2508 of the terminal 1. Notice). As a result, the session layer protocol means 2502 of the terminal 1 confirms the establishment of the session.

When the session is established, the session layer protocol means 2502 of the terminal 1 executes the application of the server 6 via the protocol conversion means 2509 of the gateway 5 for execution of the application 2501. 2511) and communication (2520, 2521).

According to the sequence described above, the gateway 1 can be switched in a short time. In addition, it is possible to switch the gateway connection with less influence on the applications 901 and 2501 and the user of the terminal 1.

In addition, the gateway of the switching destination acquires the information necessary for the information exchange and does not return the application suspended before switching of the gateway from the beginning after switching of the gateway, but can continue from the step after the interruption.

Embodiment 2

Fig. 2 shows a configuration of a wireless network via a public network or a premises network when the gateway itself according to the embodiment of the present invention also functions as a server having information for executing an application of a terminal.

The terminal 1 is, for example, a wireless information terminal such as a PDA (Personal Digital Assistant) incorporating a simple mobile phone. Also, the base station 2 is, for example, a simple cellular telephone base station, and the network 3 is, for example, a simple cellular telephone public network.

The gateways 4 and 5 each include a server storing the information 7 and 8, and the gateways 4 and 5 are connected to the network 3, and the gateways 4 and 5, respectively. ) Has a connection means for information exchange means for negotiation between gateways according to the present invention. The connection means for negotiation between the gateways may be either wired or wireless, or a connection method via the network 3 may be used.

The terminal 1 connects with the base station 2, the network 3, and the gateway 4 or 5, and uses the information 7 which the gateway 4 has, or the information 8 which the gateway 5 has, Run the application.

Also, as shown in Fig. 4, a configuration that does not go through the public network or the premises network can be considered.

That is, in the configuration of Fig. 4, the terminal 1 is connected to the base station 2 and the gateway 4 or connected to the base station 10 and the gateway 5, so that the information 7 or the gateway (the gateway 4 has) The application is executed using the information 8 of 5).

In both cases, the information 8 included in the gateway 9 includes information 7 included in the gateway 4 or at least the same meaning as the information 7.

 10 shows a sequence in which the gateway 4 is stopped when the terminal 1 is connected to the gateway 4 and the terminal 1 switches the connection to the gateway 5.

The gateway switching sequence in the second embodiment will now be described with reference to FIGS. 2 and 10.

The application 1001 of the terminal 1 communicates with the application 1005 as a server of the gateway via the session layer protocol means 1002 of the terminal 1 and the session layer protocol means 1004 of the gateway 4 ( 1003).

As described above, when the server switching instruction 1010 is issued from the operator while the terminal 1 and the gateway 4 are communicating, the management entity 1006 of the gateway 4 communicates with the terminal 1. Is exchanged with the management entity 1009 of the gateway 5 in order to switch from the gateway 4 to the gateway 5.

In other words, the management entity 1006 of the gateway 4 notifies the management entity 1009 of the gateway 5 of the session switch request 1011. At this time, the selection of the switching destination gateway to which the gateway 4 notifies the session switching request can be made according to the information of another gateway that the gateway 4 stores in advance, or according to the designation from the operator.

Herein, the information 8 of the gateway 5 includes information 7 of the gateway 4 which the terminal 1 is using for executing the application 1001 or at least the same meaning as the information 7. Information with

The procedure after the session switch request 1011, i.e., the session switch request 1011 → session switch confirmation 1012 → switch instruction 1019 → switch notification 1013, is shown in FIG. Since the procedure is the same from the request 913 to the session switching confirmation 914 to the switching instruction 922 to the switching notification 913, detailed description is omitted here.

The session layer protocol means 1004 of the gateway 4 notifies the session layer protocol means 1002 of the terminal 1 by the switch notification 1013 of the address of the switching destination gateway, whereby the terminal 1 ) Knows the address information of the gateway 5 which is the switching destination gateway.

In addition, the procedure after receiving the conversion notification 1013, the conversion notification (1013) → stop notification (1014) → stop notification (1020) → stop confirmation notification (1015) → resume notification (1016) → resume confirmation notification ( 1017), the procedure described with reference to FIG. 9, i.e., switching notification 915 → stop notification 916 → stop instruction 923 → stop confirmation notification 917 → resume notification 918 → resume confirmation notification Since it is the same as the procedure to 919, description is abbreviate | omitted here.

By the resumption confirmation notification 1017 from the session layer protocol means 1007 of the gateway 5, the session of the suspended terminal 1 resumes immediately, and if the session resumes, the session layer protocol of the terminal 1 The means 1002 communicates 1018 with the application 1008 of the gateway 5 because it executes the application 1001.

As shown in Fig. 9, after the terminal 1 sends the interruption notification 1014 to the session layer protocol means 1004 of the gateway 4, the server connection switching sequence is generated regardless of the state of the gateway 4; It is possible to proceed, and thus, the procedure of the interruption instruction 1020 and the interruption confirmation notification 1015 may be omitted, and the session layer protocol means 1004 autonomously sends the interruption confirmation notification 1015 to the terminal 1 without the interruption indication 1020. May be sent to the session layer protocol means 1002.

In addition, as shown in Fig. 9, depending on the type of the gateway 4, only the interruption instruction 1020 may be performed, and there may be no interruption confirmation notification 1015. In any case, if there is no interruption confirmation notification 1015, the session of the terminal 1 stops after sending the interruption notification 1014. When the session layer protocol means 1002 of the terminal 1 receives the switch notification 1013, it instructs the application 1001 to display the switching of the gateway and stops by the function of the application 1001 or the user's instruction. The notification 1014 may be sent to the session layer protocol means 1004 of the gateway 4.

According to the sequence described above, the gateway 1 can be switched in a short time. In addition, the gateway connection can be switched with less influence on the application 1001 or the user of the terminal 1.

Embodiment 3

3 shows the configuration of a wireless network via a public network or a premises network of a gateway connected to another server according to an embodiment of the present invention.

The terminal 1 is, for example, a mobile phone terminal having an information processing function such as a smartphone, the base station 2 is, for example, a mobile phone base station, and the network 3 is, for example, an internal network. The gateway 4 connects the network 3 and the server 6, and the gateway 5 connects the network 3 and the server 9.

The gateways 4 and 5 also have connection means for negotiating between gateways by the information exchange means according to the present invention. The connection means for negotiation between the gateways may be either wired or wireless, or may use a connection means via the network 3.

The terminal 1 connects to the server 6 via the base station 2, the network 3, and the gateway 4, and executes an application using the information 7 included in the server 6. Alternatively, the terminal 1 connects to the server 9 via the base station 2, the network 3, and the gateway 5, and executes an application using the information 8 included in the server 9. .

On the other hand, the information 8 which the server 9 has includes the information 7 which the server 6 has, or the information which has the same meaning as the information 7 at least.

In FIG. 11, when the terminal 1 is connecting to the server 6 via the gateway 4, the gateway 4 stops, and the terminal 1 switches the connection to the gateway 5 and the server 9. FIG. Shows the sequence in which case.

3 and 11, the gateway switching sequence in the third embodiment will be described.

The session layer protocol means 1102 of the terminal 1 communicates with the application 1108 of the server 6 via the gateway 4 to execute the application 1101.

