JP2005033317A - Radio access point apparatus and control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make IP communication between radio terminals without depending on a preset operation mode by assigning a private IP address to a connected radio terminal, even if an access point is set at a bridging mode, if the terminal is not connected to an active wired network. <P>SOLUTION: Even if an access point is set at a bridging mode (bridging in S703), when the access point cannot communicate with a network device on the wired network (NO in S704), the access point assigns an IP address to the radio terminal (S705). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wireless access point device and a control method, and more particularly to a wireless access point device that relays a data frame between a wired network and a wireless network, and a control method of the wireless access point device.
[0002]
[Prior art]
Along with the rapid development of information communication technology, there are increasing cases of building a LAN (Local Area Network) in an office or home. As a method for constructing a LAN, a wireless LAN that connects a terminal and a network without using a cable by using wireless communication such as radio waves has recently become widespread instead of a method of connecting a terminal and a network via a cable. Yes.
[0003]
As a communication form of a wireless LAN, an infrastructure type communication form wireless LAN using a wireless access point device (hereinafter referred to as “access point”) that relays data frames between a wired network and a wireless network is widely used. ing. In such a wireless LAN, each wireless terminal on the wireless LAN can access a server or the like on the wired LAN via an access point.
[0004]
In general, an access point has two operation modes of a routing mode and a bridging mode, and can be used by setting to one of the operation modes. The access point in the routing mode assigns a private IP (Internet Protocol) address to the wireless terminal to be connected, and when the data frame is relayed from the wireless terminal to the wired network, the transmission source private IP address is set to the global IP address of the access point. And then relay it (see, for example, Patent Document 1). Address translation methods mainly include network address translation (NAT) that translates only IP addresses, and IP masquerading that translates IP addresses and TCP (Transmission Control Protocol) / UDP (User Datagram Protocol) port numbers. Used. The above IP address is an identifier in the network layer of the OSI (Open Systems Interconnection) reference model.
[0005]
On the other hand, an access point in bridging mode does not assign a private IP address and relays a data frame between the wireless terminal and the wired network without converting the IP address. In this case, IP addresses corresponding to the number of wireless terminals are required, but each wireless terminal can use the same network environment as when connected to the network via a cable. Further, since the wireless terminal constitutes the same network segment as the wired network connected to the access point, it is also possible to receive an IP address assignment from a DHCP (Dynamic Host Configuration Protocol) server on the wired network.
[0006]
When using a wireless LAN, a portable access point is brought into the conference room, and a wireless terminal carried by the conference participant accesses a server on the wired network, or the conference participant's wireless terminal without being connected to the wired network It is possible to exchange data by forming a wireless network with each other.
[0007]
[Patent Document 1]
JP 2003-032642 A
[0008]
[Problems to be solved by the invention]
However, in the above conventional access point, when a wired network is not connected when used in the bridging mode, an IP address cannot be assigned to a wireless terminal, and IP-based communication cannot be performed. There was a point. In order to avoid this, is it necessary to set the access point to the routing mode again or use the DHCP server by connecting the wired network even though it is not necessary to access the server on the wired network? Or, complicated operations such as setting a temporary fixed IP address for each wireless terminal have been required.
[0009]
The present invention has been made in view of such problems, and it is effective to enable an identifier assigning function to a wirelessly connected device depending on whether or not it is connected to an effective wired network. Objective.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a wired network connection means for connecting to a wired network via a cable in a wireless access point device that relays a data frame between the wired network and the wireless network, and at least Determining whether there is a wireless communication means for forming a wireless network by connecting to one wireless terminal by wireless communication, and whether there is a network device capable of data communication in the wired network connected by the wired network connection means Determining means for performing, at least in the first operation mode, identifier assigning means for assigning an identifier for identifying the wireless terminal on the wireless network to the wireless terminal connected by the wireless communication means; Second operation mode different from the first operation mode In, in accordance with the determination by said determining means, for providing a wireless access point device, characterized in that a control means for operating the identifier assigning means.
[0011]
Further, in the control method of a wireless access point device that can be connected to a wired network and can form a wireless network wirelessly, a determination step of determining whether or not a network device capable of data communication exists in the wired network In the first operation mode, an identifier for identifying the wireless device on the wireless network is assigned to the wireless device forming the wireless network, wireless communication is performed based on the identifier, and the second operation is performed. In the mode, there is provided a method for controlling a wireless access point device, comprising: a step of selectively assigning the identifier according to the determination in the determination step.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 is a block diagram showing a configuration of an embodiment of a wireless access point device (hereinafter referred to as “access point”) according to the present invention.
