JPH07212364A - Radio lan device - Google Patents

Abstract

PURPOSE:To perform communication by moving a radio terminal over the sub network by adopting the capsule frame transfer radio LAN system for mobile communication without changing the logic address of the radio terminal. CONSTITUTION:A cable LAN segment 1 is connected by a rooter 2. Then the routing of the frame between a cable terminal 3 and a host computer 4 is performed. When a connection request comes from a radio terminal 7 with an adapter 6 mounted by taking the unregistered radio station as an agent master, the frame related to the radio terminal 7 is packed in the frame system to be propagated between the agent master and the master in the radio base station 5 at the transmission. Thus, the capsule frame transfer route is formed on the cable LAN for the master of the radio terminal and the same network environment as connecting to the master directly is constructed. Thus, the radio terminal can be moved over the sub network and the compatibility of the conventional network is available.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless LAN device for freeing a user from wiring of a conventional wired LAN and expanding an existing wired LAN without wiring.

[0002]

2. Description of the Related Art For example, Japanese Unexamined Patent Publication No. 3-250820 and a wireless LAN device manufactured by Motorola, Inc. ("Altai")
The wireless LAN device of the conventional example shown in FIG.
The wired LAN segment 1 includes several wired LANs such as a CSMA / CD medium access control system from the viewpoints of performance limitations, traffic distribution, security, etc., as the number of terminals and scale increase.
It is divided into 1d to form a sub-network. Router device 2
Are router devices 2a to 2 as one of the LAN connecting devices.
Each wired LAN segment 1a through the ports A and B of c.
Connect 1d to connect TCP / IP protocol (industry standard OS
IP according to the standard network protocol adopted by "UNIX" host computers and workstations
Performs frame routing (selection of communication path). The wired terminal 3 connects portable terminals 3a and 3b such as workstations and personal computers to the wired LAN segments 1c and 1d by wire, and provides client / server services. The host computer 4 is a central processing unit 4a or 4b such as a mainframe or a minicomputer.
Is connected to each of the wired LAN segments 1b and 1c by wire to perform distributed transaction processing. Wireless base station 05
Connects wireless equipment 05a to 05c such as a simple wireless station to each wired LAN segment 1b to 1d. Each wired LAN segment 1b to 1d transmits an IP frame transmitted / received to / from the wireless terminal 7 which is connected and accommodated via the wireless channel.
Convert to access procedure. Frames related to the wireless terminal 7 are fixedly communicated. The wireless adapter 6 is connected to the wired LAN interface of the wired terminal 3 and becomes a wireless terminal. The wireless terminal 7 includes wireless terminals 7a and 7b before and after moving.
In addition, a wireless channel is acquired with the wireless base station 05 in accordance with a general transmission request procedure, and the
Send and receive frames. Further, for example, Japanese Patent Laid-Open No. 4-22
The wireless LAN device of the conventional example shown in Japanese Patent No. 7149 adopts a wireless LAN system in which a network environment is sub-networked by a router device as in the above-described conventional example, but some suitable IP addresses are pooled for wireless terminals. However, the allocation is made according to the request from the wireless terminal.

The above-mentioned conventional wireless LAN device adopts a system (fixed frame wireless LAN system) in which frames related to wireless terminals are fixedly mobile-communicated between wireless base stations.

As shown in FIG. 8, the router device 2 holds a routing table and determines which communication path a frame is to be transferred to. The routing table is shown in FIGS.
As shown in (c), each field that stores a subnet address that extends the IP address configuration and a subnet mask that divides the IP address configuration host address bits into sub-networks, an output port, and a relay destination router device IP address With. For example, router device 2
8a and 2b are router devices 2b that temporarily receive an IP frame from the wired terminal 3a via the port B when bidirectional IP protocol communication is performed between the wired terminal 3a and the host computer 4a. Routing table of the host computer 4a, subnet mask processing of the destination IP address of the host computer 4a (for example, 130.10.2.5) is performed, and the subnet address (for example, 130.1
0.2.0) is determined. Next, the router device 2a receiving via the port B searches the routing table of FIG. 8A and relays the IP frame to the wired LAN segment 1b of the subnet address.

