JP2005252619A - Switching destination information notification method, switching destination information transmitting device, switching destination information receiving device, switching destination information notification program, and recording medium recording the switching destination information notification program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent loss of data caused by disconnection when a switching information receiving device of a radio access system executes a handover and searches for an access point to be connected after moving.
A switching information transmitting apparatus 2 includes information collecting means 21 for collecting access point information and information transmitting means 22 for transmitting the collected access point information to a switching information receiving apparatus 5. The switching information receiving apparatus includes information receiving means for receiving a packet transmitted by the switching information transmitting apparatus 2, information selecting means for selecting access point information from the access point information table, and the selected access point information to the wireless access system device. It comprises information setting means for setting and a radio access system device.
[Selection] Figure 2

Description

  The present invention notifies the switching destination information receiving device in advance of the information on the switching destination access point when executing the handover for switching the access point to which the switching destination information receiving device moves and connects in the wireless access system. Switching destination information notification method, switching destination information transmitting device and switching destination information receiving device for executing switching destination information notification method, switching destination information notification program for causing computer to execute switching destination information notification method, and switching destination information notification program The recording medium.

  In recent years, public wireless access services using wireless access systems represented by hot points have become widespread. For example, as shown in FIG. 8, the wireless access system includes an access point (described later) 82 that forms part of a network 81 and a terminal 83 that communicates with the access point 82 via a wireless line. Composed. The terminal 83 can switch the access point to move and connect. In FIG. 8, two access points 82 and three terminals 83 are shown, but the number is not limited to this.

  A typical wireless access system is a wireless LAN. The specification of the wireless LAN is being standardized as IEEE 802.11 by IEEE (The Institute of Electrical and Electronics Engineers) (see Non-Patent Document 1). Also, standardization is underway as IEEE 802.16 and IEEE 802.20. According to IEEE 802.11, a terminal can connect to an access point and communicate via a wireless line. If the access point is in the same network as the connected access point, the terminal can perform handover without any problem. can do. However, there is no provision for handover to an access point in a network different from the network formed by the connected access points. For this reason, when a terminal moves and performs a handover to an access point of a different network, there arises a problem that the connection is disconnected and communication is interrupted.

  As a method for solving this problem, FMIP (Fast Hands for Mobile IPv6), which is an improvement of mobile IP, is proposed as a method for realizing seamless handover that can be applied to various wireless access methods including a wireless LAN. ing. FMIP is a method for preventing data loss when a terminal moves and performs handover between different networks, and data that may be lost is stored in memory as a result of the start of handover. Then, after executing the handover, it is read out and transmitted to the terminal, thereby realizing seamless communication without data loss.

By the way, when performing a handover, the terminal needs to perform a procedure of disconnecting from the original access point, searching for an access point to be connected after movement, and connecting to the access point after discovery. There is. For this reason, when the execution of the handover overlaps with the transmission of data, the communication line is disconnected and data is lost.
“IEEE Std 802.11, 1999 Edition (R2003) (ISO / IEC8802-11: 1999) IEEE Standard for Information Technology- Telecommunications and Information Exchange between Systems- Local and Metropolitan Area Network- Specific Requirements- Part 11: Wireless LAN Medium Access Control ( MAC) and Physical Layer (PHY) Specifications ” “Fast Handover for Mobile IPv6 (draft-ietf-mipshop-fast-mipv6-00.txt)”, Rajeev Koodli, October 2003

  However, FMIP, which should solve the problem of data loss that occurs when a handover is executed, is an access point that is newly connected when such a terminal moves and switches a connection to an access point of a different network. It does not specify how to solve the problem of data loss that occurs during the search. FMIP defines a method for solving data loss caused by disconnection due to handover. Therefore, the problem of data loss that occurs while a wireless LAN terminal searches for an access point to be connected after moving cannot be solved by FMIP.

  The present invention has been made in view of such a problem, and the data of the data generated by the disconnection of the connection while the terminal of the wireless access system including the wireless LAN performs a handover and searches for an access point to be connected after the movement is performed. The purpose is to prevent loss.

  In order to solve the above-mentioned problems, the present invention uses the following method, apparatus, program, and recording medium on which the program is recorded.

