JP2002185462A - Radio data communication apparatus and system thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio data communication apparatus executing communi cation in a central control communication mode when the content of communica tion service places great importance on real time performance and executing communication in a autonomous distributed communication mode when the content of communication serviced places great importance on the reliability of communication data. SOLUTION: The radio data communication apparatus comprises means for specifying a communication mode with other radio data communication units among a plurality of predetermined modes, and a data link control means executing communication with other radio data communication units in a communication mode specified by the communication mode specifying means. In a radio data communication system comprising two or more radio data communication units, aforementioned radio data communication units are applied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wireless data communication device and a wireless data communication system. For example, carrier sensing multiple access / collision detection between multiple terminals (CSMA with CA: Carrier Sense Multip
le Access with Collision Avoidance) system.

[0002]

2. Description of the Related Art For example, a wireless LAN communication system for transmitting data by means of radio waves or infrared rays through a transmission medium is more effective than a wired LAN system in terms of simplifying wiring and allowing terminals to be freely rearranged. There are LAN communication systems and wireless LAN communication devices having the contents described in the following literatures 1 and 2, both of which aim to speed up data transmission.

Reference 1: "Details of wireless network standard IEEE 802.11 capable of high-speed data communication", In
terface, 2000, February issue, p105-11
1. Literature 2: Masugi Inoue et al., "Millimeter-wave High-speed Wireless LAN for IP
Prototype ”, IEICE Technical Report, RCS99-13, p37
-42. The above document 1 describes the contents of the IEEE 802.11 standard, which is a global standard for wireless LAN communication systems. That is, IEEE 802.11 is 2.4G
IEEE 802.11b aiming at 5.5 Mbps and 11 Mbps in the Hz band and IEEE 8 aiming at 20 Mbps or more using radio waves in the new 5 GHz band
Both committees of 02.11a are working.

[0004] Reference 2 mentioned above is a prototype, but RS
−ISMA (Reservation-Based Slotted Idle Sign
al Multiple Access) system is described. This high-speed wireless LAN device is assumed to be a centralized control type LAN in order to maintain compatibility with a conventional wired LAN and to speed up transmission, and provides a data link control layer for controlling access to a transmission medium. RS
-Adopts ISMA NACK method.

[0005] Here, the RS-ISMA NACK scheme refers to a plurality of user terminal devices (St: Station; hereinafter referred to as St) and a relay device (AP: Access Point; hereinafter AP) in order to achieve smooth data transmission. This is an access control method for exchanging transmission status information between the two. In other words, before the start of transmission, whether or not there is a vacancy in the transmission path between the plurality of Sts and the AP is performed by passing a short packet signal. In order to grasp whether St failed to receive, only the St that failed to receive transmits a NACK signal to the AP indicating that it has not received, so that the AP can receive the signal for a short time without receiving a plurality of signals. In this method, the transmission speed can be set at an early stage.

[0006] Communication modes in a wireless LAN communication system can be broadly classified into two types, a centralized control type and an autonomous decentralized type, according to communication service contents. The centralized control type is suitable for high-speed transmission. As shown in FIG. 6, all communication including communication between Sts is performed via the AP of the wireless LAN and the wired LAN, and the AP performs communication control. Yes,
The autonomous decentralized type is suitable for transmission reliability,
Is a communication method that enables equal communication.

[0007]

However, in the above two documents, a predetermined wireless access control method is set in advance, and the communication service contents to be provided and the communication service contents correspondence function of the peripheral terminal are provided by the peripheral terminal. There is a problem that it is difficult to appropriately change the communication mode based on the recognition by communication with the user.

[0008] That is, the communication form of the high-speed communication system as shown in the above two documents is based on AP (master) in advance.
r) and St (slave station) are set in many cases.

However, due to the diversification of communication service contents, there are many cases where importance must be placed on real-time characteristics, and there are many cases where importance is placed on reliability of communication data. It was necessary to set or change or use another device.

[0010] Therefore, when the contents of the communication service emphasize real-time properties, a communication form of a centralized control type is desirable, and when importance is placed on the reliability of communication data, communication of an autonomous distributed communication form is desirable. There is a demand for such an access control device.

