JPH0787009A - Radio communication equipment - Google Patents

Abstract

PURPOSE:To set up a radio channel route stably and to devise the equipment in such a way that the set-up route is not easily interrupted. CONSTITUTION:In a radio equipment in which transmission data given to a terminal Tx are modulated by a predetermined frequency given from an oscillation circuit 6 at a modulator 3, the modulated data are amplified by a power amplifier 2 and sent via an antenna 1, and a received signal from the antenna 1 is amplified by a high frequency amplifier 4 and extracted at a detector 5 as desired data, at least either of transmission power and reception sensitivity is devised to be controlled and it is decreased in the setup of a radio channel route more than in the normal state. Furthermore, when the channel route is once set up, dummy data are sent from a receiver side to maintain the route.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device using a so-called multi-channel access (also referred to as MCA) system, for example, which selects a free one from a plurality of wireless channels for communication, and particularly, The present invention relates to a wireless communication device suitable for use in a case where wireless communication is performed based on a rule specified for a specific low power wireless equipment for low speed data transmission, for example, a rule of RCR STD-17.

[0002]

2. Description of the Related Art According to the above-mentioned RCR STD-17, the structure is roughly as follows. 1) There is no difference between communication for establishing a line and communication for data transmission, and no particular distinction is made. 2) The wireless communication device does not have the function of interpreting the data internally, but the device connected to the outside makes a judgment, and as a result, it receives the transmission data from the external device and works to establish the communication line. .

FIG. 7 shows an example of a hierarchical structure of a general wireless system. Here, it is assumed that the radio device performs a specific low power radio for low speed data transmission, and the details thereof are RCR STD-
The same as that specified in 17 Also, this wireless device uses the MCA method, and has a usable wireless channel (ch) for control of 1 channel and data transmission of 9 channels, and a plurality of wireless devices are vacant among these 9 channels. I try to find the channel and transmit the data. 7, M is a main station, T1 to T3 are relay stations, S11 to S1N, S21 to S2N, S31 to S3N.
Indicates the slave stations, respectively.

Each of the radios has an external device for transmitting and receiving data by utilizing the radio, and in actuality, the functions required as the external device are used for data transmission using the radio as a medium. The system shown in FIG. 7 is a case where wireless devices are scattered over a wide range, and the distance over which one wireless device can send data is typically about 100 m. Also, if the radio is placed in the building or underground mall,
The transmission distance is naturally shortened.

Therefore, in FIG. 7, it can be considered that the data are scattered in a range of several hundred meters where data cannot be directly transmitted. At this distance, the main station cannot directly communicate with all the slave stations. For this reason, the master station first communicates with the relay station, so the relay station functions as a slave station and collects data from the slave stations below it and transmits data from the master station to the slave stations. It has a function to do. From this,
In the communication between the main station and the relay station, the data of the relay station and the slave stations are handled together. In such a system, a grand station may be further provided below the slave station to increase the number of layers.

By the way, such a system has the following problems peculiar to the radio system. (1) Even if a layered system of wireless devices is constructed, the communication range changes due to surrounding noise and changes in the environment near the antenna, such as building building and antenna position changes. What was done suddenly becomes unable to communicate.

(2) If the number of slave stations is first determined and the installation location of the wireless device is also clearly known, an address can be assigned to each wireless device to determine a wireless system as shown in FIG. 7, for example. In communication, it is possible to specify a partner address (for example, the slave station number in FIG. 7) and communicate.

However, when a slave station is removed or a slave station is added, it is necessary to automatically reconstruct the wireless system. If this is not done, the maintenance work of the system will increase as the number of slave stations increases and decreases, and the usability of the radio will be significantly reduced. As described above, what becomes a problem is how to reconstruct the wireless system when communication becomes impossible, is removed, or is newly installed.