  According to the first aspect of the present invention, the switching destination information transmitting device transmits the information about the access point collected from the area in charge and the area in charge of the neighboring switching destination information transmitting device to the switching destination information receiving device, and moves. Accordingly, the switching destination information receiving apparatus that switches the connection with the access point selects the access point to be newly connected using the received information on the access point and switches the connection.

  The switching destination information transmitting device communicates with the neighboring switching destination information transmitting device as well as the access point information of the access point in the connection area that it is in charge of, and accesses the access point that the neighboring switching destination information transmitting device is in charge of. Point information is collected, processed into information about access points, and periodically transmitted to the switching destination information receiving apparatus. Further, the switching destination information receiving apparatus receives the access point information and presets it in the wireless access device, thereby switching the connection without searching for a new access point when performing handover.

  In the second aspect of the invention, the information about the access point is an access point information table created from the access point information collected by the switching destination information transmitting device, or the switching destination information transmitting device is an access point information table. The access point information of the access point that was predicted to be optimal from the inside was decided.

  If the access point information table is sent to the switching destination information receiving device as information relating to the access point, the switching destination information receiving device selects the access point information from its own judgment. If the switching destination information transmitting apparatus selects access point information from the access point information table and sends it to the switching destination information receiving apparatus, the switching destination information receiving apparatus uses the received access point information as it is.

  In the invention according to claim 3, the switching destination information receiving device selects the access point information of the access point predicted to be optimal from the access point information table received from the switching destination information transmitting device.

  The switching destination information receiving apparatus selects an access point that is predicted to be optimal based on its own judgment.

  According to the fourth aspect of the present invention, the selection of the access point information of the access point predicted to be optimal is performed based on the information collected by the switching destination information receiving apparatus.

  The switching destination information receiving apparatus selects an access point that is predicted to be optimal using information collected by itself.

  According to the fifth aspect of the present invention, the information collected by the switching destination information receiving device is position information of the switching destination information receiving device.

  The switching destination information receiving apparatus uses its own location information as information collected by itself.

  In the invention according to claim 6, the switching destination information transmitting device switches information collecting means for collecting information on the access point from the region in charge and the region in charge of the neighboring switching destination information transmitting device, and the information on the access point is switched. And an information transmitting means for transmitting to the destination information receiving apparatus.

  The switching destination information transmission apparatus realizes a switching destination information notification method by information collection means and information transmission means.

  In the invention according to claim 7, the switching destination information receiving device includes information receiving means for receiving information on the access point from the switching destination information transmitting device, and information selection means for specifying the access point from the received information on the access point. And an information setting means for setting the specified access point in a wireless access device included in the switching destination information receiving apparatus.

  The switching destination information receiving apparatus realizes a switching destination information notification method by information receiving means, information selecting means, and information setting means.

  In the invention described in claim 8, the switching destination information notification method according to any one of claims 1 to 5 is caused to be executed by a computer.

  In a ninth aspect of the present invention, a program for causing a computer to execute the switching destination information notification method according to any one of the first to fifth aspects is recorded on a computer-readable recording medium. .

  According to the first aspect of the present invention, according to the switching destination information notification method, the switching destination information receiving device is predicted to connect after execution of the handover based on the information regarding the access point received from the switching destination information transmitting device. Points can be known in advance. As a result, it is not necessary for the switching destination information receiving apparatus to search for a newly connected access point after executing the handover, and it is possible to prevent data loss caused by disconnection during the search.

  According to the second aspect of the present invention, it is predicted that the information about the access point is the access point information table created from the access point information collected by the switching destination information transmitting apparatus or the optimum from the access point information table Access point information of the access point can be used. As a result, it is possible to realize both the case where the switching destination information transmitting apparatus does not have the function of predicting the access point and the case where the function is provided.

  According to the third aspect of the present invention, the switching destination information receiving apparatus can select the access point predicted to be optimal. This also allows the switching destination information receiving apparatus to have a function of predicting an access point.

  According to the fourth aspect of the present invention, the switching destination information receiving apparatus can select an access point that is expected to be optimal using information collected by the switching destination information receiving apparatus. Thereby, the switching destination information receiving apparatus can select the access point by itself.

