Abstract:
A communication system in which, even when an HTTP session is disconnected from a mobile device, the HTTP session can be continued or a response from a Web server can be returned to a user, without installing a special application in the mobile device. A load-distributable system is provided for realizing such operation. To that end, in a communication system having a relay device that relays a request from a portable telephone terminal ( 110 ) to a Web server ( 120 ), the relay device ( 130 ) relays a processing request from the portable telephone terminal ( 110 ) to the Web server, and stores a processing response from the Web server. The relay device ( 130 ) sends the portable telephone terminal a message to the effect that the processing response should be acquired from the relay device ( 130 ) or a message with the processing response added.

Description:
INCORPORATION BY REFERENCE  
       [0001]     This application claims a priority from the Japanese patent application No. 2006-183251 filed on Jul. 3, 2006, the entire content of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to a technique of relaying communication between a communication terminal and a communication server.  
         [0003]     Recently, Web (World Wide Web) servers perform various kinds of processing in reply to processing requests from portable telephone terminals.  
         [0004]     When a Web server performs complex processing, processing time in the Web server becomes longer and thus sometimes a HyperText Transfer Protocol (HTTP) session is disconnected. In addition, since a portable telephone terminal communicates by radio, its communication line is frequently disconnected in the course of communication.  
         [0005]     In connection with this, in the field of database access processing, Japanese Unexamined Patent Application Laid-Open No. 2000-57089 (hereinafter, referred to as Patent Document 1) discloses a technique in which a Web browser sends a processing request to a Web server, the Web server performs processing of a database offline, and the Web browser periodically sends an HTTP request to the Web server so that the Web browser can acquire a processing result from the Web server when the processing is finished.  
       SUMMARY OF THE INVENTION  
       [0006]     According to the technique described in Patent Document 1, an HTTP request cannot be sent to the same Web server to which an HTTP request was sent the previous time, when workload is distributed among Web servers by a load balancer. Further, according to that technique, it is required to install, in a client-side terminal, a Web browser or an application that periodically sends an HTTP request.  
         [0007]     Accordingly, in the case of a mobile device such as a portable telephone terminal, such a Web browser or application must be installed in each device and a program must be developed for such a Web browser or application for each device, which is inconvenient.  
         [0008]     The present invention enables the HTTP session to be continued or a response from a Web server to be returned to a user, even when an HTTP session is disconnected from a mobile device such as a portable telephone terminal, without installing a special application in that mobile device, and provides a load-distributable system for realizing this.  
         [0009]     According to the present invention, a result of processing in a Web server is stored in a relay device. The relay device sends a message according to a prescribed protocol to a portable telephone terminal, so as to provide a system that performs processing corresponding to the message received by the portable telephone terminal and acquires the processing result from the relay device.  
         [0010]     For example, the present invention provides a relay device that relays communication between a communication terminal and a communication server, comprising: a storage part that stores a response from the communication server; and a control part that controls processing of sending a message according to a predetermined protocol to the communication terminal when the response is received.  
         [0011]     Thus, according to the present invention, a portable telephone terminal that has received a message according to the prescribed protocol from a load-distributed relay device can perform processing corresponding to the received message and acquire the processing result from the relay device that has stored the processing result of the Web server. Therefore, even when the line is disconnected before receiving the processing result, the portable telephone terminal can assuredly acquire the processing result and continue the processing that was being performed before the disconnection of the line.  
         [0012]     These and other benefits are described throughout the present specification. A further understanding of the nature and advantages of the invention may be realized by reference to the remaining portions of the specification and the attached drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a schematic diagram showing a communication system as a first embodiment of the present invention;  
         [0014]      FIG. 2  is a schematic diagram showing an ID information table;  
         [0015]      FIG. 3  is a sequence diagram showing processing in sending and receiving information in the communication system;  
         [0016]      FIG. 4  is a sequence diagram showing processing performed when a portable telephone terminal receives a message according to a push-type protocol;  
         [0017]      FIG. 5  is a flowchart showing processing performed when a relay device receives a request from a portable telephone terminal;  
         [0018]      FIG. 6  is a schematic diagram showing a communication system;  
         [0019]      FIG. 7  is a schematic diagram showing a communication system as a second embodiment of the present invention;  
         [0020]      FIG. 8  is a schematic diagram showing an ID information table; and  
         [0021]      FIG. 9  is a sequence diagram showing processing in sending and receiving information in the communication system.  