That is, if the radio is removed, the operation of the system is not hindered if the communication of the slave station is excluded from the main station or the relay station. Also, if the slave station becomes unable to communicate, is newly established, or wants to recover its function and want to restart communication, the slave station checks for a predetermined time and finds the communication partner. All you have to do is start the call communication. If the partner slave station or relay station catches the interrogation communication, it may be added to the wireless system, and it is not particularly difficult to realize such a wireless system, and it can be easily constructed.

[0010]

That is, in a system that creates a specific wireless line route via a main station, a relay station, a slave station, and a number of radios, the situation around the radios, the movement of the radios, and the surroundings. Even if there is an influence of noise, since the wireless communication function remains the same, there is a problem that a predetermined wireless line route cannot be maintained. Also, in the simplex method of wireless communication, when one radio transmits, the receiving device (the radio constitutes a part of it) interprets the received data and prepares the necessary transmission data, Then, the carrier sense for establishing the communication line is started.

[0011] In the MCA system, a large number of radios find a vacant one among a plurality of communication bands and perform communication using the vacant band. Therefore, during the series of communications previously performed, other radios are used. There is also a problem that when the machine acquires the band, the communication may be interrupted, resulting in a communication failure. Therefore, an object of the present invention is to make it possible to stably establish a wireless line route and prevent the established communication from being interrupted.

[0012]

In order to solve such a problem, in the first invention, a main station and a plurality of slave stations which issue a predetermined command and collect data, or between a main station and a plurality of slave stations. In a wireless communication device that has the same function as a slave station and performs wireless communication through a relay station that relays communication between the master station and the slave station, all or one of the master station, the slave station, or the relay station. The section is divided into a communication mode for establishing a line and a data transmission mode using the line, and has a function of executing at least one of the setting of the receiving sensitivity and the setting of the radio output for each mode. It is characterized by that. In the first aspect of the invention, in the communication mode for establishing the line, at least one of the reception sensitivity and the output of the radio can be gradually increased, or the communication mode for establishing the line and the line can be changed. It is possible to provide a control terminal for the data transmission mode used and to enable external control via this control terminal.

In the second invention, a main station and a plurality of slave stations which issue a predetermined command and collect data, or between the main station and a plurality of slave stations have a function equivalent to that of the slave station and the main station and the slave stations. In a wireless communication device that performs wireless communication by a multi-channel access method via a relay station that relays communication between the two, the receiving side of the wireless communication device has a function of receiving data and decoding the contents , The sending side has a function of sending information by indicating the end of communication, and when the receiving side receives the data and detects the information indicating the end of communication, it has been used until then. It is characterized in that carrier sense of a frequency channel is started, and if it is an empty frequency channel, dummy data is transmitted to hold the line.

[0014]

(B) (B) When establishing a wireless line route, the performance level of the wireless device is lowered. (B) By transmitting the dummy data, it is possible to prevent a line from being taken to another radio during an organization in which communication control is interrupted. By providing functions such as this, flexibility is increased and reliable communication is possible.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, it is assumed that a wireless network is established and constructed by interrogation communication. For this reason, we want to maintain the system once created as much as possible, so here we do the following. (B) In communication when establishing a communication line based on interrogation communication, communication is performed at a lower level than in normal data transmission, and communication is performed at a normal level after the line is established.

(B) The above level difference is due to a change in ambient noise,
Or, it absorbs changes in the operating environment of the wireless device. That is,
Even if the surrounding conditions change, the communication function can be maintained. (C) If communication capacity (reception sensitivity, transmission power, etc.) is gradually increased when establishing a line such as interrogation communication,
When there are multiple communication systems as shown in FIG. 7,
It becomes possible to incorporate it in the communication system in the form that is the closest, that is, the easiest to communicate.

FIG. 1 shows an embodiment for embodying the above functions. This is an example of the internal configuration of a wireless device used in the wireless system as shown in FIG. 1 includes an antenna 1, a power amplifier 2, a modulator 3, a high frequency amplifier 4,
It is composed of a detector 5 and an oscillation circuit 6. Tx indicates a data transmission terminal, and Rx indicates a data reception terminal.