  According to the fifth aspect of the present invention, the switching destination information receiving apparatus can use its own location information as the collected information used for selecting the access point expected to be optimal.

  According to the sixth aspect of the present invention, the switching destination information transmitting device can execute collection of information relating to the access point and transmission of information relating to the access point to the switching destination information receiving device. Thereby, the switching destination information transmitting device can realize a switching destination information notification method.

  According to the seventh aspect of the present invention, the switching destination information receiving device receives information on the access point from the switching destination information transmitting device, specifies an access point using the received information on the access point, and specifies It is possible to set the wireless access device provided in the access point switching destination information receiving apparatus. Thereby, the switching destination information receiving apparatus can implement a switching destination information notification method.

  According to the invention described in claim 8, it is possible to cause a computer to execute the program of the switching destination information notification method.

  According to the ninth aspect of the invention, it is possible to execute the switching destination information notification method on an arbitrary computer by recording the switching destination information notification program on the recording medium and causing the computer to read the program. .

Next, embodiments of the invention will be described in detail with reference to the drawings.
[First Embodiment]
As the first embodiment, the switching destination information receiving apparatus previously stores AP information of an AP that is expected to be optimal as a connection destination from the provided access point (hereinafter abbreviated as “AP”) information table. A case of selection will be described.

  FIG. 1 is a configuration diagram of a network system according to the first embodiment of the present invention. The network system includes an IP network 1, a switching destination information transmission device 2 installed in the subnetwork 3, a subnetwork 3 that is a local network branched from the IP network 1, a switching destination information reception device 5, and a wireless network. It is composed of an AP 4 connected via a wireless line of the access system, a switching destination information receiving device 5 connected to the AP 4 via a wireless line of the wireless access system, and a router 6 connecting the IP network 1 and the sub-network 3. The

  The switching destination information transmitting apparatus 2 may be an independent apparatus, but can also be realized by implementing its function by hardware or software and incorporating it into a conventional network apparatus such as a router or a server. The switching destination information receiving device 5 can also be realized by implementing its function by hardware or software and incorporating it into a terminal or a router having a wireless LAN function.

  In FIG. 1, the switching destination information transmitting apparatus 2 is individually switched to the switching destination information transmitting apparatus 2a and the switching destination information transmitting apparatus 2b, the subnetwork 3 is individually connected to the subnetwork 3a, the subnetwork 3b is individually connected to AP4, and the AP4a is individually connected to AP4a. Both the AP 4b and the switching destination information receiving device 5 are individually connected to the switching destination information receiving device 5a, the switching destination information receiving device 5a ′, the switching destination information receiving device 5b, and the switching destination information receiving device 5c, respectively. The router 6b is also indicated.

  The IP network 1 is a communication network represented by the Internet that transmits IP packets using TCP / IP (more precisely, TCP / IP protocol group, hereinafter the same) as a communication protocol.

  The switching destination information transmitting device 2 collects AP information of the switching destination information notification method, creates an AP information table, and transmits the AP information or the AP information table to the switching destination information receiving device 5.

  The subnetwork 3 is configured as a local network separated from the IP network, and connects the switching destination information transmission apparatus 2 to the AP 4 and the router 6.

  The AP 4 constitutes a part of the sub-network 3 and serves as a connection point from the switching destination information receiving device of the wireless access system to the network.

  The switching destination information receiving device 5 is realized, for example, by realizing its function by software and incorporating it into a personal computer or an Internet appliance that the user uses as a terminal. In addition, a wireless access device 50 for using the wireless access system is provided. The switching destination information receiving apparatus 5 performs a handover for switching the connection destination AP by moving.

  The router 6 constitutes a part of the IP network 1, and implements TCP / IP IPv4 or IPv6 as a communication protocol, and sends IP packets sent in the network layer of the OSI (Open System Interconnection) protocol layer. Transfer to the destination.

  FIG. 2 shows the configuration of the switching destination information transmitting apparatus 2. The switching destination information transmitting device 2 includes an information collecting unit 21 that collects AP information and an information transmitting unit 22 that transmits the collected AP information to the switching destination information receiving device 5.