At this time, the communication protocol used in the communication 1103 between the session layer protocol means 1102 of the terminal 1 and the session layer protocol means 1104 of the gateway 4 and the session layer protocol means 1104 of the gateway 4. Since the communication protocol used in the communication 1107 between the server 1 and the server 6 is different, the protocol conversion is performed by the protocol conversion means 1105 of the gateway 4.

The communication 1103 converts the communication protocol used in the communication 1107 between the gateway 4 and the server 6 by the above-described protocol conversion means 1105, and thereby the terminal 1 and the server 6 ) Communication is possible. Some applications do not require protocol conversion means, and in this case, no protocol conversion means is required at the gateway.

Here, if the server switching instruction 1113 is issued from the operator when the terminal 1 and the server 6 are communicating, the management entity 1106 (information exchange means) of the gateway 4 is in communication. Since the terminal 1 is switched to the gateway 5 and the server 9, the terminal 1 is negotiated with the management entity 1111 of the gateway 5.

The procedure from the session switch request 1114 to the session switch confirmation 1115 to the switch instruction 1123 to the switch notification 1116 is as shown in FIG. 9, the session switch request 913 to the session switch confirmation 914. Since it is the same as the procedure from () → switch instruction (922) to switch notification (915), detailed description is abbreviate | omitted here.

When the session layer protocol means 1102 of the terminal 1 receives the switch notification 1116, the session layer protocol means 1102 stops the session, for example, when the running application 1101 does not communicate with the application 1108 of the server 6. At a convenient timing, the interruption notification 1117 is sent to the session layer protocol means 1104 of the gateway A4.

The procedure for interrupt notification 117 → interrupt instruction 1124 → interrupt confirmation notification and resumption notification 1119 → resume confirmation notification 1120 is shown in FIG. 9 as the transition notification 915 → interruption 916 → Since it is the same as the procedure from the interruption instruction 923 to the interruption confirmation notification 917 and the resume notification 918 to the restart confirmation notification 919, the description is omitted.

In addition, as in FIG. 9, after the terminal 1 sends the interruption notification 1117 to the session layer protocol means 1104 of the gateway 4, the server connection switching sequence is performed regardless of the state of the gateway 4; Since it is possible to proceed, the procedure of the interruption instruction 1124 and the interruption acknowledgment 1118 is not necessarily necessary, and if there is no interruption acknowledgment 1118, the session of the terminal 1 is interrupted 1117. ) Is sent out and stop.

In addition, as in FIG. 9, when the session layer protocol means 1102 of the terminal 1 receives the switch notification 1116, it instructs the application 1101 to display the gateway switch or the application 1101. According to the function of the user or the user's instruction, the session layer protocol means 1102 of the terminal 1 may send the interruption notification 1117 to the session layer protocol means 1104 of the gateway 4.

By the resumption confirmation notification 1120 from the session layer protocol means 1109 of the gateway 5, the session of the suspended terminal 1 is resumed. When the session resumes, the session layer protocol means 1102 of the terminal 1 communicates 1121 and 1122 with the application 1112 of the server 9 via the gateway 5 to execute the application 1101. .

According to the sequence described above, the gateway connection switching of the terminal 1 can be performed in a short time.

In addition, it is possible to switch the gateway connection with less influence on the application 1101 or the user of the terminal 1.

Embodiment 4

Hereinafter, specific application examples of the gateway switching sequence according to the configuration of FIG. 1 will be described with reference to FIGS. 12 to 17.

Fig. 12 shows that the gateway 4 stops when the user is connected to the WWW server software of the server 6 via the gateway 4 using the WWW browser from the terminal 1, and the terminal 1 is gatewayed. The sequence in the case of changing from (4) to connection to the gateway 5 is shown.

The session layer protocol means 1202 communicates with the WWW server software 1211 of the server 6 via the gateway 4 a command generated by the user using the WWW browser 1201 of the terminal 1.

At this time, the communication protocol between the session layer protocol means 1202 of the terminal 1 and the session layer protocol means 1204 of the gateway 4 is a wireless communication protocol, and the session layer protocol means 1204 of the gateway 4 The communication protocol used between the servers 6 is (HTTP Hyper Text Transfer Protocol). Therefore, protocol conversion is performed by the protocol conversion means 1205 of the gateway 4 in order to achieve the matching of both.

Here, for example, the user operates the WWW browser 1201 of the terminal 1, and // www. xxx / xyz. When an instruction to access the file stored in the server 6 called htm is given, the command INVOKE <REQUEST (get, // www.xxx/xyz.htm)> 1203 of the wireless communication protocol is set to protocol conversion means 1205. Is converted into an HTTP command REQUEST (get, // www. Xxx / xyz.htm) 1207, and transmitted to the server 6 by using the command.

When the WWW server software 1211 of the server 6 receives the command REQUEST (get, // www. Xxx / xyz.htm) 1207, // www. xxx / xyz. Data of the file htm is sent out by the RESP0NSE (data) 1212.

This HTTP response RESP0NSE (data) 1212 is converted by the protocol converting means 1205 of the gateway 4 into a response REPLY <RESP0NSE (data)> 1213 of the wireless communication protocol, and is a session layer protocol means of the gateway. It is transmitted from the terminal 1204 to the terminal 1. As a result, communication between the terminal 1 and the server 6 becomes possible, and the user has a file /// www. xxx / xyz. You can browse the data of htm.

When the server switching instruction 1214 is issued from the operator while the terminal 1 and the server 6 are communicating as described above, the management entity 1206 of the gateway 4 is connected to the terminal 1 in communication. In order to switch the connection to the gateway 5, the communication entity 1210 negotiates with the management entity 1210 of the gateway 5.

That is, the management entity 1206 of the gateway 4 notifies the management entity 1210 of the gateway 5 of the session switch request 1215. The procedure from the session switch confirmation 1216 to the switch instruction 1217 to the switch notification 1218 and the stop notification 1219 to the stop instruction 1220 to the stop confirmation notification 1221 is described in FIG. The detailed description is omitted since it is the same as the procedure from the session switch confirmation (914) to the switch instruction (922) to the switch notification (915) and the stop notification (916) to the stop instruction (923) to the stop confirmation notification (917).

In addition, as shown in FIG. 9, after the terminal 1 sends the interrupt notification 1219 to the session layer protocol means 1204 of the gateway 4, the server connection switching sequence is performed regardless of the state of the gateway 4; Therefore, the procedure of the abort instruction 1220 and the abort acknowledgment 1221 is not necessary, and the session layer protocol means 1204 autonomously transmits the abort acknowledgment 1221 to the terminal without the abort instruction 1220. You may send to the session layer protocol means 1202 of 1).

In addition, depending on the type of the gateway 4, there is a case where only the stop instruction 1220 is provided and there is no stop confirmation notification 1221. In either case, when there is no interruption confirmation notification 1221, the session of the terminal 1 stops after sending the interruption notification 1219.

At this time, the www browser 1201 displays the file // www. xxx / xyz. If the data of htm has already been received, the user can continue to read the data even if the session is interrupted. It goes without saying that it is not necessary to stop the execution of the www browser 1201, which is the application of the terminal 1, of course.

When the session layer protocol means 1202 of the terminal 1 receives the switching notification 1218, the gateway switching indication is displayed on the www browser 1201, and according to the function of the www browser 1201 or the instruction of the user, the terminal ( The session layer protocol means 1202 of 1) may send the interruption notification 1219 to the session layer protocol means 1204 of the gateway 4.

