JP2007082070A - Wireless communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assign addresses quickly and autonomously in an ad hoc network without using the functions of a DHCP server and APIPA.
In an ad hoc network wireless communication device that connects wireless communication devices in ad hoc mode, an address that is an identifier of the wireless communication device at startup is selected at random from an address area in a specified range. If it is found that there is a conflict between the wireless communication devices by mutually informing the address, the wireless communication device that has selected the address later will randomly select one address from the address area in the redefined range. Control means for performing processing for selecting an address is provided.
[Selection] Figure 1

Description

  The present invention relates to a radio communication apparatus that performs autonomous and distributed allocation of each address of a radio communication apparatus constituting an ad hoc network. The “address” here is an identifier of a wireless communication device in an ad hoc network.

  The wireless packet communication is a communication form adopted in various systems including a wireless LAN. The wireless LAN standard is being standardized by the IEEE802.11 committee and established as the IEEE802.11 standard (Non-Patent Document 1). In this standard, two communication modes (infrastructure mode and ad hoc mode) are defined.

  The infrastructure mode is composed of an access point (AP) and a terminal station existing within the radio wave coverage (wireless cell), and a wireless network in which the AP and a terminal station under the AP form a connection relationship via a wireless medium. Is the communication mode used in The AP is connected to a network such as Ethernet (registered trademark), and relays packets between the network and the terminal station when a subordinate terminal station that establishes a connection relationship communicates with the network. That is, when viewed from the terminal station, the AP plays a role as an entrance to the network.

  The ad hoc mode is a communication mode used in a closed network that does not require an AP and includes only terminal stations. Terminal stations generally do not have a function of relaying wireless packets, and directly communicate with each other by exchanging wireless packets.

In a wireless communication network (ad hoc network) configured in this ad hoc mode, as a method for a terminal station to acquire an address, for example, a method using an assignment from a DHCP server (for example, non-patent document 2) for an IP address, or a general purpose There is a method of using APIPA (Automatic Private IP Addressing) installed in Windows (registered trademark) of Microsoft Corporation which is an OS (Non-patent Document 3).
IEEE802.11, "Wireless LAN Medium Access Control (MAC) and Physical (PHY) Layer Specifications", August 1999 IETF RFC2131: Dynamic Host Configuration Protocol Microsoft home page: How to Use Automatic TCP / IP Addressing Without a DHCP Server, http://support.microsoft.com/default.aspx?scid=kb;EN-US;q220874

  Of the methods by which the terminal station of the ad hoc network obtains an address, in the method described in Non-Patent Document 2, the DHCP server assigns an IP address. Therefore, it is necessary to install a DHCP server even when an ad hoc network is temporarily configured.

  On the other hand, in the method of Non-Patent Document 3, when a request packet is transmitted to the DHCP server and a response packet from the DHCP server is not received within a certain time, it is determined that the address allocation from the DHCP server has failed. , One IP address is randomly selected and assigned from “169.254.1.0 to 169.254.254.255” by the function of APIPA. For this reason, there is a problem that it takes time until the address allocation from the DHCP server times out, and it is impossible to quickly allocate an address to the terminal stations constituting the ad hoc network temporarily.

  An object of the present invention is to provide a wireless communication apparatus that can perform address assignment in a prompt and autonomous manner without using the functions of a DHCP server and APIPA in an ad hoc network.

  The wireless communication device of the present invention is an ad hoc network wireless communication device that connects wireless communication devices in ad hoc mode, and randomly selects one address from a specified range as an address that is an identifier of the wireless communication device at the time of activation. If an address is selected and it is found that there is a conflict between the wireless communication devices by notifying each other, the wireless communication device that has selected the address from the address area in the range specified again Control means for performing processing for selecting one address at random is provided.

  The control means periodically notifies the address information packet including the randomly selected address and the sequence number, and increments each time the sequence number is notified, and the address information packet notified mutually between the wireless communication devices Therefore, if it is found that the same address is selected by another wireless communication device, the sequence number of the other wireless communication device is compared with the sequence number of the other device, and the sequence number of the other wireless communication device is automatically determined. If the sequence number is smaller than the sequence number of the device, the address is used as it is. If the sequence number in another wireless communication device is equal to or greater than the sequence number of the own device, 1 is randomly selected from the address area in the redefined range. Means for selecting one address.