  The information collecting means 21 automatically collects AP information of the AP 4 in charge of the switching destination information transmitting apparatus 2 and AP information of the AP 4 in charge of the switching destination information transmitting apparatus 2 in the vicinity or collects it manually. The AP information is input to create an access point information table (hereinafter abbreviated as “AP information table”).

  For the AP information, for example, ESSID, BSSID (substance is MAC address), communication channel, and IP address of the terminal to which the AP is connected can be used.

  The information transmitting unit 22 reads the AP information table created by the information collecting unit 21, encapsulates it using a packet, and periodically transmits it to the switching destination information receiving device 5 by multicast.

  FIG. 3 shows the configuration of the switching destination information receiving device 5. The switching destination information receiving device 5 includes an information receiving unit 51 for receiving a packet storing the AP information transmitted by the information transmitting unit 22 of the switching destination information transmitting device 2, and an information selecting unit 52 for selecting AP information from the AP information table. And information setting means 53 for setting the selected AP information in the wireless access device 54, and a wireless access device 54 that enables the switching destination information receiving apparatus 5 to use the wireless access system.

  The information receiving unit 51 receives a packet from the information transmitting unit 22 of the switching destination information transmitting apparatus 2 and extracts the encapsulated AP information table from the packet.

  The information selecting unit 52 selects AP information from the AP information table extracted by the information receiving unit 51.

  The information setting unit 53 sets the AP information selected by the information selection unit 52 in the wireless access device 54.

  The wireless access device 54 is a wireless access system board or a wireless access system PCI card mounted on a personal computer or the like when using the wireless access system, and is generally required when using the wireless access system. Equipment.

  Next, operations of the switching destination information transmitting apparatus and the switching destination information receiving apparatus for realizing the switching destination information notification method will be described using the sequence chart shown in FIG. In addition, FIGS. 1-3 is referred suitably.

  The switching destination information receiving device 5a communicates with the AP 4a while moving. At the same time, the switching destination information receiving apparatus 5a grasps its own current position using a provided function (not shown) for detecting its own position (step S100).

  The information collecting means 21 of the switching destination information transmitting device 2a collects AP information under the management of the switching destination information transmitting device 2a, AP information under the management of the switching destination information transmitting device 2b in the vicinity, and the like. An information table is created (step S101). Note that the order of step S100 and step S101 may be reversed. The information transmitting unit 22 encapsulates the AP information table using a packet, and periodically transmits the AP information table to the switching destination information receiving device 5a by multicast (step S102).

  The information receiving means 51 of the switching destination information receiving apparatus 5a receives the packet transmitted by the information transmitting means 22 of the switching destination information transmitting apparatus 2a, takes out the AP information table encapsulated therein and presents it ( Step S103).

  The information selection unit 52 of the switching destination information receiving apparatus 5a executes a handover for switching the AP 4 to be connected based on its own location information from the AP information table presented by the information receiving unit 51. AP information of AP4 that is expected to be the optimum connection destination later is selected (step S104).

  The switching destination information receiving device 5a detects the deterioration of the state of the radio line with the AP 4a to which the switching destination information receiving device 5a is connected by detecting a decrease in radio wave intensity or an increase in transmission error accompanying the movement. In such a case, a signal requesting the stop of data transmission is transmitted to the router 6a by using a communication function provided conventionally (step S105).

  The router 6a that has received the signal requesting the stop of data transmission from the switching destination information receiving device 5a stops the data transmission, and temporarily stores data to be transmitted to the switching destination information receiving device 5a in the future (step). S106).

  When the information setting means 53 of the switching destination information receiving device 5a confirms the stop of data transmission from the router 6a, the wireless access device 54 sends the AP information of the AP 4b that is expected to be optimal as the connection destination when executing the handover. And the connection destination AP is switched (step S107). The switching destination information receiving device 5a connects to the new AP 4b using normal means to become the switching destination information receiving device 5a '(step S108). The switching destination information receiving device 5a 'requests the router 6a to resume data transmission (step S109).