[0014]
Reference numeral 100 in the figure denotes an access point, and the access point 100 includes a wireless communication circuit unit 101, a wired network interface unit 102, a CPU 103, a ROM 104, and a RAM 105, and these components are mutually connected via a bus line 106. Connected. The access point 100 includes an EEPROM 107 and a power supply circuit unit 108.
[0015]
The wireless communication circuit unit 101 includes an antenna, a high frequency circuit, an encoding / decoding circuit, and the like, and forms a wireless network with a wireless terminal such as an information processing apparatus having an equivalent wireless communication function, and transmits and receives data to and from each other. Receive.
[0016]
The wired network interface unit 102 includes a connector for connecting a cable, and is physically and logically connected to an external wired network via the cable connected to the connector. The wired network interface unit 102 has a function of receiving a data frame transmitted from a connected wired network and a function of transmitting a data frame to the wired network.
[0017]
In this embodiment, in both the wired network and the wireless network, a unique MAC address is allocated to each server and terminal on the network including the access point 100, and data frames are transmitted and received between adjacent nodes. Performs communication by specifying a transmission destination and a transmission source by a MAC address.
[0018]
Further, end-to-end communication such as between wireless terminals or between a wireless terminal and a server is performed based on the IP address.
[0019]
The access point 100 has two operation modes, ie, a routing mode and a bridging mode. The access point 100 appropriately reconfigures the data frame header information according to each operation mode, and wirelessly connects the wireless terminal and the wired network. Data frame transmission / reception relayed between the two is relayed.
[0020]
The CPU 103 performs control of the wireless communication circuit unit 101, control of the wired network interface unit 102, and the like by reading and sequentially executing control procedures stored in the ROM 104.
[0021]
In addition, the CPU 103 assigns a private IP address to the wireless terminal that is wirelessly connected, converts the IP address portion of the packet that constitutes the data frame transmitted from the wireless terminal to the global IP address of the access point 100, and relays it to the wired network. Address translation control can be performed.
[0022]
Address translation methods mainly include network address translation (NAT) that translates only IP addresses, and IP masquerading that translates IP addresses and TCP (Transmission Control Protocol) / UDP (User Datagram Protocol) port numbers. Used. The above IP address is an identifier in the network layer of the OSI (Open Systems Interconnection) reference model.
[0023]
The ROM 104 is a non-volatile memory that stores in advance control procedures executed by the CPU 103. The ROM 104 outputs the stored contents to the bus line 106 in response to a read command from the CPU 103.
[0024]
The RAM 105 temporarily buffers data frames received by the wireless communication circuit unit 101 and the wired network interface unit 102, and temporarily transmits data transmitted from the wireless communication circuit unit 101 and data frames transmitted from the wired network interface unit 102. Functions such as storage and work memory of the CPU 103 are provided. Further, the RAM 105 is provided with an area for storing the assigned IP address and the MAC address of each wireless terminal when the access point 100 assigns the IP address to the wireless terminal.
[0025]
The EEPROM 107 is a rewritable nonvolatile memory element that stores various operating parameter values that define the operation of the access point 100. The EEPROM 107 is connected to the CPU 103 via the serial communication interface 109, and outputs stored data to the CPU 103, and stores and stores data output from the CPU 103.
[0026]
The EEPROM 107 can store settings for operating the access point 100 in either the routing mode or the bridging mode, and the number and range of private IP addresses assigned to the wireless terminals.
[0027]
The power supply circuit unit 108 is configured by a DC / DC converter or the like, and has a function of converting electric power supplied from an AC adapter (not shown) into an appropriate voltage and supplying the converted voltage to each component of the access point 100 via the power supply line 110. I have.
[0028]
Next, an end-to-end communication method performed on a wired network and a wireless network including an access point according to the present embodiment will be described with reference to FIG.
[0029]
FIG. 2 is a diagram showing a datagram format in end-to-end communication.
[0030]
The end-to-end communication in this embodiment is performed based on the IP address assigned to each wireless terminal or server, and as shown in FIG. 2, the transmission source IP address and the transmission destination IP address are added to the communication data. Prefix forms a datagram and sends and receives data. In the figure, header information such as packet length and version information is omitted.