When the port B of the router device 2b allocates the subnet address of the wired LAN segment 1c, the wireless base station 05 is, for example, the wireless base station 05b which accommodates the pre-movement wireless terminal 7a belonging to the wired LAN segment 1c. The IP frame can be communicated between the pre-movement wireless terminal 7a and the host computer 4a. Wired LAN
When the wireless base station 05c that accommodates the moved wireless terminal 7b that does not belong to the segment 1d, the moved wireless terminal 7b
To send to the host computer 4a. On the other hand, the IP frame from the host computer 4a is sent to the router device 2b, but not sent to the router device 2c. Therefore, the IP frame cannot be communicated between the wireless terminal 7b and the host computer 4a after moving. Further, when communication other than the IP protocol is performed between the wired terminal 3a and the host computer 4b, and the router device 2a
2c relays only the IP frame to the wired LAN segment 1a for security or billing, the wireless base station 05b that accommodates the pre-movement wireless terminal 7a can communicate, but the wired LAN segment 1 except the IP frame can communicate.
Since it cannot be sent to a, the wireless base station 05c, which accommodates the wireless terminal 7b after moving, cannot communicate in a format other than the IP protocol.

[0006]

The conventional wireless LAN device as described above adopts the fixed frame wireless LAN system in which the frames related to the wireless terminals are fixedly mobile-communicated between the wireless base stations. When moving the wireless terminal over the network, communication becomes impossible. Also, in software countermeasures that have a mechanism for dynamically obtaining a logical address in response to a request from a wireless terminal, most of the existing terminals that do not have such a mechanism are designed on the assumption that they are connected to a wired LAN. Since there is a problem of consistency and the IP address becomes undefined, there is a problem that it is difficult to apply to a host computer having a server function that is accessed from many terminals.

The problem to be solved by the present invention is that a wireless base station other than the parent that connects and accommodates wireless terminals in a wireless LAN device forms a transfer path for the parent on the wired LAN, and the wireless base station directly serves as the parent. Method to build the same environment as when a station accommodates connection (encapsulated frame transfer wireless LAN method)
To provide.

[0008]

A wireless LAN device according to the present invention segments a wired LAN and connects wired LAN segments constituting a sub-network with an inter-LAN connecting device to select a frame communication path in accordance with, for example, a network layer protocol. , Connect a wired terminal to a wired LAN segment by wire, convert a frame communicating with the wireless terminal on the wireless channel to an access procedure of the wired LAN segment at the wireless base station, and attach an adapter to a portable wired terminal, for example. In order to solve the above-mentioned problem, the following means are provided to solve the above problems, and the encapsulated frame is provided. Transfer wireless L
It is characterized by adopting the AN method.

The wireless base station has means for registering a physical address of a wireless terminal which is to be connected and accommodated as a parent, and when receiving a connection request as a proxy parent from a wireless terminal which has not been registered, the wireless base station and the parent wirelessly connect. A frame related to a wireless terminal is wrapped and transferred in a frame format that can be propagated between base stations.

The router base station is provided in place of the inter-LAN connecting device and the radio base station, and the inter-LAN connecting device is provided with the function of the radio terminal contents of the radio base station, and at the same time the logical address of the radio terminal to be connected is accommodated. Try to capture matching frames.

[0011]

According to the wireless LAN apparatus of the present invention, when the wireless terminal is connected and accommodated in a wireless base station other than the wireless base station which is the parent of the wireless LAN apparatus, a route for encapsulating frame transfer to the parent of the wireless terminal is provided. It is formed on a wired LAN to build the same network environment as when connecting and accommodating directly to the parent. A router base station that adds a wireless base station function to an inter-LAN connecting device takes in a frame that matches the logical address of a wireless terminal that is connected and accommodated, and omits encapsulation frame transfer to the parent of the wireless terminal.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wireless LAN device according to an embodiment of the present invention has a wired LAN segment 1 and a router device 2 as shown in FIG.
, Wired terminal 3, host computer 4, wireless adapter 6
The wireless terminal 7 corresponds to FIG. 7 of the above conventional example. The wireless base station 5 connects wireless facilities 5a to 5c such as simple wireless stations to the wired LAN segments 1b to 1d. The IP frame transmitted / received to / from the wireless terminal 7 for connection accommodation is converted into an access procedure for each of the wired LAN segments 1b to 1d. A frame related to the wireless terminal 7 which accommodates the connection is encapsulated and transferred.