  The router 6a receives the request to resume data transmission from the switching destination information receiving device 5a ′, reads the data to be transmitted to the switching destination information receiving device 5a ′ that has been temporarily stored, and passes the router 6b and the AP 4b. Then, the data is sequentially transmitted to the switching destination information receiving device 5a ′ to resume communication (step S110).

  As described above, according to the first embodiment, the switching destination information transmitting device periodically provides the AP information table to the switching destination information receiving device, and the switching destination information receiving device includes the AP information table provided in advance. A method has been described in which AP information of an AP that is expected to be optimal as a connection destination is selected, and the selected AP information is set in the radio access device after handover is executed.

  Thereby, the switching destination information receiving apparatus can set the AP information of the AP that is the new connection destination prior to the handover, and when executing the handover, without searching for the new AP of the connection destination, Connections can be switched. As a result, it is possible to prevent data loss due to line disconnection that has occurred while searching for a new connection destination AP, and to use only FMIP for data loss caused by line switching. You just need to protect it.

[Second Embodiment]
As a second embodiment, the switching destination information transmitting apparatus dynamically predicts the optimum AP to which the switching destination information receiving apparatus connects after handover and notifies the switching destination information receiving apparatus of the AP information. explain.

  The configuration of the network system is the same as the configuration shown in FIG. 1 of the first embodiment. The functions of each device and network are the same. FIG. 5 shows the configuration of the switching destination information transmitting device 2. The function of each means is the same as that shown in the first embodiment. FIG. 6 shows the configuration of the switching destination information receiving apparatus 5. The function of each means is the same as that shown in the first embodiment. As mentioned above, about the structure of 2nd Embodiment, the same code | symbol as 1st Embodiment is attached | subjected and description is abbreviate | omitted.

  Operations of the switching destination information transmitting apparatus and the switching destination information receiving apparatus for realizing the switching destination information notification method in the second embodiment will be described using the sequence chart shown in FIG. Here, FIG. 1, FIG. 5, and FIG. 6 are referred to as appropriate.

  The switching destination information receiving device 5a communicates with the AP 4a while moving.

  The information collecting unit 21 of the switching destination information transmitting device 2a collects information on neighboring networks (congestion information and the like), dynamically predicts the optimum AP 4 for the switching destination information receiving device 5a based on the information, and determines the AP information. Collect (step S200). Here, “dynamic” means that the optimum AP 4 changes and the AP information changes every time the information of the neighboring network changes. The information transmitting unit 22 encapsulates the AP information collected by the information collecting unit 21 using a packet, and transmits it to the switching destination information receiving device 5a (step S201).

  The information receiving unit 51 of the switching destination information receiving device 5a receives the packet transmitted by the information transmitting unit 22 of the switching destination information transmitting device 2a, and extracts and stores the AP information encapsulated therein ( Step S202).

  The switching destination information receiving device 5a detects the deterioration of the state of the radio line with the AP 4a to which the switching destination information receiving device 5a is connected by detecting a decrease in radio wave intensity or an increase in transmission error accompanying the movement. In such a case, a signal requesting the stop of data transmission is transmitted to the router 6a using a communication function provided conventionally as a trigger (step S203).

  The router 6a that has received the signal requesting the stop of data transmission from the switching destination information receiving device 5a stops the data transmission, and temporarily stores data to be transmitted to the switching destination information receiving device 5a in the future (step). S204).

  When the information setting unit 53 of the switching destination information receiving apparatus 5a confirms that data transmission from the router 6a is stopped, the information setting unit 53 sets the AP information stored in the information receiving unit 51 in the wireless access device 54 when executing the handover. Then, the connection destination AP4 is switched (step S205). The switching destination information receiving device 5a connects to the new AP 4b using normal means to become the switching destination information receiving device 5a '(step S206). The switching destination information receiving device 5a 'requests the router 6a to resume data transmission (step S207).

  The router 6a receives the request to resume data transmission from the switching destination information receiving device 5a ′, reads the data to be transmitted to the switching destination information receiving device 5a ′ that has been temporarily stored, and passes the router 6b and the AP 4b. Then, the data is sequentially transmitted to the switching destination information receiving device 5a ′, and communication is resumed (step S208).

