KR100698666B1 - Mobile communication terminal be able to control communication according to network error and method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication terminal, and more particularly, to a mobile communication terminal technology that can cope with a network error that may occur in a service using TCP / IP.

In the mobile communication terminal according to the present invention, among the Internet Control Message Protocol (ICMP) messages transmitted and received from the network during the communication service according to the execution of the application using TCP / IP, the message type cannot reach the destination ( Destination unreachable) message. Recognizing the destination unreachable message, the mobile communication terminal determines that an error has occurred on the network, and performs processing such as terminating the corresponding application.

Accordingly, the mobile communication terminal can recognize a destination unreachable message transmitted and received from the network during service using TCP / IP, thereby preventing unnecessary waste of network communication resources.

Mobile terminal, Internet Control Message Protocol (ICMP), Destination unreachable message

Description

Mobile communication terminal be able to control communication according to network error and method thereof

1 is a schematic diagram of a typical communication layer.

2 is a table showing message types of ICMP.

Figure 3 is a block diagram schematically showing the configuration of a mobile communication terminal according to an embodiment of the present invention.

4 illustrates an ICMP message format.

5 is a diagram illustrating a destination unreachable message format among ICMP messages.

6 is a flowchart illustrating a control method according to a network error of a mobile communication terminal according to a preferred embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication terminal, and more particularly, to a mobile communication terminal technology that can cope with a network error that may occur in a service using TCP / IP.

1 is a schematic diagram of a typical communication layer. Transmission Control Protocol (TCP) is a protocol used with the Internet Protocol (IP) to send data in the form of messages between computers on the Internet. While IP actually manages the delivery of data, TCP keeps track of data packets. The message is broken up into several small pieces that allow efficient routing within the Internet. These are called packets. TCP is known as a connection-oriented protocol, which means that a connection is established and maintained for the time that messages are exchanged by each application. TCP is responsible for ensuring that the message is divided into packets for IP to process, and on the other side, the packets are assembled into complete messages. In the Open Systems Interconnection (OSI) communication model, TCP belongs to a four-layer transport layer.

A socket is an application program interface (API) using TCP / IP, and serves as a window using TCP / IP in an application. A socket may be referred to as a communication connection point written in software. The illustrated application (which may be a WAP browser, for example), which is a network application, transmits and receives an IP packet through a socket to a communication network. Note that the interface between the application and the socket is called the socket interface.

The Internet Control Message Protocol (ICMP) is a TCP / IP-based Internet communication service that combines IP with a connectionless transmission (that handles control messages for handling errors and changes in transmission paths). Protocol for connectionless transmission, as defined in RFC 792. Request For Comments (RFC) is an online public document published by the US Internet Architecture Council (IAB) that publishes research, proposals, technologies, and findings about the Internet. It includes information about the Internet, including the procedures and formats required to implement network protocols or services. It is used as a major means of communicating information. ICMP, defined in RFC 792, belongs to the network layer in the OSI communication model. 2 is a table showing a message type of ICMP as known. As shown, ICMP can be largely divided into two types: error messages for error notification and diagnostic question and answer messages.

On the other hand, most mobile terminals are equipped with Qualcomm's MSM (Mobile Station Modem) chip that controls the entire terminal.Qualcomm Source is an ICMP message transmitted from the network side under an application execution environment using TCP / IP. Only Echo request, Timestamp request, and Information request are recognized. Originally, each recognized request message should send an Echo reply, Timestamp reply, and Information reply containing the requested information, but at present Qualcomm Source has no meaning that it has received only request messages such as Echo request, Timestamp request, and Information request. It is implemented to send.

When a mobile communication terminal executes an application using TCP / IP, it transmits a packet to a host to access through a network. When a special problem occurs on a network, a router or a host sends an ICMP to a client, which is a client. Among the messages, a destination unreachable message of type 3 shown in FIG. 2 is transmitted. In this case, the Destination unreachable message handles a communication request from a mobile terminal when a router on the network cannot find a corresponding route, a specific port number of the destination system (host) cannot be answered at present, and various other problems occur. Generated if it can't.

