JPH03250820A - Local area network and communication network - Google Patents

Abstract

PURPOSE:To improve the degree of freedom of network layout by adopting 2-layer structure comprising a host network whose communication medium is a wired line and a subsequent network whose communication medium is a radio for a local area network(LAN). CONSTITUTION:A communication medium for a host network is a wired line and a communication medium for a subsequent network is a radio, The communication between terminal equipments 4 on the host network is executed according to the network of 2-layer structure in this way and the communication between radio terminal equipments 7 using the host network is executed and the communication between the radio terminal equipment 7 and the terminal equipment 4 is executed via the host network. Moreover, the communication may be executed between the radio terminal equipment 7 and a radio base station 6 in order to decide the radio base station 6 accommodating the radio terminal equipment 7. Since the 2-layer structure is adopted for the network in this way, the degree of freedom of network layout is enhanced more than that of a network employing only wired lines.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to local area networks (LANs) and communication networks.

"Conventional technology" Recently, medium- and low-speed LANs have become popular, and high-speed LANs are also becoming commonplace.Regardless of communication speed, current LANs have short distances between multiple terminals and/or host computers. For these reasons, wires were used to connect multiple terminals and/or host computers.

[Problems to be Solved by the Invention] However, according to the conventional LAN, connecting a new terminal to the network requires a physical connection, which requires complicated work. Even when removing it, complicated work is required due to the physical connection. As a result, it is not easy to change the location of the terminal, and the degree of freedom regarding the network layout is low.

In fact, terminals are often rearranged in places such as offices.

The present invention has been made in consideration of the above points, and aims to provide a local area network with a high degree of freedom in network layout.

Furthermore, it is an attempt to provide a terminal protocol suitable for a communication network having a predetermined structure, including a provided local area network.

[Means for Solving the Problems] A first aspect of the present invention includes a local area network including a plurality of wireless terminals and at least one wireless base station connected to a wired network and accommodating the wireless terminals. It was established.

The second and third aspects of the present invention provide a local area network according to the first aspect of the present invention, which includes a plurality of wireless terminals and a plurality of wireless base stations that accommodate the wireless terminals and are interconnected by wires. It is related to communication networks including.

In the second aspect of the present invention, a wireless terminal transmits an accommodation request to a wireless base station, and the wireless base station that first and accurately returns a response to the request is determined to be the wireless base station to be accommodated. be.

In the third aspect of the present invention, each wireless base station manages the wireless terminal information it accommodates, and also allows communication from a wireless base station or a terminal on a wired network to a wireless terminal via another wireless base station. In this case, the group relay function is used to communicate with other radio base stations, and the radio base station accommodating the destination radio terminal communicates with that radio terminal.

[Operation] The first invention provides, in addition to an upper network that uses wires as a communication medium, a lower network that uses wireless as a communication medium and is made up of wireless terminals and wireless base stations,
This solves the problem of flexibility in network layout.

The second and third aspects of the present invention have been made in consideration of the local area network according to the first aspect of the present invention;
It can also be applied to other communication networks having upper and lower networks.

In such communication networks, the problem is which wireless base station should accommodate a wireless terminal, but the method of determining the accommodation location fixedly or based on the average reception level is
In the case of local area networks, this is not the best method because there are problems such as reflection and attenuation of radio waves. In that case, it is only necessary to determine a wireless base station where communication is accurately performed as the accommodation destination.Therefore, in the second aspect of the present invention, the wireless terminal transmits an accommodation request to the wireless base station, and responds to the request first and accurately. The wireless base station that returned a response was determined to be the wireless base station to be accommodated.

When communicating from a wireless base station or a terminal on a wired network to a wireless terminal via another wireless base station, it is preferable that the entire network learns the accommodation information.

However, considering the fact that the accommodation destination changes due to the movement of wireless terminals and the control configuration of accommodation information becomes complicated, it is difficult for each radio base station to manage accommodation information only for the radio terminals that it accommodates. preferable.