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0022]      FIG. 1  is a schematic diagram showing a communication system  100  as a first embodiment of the present invention.  
         [0023]     As shown in the figure, the communication system  100  comprises a portable telephone terminal  110 , a Web server  120 , and a relay device  130 . The portable telephone terminal  110  and the relay device  130  are connected through a carrier communication network  150 , and the Web server  120  and the relay device  130  are connected through the Internet  151 .  
         [0024]     The portable telephone terminal  110  of the present embodiment can be connected to the carrier communication network  150  by radio so that the portable telephone terminal  110  can send and receive data to and from the Web server  120  through the carrier communication network  150  and the Internet  151 .  
         [0025]     Here, it is arranged that the portable telephone terminal  110  of the present embodiment stores a terminal ID for identifying uniquely the portable telephone terminal  110  in a header (for example, an HTTP header) of a message for requesting some kind of processing to the below-described Web server  120 , before sending the message.  
         [0026]     Further, the portable telephone terminal  110  of the present embodiment has a Web communication function (an HTTP communication function), a function of sending and receiving mails, a function of receiving messages according to a push-type protocol, and a function of connecting to the below-described relay device  130 .  
         [0027]     The push-type protocol is protocol used when relay device  130  can push data to a portable telephone terminal, for example, SMPP (Short Message Peer-to-peer Protocol), PAP(Push Access Protocol) etc.  
         [0028]     Although  FIG. 1  shows only one portable telephone terminal  110 , a plurality of portable telephone terminals  110  can be connected to the carrier communication network.  
         [0029]     The Web server  120  of the present embodiment performs prescribed processing in reply to a processing request from a portable telephone terminal  110 , and sends a processing result as a result response to the portable telephone terminal  110 .  
         [0030]     As shown in the figure, the relay device  130  comprises an ID information table storage part  131 , a relay processing part  132 , a data storage part  133 , and a sending/receiving part  134 . The relay device  130  has a proxy function, a sending/receiving function according to a push-type protocol, and a sending/receiving function according to a mail protocol.  
         [0031]     The ID information table storage part  131  stores, for each portable telephone terminal  110 , a terminal ID for identifying the portable telephone terminal uniquely, a mail address of the portable telephone terminal  110  in question, a communication address of the portable telephone terminal  110 , an initial value of a period for time-out at which a session is disconnected, and an extended value of time-out, at which a session is disconnected.  
         [0032]     In detail, the ID information table storage part  131  stores an ID information table  131   a  as shown in  FIG. 2 .  
         [0033]     The ID information table  131   a  has a terminal ID registration field  131   b,  a mail address registration field  131   c,  a communication address registration field  131   d,  a default time-out registration field  131   e,  and an extended time-out registration field  131   f.    
         [0034]     The terminal ID registration field  131  registers a terminal ID for identifying a portable telephone terminal  110  uniquely. Here, for example, a telephone number, a machine number, subscriber ID or the like, of a portable telephone terminal  110  can be used as a terminal ID.  
         [0035]     The mail address registration field  131   c  registers a mail address of the portable telephone terminal  110 .  
         [0036]     The communication address registration field  131   d  registers a communication address that is used by the portable telephone terminal  110  for sending and receiving push-type protocol data through the carrier communication network  150 .  
         [0037]     The default time-out registration field  131   e  registers an initial value for time-out on which a session is disconnected.  
         [0038]     The extended time-out registration field  131   f  registers an extended value for time-out at which a session is disconnected.  
         [0039]     The relay processing part  132  performs so-called proxy processing. That is, the relay processing part  132  receives a communication request from a portable telephone terminal  110  through the below-described sending/receiving part  134 , and relays the received communication request to the Web server  120  through the Internet  151 .  
         [0040]     Further, the relay processing part  132  receives a processing request from a portable telephone terminal  110 , and determines a time-out period for disconnecting a session with the portable telephone terminal  110  according to content of the processing request.  