Since the sending of the resume notification 1222 from the terminal 1 and the sending of the resume confirmation notification 1223 from the gateway 5 are the same as the resume notification 918 and the resume confirmation notification 919 shown in FIG. Omit the description.

By the above procedure, the session of the terminal 1 which has been interrupted is resumed.

In this state, the user operates the www browser 1201 of the terminal 1, and // www. xxx / xyz. When an instruction to access the file htm is given, the command INV0KE <REQUEST (get, // www. xxx / xyz.htm> 1224 of the wireless communication protocol is set by the protocol converting means 1209 of the gateway 5 to HTTP. Is converted to the command REQUEST (get, //www.xxx/xyz.htm) 1225 and sent to the server 6.

The www server software 1211 of the server 6 receives the command REQUEST (get, // www. Xxx / xyz.htm) 1225, // www. xxx / xyz. Data of the file htm is sent out by RESP0NSE (data) 1226.

The HTTP response RESP0NSE (data) 1226 is converted by the protocol converting means 1209 of the gateway 5 to the response REPLY <RESP0NSE (data)> 1227 of the wireless communication protocol, and is the session of the gateway 5. It is transmitted from the layer protocol means 1208 to the terminal 1.

This enables communication between the terminal 1 and the server 6 using the gateway 5, so that the user can access the file // www. xxx / xyz. You can browse the data of htm.

(Occurrence of new communication during negotiation)

A sequence when new communication occurs between the terminal and the server during negotiation will be described with reference to FIG.

12 shows the session switching request from the gateway 4 to the gateway 5, and the instruction and confirmation between the session layer protocol means of the gateway 5 and the management entity.

In Fig. 13, thereafter, the communication between the terminal 1 and the server 6 has occurred, before the session switching confirmation from the gateway 5 to the gateway 4 is notified.

For this reason, information indicating the communication state between the terminal 1 and the gateway 4 included in the information that the gateway 4 notifies the gateway 5 of the session switching request, and before the session switching confirmation is notified, is received. The communication state of the terminal 1 and the gateway 4 after (1) and the server 6 have communicated is not matched.

That is, the information indicating the communication state between the terminal 1 and the gateway 4 or 5 is the TID shown in the left end of FIG. Here, the TID notified by the session switching request from the gateway 4 to the gateway 5 is TID = 1 shown at the top. In addition, the TID after the terminal 1 and the server 6 have communicated is TID = 2 indicating the interruption. In this manner, since the TID1 notified to the gateway 5 and the actual TID2 are different, there is a problem of communication processing between the gateway 5 and the terminal 1 after the gateway connection switching.

In this way, even if communication between the terminal 1 and the server 6 occurs during negotiation between the gateways, in order to maintain TID consistency, the latest TID, TID = 2 in FIG. 5) Notice is given at the time of reopening notice to.

(Conversion processing of the word means)

Next, the stop timing of the gateway connected to the plurality of terminals will be described with reference to FIG.

The gateway 4 is in the state connected with the terminal 1, the terminal 15, and the terminal 17. Here, session switching negotiation between the gateway 4 and the gateway 5 is as shown in FIG.

In Fig. 14, the terminal 1, the terminal 17, and the terminal 15 are dealt with in one session switching negotiation. However, the negotiation may be divided for each terminal 1 unit.

After the session switching negotiation (session switching request 1401 to session switching confirmation 1402) between the gateway 4 and the gateway 5, the gateway 4 is connected to the terminal 1, the terminal 17, and the terminal ( 15) Provide a conversion notice for each. Subsequently, the terminal 1, the terminal 17, and the terminal 15 send out the interruption notifications 1403a, 1403b, and 1403c to the gateway 4, respectively, and provide the interruption notifications 1404a and 1404b to each of the connected terminals. After receiving 1404c, the gateway 4 issues stop confirmation notifications 1405a, 1405b, and 1405c to stop.

Apart from the above, if the gateway 4 has an allowable time from the notification of switching to the terminal to the stop notification to the gateway 4 and the allowable time passes, the gateway 4 stops even if there is a terminal that does not give the stop notification to the gateway 4. You can think of a sequence.

(When switched to gateway)

The following describes the sequence when the connection switching of the terminal is denied from the switching destination gateway through negotiation with reference to FIG.

The sequence from the gateway 4 to the gateway 5 of notifying the session switch request is as shown in FIG. The gateway 5 notifies the gateway 4 of the session switchback 1501 for reasons of lack of capability or overload. The gateway 4, which has received the session switch rejection 1501, notifies the gateway 16 of the session switch request 1502 as a new switch destination, and when the gateway 16 has the ability to accept the terminal, the gateway 16 Notifies the gateway 4 of the session switching confirmation 1503, and then the connection switching is executed.

In this way, even if connection switching is rejected from the switching destination gateway, the gateway 4 negotiates with the new switching destination gateway to find the connection switching destination gateway. This function is fundamental to the management entity of the switching source gateway 4, but is registered in the memory of the gateway 4 with a plurality of switching source gateways prioritized, and the management entity has said rejection notification. When receiving, the switching candidate gateway of the next candidate may be read from the memory to automatically execute the information exchange procedure.

(When switching destination gateway is insufficient)

The following describes the sequence when the switchover destination informs the negotiation that the switchover gateway does not have the terminal accommodating capability along with the session switching confirmation notification.

The sequence from the gateway 4 to the gateway 5 of notifying the session switch request is as shown in FIG.

When the gateway 5 cannot provide all of the resources required by the terminal from information such as the maximum data length and window size notified together with the session switch request from the gateway 4, the session switch confirmation 1601 is performed. In addition, the gateway 4 is notified of the upper limit of the resources that can be provided to the terminal seeking connection switching.

The gateway 4 notifies the terminal 1 of the upper limit of the resources that the gateway 5 can provide together with the switching notification 1602. As a result, the terminal 1 changes the capability, that is, its capability information, to match the upper limit of the resources that the gateway 5 can provide.

As a result, the terminal 1 switches to the gateway 5 and communicates with the changed capability. On the other hand, the gateway 4 of the switching source may be provided with determination means for determining whether or not the communication between the gateway 5 of the switching destination and the terminal 1 is possible, and when it is not possible, the communication may be stopped. . In addition, the terminal may be provided with a judging means for judging whether or not communication is possible by the capacities that have been notified as described above, and may stop receiving the service when communication is not possible.

(If there is a procedure for retransmission)

19 shows a sequence in the case where a data retransmission protocol is organized in the terminal 1, the gateway 4, and the gateway 5. FIG. In FIG. 19, although the retransmission protocol is located below the session layer, it is a matter of course that the retransmission protocol may be organized in the session layer.

As described in Fig. 12, the command INV0KE <REQUEST (get, // www. Xxx / xyz.htm)> 1203 is an HTTP command REQUEST (get, // www.xxx/ xyz, htm) 1207 and transmitted to the server 6, the session layer protocol means 1204 of the gateway 4 sends an ACK 1228 of the wireless communication protocol to the session layer protocol of the terminal 1; Send to means 1202. By receiving this ACK 1228, the terminal 1 determines that the command INV0KE <REQUEST (get, // www. Xxx / xyz.htm)> 1203 of the wireless communication protocol has been received by the gateway 4. .