[0011]

In order to solve this problem, a wireless data communication apparatus according to the present invention provides a communication method for designating a communication mode with another wireless data communication apparatus from a plurality of types specified in advance. It is characterized by having a mode designating unit and a data link control unit for executing communication with another wireless data communication device in the communication mode specified by the communication mode specifying unit.

[0012] The present invention is also characterized in that the above-mentioned wireless data communication device is applied to a wireless data communication system having at least two or more wireless data communication devices.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (A) First Embodiment Hereinafter, a wireless data communication apparatus and a wireless data communication system according to the present invention will be described with reference to a MAC (Media Access C).
A first embodiment applied to a wireless data communication system employing a CSMA / CA scheme as a basic scheme of an (control) layer will be described in detail with reference to FIGS.

(A-1) Configuration of First Embodiment FIG. 1 is a block diagram showing a configuration of an access control device according to the first embodiment.

FIG. 1 shows a plurality of Sts having the same device configuration, each St being an application control unit 1, a data link control unit 2, a physical layer 7, an SW (transmission / reception switching unit) 8, an antenna 9 is provided. Hereinafter, S
Each component will be described as a configuration of t1.

The application control unit 1-1 has a transmission instruction function and an access control instruction function, and provides transmission data to the error control unit 4 included in the data link control unit 2-1. . When the communication mode is converted, transmission data including communication service conversion request information requesting conversion is provided to the error control unit 4.

For example, when requesting conversion from the autonomous distributed type to the centralized control type to another station, communication service conversion request information is transmitted to the other station in the autonomous distributed type communication mode. At this point, the communication mode of the data link control unit 2-1 is:
It has not yet been converted to a centralized control type, and is an autonomous decentralized type.

Further, the application control unit 1-1 includes:
After confirming that the other stations (St2,..., Stn) have recognized the service content to be changed in the communication form by the two-way communication,
As shown by the dotted line, the communication service conversion information is provided to the access control function setting unit 3 of the data link control unit 2A.

The data link control section 2-1 has a function of adjusting transmission of transmission data, and has an access control function setting section 3, an error control section 4, and a wireless media access control (MAC: Media Access Controller).
ol) section 5.

The access control function setting section 3 has an access control parameter setting function, receives communication service conversion information from the application control section 1-1, and, based on the communication service conversion information, a communication suitable for the communication service content. Access control parameters (e.g., packet size, transmission rate,
Information update cycle and packet data content parameters) are set, and these access control parameters are given to the error control unit 4 and the MAC unit 5. Further, a storage function is provided for storing these access control parameters until the communication mode is determined.

That is, for example, when a request is made to change the communication mode from the autonomous decentralized type to the centralized control type, the access control function setting unit 3 performs centralized control adapted to the protocol of the MAC layer based on the communication service conversion information. This is to set the type of access control parameter and give it to the MAC unit 5 and the error control unit 4. However, the access control parameters are temporarily stored until another station recognizes the communication service conversion content and the communication mode of the data link control unit 2-1 is started as a centralized control type.

This access control parameter is set, for example, by setting a correspondence table between the communication service conversion information and the access control parameter in advance, and performing access control based on the communication service conversion information from the application control unit 1-1. A parameter may be set. In the case of a centralized control type communication mode, each station needs to recognize the master station (AP) and the slave station. Therefore, the access control parameter dedicated to the master station or the slave station is previously stored in the correspondence table. Must be set. On the other hand, in the case of the autonomous distributed communication mode, the master station and the sla
Since it is not necessary to recognize the station, the access control parameter dedicated to the master station or the slave station may not be set.

The error control unit 4 has an error control processing function, receives transmission data from the application control unit 1-1, and gives it to the MAC unit 5.

When converting the communication mode, the error control unit 4 obtains the stored access control parameters from the access control function setting unit 3 and, based on the access control parameters, switches to an error control function corresponding to the communication service. It can be converted.

Here, the error control unit 4 may adopt, for example, a retransmission method in order to place importance on reliability, or, for example, in order to reduce delay in placing importance on real-time transmission, An error correction code or an error detection code may be provided. However, the retransmission method requires repetitive transmission, and is not effective for services that emphasize real-time properties.