However, even if the mobile communication terminal receives a destination unreachable message transmitted from a router or a host, the mobile terminal cannot recognize the message and ignores the message. When a problem occurs that a packet is not properly delivered to a destination, a transport layer such as TCP repeatedly retransmits a predetermined time and a predetermined number of times, and thus cannot identify and cope with a network problem early. As a result, the mobile communication terminal maintains unnecessary network connection or causes resource waste due to continuous connection attempts.

The present invention is to solve such a problem, the mobile communication terminal to recognize the network error in the service using TCP / IP to maintain unnecessary network connection state, or to avoid causing resource waste due to continuous connection attempts, etc. The purpose.

Mobile communication terminal according to an aspect of the present invention for achieving the above object is Internet Control Message Protocol (ICMP: Internet Control Message Protocol) messages transmitted and received from the network during the communication service according to the execution of the application using TCP / IP Recognizes whether the message type is a destination unreachable message. Recognizing the destination unreachable message, the mobile communication terminal determines that an error has occurred on the network, and performs processing such as terminating the corresponding application.

According to this aspect of the present invention, the mobile communication terminal can recognize a destination unreachable message transmitted and received from the network side during a service using TCP / IP, thereby preventing unnecessary network communication resource waste. .

The foregoing and further aspects of the present invention will become more apparent through the preferred embodiments described with reference to the accompanying drawings. Hereinafter, the present invention will be described in detail to enable those skilled in the art to easily understand and reproduce the present invention.

3 is a block diagram schematically showing the configuration of a mobile communication terminal according to a preferred embodiment of the present invention. As shown, the mobile communication terminal basically includes a keypad 110, a display unit 120 for displaying a menu and an operation state, and a wireless communication unit 130 for extracting a voice and data signal from a radio signal transmitted and received through an antenna. And a voice input / output circuit 140 for inputting and outputting a voice call signal from the wireless communication unit 130 through a microphone and a speaker, and a memory 150 for storing control program data for overall control of the operation of the mobile communication terminal. And a configuration of a typical mobile communication terminal such as the controller 160 for controlling the entire system.

First, the keypad 110 and the display unit 120, which is usually a liquid crystal display, may have a conventional well-known configuration. The memory 150 is divided into a ROM region in which control program data for controlling the operation of the terminal is stored, and a RAM region in which data generated during the terminal control operation are temporarily stored. The memory 150 according to the present invention preferably stores an application such as, for example, a WAP browser using TCP / IP.

The wireless communication unit 130 is configured to include an antenna and RF circuit for communication with the base station. The voice input / output circuit 140 is a well-known configuration that processes digital voice data into an analog voice signal or vice versa, and includes an additional circuit such as an audio amplification circuit or a filter. The baseband circuit of the wireless communication unit 130 and most of the circuits of the control unit 160 are commercially provided as a single integrated circuit. This integrated circuit, commonly referred to as an MSM chip, includes internally dedicated hardware for processing communications, a digital signal processor and a general purpose microprocessor. Each part constituting the control unit 160 may be configured by dedicated hardware or software or a mixture thereof.

According to a characteristic aspect of the present invention, the controller 160 further includes a network error recognizer 163 and an event processor 165. First, when a user manipulates the keypad 100 to use an application such as a WAP browser using TCP / IP, the controller 160 loads and executes the corresponding application stored in the memory 150. . The application executed by the controller 160 attempts to connect and communicate with the host by generating a packet necessary for accessing and communicating with the host and transmitting the packet to the network through the wireless communication unit 130. However, because the IP protocol is connectionless and there is no guarantee that the packet will be transmitted, there may be cases where routers or hosts (nodes) on the network fail and cannot reach their destination.

If a problem occurs in the network such as a router or the like not properly routing a packet transmitted from the mobile communication terminal, the ICMP message is transmitted to the mobile communication terminal which is a client. In this case, the type of ICMP message transmitted is a destination unreachable message. ICMP is a protocol designed to provide information about errors or unexpected conditions in transmission by allowing routers on the Internet to send error or control messages to other routers and hosts. ICMP is a protocol for controlling a message and reporting an error between a host server and an internet gateway, and is defined in RFC 792 as described above.