As described above, the HTTP response RESP0NSE (data) 1212 is converted into the response REPLY <RESP0NSE (data)> 1213 of the wireless communication protocol by the protocol conversion means 1205 of the gateway 4, and the gateway. Is transmitted from the session layer protocol means 1204 to the terminal 1, the session layer protocol means 1202 of the terminal 1 that has received this response REPLY <RESP0NSE (data)> 1213 is connected to the wireless communication protocol. The ACK 1230 is sent to the gateway 4. The gateway 4 determines that the response REPLY <RESP0NSE (data)> 1212 of the radio communication protocol has been received by the terminal 1 by receiving the ACK 1230 of the radio communication protocol.

After the resumption confirmation notification 1223, the command INV0KE <REQUEST (get, //www.xxx/xyz.htm)>1224 of the wireless communication protocol is determined by the protocol conversion means 1209 of the gateway 5. HTTP command REQUEST (get, / www. Xxx / xyz.htm) 1225 is converted and sent to the server 6. At this time, the session layer protocol means 1208 of the gateway 5 transmits the ACK 1231 of the wireless communication protocol to the session layer protocol means 1202 of the terminal 1. In addition, the session layer protocol means 1202 of the terminal 1 that has received the response REPLY <RESP0NSE (data)> 1227 is configured to transmit the wireless communication protocol ACK 1233 to the gateway 5.

Here, the retransmission protocol in the terminal 1, the gateway 4, and the gateway 5 will be described below with reference to FIG.

After the terminal 1 transmits the command INV0KE <REQUEST (get, // www. Xxx / xyz.htm)> (1309) of the wireless communication protocol, the terminal 1 sends an ACK 1314 of the wireless communication protocol from the gateway 4 for a prescribed time. If not received, the retransmission protocol 1303 of the terminal 1 retransmits the command INV0KE <REQUEST (get, // www. Xxx / xyz.htm)> 1319 of the wireless communication protocol.

When the ACK 1314 of the wireless communication protocol is returned from the gateway 4, the terminal 1 stops retransmission. In addition, to measure the prescribed time, the terminal 1 has a timer and also has a maximum predetermined value of the number of retransmissions. When the number of retransmissions exceeds the maximum predetermined value, the terminal 1 disconnects the communication because any abnormality has occurred in the communication between the terminal 1 and the gateway 4.

Similarly, if the gateway 4 does not receive the ACK 1319 of the wireless communication protocol from the terminal 1 after the transmission of the response REPLY <RESP0NSE (data)> 1316 of the wireless communication protocol, the gateway ( The retransmission protocol 1304 of 4) resends the response REPLY <RESP0NSE (data> 1317) of the wireless communication protocol.

When the ACK 1319 of the radio communication protocol is returned from the terminal 1, the gateway 4 stops retransmission. In addition, the gateway 4 has a timer to measure the specified time, and also has a maximum predetermined value of retransmission. When the number of retransmissions exceeds the maximum predetermined value, the gateway 4 disconnects the communication because any abnormality has occurred in the communication between the terminal 1 and the gateway 4.

(Stop display)

Fig. 17 shows the sequence when the interruption display is made to the user.

Since the sequence up to the switching notification 1714 is the same as that in Fig. 12, description thereof is omitted.

The session layer protocol means 1702 of the terminal 1 sends the interruption notification 1706 to the session layer protocol means 1704 of the gateway 4, and at this time, the interrupt indication notification to the application 1701 of the terminal 1. (1708) is issued. When the application 1701 receives the interruption display notification 1708, the application 1701 executes the interruption display 1709 on the screen of the terminal 1.

In this interruption display 1709, the user indicates that the gateway, the terminal, or the network are not faulted or disturbed, such as "the gateway 4 stops for the versioning operation and thus switches the connection to the gateway 5". Displays a clear message.

Thereafter, the session layer protocol means 1702 of the terminal 1 sends a reopen notification 1711 to the session layer protocol means 1710 of the gateway 5, and the session layer protocol means 1710 of the gateway 5. The resume confirmation notification 1712 is sent to the session layer protocol means 1702 of the terminal 1.

Alternatively, the session layer protocol means 1702 of the terminal 1 sends a reopening notification 1711 to the session layer protocol means 1710 of the gateway 5 when the user is instructed while displaying the interruption indication 1709. You may.

The session layer protocol means 1702 of the terminal 1 notifies the application 1701 of the resume indication 1713 upon receiving the resume confirmation notification 1712, and the application 1701 is suspended when receiving the resume indication 1713. The display 1709 ends.

On the other hand, in addition to the display of the interruption, it is also possible to display this notification even when receiving the intermediate stop value at the switching source gateway as described above.

(Generation of wireless communication protocol after switching notice)

Fig. 21 shows a sequence in the case where a command of the wireless communication protocol has occurred from the terminal 1 immediately after the switching notification. Here, the concept of transaction is introduced.

In other words, the logical connection between the terminal 1 and the gateway 4 is called a session, and the data communication of the actual application is called a transaction. A transaction represents a series of operational processes of a response from a server corresponding to a request or notification from a user, or a response from a user corresponding to a request or notification from a server. Here, a plurality of transactions exist for one session. It also has an identifier (TransactionID) on a transactional basis so that the corresponding request / notification / response can be identified.

Since the sequence up to the switch notification 1713 is the same as in FIG. 19, description thereof is omitted.

Since the gateway 4 has already sent the gateway switching notification 1713 to the session layer protocol means 1702 of the terminal 1, the command INV0KE <REQUEST (get, 1 / www.xxx / xyz) of the wireless communication protocol. htm)> (1719).

The session layer protocol means 1702 of the terminal 1 sends a stop notification 1714 to the session layer protocol means 1705 of the gateway 4 when receiving the switch notification 1713. The session layer protocol means 1705 of the gateway 4 sends the reception notification 1714 to the management entity 1707, and the management entity 1707 transmits the transaction information (1711) to the management entity 1711 of the gateway 5. The state of the transaction, the transaction ID, and the like, and the command INV0KE REQUEST (get, /// www. Xxx / xyz.htm)> of the wireless communication protocol) are reported.

The sequence thereafter, i.e., the interruption confirmation notification 1715 → resume notification 1917 → resume confirmation notification 1718, is the interruption confirmation notification 917 → resume notification 918 → resume confirmation notification (Fig. 9). Since it is the same as the sequence of 919, the description is omitted. When the session of the session layer protocol means 1702 of the terminal 1 and the session layer protocol means 1709 of the gateway 5 is resumed, the session layer protocol means 1709 of the gateway 5, the transaction information 1716 By using the transaction status and transaction ID received from the server, the contents of the REQUEST are converted into the HTTP command REQUEST (get, // www. Xxx / xyz.htm) 1720 by the protocol conversion unit 1710, and the server ( 6) requires.

Subsequent sequences up to ACK 1725 of the wireless communication protocol are the same as in FIG.

Here, the command INV0KE <REQUEST (get, // www xxx / xyz.htm)> 1719 of the wireless communication protocol transmitted from the terminal 1 is set by the protocol conversion means 1706 of the gateway 4 in HTTP. It may be converted to the command REQUEST (get, // www. Xxx / xyz.htm) 1720 and then transmitted as the transaction information 1716 to the management entity 1711 of the gateway 5.

After the interrupt notification 1714 is received, the management entity 1707 of the gateway 4 communicates with the management entity 1711 of the gateway 5, but may be performed before the interrupt notification 1714 is received.