The MAC unit 5 obtains error-controlled transmission data from the error control unit 4, processes the transmission data according to a protocol related to an access control system (for example, CSMA / CA system), and provides the processed data to the physical layer 7-1. Things. Further, when converting the communication mode, the MAC unit 5 converts the communication mode into a MAC layer function corresponding to the communication service based on the access control parameter obtained from the access control function setting unit 3 and sets it.

The physical layer 7-1 obtains transmission data from the MAC unit 5, performs protocol processing (eg, addition of a preamble and a start delimiter, and modulation processing) on transmission, and performs SW processing.
(Transmission / reception switching unit) This is given to 8-1.

The physical unit 7-1 includes a transmitting / receiving antenna 9
The received data obtained by -1 is obtained via the SW 8A, the received data is subjected to protocol processing (for example, processing for removing the preamble and start delimiter or demodulation processing), and is provided to the MAC unit 5 as received data. The physical layer 7-1 provides received data to a CS (carrier sense) unit 6 included in the MAC unit 5 to perform carrier sense when transmitting.

The SW 8-1 switches the transmission / reception mode. After switching to the transmission mode, the physical layer 7-1 is switched.
Is transmitted via the transmission / reception antenna 9-1.

At the time of transmission, the CS (carrier sense) unit 6 transmits a CS signal from the physical layer 7A to monitor the propagation path condition.
For receiving carrier data for carrier sensing.

When a plurality of stations transmit communication service conversion request information to the autonomous decentralized type or communication service conversion request information to the centralized control type at the same time, When the communication service is transmitted, priority may be given to the ID number or communication service content assigned to each station, and the communication service to be started by two-way communication may be determined.

In the centralized control type communication, for example, when a station having no centralized control function first generates communication service conversion request information, the master station / sla
ve station cannot be assigned to each station. For this purpose, the communication service contents and the communication function of the own station are transmitted in two directions, and the application is enabled by allocating a master station / slave station.

(A-2) Operation of First Embodiment Next, the operation of the first embodiment having the above configuration will be described with reference to FIGS.

In FIG. 1, St1, St2,..., St
The initial state of all the n stations is an autonomous decentralized communication mode, in which St1 requests a communication service conversion by a centralized control communication mode for high-speed transmission, and St1 is a master.
, Stn,..., And Stn become slave stations and are converted to a centralized control type until a link is established.

First, the application control unit 1 of St1
At -1, the communication service conversion request information for the centralized control type is determined.

The communication service conversion request information for the centralized control type is transmitted to another station (St2,...) By the CSMA / CA method.
., Stn). At this time, the data link unit 2-1 does not form the communication form of the centralized control type, and the communication service conversion request information is communicated in the autonomous distributed communication form.

At this time, St1 indicates that the own station is m
.., Stn similarly do not recognize that the own station is a slave station.

The communication service conversion request information transmitted from St1 to St2,..., Stn is received by the application control units 1-2,..., 1-n of St2,. -2, 1-n recognizes that its own station is a slave station (FIG. 2).

At this time, the application control unit 1-
2,..., 1-n are received according to the CSMA / CA method (recognizing that the own station is a slave station)
ACK signal containing the own station ID number to confirm
Return at t1.

The ACK signal including the own station ID number is St1
St1 determines that the other station has received the centralized control type communication service conversion request information, and recognizes that the station is the master station.

At this time, the communication service conversion information is provided from the application control section 1A to the access control function setting section 3 (dotted line shown in FIG. 1), and the access control parameters dedicated to the master station are determined and stored. At the same time, the communication service start command information is
t2,..., Stn.

The determined access control parameter dedicated to the master station is provided to the error control unit 4 and the MAC unit 5, and the data link control unit 2-1 is converted into a centralized control communication mode.

On the other hand, in St2,..., And Stn, the access control parameter dedicated to the slave station is given to the error control unit 4 and the MAC unit 5 by receiving the centralized control type communication service start command signal. ,..., 2-n are converted into a centralized control type communication mode.