  As described above, in the second embodiment, the switching destination information transmitting apparatus dynamically predicts the optimum AP to which the switching destination information receiving apparatus connects after handover, and notifies the AP information to the switching destination information receiving apparatus. Explained the case.

  Thereby, the switching destination information receiving apparatus can set the AP information of the AP that is the new connection destination prior to the handover, and when executing the handover, without searching for the new AP of the connection destination, Connections can be switched. As a result, it is possible to prevent data loss due to line disconnection that has occurred during the search for a new connection destination AP, and to use only FMIP for data loss caused by line switching. You just need to protect it.

1 is a configuration diagram of a network system according to a first embodiment of the present invention. It is a block diagram of the switching destination information transmitter which concerns on the 1st Embodiment of this invention. It is a block diagram of the switching destination information receiver which concerns on the 1st Embodiment of this invention. It is a sequence chart which shows operation | movement of the switching destination information transmission apparatus and switching destination information receiving apparatus using the switching destination information notification method which concerns on the 1st Embodiment of this invention. It is a block diagram of the switching destination information transmitter which concerns on the 2nd Embodiment of this invention. It is a block diagram of the switching destination information receiver which concerns on the 2nd Embodiment of this invention. It is a sequence chart which shows operation | movement of the switching destination information transmission apparatus and switching destination information receiving apparatus using the switching destination information notification method which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of a radio | wireless access system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 IP network 2 (2a, 2b) Switching destination information transmitter 21 Information collection means 22 Information transmission means 3 (3a, 3b) Subnetwork 4 (4a, 4b) Access point (AP)
5 (5a, 5a ', 5b, 5c) Switching destination information receiving apparatus 51 Information receiving means 52 Information selecting means 53 Information setting means 54 Wireless access device 6 (6a, 6b) Router

Claims (9)

In a wireless access system that connects an access point in a region in charge of a switching destination information transmitting device and a switching destination information receiving device via a wireless line,
A switching destination information notification method for notifying the switching destination information receiving apparatus of information related to an access point that may be connected after executing a handover, prior to the handover,
The switching destination information transmitting device transmits the information about the access point collected from the region in charge and the region in charge of the neighboring switching destination information transmitting device to the switching destination information receiving device;
A switching-destination information receiving device that switches connection with an access point as it moves is used to specify a newly connected access point using information about the received access point, and execute a procedure for switching the connection. Switching destination information notification method. Information about the access point is:
Whether the switching destination information transmitting device is an access point information table created from the collected access point information,
2. The switching destination information notifying method according to claim 1, wherein the switching destination information transmitting device is access point information of an access point predicted to be optimal from the access point information table. The switching destination information receiving device is
3. The switching destination information notifying method according to claim 2, wherein access point information of an access point predicted to be optimal is selected from the access point information table received from the switching destination information transmitting apparatus. Selection of access point information of the access point predicted to be optimal is
The switching destination information notification method according to claim 3, wherein the switching destination information notification method is performed based on information collected by the switching destination information receiving apparatus. Information collected by the switching destination information receiving device is:
5. The switching destination information notifying method according to claim 4, wherein the switching destination information receiving device is location information. In a wireless access system that connects an access point in a region in charge of a switching destination information transmitting device and a switching destination information receiving device via a wireless line,
A switching destination information transmitting device that collects information about the access point and transmits the information to the switching destination information receiving device,
Information collecting means for collecting information about the access point from the area in charge and the area in charge of the neighboring switching destination information transmitting device;
A switching destination information transmitting device comprising: information transmitting means for transmitting information relating to the access point to a switching destination information receiving device. In a wireless access system that connects an access point in a region in charge of a switching destination information transmitting device and a switching destination information receiving device via a wireless line,
A switching destination information receiving device that switches connection with an access point as it moves,
Information receiving means for receiving information about the access point from the switching destination information transmitting device;
Information selecting means for identifying the access point from the received information on the access point;
A switching destination information transmitting apparatus comprising: information setting means for setting the identified access point in a wireless access device included in the switching destination information receiving apparatus.   A switching destination information notification program that causes a computer to execute the switching destination information notification method according to any one of claims 1 to 5.   A computer-readable recording medium storing a program for causing a computer to execute the switching destination information notification method according to any one of claims 1 to 5.

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