Further, even when the terminal 1, the gateway 4, and the gateway 5 do not transmit an ACK, the same procedure as in the sequence in which the ACKs 1722 and 1725 of the radio communication protocol are not transmitted is performed. In other words, the procedure of ACK is not necessary.

The same procedure is also performed when the retransmission protocol is organized in the terminal 1, the gateway 4, and the gateway 5.

(Instruction to switch before response from server)

Next, using Fig. 22, the gateway 4 receives the command of the wireless communication protocol from the terminal 1, and transmits the ACK of the wireless communication protocol corresponding to the terminal 1 from the gateway 4. However, the sequence in the case where the instruction of server switching occurs from the operator of the gateway 4 before receiving the HTTP response from the server 6 will be described.

In Fig. 22, the sequence from the server 6 to the switch notification 1813 is excluded, except that an HTTP response does not occur, and an ACK corresponding to this response does not occur in the terminal 1. 19, the description is omitted.

The gateway 4 responds to the HTTP response RESP0NSE (data) of the HTTP command REQUEST (get, //www.xxx/xyz.htm) 1823 sent to the server 6 from the server 6. (1819) until it is received.

When the session layer protocol means 1702 of the terminal 1 receives the switch notification 1813, the session layer protocol means 1702 sends the stop notification 1814 to the session layer protocol means 1805 of the gateway 4. The session layer protocol means 1805 of the gateway 4 sends the reception notification 1814 to the management entity 1807, and sends the HTTP command REQUEST (get, // www. Xxx / xyz.htm) ( An HTTP response RESP0NSE (data) 1819 is received from the server 6 corresponding to 1823. As a result, the protocol conversion means 1806 of the gateway 4 sends the HTTP command REQUEST (get, // www. Xxx / xyz.htm) to the response of the wireless communication protocol (described later in REPLY <RESP0NSE (data)). > (1820) equivalent data).

Next, the transaction information (transaction status, transaction ID, etc., response of the converted wireless communication protocol, REPLY <RESP0NSE (data) is transmitted to the management entity 1811 of the gateway 5 through the management entity 1807 of the gateway 4. )> (1816).

Since the interruption confirmation notification 1815 and the resume sequence thereafter are the same as in Fig. 19, description thereof is omitted. When the session of the session layer protocol means 1702 of the terminal 1 and the session layer protocol means 1809 of the gateway 5 is resumed, the session layer protocol means 1809 of the gateway 5, the transaction information 1816 The response REPLY <RESP0NSE (data)> 1820 of the wireless communication protocol is transmitted from the session layer protocol means 1809 to the session layer protocol means 1702 of the terminal 1 using the state of the transaction received and the transaction ID. Send.

The sequence of the ACK 1821 of the radio communication protocol is omitted as shown in FIG.

Here, the response REPLY <RESP0NSE (data) 1819 of the HTTP protocol transmitted from the server 6 is not converted by the protocol conversion means 1806 of the gateway 4, and the management entity 1807 of the gateway 4 is used. Is transmitted to the management entity 1811 of the gateway 5 as transaction information 1816, and the protocol conversion means 1810 of the gateway 5 responds to the radio communication protocol REPLY <RESP0NSE (data)> 1820. It can be converted to.

In the case where the terminal 1, the gateway 4, and the gateway 5 do not transmit an ACK, the same procedure is performed in a sequence in which the ACKs 1824 and 1821 of the radio communication protocol are not transmitted. The procedure of ACK is not necessary.

At this time, as shown in FIG. 21, the transaction information 1816 notifies the gateway 5 of the contents of the REQUEST, and transmits the HTTP command from the gateway 5 to the server 6 as shown in FIG. Can be. The same procedure is also performed when the retransmission protocol is organized in the terminal 1, the gateway 4, and the gateway 5. FIG.

(If there is no ACK at the terminal)

Next, using Fig. 23, the gateway 4 receives a command of the wireless communication protocol from the terminal 1, receives an HTTP response from the server 6, and receives a response of the wireless communication protocol from the terminal 1. Is sent to the terminal 1, but the ACK of the radio communication protocol is not returned from the terminal 1, the sequence in the case where the instruction of server switching occurs from the operator of the server 4 will be described.

Since the ACK from the terminal 1 is not returned to the gateway 4 with respect to the response REPLY <RESP0NSE (data)> 1924, since the sequence up to the switching notification 1913 is the same as in FIG. Omit the description.

In the meantime, the retransmission control of the response REPLY <RESP0NSE (data)> 1924 is performed in the retransmission protocol 1904 of the gateway 4.

The session layer protocol means 1902 of the terminal 1 sends a stop notification 1914 to the session layer protocol means 1905 of the gateway 4 when the switch notification 1913 is received.

The session layer protocol means 1905 of the gateway 4 sends the reception notification 1914 to the management entity 1907, and the management entity 1907 transmits the transaction information to the management entity 1911 of the gateway 5. (Contents of Response REPLY <RESP0NSE (Data)> of the Wireless Communication Protocol, etc.) (the status of the transaction, the number of times of retransmission of the transaction ID, the elapsed value of the retransmission timer value, etc.) is notified.

The interruption confirmation notice 1915 and the resume sequence thereafter are omitted because they are the same as in FIG.

When the session of the session layer protocol means 1902 of the terminal 1 and the session layer protocol means 1909 of the gateway 5 is resumed, the session layer protocol means 1909 of the gateway 5, the transaction information (1916) The contents of the RESP0NSE (data) 1926 are transmitted from the retransmission protocol 1908 to the session layer protocol means 1902 of the terminal 1 using the state of the transaction received, transaction ID, retransmission count, and retransmission timer. .

The sequence of the ACK 1927 of the radio communication protocol is omitted as shown in FIG.

Here, the RESPONSE (data) 1923 is first converted into REPLY <RESPONSE (data)> of the wireless communication protocol by the protocol conversion means 1906 of the gateway. However, the contents of the RESPONSE (data) included in the transaction information 1916 in the management entity 1907 of the gateway 4 and transmitted to the management entity 1911 of the gateway 5 are the response REPLY <RESPONSE of the HTTP protocol. It may be in the form of (data) and converted into the response REPLY <RESPONSE (data) 1926 of the radio communication protocol by the protocol conversion means 1910 of the gateway 5 again.

Also in the case where the ACK is not transmitted to the gateway 4 and the gateway 5, the same procedure as in the sequence in which the ACK 1922 of the radio communication protocol is not transmitted is performed.

The same procedure is also performed when the retransmission protocol is organized in the terminal 1 and the gateway 5.

According to the sequence described above, even if the application of the terminal does not receive the data for the request, the gateway can be switched in the terminal, and the gateway can be switched in less influence on the application or the user of the terminal.

Embodiment 5

Even if there is no connection path between the gateways and no gateway-to-gateway connection through the network or negotiation between the gateways in the connection means of a plurality of gateways and servers, for example, the conventional configuration as shown in FIG. It is possible to get the effect.

5 and 24, 25, 26, and 27, a description will be given of a gateway switching sequence when there is no information interrogation means between the gateways in the fifth embodiment. The gateways 11 and 12 share the server 6 and connect the network 3 and the server 6. In addition, the gateways 11 and 12 do not have information exchange means for performing negotiation between the gateways. The terminal 1 connects to the server 6 via the base station 2, the network 3, the gateway 11 or 12, and executes an application using the information 7 included in the server 6. .