Therefore, in the third aspect of the present invention, each wireless base station manages only the wireless terminal information that it accommodates. but,
In this case, it is not possible to communicate from a wireless base station or a terminal on a wired network to a wireless terminal via another wireless base station.

Therefore, in the third aspect of the present invention, in such a case, communication is performed to other wireless base stations using the group broadcasting function, and the wireless base station accommodating the wireless terminal that is the transmission destination communicates with the wireless terminal. I decided to communicate.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

(A> Overall configuration of local area network First, the overall configuration of the LAN in this embodiment will be explained using FIG. 1.

FIG. 1 shows this overall configuration. In FIG. 1, this local area network 1 has a two-layer structure consisting of an upper network that uses wires as a communication medium and a lower network that uses wireless communication.

The upper network consists of a common bus 2, a plurality of terminals 4, and at least one host computer 5, which are connected to the common bus 2 via input/output stations 3. Furthermore, one or more wireless base stations 6 that serve as a gateway and connect between an upper network and a lower network are connected to the common bus 2 via input/output stations 3.

The lower station is composed of the above-described wireless base station 6 and a plurality of wireless terminals 7 that can perform wireless communication with the wireless base station 6. A zone 8 in which each wireless base station 6 can accommodate wireless terminals 7 is defined within a predetermined range.

Note that it is preferable that there be a plurality of wireless base stations 6.

That is, it is preferable to create zones. this is,
In the case of a single zone configuration, all wireless terminals 7 must have a communication range that covers the entire network, which increases the required transmission output and increases the size of the device configuration. This is because only one wireless terminal can use the same frequency at the same time.

As described above, since the communication medium of the upper network is wired and the communication medium of the lower network is wireless, the protocol control configuration of each component related to the lower network is as shown in FIG. That is, the wireless terminal 7 includes a wireless protocol control unit 7a for realizing wireless communication, and the wireless base station 6 includes a wired protocol control unit for realizing wired communication in addition to the wireless protocol control unit 6a for realizing wireless communication. 6b.

According to such a two-layer network, it is possible to carry out communication between the terminals 4 on the upper network, communication between wireless terminals 7 using the upper network, and wireless communication via the upper network. Communication between terminal 7 and terminal 4 can be performed. Note that in order to determine the wireless base station 6 that accommodates the wireless terminal 7, communication may be performed between the wireless terminal 7 and the wireless base station 6.

The reason why the network has a two-layer structure is that the degree of freedom in network layout can be increased compared to a wired-only network.

Incidentally, a car phone system already exists as a network with a two-layer structure of wired and wireless, but in the case of LAN, it is difficult to determine the location of the wireless terminal 7, there are restrictions on the placement of the wireless base station 6, and the wireless Conventional LANs have not adopted a two-layer structure because the terminal 7 is not constantly moving and the actual range required for the LAN is narrow.

However, due to the above-mentioned reason for the degree of freedom in network layout, it was decided to adopt a two-layer structure for the LAN as well.

In addition, in view of the differences from existing two-layer networks, and the problem that wireless networks have problems with line quality and the presence of overheads at the start and end of communication, it is difficult to realize a practical network. In view of this, we decided to adopt a new accommodation protocol and communication protocol for the wireless terminal 7, which will be described later, to realize a two-layered LAN 1.

Note that the upper network of this embodiment is required to have a group relay function, as will be described later.

(B) Accommodating the wireless terminal 7 in the wireless base station 6 and reaccommodating it when moving Next, a method of housing the wireless terminal 7 in the wireless base station 6 and a method of reaccommodating the wireless terminal 7 when moving will be explained. In addition,
The logical connection work of lower-level networks is expressed here as accommodating a wireless terminal in a wireless base station.

FIG. 3 is an explanatory diagram showing a method of accommodating (and reaccommodating) a wireless terminal.

In this embodiment, the wireless base station 6, not the wireless terminal 7, determines the wireless base station to accommodate.