[0031]
The datagram is composed by adding the destination MAC address and source MAC address of the adjacent node and other header information to this datagram, and communication between adjacent nodes is performed sequentially to realize end-to-end communication. To do.
[0032]
Next, two operation modes of the access point 100 according to the present embodiment will be described with reference to FIGS. First, the operation of the access point 100 in the routing mode will be described with reference to FIGS.
[0033]
FIG. 3 is a diagram illustrating an example of a network configured by network devices including the access point 100, and FIG. 4 is a diagram illustrating a configuration of a data frame relayed by the access point 100.
[0034]
The access point 100 set in the routing mode performs address conversion between the wireless terminal and the wired network that are wirelessly connected, and relays the data frame.
[0035]
As shown in FIG. 3, the access point 100 has a network address of X.X via the wired network interface unit 102 (FIG. 1). X. X. 0 is connected to the wired network 301. In the present embodiment, all subnet masks are assumed to be 255.255.255.0. Also, the connections in the figure indicate logical network connections, and descriptions of hub devices and the like are omitted.
[0036]
The access point 100 has an IP address X.X assigned from a DHCP server 302 (IP address: XX.X.1) on the network 301. X. X. 10 is identified on the network 301 as an IP address on the wired network side. On the network 301, the IP address is X. X. X. 2 servers 303 are connected.
[0037]
A network generally can connect other networks via a router. In FIG. 3, the network address X. X. A. 0 network 305a and network address X.0. X. B. 0 network 305b.
[0038]
The wireless terminals 306a to 306c are wirelessly connected to the access point 100 to form one wireless network. When the access point 100 is in the routing mode, each of the wireless terminals 306 a to 306 c is assigned a private IP address from the access point 100. In FIG. 3, the wireless terminal 306a has a private IP address Y.P. Y. Y. 101 is assigned to the wireless terminal 306b and the private IP address Y.Y. Y. Y. 102, the wireless terminal 306c has a private IP address Y.P. Y. Y. 103 are assigned respectively.
[0039]
The configuration of an IP datagram when data communication is performed between the wireless terminal 306a and the server 303 on the wired network via the access point 100 set to the routing mode will be described with reference to FIG.
[0040]
As shown in FIG. 4A, the wireless terminal 306a transmits an IP datagram addressed to the server 303 as the IP datagram addressed to the server 303. Y. Y. 101, destination IP address X. X. X. 2 datagram 401 is created, and a data frame to which the MAC address of access point 100 which is an adjacent node is added is transmitted wirelessly ((1) in FIG. 3).
[0041]
The access point 100 set to the routing mode replaces the source IP address of the received datagram 401 with its own IP address X.X. X. X. The datagram 402 shown in FIG. 4B rewritten to 10 is transmitted to the wired network 301 toward the server 303 ((2) in FIG. 3).
[0042]
The server 303 that has received the datagram 402 returns the result of the internal processing. At this time, the IP address X.X of the access point 100 that is the source of the original datagram 402 is sent. X. X. A datagram 403 shown in FIG. 4C with 10 as the transmission destination is created and transmitted to the network 301 ((3) in FIG. 3).
[0043]
The access point 100 that has received the datagram 403 determines that the datagram 403 is a response to the datagram 401 transmitted from the wireless terminal 306a to the server 303, and sets the destination IP address as the IP address Y.Y of the wireless terminal 306a. Y. Y. A datagram 404 shown in FIG. 4D shown in FIG. 4 is created, and a data frame to which the MAC address of the wireless terminal 306a is added is transmitted from the wireless communication circuit unit 101 ((4) in FIG. 3).
[0044]
The wireless terminal 306a receives the datagram 404 and processes it as a response to the datagram 401 because this signal is the MAC address addressed to itself.
[0045]
Next, the operation of the access point 100 in the bridging mode will be described with reference to FIGS.
[0046]
FIG. 5 is a diagram illustrating an example of a network including the access point 100 set to the bridging mode and other network devices, and FIG. 6 is a diagram illustrating a configuration of a data frame relayed by the access point 100. It is.
[0047]
The access point set in the bridging mode does not perform address conversion when relaying a data frame between the wireless terminal and the wired network.
[0048]
As shown in FIG. 5, the access point 100 has a network address X.X. X. X. 0 from the DHCP server 502 (IP address: XX.X.1) to the IP address X.X. X. X. 10 is assigned. On the network 501, the IP address is X. X. X. 2 servers 503 are connected.