  In addition, when the control unit randomly selects one address from the address range in the specified range, the control unit randomly selects one address from the address region excluding the address notified from another wireless communication device. Also good.

  The control means is configured to stop the periodic notification of the address information packet when all of the sequence number of the own device and the sequence number notified from another wireless communication device exceed a predetermined threshold. Also good. Further, the control means receives the address information packet broadcast from another wireless communication device while stopping the periodic notification of the address information packet, and when the sequence number is smaller than the threshold, It is good also as a structure which restarts alerting | reporting of the address information packet of an apparatus.

  The wireless communication apparatus of the present invention selects one address randomly from the address area in the range defined at the time of activation, and performs reselection when an address conflicts with another wireless communication apparatus, thereby quickly addressing To avoid address conflicts.

  As a method for detecting an address conflict with another wireless communication device, the wireless communication device according to the present invention periodically notifies the selected address and a periodically incremented sequence number, thereby allowing the other wireless communication device to By comparing the sequence number with the sequence number of its own device, it is possible to easily detect an address conflict.

  The wireless communication device of the present invention can reduce the probability that the same address is selected by randomly selecting one address from the address area excluding the address notified by another wireless communication device.

  The wireless communication device of the present invention stops useless traffic by stopping the notification of an address when all of the sequence number of the own device and the sequence number notified from another wireless communication device exceed a predetermined threshold. Increase can be prevented. In addition, when an address and sequence number are notified from another new wireless communication device during the stoppage, by resuming the notification of the address and sequence number of the own device, the new wireless communication device Can be used to notify the address being used and avoid address conflicts.

  With such a configuration, even if a wireless communication device is temporarily connected to an ad hoc network, the address of the device itself can be quickly, autonomously distributed and efficiently without using the functions of the DHCP server and APIPA. Can be set.

FIG. 1 shows a configuration example of an ad hoc network including a wireless communication apparatus of the present invention.
In the figure, a plurality of wireless communication devices 1, 2, and 3 constitute an ad hoc network 4 that communicates with each other in an ad hoc mode.

FIG. 2 shows a configuration example of the wireless communication apparatuses 1 to 3 according to the present invention.
In the figure, the wireless communication device of the present invention includes an antenna 11, a transmission / reception unit (TRX) 12 connected to the antenna 11, a baseband processing unit (BB) 13 sequentially connected to the transmission / reception unit 12, and a control unit (CNT ) 14 and an interface unit (I / F) 15.

FIG. 3 shows a configuration example of a table used in the control unit 14.
In the figure, the control unit 14 has an address table and an address management table. The address table is composed of the address and sequence number of its own device that is randomly selected from the address range of the range defined by the wireless terminal device. The randomly selected address and sequence number are periodically broadcast to other wireless terminal devices as address information packets. The sequence number is incremented (+1) every time an address information packet is broadcast. The address management table manages each address and sequence number notified from other wireless terminal devices, and provides a process for setting or changing the address of the own device.

FIG. 4 shows a configuration example of the address information packet.
In the figure, the address information packet has fields of a destination address, a source address, and a sequence number. The control unit 14 sets a transmission source address and a sequence number based on the information in the address table. For example, a broadcast address is used as the destination address.

FIG. 5 shows a processing procedure in the control unit 14.
When the wireless communication device (self device) in the ad hoc network is activated, a timer for waiting for a predetermined time is first activated (S1). If an address information packet transmitted from another wireless communication device (other device) is received before this timer times out, the source address and sequence number of the received packet are registered in the address management table (S2 , S3, S4). When a certain time elapses and a time-out occurs, one address is randomly selected from the address area excluding the addresses registered in the address management table and determined as the address of the own device (S4, S5).

  Next, the determined address is registered in the address table, and the sequence number in the address table is reset (S6). Then, an address information packet created based on the information in the address table is notified (S7), and a timer for waiting for a predetermined time is started (S8).