First, after turning on the power, the wireless terminal 7A sends out an accommodation request packet to which its own identification number is added (step 100).

When receiving an accommodation request packet from the wireless terminal 7A, the wireless base station responds to the wireless terminal 7A by adding its own identification number (step 101). In the case of this embodiment, there is not a one-to-one correspondence between the wireless terminal and the accommodation destination wireless base station, and all the wireless base stations 6A, 6B, and 6C that have received the accommodation request packet respond to the wireless terminal 7A. Do this. Although zoning is carried out centering around the wireless base stations, zones 8 are overlapped to some extent to ensure communication even in the presence of fading and noise, so multiple wireless base stations 6A to 6C are zoned. At the same time, an accommodation request packet may be received.

The wireless terminal 7A transmits the first response that was correctly received among the received responses, for example, the wireless base station 6A.
is identified using the identification number, and an accommodation request packet is output again (step 102).

Only the designated wireless base station 6A responds, and accommodation is completed (step 103). Note that the wireless base station from which a response was first received is not necessarily the closest. This is because competition control of control channels is performed using the upper network.

For communication for such accommodation, for example, one channel for communication control, which is prepared separately from a channel for data communication, is used.

By the way, if the wireless terminal 7 is moved due to changes in the layout of the office where the LAN is applied, the own terminal 7
may go out of the communication range of the wireless base station 6 in which the wireless base station 6 is accommodated. At this time, a reaccommodation operation is performed. The reaccommodation operation is executed when retransmission requests are received from the wireless base stations 6 that have been accommodated at a rate exceeding a certain rate. Note that the re-accommodation operation is similar to the accommodation operation except that a re-accommodation request packet is sent instead of the accommodation request packet, and thereby the base station is accommodated in another radio base station.

The reason why the accommodation operation and re-accommodation operation are performed in the above-described manner is as follows. The reason will be explained by comparing it with the accommodation method used in car phone systems.

The accommodating method (method for determining wireless base stations) in a car phone system is to select the wireless base station with the highest reception average level of control signals on the control channel transmitted from each wireless base station as the accommodating wireless base station. It is something to do.

According to the accommodating method in the car telephone system, it is necessary to equip the wireless terminal with a function to measure the reception level and determine the wireless base station closest to the wireless terminal, which results in an increase in the size of the wireless terminal.

Furthermore, wireless terminals are not always on the move like cars, and it is difficult to determine the average value of the reception level. moreover,
In the method used in the car telephone system, there is a very high possibility that the terminal will be accommodated in the nearest wireless base station, but if the traffic density of other wireless terminals accommodated in the same wireless base station is high, other wireless base stations may Preferably, such accommodation is achieved by determining one response to be the first one.

(C) Communication Method/Communication Protocol Next, the communication method and communication protocol between the wireless terminal 7 and the wireless base station 6 will be explained.

For communication between the terminals 4 (including the host computer 5) on the upper network, a conventional LAN method can be applied, so a description thereof will be omitted. Further, since a conventional LAN method can be applied to communication from the wireless base station 6 to the terminal 4 (including the host computer etc.) on the wired network, a description thereof will be omitted.

Communication from the wireless terminal 7 to the terminal 4 on the upper network can be divided into communication from the wireless terminal 7 to the wireless base station 6, and communication from the wireless base station 6 to the terminal 4 on the wired network. For the latter, conventional methods can be applied as described above.

Communication between the wireless terminals 7 includes communication from the first wireless terminal 7 to the first wireless base station 6, communication between the wireless base stations 6, and (
There is no such communication when the terminals are accommodated in the same wireless base station), and communication from the second wireless base station to the second wireless terminal. In this case, the conventional method described above cannot be applied, and it was decided to apply another method to the second communication in consideration of reducing the load on the network.

Communication from the terminal 4 of the upper network to the wireless terminal 7 is as follows.
Communication can be divided into communication from the terminal 4 to the wireless base station 6 and communication from the wireless base station to the wireless terminal.For the former, conventional methods can be applied, but a new method will be applied, and for the latter, Naturally, conventional methods such as those described above cannot be applied.