         [0041]     In detail, the relay processing part  132  analyzes a header of a message of a processing request from a portable telephone terminal  110 , to specify content of the processing requested from the portable telephone terminal  110 . That is, the relay processing part  132  specifies content of the processing requested from the portable telephone terminal  110 , based on whether a specific character string exists in the header of the message. When a specific character string does not exist in the header of the message, the relay processing part  132  selects the initial value for time-out, which is registered in the default time-out registration field  131   e  of the ID information table  131   a.  On the other hand, when a specific character string exists in the header, the relay processing part  132  selects the extended value for time-out, which is registered in the extended time-out registration field  131   f  of the ID information table  131   a.  Thus, the period specified by the initial value or the extended value is determined as the time-out period for the session.  
         [0042]     It is desirable that sending of another request from the portable telephone terminal  110  be prohibited until the time-out period elapses.  
         [0043]     Here, when some type of character string exists in a header of a message of a processing request from a portable telephone terminal  110 , a suitable selection may be made as to an extended value for time-out, depending on content of the processing that the Web server  120  is requested to perform. For example, in the present embodiment, the initial value for time-out is selected in the case where a request is, for example, a simple one for acquisition of data such as a front page from the Web server  120 . In the other cases where processing is expected to require a lot of time such as, for example, a case where a request follows Simple Object Access Protocol (SOAP) and a case where a request includes a specific User-Agent header or Cookie information, the extended value for time-out is selected.  
         [0044]     Further, when the relay processing part  132  receives a response of the Web server to a request from a portable telephone terminal  110 , then the relay processing part  132  stores the response into the below-described data storage part  133 .  
         [0045]     Then, in the case where the time-out period determined by the request from the portable telephone terminal  110  has not elapsed, the relay processing part  132  relays the response stored in the data storage part  133  to the portable telephone terminal  110 . On the other hand, in the case where the time-out period has elapsed, the relay processing part  132  suitably selects the push-type protocol or the mail protocol by a predetermined algorithm, and sends a message according to the selected protocol to the portable telephone terminal  110 .  
         [0046]     Here, in the case where a message according to the push-type protocol is sent to the portable telephone terminal  110 , the message includes a relay device Uniform Resource Locator (URL) for connecting to the relay device  130  and information ID for identifying the response received from the Web server. Receiving the message, the portable telephone terminal  110  connects to the relay device  130  corresponding to the relay device URL through the carrier communication network  150  according to the received message, and acquires the result response corresponding to the information ID included in the received message from the relay device  130 .  
         [0047]     On the other hand, in the case of a message according to the mail protocol, the response is attached to the message.  
         [0048]     The data storage part  133  stores a response received from the Web server  120 , associating the response with an information ID for identifying the response uniquely.  
         [0049]     The sending/receiving part  134  is an input/output interface for sending and receiving information through the carrier communication network  150 .  
         [0050]     The relay device  130  of the above configuration can be implemented by an ordinary computer. For example, the ID information table storage part  131  and the data storage part  133  can be implemented by external storage such as a hard disk. The relay processing part  132  can be implemented when a Central Processing Unit (CPU) executes a predetermined program stored in the external storage. The sending/receiving part  134  can be implemented by a Network Interface Card (NIC).  
         [0051]     Furthermore, the predetermined program may be downloaded, to an external storage device, from a storage medium via a reading device, or from a network, via a communication device. The program may be directly downloaded from the medium via the reading device, or from the network via the communication device, to be executed by the CPU. It is assumed that the program includes code or a module for making the computer perform predetermined processing. In addition, “medium” includes all media, including storage media, communication media, and the like, that can provide a program.  
         [0052]     The carrier communication network  150  includes a base station for sending and receiving information to and from a portable telephone terminal  110  by radio, and a gateway for performing protocol conversion between the Internet  151  and the carrier communication network  150 . Whenever a portable telephone terminal  110  connected to the carrier communication network  150  connects to the Web server  120 , the portable telephone terminal  110  connects to the Web server  120  through the relay device  130 .  
         [0053]     In the present embodiment, a plurality of relay devices is connected to the carrier communication network  150  to distribute workload. However, this mode is not restrictive, and the processing may be performed by only one relay device  130 .  