That is, the transmission data Dt given to the terminal Tx is modulated by the modulator 3 at a constant frequency given from the oscillation circuit 6, amplified by the power amplifier 2, and then transmitted as a radio signal from the antenna 1. On the other hand, the signal received from the antenna 1 is amplified by the high frequency amplifier 4, and then the desired reception data Dr is extracted by the wave detector 5 and appears at the terminal Rx. Although such a configuration is general as a wireless device, here, in addition to such a configuration,
The power amplifier 2 and the high frequency amplifier 4 are controlled as shown in FIG.

In FIG. 2, the power amplifier 2 and the high frequency amplifier 4 are supplied with such signals to lower the communication functions such as transmission power and reception gain from normal levels. That is, the power of the power amplifier 2 is changed to change the transmission output, and the gain of the high frequency amplifier 4 is changed to change the reception sensitivity. Further, such control may be performed not only for both the transmission power and the reception gain but also for at least one of the transmission power and the reception gain. When returning from the state in which the communication function is lowered to the normal state, it may be returned all at once or gradually.

FIG. 3 shows an example of a wireless module with a control terminal as described above. That is, if the radio device or the radio module 10 has a terminal indicating whether it is in the state for establishing a line or in the data transmission state, the above-mentioned control can be performed externally using the terminal. However, since it is normal that such a terminal is not actually provided, the terminal Tc is positively provided as shown in FIG. 3 and the signal applied to this terminal Tc is changed to establish a line from the outside. It can be set to a state for data transmission or a state of data transmission. In the above, MCA
Although the case of applying it to the system has been described, it goes without saying that the above configuration is not limited to the MCA system.

FIG. 4 is a block diagram showing another embodiment of the present invention, and FIG. 5 is a flow chart for explaining the operation thereof. This is an operation when the wireless device A, which is the calling side, carries out carrier sense and transmits a control signal, and the wireless device B, which is the called side of the other party, sends back a control signal and performs control after the communication is completed. 4 for both the calling side and the called side.
It is configured as follows. The operation of FIG. 4 will be described below with reference to FIG.
Will be described with reference to.

That is, in the radio device on the calling side, the transmission signal Dt from the external device 20 is transmitted as a radio wave signal via the OR gate 13, the modulator 3, the power amplifier 2 and the antenna 1. Since the called side has the same configuration, the transmission signal D
t is a received signal Dr as a processing unit (CPU) 1 on the called side
1 is received (step S1). Where C of the called party
The PU 11 analyzes the transmitted transmission signal Dt and makes it easy to detect the end thereof. For example, the transmission signal Dt has a special signal indicating the end such as EOT. Depending on the case, it may be possible to detect from the state immediately before the end.

When the CPU 11 detects the end of the signal (step S2), it carries out carrier sense of the wireless channel used up to that point (step S3).
After determining whether the wireless channel is available (step S4), dummy data is transmitted (step S4).
5). If the communication is not completed in step S2, the process proceeds to step S8 to continue the reception mode. In addition, when carrier sense is not established for a long period of time, it is desirable to terminate the route.

After that, it is judged whether or not there is a transmission signal Dt (step S6), and if there is not, the dummy data Dt '.
Is transmitted, the transmission of the dummy data Dt ′ is stopped and the original transmission data is transmitted (step S7). As a matter of course, it is assumed that the calling side having received the dummy data Dt 'has a function of ignoring this. If the transmission of the transmission signal Dt is unnecessary, the external device may notify the CPU of the situation and the transmission of the dummy data Dt ′ may be ended. Alternatively, for example, NUL data indicating the end of data transmission in the transmission signal Dt may be sent as an end signal to notify. Then, on the side that receives this NUL data, the dummy data Dt ′ is not sent, and the communication ends.