Therefore, in the following, the uplink and downlink communication methods and communication protocols between the wireless terminal 7 and the wireless base station 6, the communication method and communication protocol between the wireless base stations 6, and the communication method and communication protocol from the terminal 4 on the upper network to the wireless base station The communication method and communication protocol to 6 will be explained.

In addition, for lower-level networks that use radio as a communication medium, multiple frequency channels are prepared, one of which is assigned as a communication control channel, and the other channel is assigned as a data communication channel. The following description assumes that a multi-channel access method is applied that takes into account partial overlapping of zones.

FIG. 4 is an explanatory diagram showing an uplink communication procedure from a wireless terminal to a wireless base station.

When a communication request is generated, the wireless terminal 7A sends out a communication channel allocation request packet in which an identification number for itself is added to the communication control channel (upstream) (step 200).

This communication assignment request may be received by a plurality of wireless base stations 6A to 6C. Only the wireless base station 6A accommodating the wireless terminal 7A that sent the request determines the data channel to be allocated and sends a response back to the wireless terminal 7A (step 201). Other wireless base stations 6B and 6 that are not accommodated
C ignores the communication channel allocation request packet in communication processing. The methods for determining the channels for data communication include the fixed channel allocation method, which determines channels that are predetermined for each zone, and the dynamic channel method, which determines the channels to be allocated by considering the overall frequency usage situation. However, in this embodiment, an intermediate method described later is applied.

Upon receiving the response, the wireless terminal 7A transmits data to the wireless base station 6A using the assigned data channel (
Step 202).

The wireless base station 6A that has received the transmission data determines whether the destination of the data is another wireless terminal that it accommodates, and whether it is the terminal 4 or host computer 5 on the upper network. Discern.

If the destination of the data is another wireless terminal that it accommodates, it executes the downlink communication procedure of the wireless channel (see steps 205 and 206 in FIG. 5), which will be described later.

Terminal 4 or host computer 5 on the upper network
, the destination terminal 4 or host computer 5
be transferred using the same transfer method as before.

When it is determined that the destination is neither the terminal 4 nor the host computer 5 on the upper network, nor any other wireless terminal it accommodates, it uses the group broadcasting function (see Figure 5) of the upper network. , the identification number of the source wireless terminal and the data are transmitted as one packet.

The reason why the group broadcasting function is used for transmission is that although the radio base station 6 knows which radio terminals it accommodates, it also knows which radio terminals are accommodated by other radio base stations. This is because we do not have all the information about what is happening. The destination of data sent by the group broadcast function is
The radio base station, which is for the radio terminals that it accommodates, follows the downlink communication procedure of the radio channel (fifth
(see figure).

FIG. 5 is an explanatory diagram showing a communication procedure between radio base stations and a communication procedure downlink from a radio terminal to a radio base station. This illustration shows a case where data received by the wireless base station 6A is destined for a wireless terminal 7B accommodated in the wireless base station 6B.

The wireless base station 6A uses the group broadcasting function to transmit the identification number and data of the destination wireless terminal 7B as one packet to all other wireless base stations 6B and 6C (
Step 203).

Even if the wireless base station 6C that does not accommodate the destination wireless terminal 7B receives this packet, it does not perform any operation. On the other hand, the wireless base station 6B accommodating the wireless terminal 7B first returns an acknowledgment to the wireless base station 6A to which the packet is transmitted (step 204).

Thereafter, the wireless base station 6B determines the channel to be allocated as described below, and notifies the wireless terminal 7B, which is the destination of the packet, of the determined channel information using the communication control channel. The packet is transferred using the data channel determined by step 205.
206).

Note that at this time, if another radio base station is using the communication control channel, a collision will occur and communication will have to be repeated several times. In particular, overhead in wireless communication significantly reduces sloop and sorting, so before using communication control channels, each wireless base station must communicate with other wireless base stations using the group broadcast function within the upper network. The communication control channel will be used from now on.