That is, after the setting of the access control parameters is completed by the two-way communication, the communication mode is changed from the autonomous distributed type to the centralized control type.

As described above, St1 is the master.
The stations St2,..., Stn establish a centralized control type communication mode that functions as a slave station.

Next, a case in which St1 shown in FIG. 1 is converted to an autonomous distributed communication mode in which the reliability of transmission data is emphasized will be described with reference to FIG.

FIG. 3 shows the process from the change of the communication mode from the centralized control type to the autonomous decentralized type until the link is established.

In FIG. 3, each station St1, St2,.
When Stn is communicated in a centralized control communication mode, St1 transmits autonomous distributed communication service conversion request information and communication service conversion information (communication service name) to St2,... Stn at the same time.

Here, unlike the conversion to the centralized control type, the conversion to the autonomous decentralized type in which the respective stations have an equal relationship does not require the recognition of the master station / slave station. No need to send.

The autonomous distributed communication service conversion request information and communication service conversion information are received by St2,.
The K signal is returned to St1.

At this time, the application control units 1-2,..., 1-n of the own station recognize that St2,.
And the access control parameters are set, and the communication mode is changed from the centralized control type to the autonomous decentralized type.

In St1, St2,..., S
An ACK signal including the ID number from tn is received, access control parameters are set, and the communication mode is changed from the centralized control type to the autonomous distributed type.

Here, unlike the conversion to the centralized control type, the conversion to the autonomous decentralized type does not require recognition of the master station / slave station, so that each St is converted to the autonomous decentralized type simultaneously with the transmission or reception of the ACK signal. The access control parameter is set to convert

When a plurality of stations simultaneously transmit communication service conversion request information to the autonomous decentralized type or communication service conversion request information to the centralized control type, or transmit different communication service conversion request information from the plurality of stations. In the case of transmission, a priority may be given to an ID number or transmission service content assigned to each station, and a transmission service to be started by two-way communication may be determined.

(A-3) Effects of the First Embodiment As described above, according to the first embodiment, by providing the access control function setting unit 3, the access control parameters are set according to the contents of the communication service. Therefore, the communication mode can be changed, and the speed or reliability of data transmission according to the communication mode can be increased.

When a central control type communication mode is adopted,
Since the access control parameters dedicated to the centralized station can be set, the station itself can be the master station and the communication link can be established.
It is possible to take a communication form without assigning a ve station.

(B) Second Embodiment A case where the wireless data communication apparatus and the wireless data communication system according to the present invention are applied to the second embodiment will be described below with reference to FIG.

(B-1) Configuration of the Second Embodiment FIG. 4 shows a plurality of Sts applied to a wireless communication system employing the CSMA / CA system as the basic system of the MAC layer, as in the case of the first embodiment. 1 is a block diagram showing a configuration of an access control device.

In the second embodiment, the data link control unit 1
1-1 is characterized in that the components of the communication mode are autonomously distributed and the components of the centralized control type are provided separately.

That is, the application control unit 10-
The connection between the physical layer 17-1 and the data link control relating to the determination of communication service contents and transmission / reception in 1, 10-2,..., 10-n is the same as in the first embodiment. The components included in the unit 11-1 are different, and the method of establishing a communication link is the same as in the first embodiment. Therefore, the configuration of the data link control unit 11-1 of St1, which is different from the first embodiment, will be described below.

The data link control unit 11-1 comprises an access control function setting unit 12, an autonomous distributed communication system 14, a centralized control communication system 15, and SWs (transmission / reception switching units) 13, 16.
It has.

First, the configuration for transmitting communication service conversion information from the application control unit 10-1 will be described.

The access control function setting section 12 has a function of switching the communication mode.
The communication service conversion information determined in step 0-1 is obtained, and the communication service change information is stored until the communication link is established. After the communication link is established, the communication service conversion information is stored in the autonomous distributed communication system 14 or the centralized communication system. This is given to the control type communication system 15 and SW13 and SW16.