FIG. 6 is a time chart for explaining the above operation. This shows the case where the station A is the calling side and the station B is the called side, and the transmission signal Dt is transmitted from the station A at time t1 as shown in FIG. FIG. 9D shows dummy data Dt ′ transmitted from station B upon detection of the end of transmission from station A. This is due to the transmission signal Dt from station B shown in FIG. ) It is stopped like the dotted line. On the other hand, the station A which has received the transmission signal Dt from the station B also transmits the dummy data Dt ′ as shown in the figure (b), but this is also due to the transmission signal Dt from the station A, the figure (b).
It will be stopped like the dotted line.

That is, the time interval of communication between the A station and the B station is usually L, but it can be shortened to L'here by transmitting the dummy data Dt '.
In other words, it is possible to greatly reduce the possibility that another wireless device will obtain the right to use the wireless channel during this period L. In particular, it is extremely advantageous not only to obtain the L '/ L ratio but also to carry out carrier sensing of the radio wave channel almost at the same time as the transmission of the partner station is completed, so that the radio channel can be secured with a higher probability than other radios. is there.

[0027]

EFFECTS OF THE INVENTION According to the present invention, (a) the function of the radio is changed when the line is established and when the data is transmitted, so that reliable data transmission can be performed even if there is a change in the surroundings. it can. Further, by gradually improving the function of the wireless device when establishing a line, an optimal wireless system can be constructed. (B) If the above function changes can be executed via an externally provided control terminal, switching can be facilitated,
The function of the external device using wireless can be simplified. (C) If the receiving side sends dummy data,
It is possible to greatly reduce the probability of line disconnection due to interruption of other radios. The advantages such as are obtained.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram for explaining the function of FIG.

FIG. 3 is a schematic diagram showing an example of modules corresponding to FIG.

FIG. 4 is a configuration diagram showing another embodiment of the present invention.

5 is a flowchart for explaining the operation of the CPU in FIG.

FIG. 6 is a time chart for explaining the operation of FIG.

FIG. 7 is a schematic diagram showing a general example of a wireless communication system.

[Explanation of symbols]

1 ... Antenna, 2 ... Power amplifier, 3 ... Modulator, 4 ... High frequency amplifier, 5 ... Detector, 6 ... Oscillation circuit, 10 ... Wireless module, 11 ... Processing unit (CPU), 12 ... Identification number part, 13 ... OR gate, 20 ... External device.

Claims (4)

[Claims] 1. A main station and a plurality of slave stations that issue a predetermined command and collect data, or have a function equivalent to that of a slave station between the main station and a plurality of slave stations and perform communication between the main station and the slave stations. In a wireless communication device that performs wireless communication via a relay station for relaying, in all or part of the main station, slave station or relay station,
The communication mode for establishing a line and the data transmission mode using the line are divided, and each mode has a function of executing at least one of the setting of the receiving sensitivity and the setting of the radio output. Characteristic wireless communication device. 2. The wireless communication device according to claim 1, wherein at least one of the reception sensitivity and the output of the wireless device is gradually increased in the communication mode for establishing the line. 3. A communication mode for establishing a line and a control terminal for a data transmission mode using the line are provided, and control is possible from the outside through the control terminal. The wireless communication device described in. 4. A communication between a main station and a slave station having a function equivalent to that of the slave station between the main station and a plurality of slave stations that issue a predetermined command and collect data, or between the main station and a plurality of slave stations. In a wireless communication device that performs wireless communication by a multi-channel access method via a relay station that relays, the receiving side of the wireless communication device has a function of receiving data and decoding the contents, while the transmitting side has Has a function of transmitting with the information indicating the end of communication, and when the receiving side receives the data and detects the information indicating the end of communication, the carrier of the frequency channel used until then A wireless communication device characterized by starting a sense and transmitting dummy data to hold the line if it is an idle frequency channel.