         [0054]     Processing of sending and receiving information in the communication system  100  of the above-described configuration will be described referring to the sequence diagram shown in  FIG. 3 .  
         [0055]     First, a portable telephone terminal  110  sends a request for a front page to the Web server  120  ( 160 ). The HTTP header of this front page request includes the terminal ID for identifying the portable telephone terminal  110  uniquely.  
         [0056]     The front page request sent from the portable telephone terminal  110  is received by a relay device  130  through the carrier communication network  150 . The relay device  130  extracts the terminal ID from the HTTP header of the front page request ( 161 ), confirms that the HTTP header does not include predetermined kinds of data, and acquires the default time-out value corresponding to the extracted terminal ID from the default time-out registration field  131   e  of the ID information table  131   a  ( 162 ).  
         [0057]     The relay device  130  sends a service notification response to the portable telephone terminal  110  as the sender of the front page request ( 163 ). At that time, the HTTP header of the service notification response may include information (for example, a Retry-After header) that prohibits the portable telephone terminal  110  from sending of another front page request.  
         [0058]     Further, the relay device  130  sends the front page request received from the portable telephone terminal  110  to the Web server  120  ( 164 ).  
         [0059]     Receiving the front page request, the Web server  120  sends a front page response corresponding to the request to the portable telephone terminal  110  ( 165 ).  
         [0060]     The front page response sent from the Web server  120  is received by the relay device  130  through the carrier communication network  150 . The received front page response is stored in the data storage part  133  of the relay device  130  ( 166 ).  
         [0061]     Further, when the relay device  130  receives the front page response, the relay device  130  examines whether the time-out period acquired in the step  162  has elapsed or not ( 167 ). Here, it is assumed that the time-out period has not elapsed.  
         [0062]     Then, in the case where the time-out period has not elapsed, the relay device  130  sends the front page response stored in the data storage part  133  to the portable telephone terminal  110  ( 168 ).  
         [0063]     Next, through the received front page response, the portable telephone terminal  110  sends the Web server  120  a processing request that requests the Web server  120  to perform specific processing ( 169 ). The HTTP header of this processing request includes the terminal ID for identifying the portable telephone terminal  110 .  
         [0064]     The processing request sent from the portable telephone terminal  110  is received by the relay device  130  through the carrier communication network  150 . The relay device  130  extracts the terminal ID from the HTTP header of the processing request ( 170 ), confirms that the HTTP header includes a predetermined data, and acquires the extended time-out value corresponding to the extracted terminal ID from the extended time-out registration field  131   f  of the ID information table  131   a  ( 171 ).  
         [0065]     Further, the relay device  130  sends the processing request received from the portable telephone terminal  110  to the Web server  120  ( 172 ).  
         [0066]     Here, it is assumed that the session between the portable telephone terminal  110  and the relay device  130  is disconnected ( 173 ).  
         [0067]     Receiving the processing request, the Web server  120  performs the processing corresponding to the processing request ( 174 ), and sends, as a result response, a result of the processing to the portable telephone terminal  110  ( 175 ).  
         [0068]     The result response sent from the Web server  120  is received by the relay device  130  through the carrier communication network  150 . The received result response is stored in the data storage part  133  of the relay device  130  ( 176 ).  
         [0069]     Then, when the relay device  130  detects disconnection of the session between the portable telephone terminal  110  and the relay device  130  ( 177 ) the relay device  130  suitably selects a protocol for sending to the portable telephone terminal  110  ( 178 ), and sends a message corresponding to the selected protocol to the portable telephone terminal  110  ( 179 ).  
         [0070]     Here, the present embodiment assumes that a protocol can be selected from the push-type protocol and the mail protocol. The method of selection follows the following selection methods (1)-(5).  
         [0071]     (1) The relay device  130  tries a session with the portable telephone terminal  110  according to the push-type protocol, and when the number of times, that the relay device  130  detects disconnection of the session with the portable telephone terminal  110 , reaches a prescribed number, within a certain period, then the relay device  130  selects the mail protocol.  
         [0072]     (2) When the relay device  130  detects disconnection or time-out of the session with the Web server  120 , then the relay device  130  selects the mail protocol.  