The access control function setting unit 12 of the second embodiment is different from the access control function setting unit 3 of the first embodiment in that the communication mode is changed by switching the SWs 13 and 16. However, when converting to the centralized control type, the setting method of the access control parameter is m as in the first embodiment.
The master station and the slave station are set from the correspondence table. Similarly to the first embodiment, for example, in the case of conversion to a centralized control type, to request a communication service conversion from another station, transmission is performed in an autonomous distributed communication mode.

The components of the autonomous distributed communication system 14 and the centralized control communication system 15 are the same, and the error control unit 14a,
15a, MAC sections 14b, 15b and carrier sense section 1
4c, 15c, and the access control function setting unit 1
In accordance with the communication service conversion information from step 2, the transmission data corresponding to the communication mode is processed.

The SW 16 is an access control function setting unit 12
The connection is switched to either the autonomous decentralized communication system 14 or the centralized control communication system 15 according to the communication service conversion information from, and transmission data in only one of the communication forms is obtained, and the transmission data is transmitted to the physical layer 17-1. Is to give.

Next, a case where transmission data is received will be described.

The autonomous distributed communication system 14 or the centralized control communication system 15 obtains received data obtained by performing protocol processing on received data in the physical layer 17-1 and supplies the data to the SW 13.

The SW 13 is an access control function setting unit 12
Autonomous distributed system 1 according to the communication service conversion information from
4 or the centralized control type system 15 to obtain only the received data in any desired communication mode and provide it to the application control unit 10A.

(B-2) Operation of the Second Embodiment The operation of the wireless data communication apparatus having the above configuration will be described.

First, referring to FIG. 4, the case where St1 is converted to a centralized control communication mode will be described.

The initial state of the data link control section 11-1 in St 1 is connected to the autonomous distributed communication system 14.

The steps from the determination of the communication service contents in the application control section 10-1 to the establishment of the communication link to the centralized control type are the same as in the first embodiment.
That is, the content of the communication service for the centralized control type is determined by the application control unit 10-1, and is transmitted to St2,..., Stn by the autonomous distributed communication method.

In St1, when an ACK signal including the ID number returned by St2,..., Stn is received, the application control unit 10-1 recognizes that the own station is the master station, and performs an access control function. The setting unit 12 is provided with a signal indicating that the own station is the master station and communication service conversion information.

In the access control function setting section 12, the communication service conversion information is given to SW13 and SW16 to connect with the centralized control type communication system 15, and at the same time, from the correspondence table with the communication service conversion information, the master
An access control parameter dedicated to the er station is set and given to a separately provided centralized control communication system 15.

On the other hand, in St2,..., Stn, when the communication service start command information from St1 is received, the application control units 10-2,. In recognition, the access control function setting unit 12 sets an access control parameter dedicated to the slave station.

At this time, the SWs 13 and 16 disconnect the connection with the autonomous decentralized communication system 14 and switch to the centralized control communication system 15.
By switching the SW so as to connect only the connections, the data link control unit 11-1 performs communication in a centralized control type communication mode.

Also, when the communication mode is changed from the centralized control type to the autonomous decentralized communication system, the communication service conversion request information and the communication service conversion information are transmitted to another station by the centralized control type, and the received other station receives the information. After confirming that the ACK signal has been returned, the communication mode is converted to an autonomous distributed communication mode.

(B-3) Effect of Second Embodiment As described above, according to the second embodiment, the wireless data communication apparatus is separately provided for the autonomous distributed communication system and the centralized control communication system. This can also change the communication mode.

By separately providing a communication system as described above, it is not necessary to set an access control parameter according to the communication mode.

(C) Third Embodiment Hereinafter, a case of a third embodiment in which the wireless data communication apparatus according to the present invention is applied to a wireless data communication system employing the CSMA / CA method as a basic method of the MAC layer. This will be described with reference to FIG.

The third embodiment is a mode in which an error control method according to a radio data communication apparatus can be converted in accordance with a propagation path condition.

In controlling the access control method relating to the wireless data communication apparatus, error control is important as control for improving the reliability of transmission data.

However, since the occurrence of errors in transmission data differs depending on the conditions of the propagation path, it is not easy to perform error control according to the propagation path environment.

Therefore, in the present embodiment, an embodiment in which the error control method can be converted according to the following propagation path conditions will be described.