The wireless LAN device according to the above-described embodiment encapsulates and transfers a frame related to a wireless terminal between wireless base stations, and performs mobile communication without changing the logical address of the wireless terminal (encapsulated frame transfer). Wireless LA
N method).

As shown in FIG. 2, the radio base station 5 holds a radio terminal management table and a radio base station management table. The wireless terminal management table is as shown in FIG.
Address as a physical address of the wireless base station 5
And a field for storing the IP address of the wireless base station 5 and the wireless channel of "connecting as parent". As shown in FIG. 2B, the radio base station management table has fields for storing the IP address and subnet mask of the radio base station 5, respectively, and is set by an administrator in advance or RIP (route information protocol) or the like is set. Manage dynamically according to routing algorithm.

For example, when bidirectional IP protocol communication is performed between the pre-movement wireless terminal 7a to which the radio base station 5b accommodates connection and the host computer 4a, the pre-movement wireless terminal 7a first sets the broadcast destination MAC address. The ARP (Address Resolution Protocol) request frame held by the wireless base station 5b is transmitted through the wireless channel.
Send to. The wireless base station 5b uses the source MAC address (for example, 01 of the wireless terminal 7a before the movement of the ARP request frame).
234) is registered in the wireless terminal management table of FIG. 2A, it knows that it is “connecting as a parent”, and the connection state and the wireless channel fields have a value of 1 (“Connect as parent”). "Medium" and "used channel number" (for example, 12) are registered. When the ARP request frame is sent to the wired LAN segment 1c as it is, the router device 2b has the target IP address information of the host computer 4a, and therefore the destination MA of the port B is transmitted.
The C address is returned to the wireless base station 5b as an ARP response.
The wireless base station 5b performs the receiving process because the destination MAC address of the ARP response frame is registered in the wireless terminal management table of FIG. Since "connecting as parent" is registered in the connection state field, the received frame is returned to the pre-movement wireless terminal 7a on the wireless channel of "used channel number" registered in the wireless channel field as it is. Next, the pre-movement wireless terminal 7a uses the destination MAC address of the port B of the router device 2b, the source MAC address of the pre-movement wireless terminal 7a, and the destination I of the host computer 4a.
An IP frame having the P address and the source IP address of the pre-movement wireless terminal 7a is sent to the wireless base station 5b via the wireless channel. The wireless base station 5b sends the IP frame to the router device 2b and the host computer 4a via 2a. On the other hand, the host computer 4a sends the IP frame to the wired LAN segment 1 via the router devices 2a and 2b.
send to c. Since the wireless base station 5b registers the destination MAC address in the same manner as the ARP response frame, it returns the received frame as it is to the pre-movement wireless terminal 7a on the wireless channel.