[0049]
Similar to the routing mode described above, in this case, it is possible to connect to another network via a router. In FIG. 5, it is connected to the network 505a (network address: XXA.0) via the router 504a and connected to the network 505b (network address: XXB.0) via the router 504b. Yes.
[0050]
The wireless terminals 506a to 506c are wirelessly connected to the access point 100, respectively. When the access point 100 is set to the bridging mode, the wireless network composed of the wireless terminals 506a to 506c and the access point 100 is the same network as the wired network 501 to which the access point 100 is connected, The network address of the wireless network is also X. X. X. 0.
[0051]
At this time, if the wireless terminals 506a to 506c are set to receive an IP address assignment from a DHCP server on the network, the wireless terminals 506a to 506c can be assigned an IP address from the DHCP server 502 on the network 501 which is the same network. . In the figure, the IP address X. X. X. 11 is assigned to the wireless terminal 506b. X. X. 12, the wireless terminal 506c has an IP address X.X. X. X. 13 are assigned respectively.
[0052]
A configuration of an IP datagram when data communication is performed between the wireless terminal 506a and the server 503 on the wired network 501 via the access point 100 set in the bridging mode will be described with reference to FIG. .
[0053]
As shown in FIG. 6A, the wireless terminal 506a transmits the IP datagram addressed to the server 503 as the IP datagram. X. X. 11 and the destination IP address is X. X. X. 2 datagram 601 is created and wirelessly transmitted to the access point 100 which is an adjacent node ((1) in FIG. 5).
[0054]
Unlike the routing mode, the access point 100 set in the bridging mode sends the datagram 601 as it is to the server 503 to the wired network 501 without converting the address of the received datagram 601 ( (2) in FIG.
[0055]
The server 503 that has received the datagram 601 performs internal processing, and the IP address X.X of the wireless terminal 506a that is the transmission source of the original datagram 601. X. X. A datagram 602 shown in FIG. 6B is created with 11 as the transmission destination, and the result is returned. This datagram 602 is transmitted on the network 501 as a data frame addressed to the access point 100 which is an adjacent node ((3) in FIG. 5).
[0056]
The access point 100 that has received the datagram 602 determines that the destination IP address of the datagram 602 is the IP address X.X of the wireless terminal 506a. X. X. 11, the data frame having the MAC address of the wireless terminal 506a as the transmission destination is transmitted from the wireless communication circuit unit 101 without converting the address part of the datagram 602 ((4) in FIG. 5).
[0057]
The wireless terminal 506a receives the datagram 602 because this signal is a MAC address addressed to itself, and internally performs processing as a response to the datagram 601.
[0058]
Next, the operation of the access point 100 according to the present embodiment will be described in detail with reference to FIG.
[0059]
FIG. 7 is a flowchart showing an operation procedure of a connection control process executed when the access point 100 according to the present embodiment is requested to connect from a wireless terminal. This connection control process is executed every elapse of a predetermined time measured by a timer (not shown) in the CPU 103 of the access point 100.
[0060]
In step S701, the CPU 103 monitors the output signal of the wireless communication circuit unit 101 to determine whether there is a wireless terminal that requests connection. When there is no wireless terminal requesting connection, the process returns to step S701 again and this determination is repeated. On the other hand, if there is a wireless terminal requesting connection, the process advances to step S702 to perform authentication processing and establish a wireless link with the wireless terminal. Although the connection is disconnected when the authentication is not permitted, the processing procedure in this case is omitted in FIG.
[0061]
Next, in step S703, it is determined whether the operation mode of the access point 100 is set to the bridging mode or the routing mode. When the access point 100 is set to the bridging mode, the process proceeds to step S704. When the mode is set, the process proceeds to step S705.
[0062]
When the access point 100 is set to the bridging mode, in step S704, whether or not the access point 100 is connected to a valid wired network via the wired network interface unit 102, that is, connected to a communicable network device. It is determined whether or not it has been. Whether or not a valid wired network is connected is determined by whether or not auto-negotiation is possible, link pulse detection, idle signal detection, or data signal detection. Determine that the network is not connected.
[0063]
As a result of the determination, if a valid wired network is connected, the process proceeds to step S706, and if a valid wired network is not connected, the process proceeds to step S705.