The session layer protocol means 2002 of the terminal 1 communicates with the application 2011 of the server 6 via the gateway 11 to execute the application 2001. In this case, the communication protocol used in the communication 2003 between the session layer protocol means 2002 of the terminal 1 and the session layer protocol means 2004 of the gateway 11 and the session layer protocol means of the gateway 11 ( Since the communication protocol used in the communication 2007 between the 2004 and the server 6 is different, the protocol conversion means is performed by the protocol conversion means 2005 of the gateway 11.

The communication 2003 is converted into the communication protocol used in the communication 2007 between the gateway 11 and the server 6 by the above-described protocol conversion means 2005, whereby the terminal 1 and the server 6 ) Communication is possible. However, some applications do not require protocol conversion means. In that case, the protocol conversion means at the gateway is not used.

When the server switching instruction 2012 is issued from the operator when the terminal 1 and the server 6 are communicating, the management entity 2006 of the gateway 11 sends the terminal 1 in communication to the gateway ( In order to switch the connection to 12), the switch layer instruction means (2013) is given to the session layer protocol means (2004).

The session layer protocol means 2004 notifies the session layer protocol means 2002 of the terminal 1 by the switch notification 2014 of information, such as a switch destination gateway address. At this time, the selection of the switching destination gateway notified by the gateway 11 depends on whether the gateway 11 searches for a gateway that can accommodate the terminal 1 in accordance with information of the gateway other than the one stored in advance, or designation from the operator. It is also possible.

The terminal 1 first learns the address information of the gateway 12 which is the switching destination gateway by the switching notification 2014. That is, since the terminal 1 receives the information for switching the server connection by the switch notification 2014 from the gateway 11, the terminal 1 stores the information of the plurality of gateways for switching the gateway connection, for example, in the storage means of the terminal 1, for example. There is no need to always keep it in the hard disk, IC card, flash ROM, EEPROM, battery backed up RAM.

When the session layer protocol means 2002 of the terminal 1 receives the switching notification 2014, the session layer protocol means 2002 stops the session, for example, when the running application 2001 does not communicate with the application 2011 of the server 6. At a convenient timing, the interruption notice 2015 is sent to the session layer protocol means 2004 of the gateway 11.

The session layer protocol means 2004 of the gateway 11 sends the receipt of the suspension notification 2015 to the management entity 2006, and the management entity 2006 sends the interrupt indication 2016 to the session layer protocol means 2004. Notify.

When the session layer protocol means 2004 of the gateway 11 receives the stop instruction 2016, the session layer protocol means 2004 sends a stop acknowledgment 2017 to the session layer protocol means 2002 of the terminal 1.

After that, the session layer protocol means of the terminal 1 stops.

After the terminal 1 sends the interruption notification 2015 to the session layer protocol means 2004 of the gateway 11, the server connection switching sequence can be continued regardless of the state of the gateway 11.

Therefore, the stop indication (2016) and the stop confirmation notification (2017) may not be required, and without the stop indication (2016), the session layer protocol means 2004 autonomously transmits the stop confirmation notification 2017 to the session layer protocol means of the terminal 1 ( 2002). In addition, depending on the type of gateway 4, there is a case where only the stop instruction 2016 is provided and there is no stop confirmation notification 2017.

In any case, if there is no interruption confirmation notification 2017, the session of the terminal 1 stops after sending the interruption notification 2015. When the session layer protocol means 2002 of the terminal 1 receives the switch notification 2014, the gateway 2001 is displayed on the application 2001, and according to the function of the application 2001 or the user's instruction, the terminal ( The session layer protocol means 2002 of 1) may send the interruption notification 2015 to the session layer protocol means 2004 of the gateway 11.

The session layer protocol means 2002 of the terminal 1 sends a resumption notification 2018 including information on the terminal address, session ID, maximum data length, window size, and the like to the session layer protocol means 2008 of the gateway 12. do.

When the session layer protocol means 2008 of the gateway 12 receives the resume notification 2018, it sends a resume confirmation notification 2019. Subsequently, the resumption confirmation notification 2019 from the session layer protocol means 2008 of the gateway 12 resumes the session of the suspended terminal 1.

When the session resumes, the session layer protocol means 2002 of the terminal 1 executes the application of the server 6 via the protocol conversion means 2009 of the gateway 12 to execute the application 2001. (2020, 2021).

In the above-described sequence, the gateway 11 is based on the premise of notifying the terminal 1 of a gateway having a capability of accommodating the terminal 1 as a switching destination gateway. For this reason, if it turns out that the switching destination gateway does not have the ability to accommodate the terminal 1 after the connection switching to the switching destination gateway, the inefficient connection switching to switch to another gateway again is performed. It does not occur. In addition, the gateway connection can be switched with little influence on the application 2001 or the user of the terminal 1.

25, the sequence in the case where the command of the radio communication protocol is generated from the terminal 1 immediately after the switching notification 2113 will be described.

Since the sequence up to the switching notification 2113 is the same as in FIG. 24, description thereof is omitted.

The protocol conversion means 2106 of the gateway 4 converts the command INV0KE <REQUEST (get, // www. Xxx / xyz.htm) 2119 of the wireless communication protocol to the HTTP command REQUEST (get, // www. Xxx). /xyz.htm) 2116, and send it to the server 6. Here, when the gateway 4 notifies the server of the HTTP command REQUEST (get, // www. Xxx / xyz.htm) 2116, this REQUEST (get, // www. Xxx / xyz.htm) ( The address of the gateway that transmits RESPONSE (data) (here 2122) corresponding to 2116 is notified.

In the above description, the HTTP command and the address notified can be treated as other information, and can also be included in the HTTP command. In the latter case, the server 6 interprets the HTTP command to extract the address portion.

The subsequent interruption confirmation notification 2115 and the resume sequence are omitted as shown in FIG.

Thereafter, when the session layer protocol means 2102 of the terminal 1 and the session layer protocol means 2109 of the gateway 5 are resumed, the session layer protocol means 2109 of the gateway 5 resume notification. The ACK 2121 of the wireless communication protocol is transmitted to the terminal 1 by using the transaction state and the transaction ID received at 2117.

Receives HTTP response RESP0NSE (data) 2122 corresponding to HTTP command REQUEST (get, // www. Xxx / xyz.htm) 2116 from server 6, and wirelessly communicates to protocol conversion means 2110. The response is converted to the response REPLY <RESP0NSE (data)> 2123 of the protocol and transmitted to the session layer protocol means 2102 of the terminal 1. Here, the ACK 2121 of the wireless communication protocol may be transmitted from the session layer protocol means 2105 of the gateway 4 to the terminal 1.

Subsequent sequences up to ACK 2124 of the wireless communication protocol are omitted as shown in FIG.

Next, referring to Fig. 26, the gateway 4 uses the command (command INV0KE <REQUEST (get, //www.xxx/xyz.htm) 2222) → command REQUEST (of the wireless communication protocol from the terminal 1). send get, // www. xxx / xyz.htm) 2223 and send an ACK 2224 at the gateway 4, but receive a response from the server 6 corresponding to the HTTP command. Before, the sequence in the case where instruction of server switching has occurred from the operator of the gateway 4 will be described.

Since the sequence up to the switching notification 2213 is the same as in Figs. 24 and 19, description thereof is omitted.