  If an address information packet transmitted from another device is received before this timer times out, it is determined whether the source address of the received packet is the same as the address of the device registered in the address table. Check (S9, S10). If the source address of the received packet (address set by another device) is different from the address of its own device, the source address and sequence number of the received packet are registered in the address management table and the standby is continued ( S10, S11, S12, S9). On the other hand, if the addresses are the same, the sequence number of the received packet (other device) is compared with the sequence number of the own device (S13). If the sequence number of the own device is larger than the sequence number of the other device, the address is an address set by the other device after setting the address of the own device (the address set by the own device first). The standby is continued as it is (S10, S13, S12, S9). In other apparatuses, the address is changed as will be described later.

  On the other hand, when the sequence number of the own device is smaller than the sequence number of the other device, the address is an address set by the other device before the address setting of the own device (the address set later by the own device). Therefore, the address determined in S5 is changed by the own device. At this time, the source address and sequence number of the received packet are registered in the address management table (S13, S14), one address is randomly selected from the address area excluding the address registered in the address management table, The address is determined (S5).

  If the sequence number of the own device and the sequence number of the other device are the same, the address is the address set by the other device almost simultaneously with the address setting of the own device, so that the own device has the address determined in S5. Make a change. At this time, the source address and sequence number of the received packet are not registered in the address management table. The reason is that if the same processing is performed in another device, the address is registered in both address management tables and cannot be used (S13, S5).

  When a time elapses after notifying the address information packet of the own device, it is checked whether all the sequence numbers registered in the address table and the address management table are larger than the threshold (S12, S15). If there is even one sequence number smaller than the threshold, the sequence number in the address table is incremented (+1), the address information packet generated based on the incremented number is notified (S15, S16, S7), and the processing after S8 repeat.

  On the other hand, if all the sequence numbers registered in each table are larger than the threshold value, the timer is started again and the process waits until time-out (S15, S8). When an address information packet whose sequence number is less than the threshold is received from another wireless communication device during standby, it is determined that a new wireless communication device has joined and the address and sequence number are registered in the address management table. In order to notify the wireless communication device of its own address, notification of the address information packet is resumed (S8, S9, S10, S11, S12, S15, S16, S7).

The figure which shows the structural example of the ad hoc network containing the radio | wireless communication apparatus of this invention. The figure which shows the structural example of the radio | wireless communication apparatuses 1-3. The figure which shows an example of the table used with the control part. The figure which shows the structural example of an address information packet. 7 is a flowchart showing a processing procedure in the control unit 14;

Explanation of symbols

1, 2, 3 Wireless communication device 4 Ad hoc network 11 Antenna 12 Transceiver (TRX)
13 Baseband processor (BB)
14 Control unit (CNT)
15 Interface section (I / F)

Claims (5)

In an ad hoc network wireless communication device that connects wireless communication devices in ad hoc mode,
It was found that one address was randomly selected from the address range of the specified range as an address that is an identifier of the wireless communication device at the time of startup, and that address was informed by mutual notification between the wireless communication devices. In this case, the wireless communication apparatus includes a control unit that performs a process of selecting one address randomly from an address area in a range in which the wireless communication apparatus that has selected the address later is defined again. The wireless communication device according to claim 1,
The control means includes
A means for periodically informing an address information packet including a randomly selected address and a sequence number, and increasing the sequence number every time the information is notified;
When it is found from the address information packet broadcasted between the wireless communication devices that the same address is selected by the other wireless communication device, the sequence number of the other wireless communication device and the sequence number of the own device If the sequence number in the other wireless communication device is smaller than the sequence number of the own device, the address is used as it is, and the sequence number in the other wireless communication device is equal to or greater than the sequence number of the own device. Comprises a means for randomly selecting one address from the address area in the range defined again. The wireless communication apparatus according to claim 1 or 2,
The control means is configured to randomly select one address from an address area excluding an address notified from another wireless communication device when selecting one address from a specified range of address areas at random. A wireless communication apparatus. The wireless communication device according to claim 2,
The control means is configured to stop periodic notification of the address information packet when all of the sequence number of the own device and the sequence number notified from the other wireless communication device exceed a predetermined threshold. A wireless communication device characterized by the above. The wireless communication apparatus according to claim 4, wherein
The control means receives the address information packet broadcast from the other wireless communication device while stopping the periodic notification of the address information packet, and the sequence number is smaller than the threshold value. Is a configuration for resuming notification of the address information packet of the device itself.

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