[0064]
In step S705, the access point 100 assigns a private IP address to the wireless terminal that has requested connection, and proceeds to step S706. The assigned private IP address is stored in the RAM 105 together with the MAC address of the wireless terminal, and is managed until the connection is disconnected.
[0065]
In step S706, the access point 100 starts IP address-based communication with the wireless terminal. That is, when the access point 100 is set to the routing mode, the address conversion is performed, and when the access point 100 is set to the bridging mode, the data frame is relayed between the wireless terminal and the wired network without converting the address. Do.
[0066]
As described above, by performing the connection control process according to the flowchart shown in FIG. 7, even when the access point 100 is set to the bridging mode, the wireless terminal is not connected to a valid wired network. A private IP address can be assigned to each other, and it becomes possible to perform IP-based communication between wireless terminals via the access point 100.
[0067]
[Other embodiments]
The object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and a computer (or CPU, MPU, etc.) of the system or apparatus. It is also achieved by reading and executing the program code stored in the storage medium.
[0068]
In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.
[0069]
Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, and a DVD. -RW, DVD-R, magnetic tape, nonvolatile memory card, ROM, etc. can be used.
[0070]
Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code, etc. Includes a case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.
[0071]
Further, after the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. This includes the case where the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.
[0072]
【The invention's effect】
As described above in detail, according to the present invention, the function of assigning an identifier to a wirelessly connected device is enabled according to whether or not it is connected to an effective wired network. If the wired network cable is not connected, or if the cable is connected but cannot communicate with the network device, the access point assigns an IP address to the wireless terminal. . Accordingly, it is possible to easily form a wireless network and perform IP-based wireless communication between wireless terminals without performing complicated operations and operations.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an embodiment of a wireless access point device according to the present invention.
FIG. 2 is a diagram illustrating a format of a datagram in end-to-end communication.
FIG. 3 is a diagram illustrating an example of a network including network devices including an access point.
FIG. 4 is a diagram showing a configuration of a data frame relayed by an access point.
FIG. 5 is a diagram illustrating an example of a network including an access point set in a bridging mode and other network devices.
FIG. 6 is a diagram showing a configuration of a data frame relayed by an access point.
FIG. 7 is a flowchart showing an operation procedure of connection control processing executed when the access point according to the present embodiment is requested to connect by a wireless terminal.
[Explanation of symbols]
100 Wireless access point device
101 wireless communication circuit (wireless communication means)
102 Wired network interface (wired network connection means)
103 CPU (determination means, identifier assignment means, control means)
104 ROM
105 RAM
106 Bus line
107 EEPROM
108 Power supply circuit
109 Serial communication interface
110 Power line
301 Wired network
302, 502 DHCP server
303, 503 servers
304a, 304b, 504a, 504b Router
306a to 306c, 506a to 506c Wireless terminal

Claims (5)

In a wireless access point device that relays data frames between a wired network and a wireless network,
A wired network connection means for connecting to a wired network via a cable;
Wireless communication means for connecting to at least one wireless terminal by wireless communication to form a wireless network;
Determination means for determining whether or not a network device capable of data communication exists in the wired network connected by the wired network connection means;
Identifier assigning means for assigning an identifier for identifying the wireless terminal on the wireless network to a wireless terminal operated in at least the first operation mode and connected by the wireless communication means;
A wireless access point apparatus comprising: a control unit that operates the identifier assigning unit in a second operation mode different from the first operation mode in response to a determination by the determination unit. When the determining means determines that the network device capable of data communication exists, the control means does not perform identifier assignment by the identifier assigning means, and there is no network device capable of data communication. 2. The wireless access point device according to claim 1, wherein when it is determined, control is performed to execute identifier assignment by the identifier assigning means. The first operation mode is a mode for converting an identifier of a data transmission source device when relaying between a wired network connected to the wired network connection means and a wireless terminal connected by the wireless communication means. The wireless access point device according to claim 1, wherein the second operation mode is a mode in which the conversion is not performed. The wireless access point device according to claim 1, wherein the control means performs the operation only when the second operation mode is set. In a method of controlling a wireless access point device that can be connected to a wired network and can form a wireless network wirelessly,
A determination step of determining whether or not a network device capable of data communication exists in the wired network;
In the first operation mode, an identifier for identifying the wireless device on the wireless network is assigned to the wireless device forming the wireless network, wireless communication is performed based on the identifier, and in the second operation mode, Comprises a step of selectively performing the identifier assignment in accordance with the determination in the determination step.

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