When each radio base station receives this communication control channel usage notification, it determines that the communication control channel is occupied and refrains from using the communication control channel itself. . This minimizes undesired overhead on the wireless channel.

Above, we have explained communication from a wireless terminal to a wireless base station, communication from a wireless base station to another wireless base station, and communication from a wireless base station to a wireless terminal. Communication to the station will be explained.

In this case, as well as communication between radio base stations, the terminal 4 uses the group broadcasting function to communicate with all radio base stations 6A and 6.
The identification number and data of the destination wireless terminal 7B are transmitted to B and 6C as one packet. The use of the group broadcast function is similar to communication between wireless base stations.

(D> Determination of communication channel In this embodiment, as mentioned above, a multi-channel access method is adopted in consideration of effective use of frequencies. Therefore, as explained in the communication method and communication protocol section, Channels must be determined taking into account channels already used for network data communication, that is, channel placement becomes a problem.

Channel allocation methods for communication systems can be broadly classified into fixed channel allocation methods and dynamic channel allocation methods, as described above.

When the peak time of traffic volume in each zone varies, dynamic channel allocation is generally said to be more efficient. However, the dynamic channel method is complicated to control and requires time to search for free channels, so it takes time to decide which channel to allocate, and it may be less efficient than fixed allocation.

In addition, in both the fixed channel arrangement method and the dynamic channel method, if zone 8 or
This is based on the premise that the positional relationship of each radio base station is clearly defined. However, in the LAN of the embodiment, since the radio waves propagate indoors, the attenuation of the radio waves is not uniform, and the conventional channel arrangement method cannot define the necessary positional relationship of zones.

Therefore, in this embodiment, a new channel arrangement method is used which is intermediate between the fixed channel arrangement method and the dynamic channel arrangement method, which is relatively easy to control and has good arrangement efficiency.

Note that, in consideration of simplifying the control configuration and reducing the load on the upper network, the wireless base station 6 determines the channel as described above.

The channel determination method will be explained below in the order of determining adjacent base stations, creating a channel allocation table, and channel allocation algorithm.

(0-1) Determination of adjacent radio base stations By knowing which radio base station is adjacent to which radio base station, channels can be used effectively. In other words, in order to efficiently determine a channel, it is necessary to know neighboring wireless base stations.

Location information of a radio base station, which indicates which radio base station a certain radio base station is adjacent to, is essential data for the channel allocation method. Assuming that we have this location information in advance on a higher-level network (for example, host computer 5),
Since the load on the network increases, flexibility is lost, and it becomes difficult to add more wireless base stations, each wireless base station is made to be able to dynamically acquire location information. First, a method for acquiring location information of adjacent wireless base stations will be described.

When errors in a communication line are random, long data requires a low error rate on the communication line. in general,
The shorter the communication distance, the lower the error rate, so communication request packets can reach farther and more accurately than data packets. Therefore, the wireless base station 6 receives communication request packets from the wireless terminals 7 in a wider range than the zone 8 of each wireless base station.

As described above, the number of the accommodation destination wireless base station 6 and the number of the wireless terminal 7 are inserted into the communication request packet from the wireless terminal 7 and transmitted at the same time.

Each wireless base station can easily determine whether a received packet is from a wireless terminal that it accommodates (wireless terminal within the zone), so it can easily determine whether or not a received packet is from a wireless terminal that it accommodates (wireless terminal within the zone). The accommodating wireless base station is defined as an adjacent station.

In this way, the numbers of adjacent wireless base stations received within a certain period of time in the past are saved as an adjacent wireless base station list.

(D-2) Creation of channel assignment table Next, the channel assignment table (see FIG. 6) and its creation method will be explained.

In dynamic channel allocation, the channel usage status of other wireless base stations is required when determining the channel to be allocated. This information exchange has the drawback of increasing the load on the upper network. In order to minimize the amount of communication on the network and the buffer area, the amount of information held by a wireless base station should be limited to the minimum necessary.