(C-1) Configuration of Third Embodiment FIG. 5 is a block diagram showing a configuration of a wireless data communication device according to the third embodiment. In the third embodiment, the data link control unit is provided separately for transmission and reception, and has two different error control schemes corresponding to each other on the transmission and reception sides.
0A and 20B share the access control function setting unit 32 and the propagation path check unit 31.

In FIG. 5, a wireless data communication apparatus according to the present embodiment includes a transmission data link control unit 20A, a reception data link control unit 20B, and an access control function setting unit 3
2, a transmission path check unit 31, a physical layer 27, a SW (transmission / reception switching unit) 28, and a transmission / reception antenna 29.

The description of the configuration of the physical layer 27, the SW 28, and the transmitting / receiving antenna 29 having the same functions as those of the first embodiment is omitted.

The access control function setting section 32 has a function of instructing switching of an error control method, obtains error control method conversion information from the application control section 30, and transmits the error control method conversion information through a dashed signal line. SW22, 2 included in the transmission / reception data link control units 20A, 20B
4, 34 and 36.

The transmission data link control unit 20A has two different error control systems 23A and 23B, and the MAC units 25 and 2
It has two SWs 22 and 24.

SW22 and SW24 obtain error control system conversion information from the access control function setting unit 32 and are connected to one of the two error control systems 23A and 23B. And the error control method 23A connected to either
23B. SW2
The two error control systems 23A and 23 are based on the error control system conversion information from the access control function setting unit 32.
B, and can be connected to the first error control method 23A by a connection line a and connected to the second error control method 23B by a connection line b.

For example, when the application control unit 30 instructs to convert to the first error control method 23A among the two error control methods, the instruction is given to the SWs 22 and 24 via the access control function setting unit 32. Only the first error control method 23A is connected by the connection line a, and transmission data is given to the first error control method 23A.

Error control first method 23A, second method 23B
The connection is switched by the SWs 22 and 24, the transmission data is obtained via the SW 22, the predetermined error control is performed, and the transmission data is supplied to the MAC unit 25 via the SW 24.

Here, the first error control method 23A and the second error control method 23B are set in advance and are set according to different propagation path conditions.

Further, a function of adding an identifier to transmission data as error control recognition information may be provided. The identifier of the error control scheme is set so that the received data link control unit 20B recognizes the selected error control scheme and does not follow the error control information so that an error control scheme suitable for the propagation path of the received signal is performed. You may.

The MAC unit 25 obtains transmission data subjected to an error control method using one of the error control methods 23A and 23B, and gives the transmission data to the physical layer 27 in a method suitable for a predetermined access control method. is there. MAC
The unit 25 is a MAC layer related to access control, and a communication mode may be any of an autonomous distributed communication system and a centralized control communication system.

The reception data link control unit 20B has a first error control system 35A, a second error control system 35B, SWs 34 and 36, and a CS (carrier sense) unit 33.

Error control first method 35A, second method 35B
Corresponds to the error control first method 23A and the second method 23B in the transmission data link control unit 20A, and also corresponds to the connection lines a and b. Error control first method 35A, second
The method 35B obtains received data from the physical layer 27B via the SW 34, performs error control adapted to the propagation path, and
6 to the application control unit 30.

The physical layer 27 converts the demodulated reception data into
This is given to the CS unit 33 and the propagation path check unit 31. This is limited to the case of carrier sense at the time of transmission. After receiving the received data, the physical layer 27 converts the received data to the received data link control unit 20 as demodulated received data.
The error control schemes 35A, 35A are switched via SW 34 of B
B.

The CS (carrier sense) unit 33 obtains received data from the physical layer 27, performs carrier sense on the propagation path condition, and outputs it to the MAC unit 25.

The propagation path check section 31 obtains the received data from the physical layer 27B, judges the occurrence of an error or the state of the propagation path from the input received power, and transmits the judgment information to the SW22, 24, 34 and 36. That is, on the receiving side, the error control method can be converted according to the received power intensity of the propagation path.

That is, the propagation path check unit 31 monitors the received power, compares the drop in the received power with the received data, and determines whether the error correction of the received data has a strong burst error or a strong random error. , It is possible to estimate what kind of error is strong, and determine whether or not the error control method is suitable for the propagation path condition.