For example, when bidirectional IP protocol communication is performed between the moved wireless terminal 7b to which the wireless base station 5c accommodates connection and the host computer 4a, first, the wireless base station 5c transmits wirelessly from the moved wireless terminal 7b to the host computer 4a. The request for transmission is made known, and a free wireless channel is assigned. Since the source MAC address of the ARP request frame received on the wireless channel is not registered in the wireless terminal management table of FIG. 2A, it is known that it is “connecting as a proxy parent”,
Value 2 in each field of connection status and wireless channel
(Meaning "connecting as proxy parent") and "used channel number" are registered. Further, the wireless base station management table of FIG. 2B is searched, the subnet mask process of the source IP address of the ARP request frame is performed, and the IP address of the corresponding parent wireless base station 5b is read. Next, the moved wireless terminal 7b sends an ARP request frame having the format shown in FIG. 3A to the wireless base station 5c via the wireless channel. The frame format from the moved wireless terminal 7b to the wireless base station 5c is composed of a header part A and a message part B as shown in FIG. The header part A is the destination MA of the broadcast.
It consists of the C address and the source MAC address of the wireless terminal 7b after moving. The message section B is for the wireless terminal 7 after movement.
The source MAC address of b, the source IP address of the wireless terminal 7b after movement, an indefinite target MAC address, and the target IP address of the host computer 4a. The wireless base station 5c encapsulates the ARP request frame of FIG. 3A with an IP frame from the wireless base stations 5c to 5b, and the ARP request frame of FIG. 3B to FIG. Propagate while changing the header part. The wireless base station 5b uses the source IP address of the wireless base station 5c and the moved wireless terminal 7 in the IP frame of FIG.
From the source MAC address of b, another wireless base station 5c
Know that the mobile wireless terminal 7b is connected and accommodated.
In the wireless terminal management table of FIG. 2A, the connection state and the wireless base station IP address fields have a value of 3 (meaning “another wireless base station is connecting as a proxy parent”) and “of the wireless base station 5c. IP address "(eg 130.1
0.4.7) and are registered. The ARP request frame of FIG. 3E encapsulated by the IP frame of FIG. 3D is read and sent to the wired LAN segment 1c. The A
In the RP request frame, the wireless base station 5b transmits the wireless terminal 7 before moving.
The router apparatus 2b returns the ARP response frame having the format shown in FIG. 4A to the wireless base station 5b, which is the same frame as when the connection accommodation of a is performed. The wireless base station 5b is shown in FIG.
Since the destination MAC address of the wireless terminal 7b after the movement of the ARP response frame in (a) is registered in the wireless terminal management table in FIG. 2 (a), reception processing is performed. Since "other wireless base station is connecting as a proxy parent" is registered in the connection status field, an IP whose destination address is "IP address of wireless base station 5c" registered in the wireless base station IP address field The ARP response frame shown in FIG. 4A is encapsulated by a frame, and is propagated while changing the header portion as shown in FIGS. From the destination MAC address of the wireless terminal 7b after moving, the wireless base station 5c uses the IP frame of FIG.
Know that you are "connecting as a surrogate parent." Figure 4
FIG. 4 (e) in which the IP frame in (d) is encapsulated.
The ARP response frame of is read and returned to the wireless terminal 7b after moving on the wireless channel of the "used channel number" registered in the wireless channel field. After moving, the wireless terminal 7
b is an IP frame having the destination MAC address of the port B of the router device 2b, the source MAC address of the moved wireless terminal 7b, the destination IP address of the host computer 4a, and the source IP address of the moved wireless terminal 7b. It is sent to the wireless base station 5c via a wireless channel. Wireless base station 5c
Encapsulates the IP frame, and the router device 2c
And 2b via the wireless base station 5b, the decapsulation is released there, and the packet is sent to the router device 2b and the host computer 4a via 2a. On the other hand, the host computer 4a sends the IP frame to the wired LAN via the router devices 2a and 2b.
Send to segment 1c. The radio base station 5b uses the I
Receiving and encapsulating P frames, router devices 2b and 2c
The data is sent to the via wireless base station 5c, decapsulated there, and returned to the wireless terminal 7b after moving on the wireless channel.

In the above embodiment, a router base station 02 is provided in place of the router device 2c and the wireless base station 5c as shown in FIG. The frame matching the logical address of the wireless terminal may be captured. There is an effect that transfer can be omitted, traffic can be reduced, and propagation time can be shortened. The router base station 02 holds the extended wireless terminal management table as shown in FIG. For the extended wireless terminal management table, the wireless terminal I is added to the wireless terminal management table of FIG.
A field for registering the P address is added. For example, the wireless terminal 7b after movement in which the router base station 02 accommodates the connection.
When bi-directional IP protocol communication is performed between the router base station 02 and the host computer 4b, the router base station 02 first issues the AR issued by the wireless terminal 7b after moving, as in the above embodiment.
From the source MAC address of the P request frame, it is determined that the connection is being made as a proxy parent. Next, the target IP address of the ARP request frame is compared with the source IP address. Since the communication partner is the subnetwork to which the wireless base station 5b as the parent of the wireless terminal 7b after moving belongs, the ARP request frame is routed to the router. The IP frame from the base station 02 to the wireless base station 5b is encapsulated and propagated as shown in FIG. Further, the ARP response frame from the host computer 4b is encapsulated and propagated as shown in FIG. For example, when two-way IP protocol communication is performed between the moved wireless terminal 7b, which the router base station 02 accommodates, and the host computer 4a, the router base station 02 first moves the moved wireless terminal 7b as in the above embodiment. From the source MAC address of the ARP request frame first issued by 7b, it is determined to be "connecting as a proxy parent". Next, the target IP address of the ARP request frame and the source IP address are compared, and since the communication partner is other than the subnetwork to which the wireless base station 5b as the parent of the wireless terminal 7b after moving belongs, the extended wireless communication of FIG. The "IP address of the wireless terminal 7b after moving" is registered in the wireless terminal IP address field of the terminal management table. On the other hand, since the subnet address registered in the routing table of FIG. 8C corresponds to the target IP address, the router base station 02 returns an ARP response with the MAC address of port B as the target MAC address. After moving, the wireless terminal 7b sends an IP address to the host computer 4a.
When the frame is sent, the wireless terminal IP address field of the extended wireless terminal management table of FIG.
Since the "IP address of b" is registered, it is not transferred to the wireless base station 5b as a parent of the wireless terminal 7b after moving, but is relayed from the port A of the router base station 02 to the router device 2a. The router device 2a searches the routing table of FIG. 8A, relays it to the port B, and finally sends it to the host computer 4a. Further, the router device 2 sends an IP frame from the host computer 4a to the wireless terminal 7b after moving.
It is once received by a, and the routing table of FIG. Since the “IP address of the wireless terminal 7b after moving” belongs to the sub-network connected to the port B of the router device 2b, the IP frame is relayed to the router device 2b. The router base station 02 monitors all the frames, and if they match the destination IP address registered in the wireless terminal IP address field of the extended wireless terminal management table of FIG. 6, performs reception processing. The IP frame is returned to the after-movement wireless terminal 7b on the wireless channel of "used channel number" registered in the wireless channel field of the extended wireless terminal management table of FIG.

