JPH11317744A - Roaming method for radio lan equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roaming method simplified in configuration and reduced in cost by providing a master station with a slave station registering MAC address list, allowing a slave station to inform a new master station about that roaming is under execution when the slave station registers to the new master station, allowing the new master station to broadcast an effect that the register of the slave station is finished when it is finished, and allowing an original master station to recognize that the slave station moved and to delete the slave station from the list. SOLUTION: UDP/IP is mounted to the master station of a radio LAN equipment to mount a protocol for roaming on a high-order protocol. When the slave station 6A moves to a service area 5 to give information that it is under roaming by communication for registering with a second master station 3 and the registering of this slave station 6A is finished at the station 3, a packet with at least information showing the execution of roaming and MAC address information on the registered station 6A is broadcasted to the preferential network of a backbone by mounting on a UDP/IP packet 9. A first master station 2 deletes the station 6A from the MAC address list.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a 5 GHz, 19 GHz
The present invention relates to a wireless LAN device using a high-frequency radio wave such as a GHz band, and particularly to a roaming processing method (expansion or change of a service area to another area).

[0002]

2. Description of the Related Art An outline of roaming of a conventional wireless LAN device will be described with reference to FIG. In FIG. 5, 1 is a so-called back horn such as Ethernet, and 2 is a wireless LA.
A plurality of slave stations of the N device are managed so that communication can be performed between terminals connected to the slave station or between slave stations and the terminals connected to the back horn via wireless as in a wired LAN. A first master station to be controlled. Reference numeral 3 denotes a master station similar to the first master station 2, but a second master station operated at a frequency different from the frequency used by the first master station 2.

[0003] Reference numeral 4 denotes a service area of the first master station 2,
Reference numeral 5 denotes a service area of the second master station 3. Reference numeral 6 denotes a slave station located in the service area 4 where a sufficient quality service can be received. Reference numeral 7 denotes a slave station at a location where the service area 4 and the service area 5 overlap. Reference numeral 8 denotes a slave station located in the service area 5 at a place where a sufficient quality service can be received.

In such a system, for example, when the slave station 6 in the service area 4 moves to the position of the slave station 7 and further moves to the position of the slave station 8, roaming occurs.
Here, in a wireless system such as a mobile phone, when a certain threshold value is exceeded by the measurement of the electric field strength or the like by the slave station, communication is performed between the slave station and the master station to perform a roaming process for a roaming procedure.

[0005]

However, 5 GHz, 1
When a high-frequency band such as 9 GHz is used for a wireless LAN device, the high-frequency band radio wave has a propagation characteristic of strong straightness, and shadowing or the like occurs. Therefore, the roaming start condition is determined by measuring the electric field intensity. It is difficult to perform the measurement, and the number of components for measuring the electric field strength and the cost are increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. In a wireless LAN device using high-frequency radio waves in the 5 GHz, 19 GHz band, etc., it is possible to perform roaming without using electric field strength. An object of the present invention is to provide a roaming processing method for a wireless LAN device which can realize a low cost with a simple configuration.

[0007]

In order to solve the above-mentioned problems, the present invention relates to a roaming processing method for a wireless LAN device.
It has a slave station registration MAC address table that stores addresses,
When the slave station moves to a service area and registers with a new master station, it is notified that roaming is in progress. When the new master station has registered the slave station, it informs the original master station that it is roaming. Broadcasting (via a wire) on a UDP / IP packet to the station, and the original master station interprets the contents of the packet so that the slave station has already moved to another service area. Is recognized and deleted from the original master station MAC address table.

According to such a configuration, roaming can be performed without using the electric field strength.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an outline of roaming of a wireless LAN device using high-frequency radio waves in the 5 GHz and 19 GHz bands. In FIG. 1, 1 to 6 are the same as 1 to 6 in FIG. 6A shows a case where the slave station 6 has moved to the service area 5, and 9 shows an IP packet sent from the second master station 3 to the first master station 2. FIG. 2 shows Table 10 (hereinafter, simply referred to as a MAC address table) of the MAC addresses 11, 12, 13,... Of the registered slave stations possessed by the master station.

[0010] When the slave station starts communication with the master station, the master station registers the MAC address of the slave station in the MAC address table 10. delete. This table is also used for determining (filtering) whether a packet is addressed to a slave station under its control.

The operation during roaming will now be described.
When a certain slave station is located at the slave station 6, the slave station is under the control of the first master station 2, and the first master station 2 registers the MAC address 11 and the like of the slave station in the MAC address table 10. If there is a packet addressed to the slave station, it is put on the wireless packet by filtering.