         [0073]     (3) When the number of lines (the number of portable telephone terminals) that the relay device  130  handles at the same time has reached a prescribed threshold, then the relay device  130  selects the mail protocol.  
         [0074]     (4) When the usage rate of the CPU or the memory of the relay device  130  has reached a prescribed threshold, then the relay device  130  selects the mail protocol.  
         [0075]     (5) In cases other than (1)-(4), the relay device  130  selects the push-type protocol.  
         [0076]     Here, the certain time period and the prescribed number of times in the selection method (1), and the thresholds in the selection methods (3) and (4), do not need to be constant values at all times, and can be changed according to the content of the processing that the Web server has been requested to perform. For example, it is possible that these values, in the case where a processing request from a portable telephone terminal  110  includes at least one of: the enquiry character, User-Agent header and Cookie information, are different from values in the case where the processing request includes none of them.  
         [0077]     Further, in the present embodiment, when the relay device  130  selects the push-type protocol, then the relay device  130  sends a message that includes a data ID for identifying the result response stored in the data storage part  133  and the relay device URL, i.e., location information of the relay device  130 , to the portable telephone terminal  110 . On the other hand, when the relay device  130  selects the mail protocol, then the relay device  130  sends a message, accompanied by the result response stored in the data storage part  133 , to the portable telephone terminal  110 .  
         [0078]     It is possible that, in the case where the mail protocol is selected and disconnection or time-out of the session with the Web server  120  is not detected, the relay device  130  sends a message also including the relay device URL, i.e., the location information of the relay device  130 , to the portable telephone terminal  110 .  
         [0079]     Receiving such a message, the portable telephone terminal  110  performs processing according to the received message ( 180 ).  
         [0080]      FIG. 4  shows a sequence diagram showing processing performed in the case where the portable telephone terminal  110  receives a message according to the push-type protocol.  
         [0081]     Here, when the relay device  130  selects the push-type protocol, the relay device  130  sends a message including the relay device URL to the portable telephone terminal  110 , and the portable telephone terminal  110  sends a request addressed to the relay device URL included in the received message ( 181 ). Here, based on the relay device URL included in the message, the portable telephone terminal  110  can uniquely identify the relay device  130  with which the portable telephone terminal  110  had a session before disconnection of the session ( 173 ), and thus can continue the disconnected session.  
         [0082]     The relay device  130  receives the request addressed to the relay device URL, and sends the result response (which has been received from the Web server  120  and stored in the data storage part  133 ) to the portable telephone terminal  110  ( 182 ).  
         [0083]     Then, through the received result response, the portable telephone terminal  110  sends a next processing request ( 183 ), and continues the session ( 184 ). Further, in the case where the processing request received from the portable telephone terminal  110  does not include Cookie information required for a session with the Web server  120 , then the relay device  130  adds the Cookie information to the processing request ( 185 ).  
         [0084]     The relay device  130  sends the processing request to the Web server  120  to continue the session between the portable telephone terminal  110  and the Web server  120  ( 186 ).  
         [0085]     On the other hand, when the relay device  130  selects the mail protocol, the relay device  130  adds the result response received from the Web server  120  to a mail message. In the case where time-out has not occurred in the Web server  120 , then the relay device  130  also adds the relay device URL to the mail message. Then, the relay device  130  sends the mail message to the portable telephone terminal  110 .  
         [0086]     By receiving such a mail, the portable telephone terminal  110  receives, as a message of the mail, the result response from the Web server  120 . In the case where the message includes the relay device URL, the session can be continued when the portable telephone terminal  110  sends an HTTP request to the relay device URL.  
         [0087]      FIG. 5  is a flowchart showing processing performed when the relay device  130  receives a request from the portable telephone terminal  110 .  
         [0088]     When the relay device  130  receives a request from the portable telephone terminal  110  (S 190 ), the relay device  130  extracts the terminal ID included in the HTTP header of the received request (S 191 ).  
         [0089]     Then, in the case where the HTTP header of the received request does not include the predetermined data (S 192 ), the relay device  130  extracts the default time-out value corresponding to the extracted terminal ID from the default time-out registration field  131   e  of the ID information table  131   a  (S 192 ).  