[0018]

According to the wireless LAN device of the present invention as described above, a capsule for encapsulating and transferring frames related to wireless terminals between wireless base stations and performing mobile communication without changing the logical address of the wireless terminals. Since the frame transfer wireless LAN system is adopted, the wireless terminal is moved across the sub-network as compared with the conventional fixed frame wireless LAN method in which the frame related to the wireless terminal is fixedly mobile-communicated between the wireless base stations. Can communicate even if it is wired L
It has the effect of being compatible with most existing terminals designed on the premise of connecting to the AN.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a wireless LAN device of an embodiment showing the present invention.

FIG. 2 is a diagram for explaining a holding table of the wireless base station shown in FIG.

FIG. 3 is a diagram for explaining propagation of an ARP request frame from the wireless terminal shown in FIG.

FIG. 4 is a diagram for explaining propagation of an ARP response frame to the wireless terminal shown in FIG.

FIG. 5 is a configuration diagram of another embodiment showing the present invention.

FIG. 6 is a diagram illustrating a holding table of the router base station shown in FIG.

FIG. 7 is a configuration diagram of a conventional wireless LAN device.

8 is a diagram illustrating a holding table of the router device illustrated in FIG.

[Explanation of symbols]

 1 Wired LAN Segment 2 Router Device 02 Router Base Station 3 Wired Terminal 4 Host Computer 5 Wireless Base Station 6 Wireless Adapter 7 Wireless Terminal In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] 1. A wired LAN segment for segmenting a wired LAN to form a subnetwork, and the wired LA segment.
L that connects N segments and selects the communication path of the frame
An inter-AN connection device, a wired terminal that makes a wired connection to the wired LAN segment, a wireless base station that converts a frame that communicates with the wireless terminal via the wireless channel into an access procedure of the wired LAN segment, A wireless L including a wireless terminal that performs frame communication on the wireless channel acquired according to a transmission request procedure with a wireless base station.
In the AN device, the wireless base station has means for registering a physical address of the wireless terminal to be connected and accommodated as a parent, and when receiving a connection request from the unregistered wireless terminal as a proxy parent, A wireless LA characterized in that a frame related to the wireless terminal is wrapped and transferred in a frame format capable of propagating between the wireless base station and the parent.
N device. 2. The inter-LAN connecting device selects a communication path of a frame according to a network layer protocol, and the wireless terminal is equipped with an adapter to a portable wired terminal to make it a wireless terminal. Wireless LAN device. 3. A router base station is provided in place of the inter-LAN connecting device and the wireless base station, the wireless terminal accommodating function of the wireless base station is added to the inter-LAN connecting device, and the logic of the wireless terminal for accommodating the connection is provided. 3. The wireless LAN device according to claim 1, wherein a frame matching an address is taken in.