Therefore, each wireless base station is configured to accumulate only data on channel allocation status information of adjacent wireless base stations that may cause communication interference with each other.

Each wireless base station has the neighboring station list (N1
, N2, ..., Ni),
By knowing which channel the adjacent wireless base station is currently using using the group broadcasting function of the upper network and constantly updating the channel usage status of the corresponding adjacent wireless base station, the channel allocation table of the adjacent wireless base station can be created. Create in your own station.

The channel allocation table also manages the number of times communication request packets have been received from wireless terminals accommodated in the adjacent wireless base station in the past. This value is a guideline for knowing how much interference will occur between neighboring radio base stations when they use the same frequency, and is hereinafter referred to as area multiplicity.

The wireless base station determines the channel to be allocated to the wireless terminal, and before informing the wireless terminal of this, and after releasing the allocated channel, it uses the group broadcasting function of the upper network to assign the channel to each wireless base station. Notify us of changes in circumstances. When each radio base station receives a change in the channel usage status of an adjacent station through the upper network, it updates the channel usage status in its own channel allocation table based on the data. Since this method does not require information exchange with the upper network at the time of channel arrangement, the time required for channel arrangement can be reduced.

FIG. 6 is an explanatory diagram of the channel allocation table that is continuously updated in this way.

FIG. 6(B) shows that a wireless base station 61 accommodates a wireless terminal 71, a wireless base station 62 accommodates wireless terminals 72 and 73,
In the accommodating state shown in FIG. 6 (A>) in which the radio base station 63 accommodates the radio terminals 74 and 75, the first channel, second channel, etc. of each radio base station 61, 62, 63, etc. - The main body of the allocation table for the fifth channel is shown.

As shown in the area multiplicity column, the wireless base station 61
Wireless terminals 72 and 73 accommodated in the wireless base station 62
Since the wireless base station 62 has received a communication request packet from channel) is also stored in the channel usage status column along with information on the channel assigned by the user (first channel).

As shown in the area multiplicity column, the wireless base station 62
Since no communication request packets are received from wireless terminals accommodated in other wireless base stations 61, 63, etc., only the channel usage status information (second channel and fourth channel) assigned to the self-assigned channel is displayed. It is stored in the column.

As shown in the area multiplicity column, the wireless base station 63
Since a communication request packet is received from a wireless terminal 75 accommodated in the wireless base station 64, the wireless base station 64 is determined as an adjacent wireless base station, and the group broadcast function is used to transmit the communication request packet to the wireless base station 65. Regarding the assigned channel (5th channel) sent by the self-assigned channel (5th channel),
3rd channel) information is stored in the channel usage status column.

In this way, each radio base station accumulates only information on channels assigned by itself and channels assigned by adjacent radio base stations, and executes channel assignment control to be described later.

Since channels are assigned independently of wireless base stations that are so far away that they do not receive communication request packets, effective use of frequencies is achieved, and the buffer memory required to store such tables is also small. It's done.

(D-3) Channel Arrangement Algorithm Next, the channel arrangement algorithm for determining channels will be explained.

When a wireless base station receives a communication request packet from a wireless terminal that it is accommodating, it allocates the channel that is currently thought to cause the least interference to neighboring wireless base stations based on the channel allocation table that it manages. decide.

If there are adjacent wireless base stations or channels that are not used by the own station, choose one from them at random, or if there are none, choose the one with the smallest sum of area multiplicity (the base that is considered to be the farthest among the adjacent wireless base stations). channel assigned by the station).

After determining a channel, other wireless base stations are notified of the use of that channel through the group broadcast function of the upper network. If a notification to use that channel has been received from another radio base station before this packet is correctly transmitted, the process starts over from the decision on channel allocation.

Similarly, when communicating packets from a wireless base station to a wireless terminal, after determining the channel to be allocated from the table, the wireless terminal is called through the communication control channel, and at the same time, the allocated channel is notified to other wireless base stations.