The session layer protocol means 2202 of the terminal 1 sends a stop notification 2214 to the session layer protocol means 2205 of the gateway 4 when receiving the switch notification 2213.

The session layer protocol means 2205 of the gateway 4 sends the receipt of the stop notification 2214 to the management 2207, and the management entity 2207 of the gateway 4 transmits the HTTP to the server 6. A notification 2225 is sent to send the response RESP0NSE (data) 2216 to the gateway 5.

The subsequent interruption confirmation notification 2215 and the resume sequence are omitted as shown in FIG.

When the session of the session layer protocol means 2202 of the terminal 1 and the session layer protocol means 2209 of the gateway 5 is resumed, the session layer protocol means 2209 of the gateway 5 resume notification 2217. Receives HTTP response RESP0NSE (data) 2216 from the server 6 using the status of the transaction and transaction ID received from the server 6, and responds to the wireless communication protocol REPLY <RESP0NSE (data) by the protocol conversion means 2210. )> (2220) is transmitted to the terminal (1).

The sequence of the ACK 2221 of the radio communication protocol is omitted as shown in FIG.

Next, using Fig. 27, the gateway 4 receives a command of the wireless communication protocol from the terminal 1, receives an HTTP response from the server 6, and receives a response of the wireless communication protocol from the terminal 1. ), But when the terminal 1 does not return the ACK of the wireless communication protocol, the sequence in the case where an instruction of server switching has occurred from the operator of the server 4 will be described.

Since the sequence up to the switching notification 2313 is the same as in Figs. 19 and 24, description thereof is omitted.

In the meantime, the retransmission control of the response REPLY <RESP0NSE (data)> 2324 shown in FIG. 20 is performed in the retransmission protocol 2304 of the gateway 4.

The sequence of FIG. 27 is described below.

The session layer protocol means 2302 of the terminal 1 sends a stop notification 2314 to the session layer protocol means 2305 of the gateway 4 when receiving the switch notification 2313.

The session layer protocol means 2305 of the gateway 4 sends the reception notification 2314 to the management entity 2307.

The session layer protocol means 2305 of the gateway 4 reads the contents of the HTTP command REQUEST (get, // www. Xxx / xyz.htm) 2320 from the terminal 1 in an ACK 2329 of the wireless communication protocol. ) Until you receive it. In this state, the gateway 4 transmits an HTTP command REQUEST (get, // www. Xxx / xyz.htm) 2316 to the server 6.

Here, when the gateway 4 notifies the server of the HTTP command REQUEST (get, // www. Xxx / xyz.htm) 2316, this REQUEST (get, // www. Xxx / xyz.htm) ( The address of the gateway that transmits the RESPONSE (data) (here, 2327) corresponding to 2316 is notified.

In the above description, the HTTP command and the address notified can be treated as other information, and can also be included in the HTTP command. In the latter case, the server 6 interprets the HTTP command to extract the address portion.

The subsequent stop confirmation notification 2315 and the resume sequence are omitted as shown in FIG.

When the session of the session layer protocol means 2302 of the terminal 1 and the session layer protocol means 2309 of the gateway 5 is resumed, the session layer protocol means 2309 of the gateway 5 resume notification 2317. Receive HTTP RESPONSE (data) 2327 from the server 6 by using the transaction status and transaction ID received by the server 6, and the protocol conversion means 2310 responds to the response of the wireless communication protocol REPLY (Data)> ( 2328, and transmits to the session layer protocol means 2302 of the terminal (1).

Subsequent sequences up to ACK 2329 of the wireless communication protocol are omitted as shown in FIG.

According to the sequence described above, even when there is no negotiation means between the gateways, the gateway connection can be switched even if the application of the terminal does not accept the data for the request, and gateway connection switching with less influence on the application or the user of the terminal is achieved. can do.

In the above-described embodiment, the switching gateway is stopped after the connection switching, but it is not necessary to stop the operation.

As mentioned above, it is assumed that there is a switching instruction when the terminal receives a service from the server. However, the present invention is not limited to the above. That is, even when the service is not received, the switching source gateway may send only the switching notification to the terminal, or may send the terminal the information necessary for the activation of communication with the switching destination gateway in addition to the notification.

As described above, according to the present invention, even when the terminal and the connected gateway are stopped, the connection switching negotiation is performed between the gateways before the gateway is stopped, so that the terminal has the terminal capacity without terminating the application running in the terminal. The advantageous effect of being able to reconnect to another gateway in a short time is obtained.

In addition, the gateway can be switched even if the application is not accepting data about the request. In other words, since the switching gateway transfers the state of the transaction to the switching destination, the terminal side can switch the gateway without being aware of the state of the transaction.

Even when connection switching negotiation cannot be directly performed between the gateways, the gateway can be switched even if the application does not accept the data for the request, and it can be reconnected in a short time to another gateway having terminal capacity compared to the conventional one. .

In either case, the terminal does not always have to maintain the information of the plurality of gateways, so that the terminal can easily respond even if the network configuration changes.

Claims (47)