         [0090]     On the other hand, in the case where the HTTP header of the received request includes the predetermined data (S 193 ), the relay device  130  extracts the extended time-out value corresponding to the extracted terminal ID from the extended time-out registration field  131   f  of the ID information table  131   a  (S 194 ).  
         [0091]     For example, in the case where the request follows SOAP or the case where the HTTP header includes a specific User-Agent header or Cookie information, then the relay device  130  extracts the extended time-out value. Otherwise, the relay device  130  extracts the default time-out value.  
         [0092]     The relay device  130  sends a service notification response to the portable telephone terminal  110  (S 195 ).  
         [0093]     Further, the relay device  130  sends the request received from the portable telephone terminal  110  to the Web server  120  (S 196 ).  
         [0094]     Then, when the relay device  130  receives a response from the Web server  120  (S 197 ), the relay device  130  stores the received response in the data storage part  133  (S 198 ) Next, the relay device  130  judges whether the session with the portable telephone terminal  110  has been disconnected or not (S 199 ).  
         [0095]     In the case where the session has not been disconnected (S 199 ), the relay device  130  sends the response stored in the data storage part  133  to the portable telephone terminal  110  (S 200 ), to end the processing.  
         [0096]     On the other hand, in the case where the session has been disconnected (S 199 ), the relay device  130  selects a protocol by the prescribed selection method (S 201 ), and sends a message according to the selected protocol (S 202 ), to end the processing.  
         [0097]     Here, in the case where the push-type protocol is selected in step S 202  and the relay device  130  receives a send request specifying the data ID for identifying the response from the portable telephone terminal  110 , then the relay device  130  sends the response stored in the data storage part  133  to the portable telephone terminal  110 .  
         [0098]     In the above-described embodiment, the relay device  130  is connected to the carrier communication network  150 . This mode is not restrictive. For example, as the communication system  300  shown in  FIG. 6 , it is possible to connect a relay device  330  to the Internet  151 .  
         [0099]     In such a case, the address of the relay device  330  is stored in advance in a portable telephone terminal  310 . When the portable telephone terminal  310  connects to the Web server  120 , connection is established through the relay device  330 .  
         [0100]     The processing performed in the above-described relay device  130  or  330  can be distributed. For example, it is possible to provide a mail server that sends prescribed messages to a portable telephone terminal  110 ,  310 , a push-type protocol server that sends prescribed messages according to the push-type protocol to a portable telephone terminal  110 ,  310 , and a database server that stores the ID information table  131   a,  to distribute the processing performed in the relay device  130  or  330 .  
         [0101]      FIG. 7  is a schematic diagram showing a communication system  400  as a second embodiment of the present invention.  
         [0102]     As shown in the figure, the communication system  400  comprises a portable telephone terminal  110 , a Web server  420  and a relay device  430 .  
         [0103]     The portable telephone terminal  110  of the present embodiment can be connected to a carrier communication network  150  by radio, similarly to the first embodiment, so that the portable telephone terminal  110  can send and receive data to and from the Web server  420  through the carrier communication network  150  and the Internet  151 .  
         [0104]     The portable telephone terminal  110  of the present embodiment stores a terminal ID for identifying uniquely the portable telephone terminal  110  in a header (for example, an HTTP header) of a message, when the message is sent requesting some kind of processing to the below-described Web server  420 , and the message is sent.  
         [0105]     Further, the portable telephone terminal  110  of the present embodiment has a function of sending and receiving mails, and a function of receiving a message according to a push-type protocol and connecting to the below-described relay device  430 .  
         [0106]     The Web server  420  of the present embodiment sends a portable telephone terminal  110  a temporary response (hereinafter, referred to as a processing start response) for notifying start of processing, in reply to a processing request from the portable telephone terminal  110 , and performs prescribed processing. Then, the Web server puts a processing result (hereinafter, referred to as a result response) in a request (hereinafter, referred to as a relay processing request) in order to entrust the subsequent processing to the relay device  430 , and sends the request.  
         [0107]     As shown in the figure, the Web server  420  of the present embodiment comprises a service providing part  421 , a relay processing part  422 , a relay data storage part  423  and a sending/receiving part  424 .  
         [0108]     The service providing part  421  receives a processing request from the portable telephone terminal  110  through the below-described sending/receiving part  424 , performs the processing corresponding to the received processing request, and generates a result response, i.e., a result of the processing.  