When the slave station moves from the service area 4 to the service area 5 and comes to the position indicated by the slave station 6A, the slave station 6A communicates with the second master station 3 by new communication.
Under the control of the second master station 3, the second master station 3 registers the MAC address of the slave station 6A in the MAC address table, and if there is a packet addressed to the slave station as described above, Perform filtering. At this time, if the MAC address of the slave station 6A is still registered in the first master station 2,
When a packet addressed to the slave station is delivered, an unnecessary wireless packet is sent to the service area 4.
It is necessary to delete the MAC address of the slave station from the MAC address table of the master station 2.

Therefore, in this embodiment, UDP / IP is mounted on the master station of the wireless LAN device, and a roaming protocol is mounted on the upper layer protocol. Then, the slave station 6A moves to the service area 5, and the second master station 3
In the communication for registration, the roaming is informed, and when the slave station 6A is registered in the second master station 3, information indicating at least roaming to the backbone wired network; M of the registered slave station 6A
A packet having AC address information is carried on a UDP / IP packet and broadcast.

This packet has a meaning only at the parent station (here, the first parent station 2) to which the child station belonged before roaming. In this case, the corresponding first parent station 2 interprets the contents of the packet. By doing so, it knows that the slave station 6A has already moved to another service area, and deletes it from the MAC address table.

The packet for the notification only needs to have at least an identifier indicating the contents of the roaming information and the MAC address of the slave station, and thus has a roaming packet configuration as shown in FIG. This packet 19 includes only the information identifier 20 and the MAC address 21 of the slave station. However, in the roaming packet shown in FIG.
The IP header is omitted.

Here, the UDP (User Datagram Pr
otocol) is a protocol in the transport layer of the OSI reference model. In the transport layer, TCP (Transmission Control Protocol) is also provided.
tocol) and used according to the required application. For applications that handle a large amount of continuous data, connection-oriented (establishment of connection) TCP that has sequence control, error control, and flow control functions is used. However, data communication of small packets is inefficient and burdensome. It takes too much. On the other hand, UDP is a connectionless type and does not provide the above functions, but can realize a simple service and is used for data communication in which small packets are intermittently transmitted. In the embodiment of the present invention, roaming information generated when a slave station moves to a service area is small data information including only an information identifier and a slave station MAC address, and is a packet generated intermittently. Also, this packet is broadcast (broadcast notification) to the backbone, and the master station receiving the packet does not need to respond. For the above reasons, this wireless LA
In order to realize the roaming method of the N device, the master station uses UD as a transport / network layer protocol.
P / IP is implemented.

Next, the flow of the slave station management process will be described with reference to the flowchart shown in FIG. The master station receives the related wireless or wired packet, calls the slave station management processing at a certain timing, and starts the slave station management processing in step S100 of FIG. Next, the process proceeds to step S101, and the presence or absence of a roaming packet in the IP packet from the wired side is checked.

When there is a roaming packet, in step S102, the MAC in the roaming packet
The address is deleted from the MAC address table of the master station, and the process proceeds to step S103. As a result, the most correct filtering can be performed at that time.

On the other hand, if there is no roaming packet in step S101, the process proceeds directly to step S103.
Proceed to. In step S103, it is checked whether or not a new station has been registered from the wireless side. If the new station has been newly registered, the process proceeds to step S104;
Proceed to 105.

In step S104, the MA of the slave station
Add the C address to the MAC address table. Step S
At 105, it is determined whether or not the child station has moved, that is, whether or not it is a roaming child station. If it has moved, the process proceeds to step S106, and if not, the process proceeds to step S108.

In step S106, the newly registered slave station generates a roaming packet as shown in FIG.
A roaming packet transmission process is performed in step S107, and the process ends in step S108.

[0022]

As is clear from the above description, according to the roaming processing method of the wireless LAN device of the present invention, it is possible to perform roaming without using the electric field strength, and thus the high frequency band of 5 GHz and 19 GHz can be used. Also in the wireless LAN device to be used, there is an effect that the cost can be reduced with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a wireless LAN device according to an embodiment.

FIG. 2 is a table of MAC addresses of registered slave stations possessed by a master station.

FIG. 3 is a diagram showing a roaming packet configuration.

FIG. 4 is a flowchart illustrating a flow of a slave station management process.

FIG. 5 is a schematic diagram of a conventional wireless LAN device.

[Explanation of symbols]

 1 Backbone 2, 3 Master station 4, 5 Service area 6, 6A Slave station 9 UDP / IP packet

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoshifumi Suzuki 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (1)

[Claims] In a roaming processing method for a wireless LAN device, a master station has a slave station registration MAC address table for storing at least a slave station MAC address to be registered, the slave station moves to a certain service area, When registering with the master station,
When the new master station registers this slave station, it informs the original master station that it is roaming.
The broadcast is carried on the P / IP packet, and the corresponding original master station recognizes that the slave station has already moved to another service area by interpreting the contents of the packet, and the MAC of the original master station is recognized. A roaming processing method in a wireless LAN device, wherein the roaming processing method is deleted from an address table.