The network error recognizing unit 163 recognizes whether the ICMP message transmitted from the network side (router or host) and received through the wireless communication unit 130 is a destination unreachable message. According to a preferred aspect, the network error recognizer 163 determines whether the ICMP message is type 3 of the various types shown in FIG. 2. This is possible by checking whether the type information included in the received ICMP message is type 3. Figure 4 shows the ICMP message format as known. Each ICMP message type has its own format, but the first three fields (type field, code field, and check field) are identical. Accordingly, the network error recognition unit 163 may recognize that the ICMP message is a destination unreachable message through an 8-bit value indicating the type 3 of the first field.

As described above, when the network error recognition unit 163 recognizes that the destination unreachable message is received through the wireless communication unit 130, the event processing unit 165 processes the corresponding event. In this case, the event may be a process of terminating an application executed by determining that it is not necessary to perform a communication connection in a network error state, or performing a communication reconnection through another communication path. Meanwhile, the destination unreachable message may be generated by various causes. The event processing unit 165 may include a content information check unit 165a and an event processing unit 165b to perform a corresponding event according to a destination unreachable message according to various causes. ) May be further included.

If the content information checker 165a recognizes that the received ICMP message is a destination unreachable message by the network error recognition unit 163, the content information checker 165a checks the content information of the cause of the destination unreachable message transmitted from the network. According to a preferred aspect, the content information checker 165a may check destination unreachable message content information through an 8-bit code value of a code field included in a received ICMP message (here, destination unreachable message) having a format as shown in FIG. 4. have. For reference, FIG. 5 illustrates a destination unreachable message format. That is, the content information checker 165a can know additional information by checking a code value that is the second field of the destination unreachable message format shown in FIG. 5. Additional information on the Destination unreachable message according to the code value is as follows.

code 0 (Network unreachable)-This error message is generated when a route to the destination network cannot be found in the routing table of the router reporting this error.

code 1 (Host unreachable)-This error message indicates that the IP datagram was not delivered to the final destination system. For example, it is created when the final router doesn't know how to reach the destination system.

code 2 (Protocol unreachable)-This error message indicates that a particular transport protocol is not available on the destination system. For example, it may appear when a user uses a nonstandard transport protocol such as XTP to communicate with another host that does not support the program.

code 3 (Port unreachable)-This error message indicates that a specific destination port number is not used on the destination system.

In addition, code 4 (Fragmentation needed but DF bit set), code 5 (Source router failed), code 6 (Destination network unknown), code 7 (Destination host unknown), code 8 (Source host isolated), code 9 (Destination network administratively prohibited), code 10 (Destination host administratively prohibited), code 11 (Network unreachable for TOS), code 12 (Host unreachable for TOS), code 13 (Communication administratively prohibited by filtering), code 14 (Host precedence violation), code 15 (Precedence cutoff in effect), and the description is omitted.

The event processing unit 165b performs a corresponding event such as terminating an application currently executed or reconnecting a communication according to a code value checked by the content information checker 165a. For example, when the code value checked by the content information check unit 165a is code3 (Port unreachable), the event processing unit 165b changes the connection port of the host to communicate with and performs communication reconnection. You can do Alternatively, you can terminate the execution of the application to avoid unnecessary network resource waste.

According to this aspect of the present invention, the mobile communication terminal can recognize and respond to a destination unreachable message transmitted and received from the network during service using TCP / IP, thereby unnecessary waste of network communication resources and waste of power of the terminal. It can be prevented.

6 is a flowchart illustrating a control method according to a network error of a mobile communication terminal according to a preferred embodiment of the present invention. The controller 160 determines whether there is an application execution command such as a WAP browser using TCP / IP according to a user key manipulation (step 602). If there is an application execution command as a result of the determination, the controller 160 loads and executes the application. The controller 160 generates a packet by executing an application and transmits the packet to a corresponding host to communicate with via the wireless communication unit 130 (step 604). The packet processed through the wireless communication unit 130 passes through a router of a network. At this time, due to various errors of the network, the router or the host transmits a destination unreachable message among the ICMP messages to the mobile terminal, the client. do.