         [0109]     The relay processing part  422  generates a relay processing request including a result response generated by the service providing part, and sends the relay processing request to the relay device  430  through the below-described sending/receiving part  424 .  
         [0110]     Here, the relay processing request includes also the terminal ID included in the HTTP header of the portable telephone terminal  110  that has sent the processing request.  
         [0111]     The relay processing part of the present embodiment does not need to perform so-called proxy processing, differently from the first embodiment.  
         [0112]     The sending/receiving part  424  sends and receives data through the Internet  151 .  
         [0113]     The Web server  420  of the above-described configuration can be implemented by an ordinary computer.  
         [0114]     For example, the service providing part  421  and the relay processing part  422  can be implemented when a CPU executes predetermined programs stored in external storage such as a hard disk. The relay data storage part  423  can be implemented by the external storage such as a hard disk. The sending/receiving part  424  can be implemented by an NIC.  
         [0115]     As shown in the figure, the relay device  430  of the present embodiment comprises an ID information table storage part  431 , a relay processing part  432 , a data storage part  133  and a sending/receiving part  134 .  
         [0116]     The ID information table storage part  431  stores, for each portable telephone terminal  110 , a terminal ID for identifying the portable telephone terminal uniquely, a mail address of the portable telephone terminal  110  in question, and a communication address of the portable telephone terminal  110 .  
         [0117]     In detail, the ID information table storage part  431  stores an ID information table  431   a  as shown in  FIG. 8 . The present embodiment can be realized also by a configuration in which not the relay device  430  but the Web server  420  has the ID information table storage part  431  and the relay device  430  acquires the ID information table  431   a  by receiving a relay processing request.  
         [0118]     The ID information table  431   a  has a terminal ID registration field  431   b,  a mail address registration field  431   c,  and a communication address registration field  431   d.    
         [0119]     The terminal ID registration field  431   b  registers a terminal ID for identifying a portable telephone terminal  110  uniquely. Here, for example, a telephone number, a machine number, or the like, can be used as a terminal ID.  
         [0120]     The mail address registration field  431   c  registers a mail address of the portable telephone terminal  110 .  
         [0121]     The communication address registration field  431   d  registers a communication address that is used by the portable telephone terminal  110  for sending and receiving data through the carrier communication network  150 .  
         [0122]     When the relay processing part  432  receives a relay processing request from the Web server  420  through the below-described sending/receiving part  134 , the relay processing part  432  stores the relay processing request in the below-described data storage part  133 .  
         [0123]     The relay processing part  432  selects a push-type protocol or a mail protocol by a predetermined algorithm, and sends a message according to the selected protocol to the portable telephone terminal  110 .  
         [0124]     Here, in the case where a message according to the push-type protocol is sent to the portable telephone terminal  110 , the message includes a relay device URL for connecting to the relay device  430  and data ID for identifying the relay processing request received from the Web server. Receiving the message, the portable telephone terminal  110  connects to the relay device  430  corresponding to the relay device URL through the carrier communication network  150  according to the received message, and acquires the result response corresponding to the data ID included in the received message from the relay device  430 .  
         [0125]     On the other hand, in the case of a message according to the mail protocol, the massage includes the result response.  
         [0126]     Here, similarly to the first embodiment, the present embodiment assumes that a protocol can be selected from the push-type protocol and the mail protocol. The method of selection is as according to the following selection methods (1)-(5).  
         [0127]     (1) When the relay device  430  tries a session with the portable telephone terminal  110  according to the push-type protocol, and when the number of times that the relay device  430  detects disconnection of the session reaches a prescribed number, within a certain period, then the relay device  430  selects the mail protocol.  
         [0128]     (2) When the number of lines (the number of portable telephone terminals) that the relay device  430  handles at the same time has reached a prescribed threshold, then the relay device  430  selects the mail protocol.  
         [0129]     (3) When the usage rate of the CPU or the memory of the relay device  430  has reached a prescribed threshold, then the relay device  430  selects the mail protocol.  
         [0130]     (4) In cases other than (1)-(3), the relay device  430  selects the push-type protocol.  