delete delete delete A communication system for establishing communication between a wireless information terminal and a server through a gateway, To the gateway: When the gateway of the switching source relays the communication between the wireless information terminal and the server, when the gateway switch instruction is given, information necessary for communication with the server via the wireless information terminal and the gateway of the switching destination is transmitted to the wireless information terminal. An information notification means for notifying, On the wireless information terminal: Resume starting to receive information necessary for communication with the server through the gateway of the switching destination, stop the communication with the gateway of the switching source, and perform resumption of communication with the gateway of the switching destination. With means, In the process of interrupting communication with the switchover gateway, when an incomplete transaction remains, the switchover gateway notifies the switchover gateway before the resumption sequence of information on the destination of the request for the radio information terminal. A communication system, comprising: an information exchange means. 5. The communication as claimed in claim 4, wherein the incomplete transaction is a case in which the wireless information terminal arrives at the server as a request for the server, which occurs after the switching notification is sent from the gateway of the switching source to the wireless information terminal. system. 5. The wireless information terminal as set forth in claim 4, wherein the incomplete transaction corresponds to a request that arrives at the server from the wireless information terminal generated before the switch notification is sent from the gateway of the switching source to the wireless information terminal. And a case in which an ACK is returned to the communication system. 5. The method of claim 4, wherein the incomplete transaction is a request to a server in a wireless information terminal that occurs before a switching notification is sent from a switching source gateway to a wireless information terminal, and the response is sent to the switching gateway at the interruption. And a case of not arriving at a wireless information terminal. delete delete delete A gateway for use in a communication system for relaying communication between a wireless information terminal and a server providing a service to the wireless information terminal, The switching source gateway includes information notification means for notifying the wireless information terminal of information necessary for communication with the gateway of the switching destination to the wireless information terminal. The gateway of the switching source notifies the server of the response destination for the request of the radio information terminal before the resumption sequence when an incomplete transaction remains in the process of interrupting communication with the radio information terminal. Gateway. 12. The gateway as claimed in claim 11, wherein the incomplete transaction is based on a request that has not arrived at the server as a request to the server at the wireless information terminal, which occurs after a switching notification is sent to the wireless information terminal. 12. The non-complete transaction is a request that arrives at a server from a wireless information terminal generated before a switch notification is sent to the wireless information terminal, and an ACK is sent to the wireless information terminal. Gateway. 12. The non-complete transaction according to claim 11, wherein the incomplete transaction is a request to a server from a wireless information terminal generated before a switching notification is sent to the wireless information terminal, in which a response from the server has not arrived at the wireless information terminal at the interruption. Gateway characterized in that. delete A communication system for establishing communication between a wireless information terminal and a server providing a service to the wireless information terminal through a gateway, To the gateway: When the gateway of the switching source relays the communication between the wireless information terminal and the server, when the switching instruction of the gateway is given, information necessary for the wireless information terminal and the server to communicate through the switching destination gateway is switched to the switching source. Information exchange means for enabling exchange between gateways of different locations; An information notification means for notifying the wireless information terminal of the switching source of the information necessary for communication with the gateway of the switching destination; On the wireless information terminal: Resume starting to receive the information necessary for communication with the server through the gateway of the switching destination at the switching gateway, interrupting communication with the switching gateway, and executing the resumption procedure of communication with the switching gateway. Communication system comprising a means. 17. The communication status information according to claim 16, wherein when the information on the communication status between the radio information terminal and the switching source gateway is different before and after information exchange between the switching source gateway and the switching destination gateway by the information exchange means. And the resumption starting means for notifying the gateway of the switching destination at the wireless information terminal when the wireless information terminal makes a communication connection with the gateway of the switching destination. . 18. The communication system according to claim 17, wherein the mismatch occurs based on communication between the radio information terminal generated during the information exchange and the gateway device of the switching source. 17. The switching source gateway of claim 16, wherein, when an incomplete transaction remains in the process of interrupting communication with the gateway of the switching source, the switching source gateway notifies the switching destination gateway of information about the incomplete transaction before the resumption procedure. And said information exchange means. 20. The wireless information terminal according to claim 19, wherein the incomplete transaction occurs after a switching notification is sent from the gateway of the switching source to the wireless information terminal. Communication system. 20. The server according to claim 19, wherein the incomplete transaction corresponds to a request from a server in a wireless information terminal that occurs before a switching notification is sent from the switching gateway to the wireless information terminal, and after the interruption, the server to the switching gateway. And a communication system based on the case where there is a response. 20. The switching source according to claim 19, wherein the incomplete transaction is a request to a server in a wireless information terminal that occurs before a switching notification is sent from the gateway of the switching source to the wireless information terminal. Communication system based on the response to the gateway. 17. The information transmitted to the gateway of the switching destination from the switching source gateway includes the capability of the radio information terminal, and the capability of the radio information terminal can be accommodated in the gateway of the switching destination. And the information exchange means for notifying the gateway of the switching source of the capability that can be provided to the wireless information terminal when there is no information. 24. The information communication apparatus according to claim 23, further comprising: information notification means for notifying a radio information terminal of the capability of the gateway of the switching destination together with the switching notification; And a judging means on the radio information terminal side for judging whether to resume communication with the gateway of the switching destination in accordance with the capability. 24. The apparatus of claim 23, further comprising determining means at the gateway side of the switching source to determine whether or not communication with the wireless information terminal is possible by the capability of the gateway at the switching destination, and when not possible. Communication system, characterized in that one. 17. The communication system according to claim 16, further comprising: information exchange means for performing information exchange with a gateway of a switching destination of another candidate when switching from the gateway of the switching destination of the first candidate is rejected. A gateway for use in a communication system for relaying communication between a wireless information terminal and a server providing a service to the wireless information terminal, In the state of relaying communication between the wireless information terminal and the server, when there is a switching instruction of the gateway, information necessary for communication with the server via the wireless information terminal and the gateway of the switching destination is exchanged between the switching destination gateway. Information exchange means to enable the; And the information notification means for notifying the wireless information terminal of information necessary for communication with the gateway of the switching destination. 28. The method according to claim 27, wherein, when an incomplete transaction remains during communication interruption with the radio information terminal, information on the incomplete transaction is notified to the gateway of the switching destination before the resumption procedure by the radio information terminal. And the information exchange means. 29. The switching source side gateway according to claim 28, wherein the incomplete transaction is based on a request that has not arrived at the server as a request to the server at the wireless information terminal, which occurs after a switching notification is sent to the wireless information terminal. 29. The method of claim 28, wherein the incomplete transaction responds to a request from the server to the gateway of the switching source after the interruption in response to a request from the wireless information terminal that occurred before the switch notification is sent to the wireless information terminal. A gateway on the switching source side, based on the configuration. 29. The method of claim 28, wherein the incomplete transaction is a request to a server from a wireless information terminal that occurs before a switching notification is sent to the wireless information terminal, and responds to the gateway of the switching source that has not arrived at the wireless information terminal at the interruption. A gateway on the switching source side, based on the configuration. delete delete delete delete In a wireless information terminal for establishing communication with a server providing a service through a gateway, When the switchover gateway relays communication between the wireless information terminal and the server, when the switchover instruction is given, the switchover notification informs the switchover of the information necessary to communicate with the server via the switchover gateway. And a restarting means for interrupting the communication with the gateway of the switching source and resuming the communication with the gateway of the switching destination according to this information. When there is an inconsistency between the switching source gateway and the switching destination gateway, before and after the necessary information exchange after the switching, and when there is a mismatch in the notification state with the switching source gateway, information for correcting the inconsistency is sent to the switching destination gateway in the resumption procedure. Wireless information terminal, characterized in that for notifying. delete delete delete delete delete delete A communication method for establishing communication between a wireless information terminal and a server providing a service to the wireless information terminal through a gateway, When the switchover gateway relays the communication between the radio information terminal and the server, when the operator switches the gateway, the switch source provides information necessary for the radio information terminal and the server to communicate through the switchover gateway. Notifying the gateway of the switching destination at the gateway of the gateway; Notifying the wireless information terminal at the switchover source of the information necessary for communication with the gateway at the switchover point; In addition, the wireless information terminal executes a procedure of resuming communication with the gateway of the switching destination while stopping communication with the gateway of the switching source while receiving information necessary for communication with the server through the gateway of the switching destination. Communication method comprising the steps of. In a communication system for establishing communication between a wireless information terminal and a server through a gateway, When the radio information terminal needs to switch from the first gateway to the second gateway, the radio information terminal is informed of the information necessary for communicating with the server via the second gateway, The information necessary for communicating with the server through the second gateway includes an address of the second gateway, and the wireless information terminal receives the information and communicates with the server without passing through the first gateway. Communication system. In a communication system for establishing communication between a wireless information terminal and a server through a gateway, When the radio information terminal needs to switch from the first gateway to the second gateway, the radio information terminal is informed of the information necessary for communicating with the server via the second gateway, Information necessary for communicating with a server through the second gateway includes a feature of a second gateway, and the wireless information terminal receives the information and communicates with the server without passing through the first gateway. Communication system. In a wireless information terminal that establishes communication with a server through a gateway, Means for receiving information necessary for communicating with a server via said second gateway when said radio information terminal needs to switch from a first gateway to a second gateway, The information necessary for communicating with the server through the second gateway includes an address of the second gateway, and the wireless information terminal receives the information and communicates with the server without passing through the first gateway. Wireless Information Terminal. In a wireless information terminal that establishes communication with a server through a gateway, Means for receiving information necessary for communicating with a server via said second gateway when said radio information terminal needs to switch from a first gateway to a second gateway, Information necessary for communicating with a server through the second gateway includes a feature of a second gateway, and the wireless information terminal receives the information and communicates with the server without passing through the first gateway. Wireless Information Terminal.

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