As described above, the method of determining whether the error control method is suitable is based on a case where a random error is strong and a case where a burst error is strong, based on a correspondence table between a predetermined received power and a packet length of received data. May be set, or the error control method may be switched by applying a relational expression.

In addition to the above-mentioned determination method, a suitable error control method is selected from the error control method and the error control method estimated by the channel check unit 31 from the identifier added to the received data. You may be able to do. In other words, as a selection method, any method may be used as long as it is possible to select an error control method in advance and to select an error control method so that error control optimal for the propagation path condition can be performed.

When converting the error control method, the reception data link control unit 20B updates the identifier added to the received data, and transmits the error control method concerning the reception of the opposite station in the bidirectional communication without newly transmitting the error control method. Can be conveyed to.

That is, by adding an updated identifier to transmission data according to the CSMA system and transmitting the updated data to the partner station, it is possible to determine which error control system the partner station is using each time the error control system is converted. Make it recognizable.

(C-2) Operation of Third Embodiment Hereinafter, the operation of the wireless data communication apparatus according to the third embodiment will be described.

The error control system conversion information output from the application control unit 30 is stored in the access control function setting unit 3
Given to 2.

The error control conversion information in the access control function setting unit 32 includes the transmission / reception data link control units 20A,
0B is provided to each of the SWs 22, 24, 34, and 36, and is connected to the error control system that receives the command.

Therefore, the application control unit 30
Is supplied to the desired error control system via the SW 22 and error-controlled by an error control system according to a preset propagation path condition.

When converting the first error control method to the second error control method, error control method conversion information is provided from the application control unit 30 to each SW, and the SW 22 is connected to the second error control method. At this time, the transmission data link control unit 20A may add an identifier to the transmission data as information for recognizing the error control scheme.

The transmission data is provided to the MAC unit 25 via the SW 24.

At this time, when the carrier is sensed in the MAC unit 25 and the propagation path condition is in an idle state, the transmission data is given to the physical layer 27, modulated and transmitted from the transmission / reception antenna 29. When the propagation path condition is busy, it waits for a random time and transmits again after carrier sense. In this way, transmission data can be transmitted by an error control method suitable for the propagation path.

Next, the operation for receiving will be described.

The received data received by the transmission / reception antenna 29 is demodulated by the physical layer 27 and the data link control unit 20
B.

At this time, the propagation path check unit 31 can select an error control method according to the correspondence between the received power and the received data.

The received data is subjected to error correction by an error control method suitable for the propagation environment via the SW 34, and is provided to the application control unit 30.

If the error control scheme recognition information added to the received data is different from the error control scheme estimated by the receiving station, both schemes can be selected. At this time, when the error control method determined by the propagation path check unit 31 is selected, error control is performed using an appropriate error control method, and the identifier added to the received data can be updated.

As described above, information on the error control method suitable for the propagation path is read from the received data, and error control processing is performed by the appropriate error control method.

(C-3) Effect of Third Embodiment By using the error control method determined by the application control unit, the error control method adapted to the propagation path condition is performed, and the reliability of data can be further improved. it can.

Further, by monitoring the received power at the receiver and estimating an error control method suitable for the environment, it is possible to perform error control in a method suitable for the environment.

Furthermore, by adding the identifier of the selected error control method to the transmission data, the change can be made without previously notifying the partner station of the change of the error control method.

(D) Other Embodiments In the first and second embodiments, the communication system according to the communication mode is limited to two. However, the wireless data communication apparatus according to the present invention has two systems. The present invention can be applied to communication systems corresponding to two or more communication modes without limitation.

In the third embodiment, two error control systems are set and described. However, in order to set an error control system suitable for a propagation path condition, any one or more error control systems may be used. .

The MAC unit 2 in the third embodiment
5 has been described in connection with one communication mode, but when two or more communication modes are used, for example, when a centralized control type or autonomous decentralized communication system is used, the communication mode can be converted or switched to one of them. And a combination of a plurality of error control schemes and a plurality of communication mode schemes is possible.