(E) Effects of the Embodiment The two-layer LAN according to the above-described embodiment provides the following effects.

The degree of freedom in network layout is greater than with a wired-only network. In other words, there is no need to physically reconnect the terminals (wireless terminals) when rearranging them.

By creating multiple zones, the wireless communication section can be narrowed, and a portion of the wireless communication section with relatively good line quality can be used.

The same frequency wireless channel can be used simultaneously in multiple zones. That is, frequencies can be used effectively.

Because the channel placement changes dynamically, it can easily adapt to traffic fluctuations.

A two-layer structure can be easily realized using an existing wired LAN. In other words, it has good compatibility with existing LANs.

Note that the following effects are also produced, although not for the entire LAN.

A wireless terminal sends an accommodation request to a wireless base station, and the wireless base station that first and accurately returns a response is set as the accommodation destination wireless base station, so it is possible to accurately determine the accommodation destination even when the wireless terminal moves. , the storage location can be determined according to the amount of traffic.

In addition, since a wireless base station or a terminal on a wired network communicates with other wireless base stations using the group broadcast function, the upper network or wireless base station does not necessarily have information about where other wireless base stations are accommodated. There is no need to know the information, and the management structure and control of the accommodation destination can be simplified.

(F) Other Embodiments Various types of upper network can be applied as long as they have a group broadcasting function.

That is, C8MA/CD, token passing bus,
Token passing ring, broadband path method, etc. can be applied. Furthermore, the upper network may not have any terminals.

Wireless communication protocols and the like are applicable not only to LANs but also to other two-layer networks.

[Effects of the Invention] As described above, according to the first aspect of the present invention, the LAN has a two-layer structure consisting of an upper network where the communication medium is wired and a lower network where the communication medium is wireless. It is possible to realize a LAN with a high degree of freedom.

According to the second aspect of the present invention, a wireless terminal transmits an accommodation request to a wireless base station, and the wireless base station that first and accurately returns a response is determined to be the wireless base station to be accommodated. In addition, it is possible to accurately determine the accommodation location even when the radio base station moves, and it is also possible to determine the accommodation location according to the amount of traffic.

According to the third aspect of the present invention, in communication from a wireless base station or a terminal on a wired network to another wireless base station via another wireless base station, the group relay function is used to communicate with the other wireless base station. As a result, the upper network or wireless base station does not necessarily need to know information about the host wireless terminals of other wireless base stations, and the management structure and control of the host stations can be simplified. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a LAN according to the first invention;
Figure 2 is a block diagram showing the protocol control configuration, Figure 3 is an explanatory diagram of how to accommodate wireless terminals, Figure 4 is an explanatory diagram of the communication method from the wireless terminal to the wireless base station, and Figure 5 is the wireless base station. FIG. 6 is an explanatory diagram of a communication method from a station to a wireless terminal accommodated in another wireless base station, and FIG. 6 is an explanatory diagram of a channel allocation table. 1... LAN, 2... Common bus, 4... Terminal on upper network, 5... Host computer, 6...
... Wireless base station, 7... Wireless terminal.

Claims (3)

[Claims] (1) A local area network comprising a plurality of wireless terminals and at least one wireless base station connected on a wired network and accommodating the wireless terminals. (2) In a communication network that includes multiple wireless terminals and multiple wireless base stations interconnected by wires that accommodate each wireless terminal, the wireless terminal transmits an accommodation request to the wireless base station, and A communication network characterized in that the wireless base station that first and accurately returns a response is determined to be the wireless base station to be accommodated. (3) In a communication network that includes multiple wireless terminals and multiple wireless base stations that accommodate each wireless terminal and are interconnected by wires, each wireless base station manages information on the wireless terminals that it accommodates. However, when communicating from a wireless base station or a terminal on a wired network to a wireless terminal via another wireless base station, the group broadcast function is used to communicate to the other wireless base station, and the transmission destination wireless A communication network characterized in that a wireless base station accommodating a terminal communicates with the wireless terminal.