The control unit 160 of the mobile communication terminal receives the ICMP message through the wireless communication unit 130, and determines whether the received message is a Destination unreachable message (step 608). As described above, this may be determined by checking whether the 8-bit value of the type field of the ICMP message format shown in FIG. 4 indicates type 3 according to a preferred aspect. If it is determined that the received message is a destination unreachable message, the controller 160 performs an event such as terminating the application using the currently executed TCP / IP (step 612).

According to an additional aspect, the controller 160 may check a code value of a destination unreachable message as illustrated in FIG. 5 after step 608 (step 610). This is useful when the mobile terminal divides the corresponding event processing performed in step 612 according to various code values of the received Destination unreachable message. For example, when the code value is code3 (Port unreachable), the controller 160 may change an access port of a host to communicate with and perform an event processing for performing communication reconnection.

If NO in step 608, the controller 160 determines whether the received ICMP is a recognizable message (step 620). As described above, the Qualcomm Source can recognize only ICMP messages such as Echo request (type 8), Timestamp request (type 13), and Information request (type 15) as described above. ) Performs a corresponding process of transmitting a meaningless message of receiving the message as described above (step 622). When other ICMP message types are received, the controller 160 does not know what message and ignores it (step 624). If the controller 160 performs the application termination event processing in step 612, the termination command of step 614 may be, for example, a power-off command according to a user's key manipulation. The controller 160 performs termination processing according to the corresponding termination command.

As described above, the mobile communication terminal according to the present invention can recognize and cope with a destination unreachable message transmitted and received from the network during service using TCP / IP, thereby unnecessary waste of network communication resources and waste of power of the terminal. It can be prevented.

On the other hand, the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be defined only by the appended claims.

Claims (11)

delete In a mobile communication terminal to communicate with a specific host through a network by loading and executing an application using TCP / IP, A network error recognition unit for recognizing whether an Internet Control Message Protocol (ICMP) message transmitted and received from a network is a destination unreachable message; An event processing unit processing the event when the destination arrival impossible message is recognized by the network error recognizing unit; Communication controllable mobile communication terminal according to the network error, characterized in that it comprises a. The method of claim 2, wherein the network error recognition unit: And determining whether the type information included in the format of the received ICMP message is type 3, and recognizing whether the message cannot reach the destination. 4. The method of claim 3, wherein the event is: A mobile communication terminal capable of controlling communication according to a network error, comprising terminating an application to be executed and performing a communication reconnection. The method of claim 3 or 4, wherein the event processing unit: A content information checker which checks the content information of the received ICMP message upon recognizing that the destination arrival impossible message is received by the network error recognition unit; And an event processing unit for processing a corresponding event according to the content information of the ICMP message checked by the content information check unit. 6. The method of claim 5, wherein the content information checker checks the content information of the received destination impossible message: A communication terminal capable of controlling communication according to a network error, characterized by checking a code value in a received ICMP message format. In a communication control method according to a network error of a mobile communication terminal to communicate with a specific host through a network by loading and executing an application using TCP / IP, a) receiving an Internet Control Message Protocol (ICMP) message transmitted from a network; b) determining whether the received ICMP message is a destination unreachable message; c) if the ICMP message received as a result of the determination is a destination impossible message, processing the event; Communication control method according to the network error of the mobile communication terminal comprising a. 8. The method of claim 7, wherein determining whether step b) is a destination unreachable message comprises: And determining whether the type information included in the received ICMP message format is type 3. The communication control method according to the network error of the mobile communication terminal. The method of claim 8, wherein the event is: A method of controlling communication according to a network error of a mobile communication terminal, comprising terminating an executed application and performing communication reconnection. 10. The method of claim 8 or 9, wherein step c) comprises: c1) checking the content information of the received ICMP message if the ICMP message received as a result of the determination in step b) is not a destination arrival message; c2) processing a corresponding event according to the content information of the checked ICMP message. 11. The method of claim 10, wherein the checking of the content information of the received ICMP message in step c1) comprises: And a code value is checked in a received ICMP message format.

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