Further, in the third embodiment, the configuration in which the data link control section is divided into the transmission data link control section 20A and the reception data link control section 20B has been described, but both data link control sections are shared. Then, the access control function setting unit that can select one of the error control methods may be made selectable.
That is, the present invention is not limited to the third configuration.

The wireless access control devices according to the first to third embodiments can communicate both indoors and outdoors, and can communicate outdoors, for example, between buildings.

[0128]

As described above, according to the wireless data communication apparatus and the wireless data communication system of the present invention, the access control function setting means has a communication form suitable for the contents of the communication service from the communication service contents command means. Can be converted to That is, when the contents of the communication service require real-time characteristics, the communication service can be converted to a centralized control communication system.

Further, the error control method can be converted according to the propagation path condition of the access control method.

[Brief description of the drawings]

FIG. 1 is a block diagram of an overall structure of a wireless data communication device according to a first embodiment.

FIG. 2 is a diagram until a link is established when converting to a centralized control type communication mode.

FIG. 3 is a diagram until a link is established in the case of conversion to an autonomous distributed communication mode.

FIG. 4 is a block diagram of an overall structure of a wireless data communication device according to a second embodiment.

FIG. 5 is a block diagram of an overall structure of a wireless data communication device according to a third embodiment.

FIG. 6 is a structural diagram showing a communication mode of a wireless data communication system.

[Explanation of symbols]

1A, 1B, 1C, 10A, 10B, 10C ... application control units, 2A, 2B, 2C, 11A, 11B,
11C, 20A, 20B ... data link control unit, 3, 1
2, 32 ... access control function setting unit, 4 ... error control unit,
5, 15, 25 ... MAC unit, 6, 33 ... CS unit, 7A,
7B, 7C, 17A, 17B, 17C, 27A, 27B
... Physical layer, 31 ... Propagation path check unit, 23A, 23B,
35A, 35B ... error control system, 8A, 8B, 8C, 1
8A, 18B, 18C, 22, 24, 34, 36, 28
... SW, 7A, 9B, 9C, 19A, 19B, 19C,
29 ... Transceiver antenna.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kiyohito Tokuda 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. F-term (reference) 5K032 AA01 AA07 CA08 CC01 CC03 DA02 DA21 5K033 AA05 CA08 CB03 DA17 5K067 BB21 EE02 EE10 EE16 EE23 HH11 JJ41 JJ43

Claims (8)

[Claims] 1. A communication mode designating means for designating a communication mode with another wireless data communication apparatus from a plurality of types defined in advance, and another wireless data communication mode specified by the communication mode specifying means. A wireless data communication device comprising: data link control means for executing communication with the communication device. 2. The data link control means has a common configuration corresponding to a plurality of communication modes, and sets parameters relating to the communication mode according to the communication mode specified by the communication mode specifying means. The wireless data communication device according to claim 1. 3. The parameter set by the data link control means is a parameter for setting a communication system with another wireless data communication device to an autonomous distributed communication system or a parameter for setting a centralized control communication system. Claim 2
A wireless data communication device according to claim 1. 4. The parameter according to the centralized control communication system, wherein the parameter is a parameter for a central station in which the own station becomes a central station or a parameter for a dependent station in which the local station becomes a dependent station. The wireless data communication device according to claim 3. 5. The wireless data communication apparatus according to claim 2, wherein the parameter set by the data link control means is a parameter for determining at least two or more error control schemes set in advance. 6. A transmission data link control unit and a reception data link control unit corresponding to at least two or more error control systems, wherein the transmission data link control unit is specified by the communication mode designating unit. An error control information adding unit that writes error control system information into a transmission signal; and the reception data link control unit includes an error control information detection unit that reads error control system information included in the reception signal. The wireless data communication device according to claim 5, wherein: 7. The data link control unit includes a plurality of data link control units that perform all or a part of data link control for each communication mode, and the data link according to the communication mode specified by the communication mode specification unit. The wireless data communication device according to claim 1, wherein the control unit performs data link control. 8. A wireless data communication system having at least two wireless data communication devices, wherein the wireless data communication device according to claim 1 is applied as each of the wireless data communication devices. .