         [0131]     The data storage part  133  stores the relay processing request received from the Web server  420 , associating the relay processing request with the information ID for identifying the relay processing request uniquely.  
         [0132]     The sending/receiving part  134  is an input/output interface for sending and receiving information through the carrier communication network  150 .  
         [0133]     The relay device  430  of the above configuration can be implemented by an ordinary computer. For example, the ID information table storage part  431  and the data storage part  133  can be implemented by an external storage such as a hard disk. The relay processing part  432  can be implemented when a CPU executes a predetermined program stored in the external storage. The sending/receiving part  134  can be implemented by an NIC.  
         [0134]     Processing of sending and receiving information in the communication system  400  of the above-described configuration will be described, referring to the sequence diagram shown in  FIG. 9 .  
         [0135]     First, a portable telephone terminal  110  sends a front page request to the Web server  420  ( 460 ). The HTTP header of this front page request includes the terminal ID for identifying the portable telephone terminal  110  uniquely.  
         [0136]     The front page request sent from the portable telephone terminal  110  is received by the Web server  420  through the carrier communication network  150  and the Internet  151 . The Web server  420  extracts the terminal ID from the HTTP header of the front page request ( 461 ).  
         [0137]     Further, the Web server  420  sends a front page response corresponding to the front page request received from the portable telephone terminal  110  to the portable telephone terminal  110  ( 462 ).  
         [0138]     Next, through the received front page response, the portable telephone terminal  110  requests the Web server  420  to perform specific processing ( 463 ). The HTTP header of this processing request includes the terminal ID for identifying the portable telephone terminal  110  uniquely.  
         [0139]     Receiving the front page request sent from the portable telephone terminal  110 , the Web server  420  extracts the terminal ID from the HTTP of the processing request ( 464 ).  
         [0140]     Then, the Web server  120  sends a temporary service notification response (a processing start response) to the portable telephone terminal  110  ( 465 ), and disconnects the session with the portable telephone terminal ( 466 ).  
         [0141]     Further, the Web server  420  performs the processing corresponding to the processing request received from the portable telephone terminal  110  ( 467 ), and sends the relay device  430  a relay processing request that includes a result of the processing as a result response ( 468 ).  
         [0142]     The relay processing request sent from the Web server  420  is received by the relay device  430  through the carrier communication part  150 , and the received relay processing request is stored in the data storage part  433  of the relay device  430  ( 469 ).  
         [0143]     Then, the relay device  430  suitably selects a protocol used for sending to the portable telephone terminal  110  ( 470 ), and sends a message according to the selected protocol to the portable telephone terminal  110  ( 471 ).  
         [0144]     Receiving the message, the portable telephone terminal  110  performs the processing corresponding to the received message ( 472 ).  
         [0145]     In detail, in the case where the portable telephone terminal  110  receives the message according to the push-type protocol, the portable telephone terminal  110  sends a sending request that specifies the data ID for identifying the result response stored in the data storage part  133  to the relay device  430  corresponding to the relay device URL included in the message, and receives the result response from the relay device  430 . Further, the relay device  430  and the portable telephone terminal  110  can continue this session and continue processing after the result response.  
         [0146]     On the other hand, in the case where the portable telephone terminal  110  receives the message according to the mail protocol, the portable telephone terminal  110  displays the received message.  
         [0147]     In the above-described embodiment, a time-out period for a session can be selected from two values, i.e., the default time-out and the extended time-out. However, this mode is not restrictive. It is possible to arrange that a time-out period can be selected from a larger number of time-out periods. In that case, it is suitable to arrange that a time-out period can be selected from a plurality of time-out periods depending on conditions of load processing performed by the Web server.  
         [0148]     Further, it is possible to prohibit sending of another request by executing a Web browser or a certain application on a portable telephone terminal. In that case, the Web browser or the application may be installed in advance in the portable telephone terminal, or a program for prohibiting sending of another request may be sent from a relay device or a Web server and then executed.  
         [0149]     Further, the present embodiment uses a portable telephone terminal  110 . However, this mode is not restrictive, and any terminal that can connect to a Web server through a network or a relay device can be used.  
         [0150]     The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that various modifications and changes may be made thereto without departing from the spirit and scope of the invention as set forth in the claims.