JPH04360323A - Radio communication method - Google Patents

Abstract

PURPOSE:To reduce number of times of relay and to decrease the transmission time by selecting a unit so as to closest to a final arrival unit when a data is exchanged with a unit at a location which no radio wave is directly reached. CONSTITUTION:In the case of sending a data from a controller 11 to, e.g. a controller 15, the controller 11 transfers the data with information representing the final destination to be a unit 5a to the radio communication unit 1a. The unit 1a selects a unit 3a within a range of the arrival of the radio wave and closest to the data final arrival unit and sends the data to the unit 3a. When the unit 3a identifies it that the final destination of the received data is the unit 5a to which the radio wave from the unit 3a is able to be reached, the unit 3a sends the data to the unit 5a. When the unit 5a recognizes it that the final destination of the received data is its own unit, the unit 5a transfers the data to the control circuit 15.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication method for relaying and transmitting data between a plurality of units.

0002

2. Description of the Related Art In conventional wireless communication systems, it is common to select as a relay unit the unit that is closest in distance to the unit that transmits data. here,
For example, consider a case where data is transmitted from unit 1a to unit 5a in a system in which wireless communication units 1a to 5a as shown in FIG. 7 are installed. Here, r1
indicates the radio wave range of the unit 1a, r2 of the unit 2a, r3 of the unit 3a, r4 of the unit 4a, and r5 of the unit 5a. Therefore, since data cannot directly reach unit 5a from unit 1a, data is first transmitted from unit 1a to unit 2a, which is the closest in terms of distance. Since the radio waves from the unit 2a that received this data do not directly reach the unit 5, the data is transmitted from the unit 2a to the nearest unit 4a. Since direct transmission is possible from unit 4a to unit 5a, data is relayed through units 2a and 4a and sent to unit 5a.

0003

[Problems to be Solved by the Invention] As described above, in the conventional system, the unit closest to the own unit in terms of distance is selected as the next unit to relay data, and the data is transmitted. For example, even if there is a unit within the range of radio waves that can directly transmit data, there is a possibility that the data will pass through several relay units before being transmitted to that unit. Therefore, there is a problem in that the number of times the data is relayed until it is finally transmitted to the unit it should reach increases, and the data transmission delay time increases. Therefore, an object of the present invention is to provide a wireless communication method that can reduce the number of times data is relayed and shorten transmission time compared to conventional methods.

0004

[Means for Solving the Problems] In order to solve such problems, the present invention comprises a plurality of units, each having the function of transmitting and receiving data wirelessly, and each unit has a range that radio waves reach. When exchanging data with any other unit within the unit that is not directly reachable by radio waves, units that are within the range of each other's radio waves will sequentially relay data to achieve the desired goal. When transmitting data generated in a certain unit or data to be relayed by a certain unit to a unit to which wireless radio waves cannot directly reach, the next unit to relay data must be a wireless It is characterized by selecting the unit that is within the reach of radio waves and having the closest distance to the final data destination unit, and transmitting the data to that unit.

[0005]

[Operation] When exchanging data with a unit in a position where radio waves cannot directly reach, select the unit that is not only close in distance, but also the one that is the closest to the final destination unit and send the data. By reducing the number of relays,
Reduce transmission time delay time.

[0006]

[Embodiment] Fig. 1 is a block diagram showing an embodiment of this invention, Fig. 2
2 is a block diagram showing a configuration example of each wireless communication unit in FIG. 1. FIG. First, the configuration of FIG. 2 will be explained. In the figure, 21 is a receiver that receives radio waves and converts them into digital data, 22 is a transmitter that converts digital data and transmits it on radio waves, and 23 is a device that temporarily stores received data or transmitted data. 24 is a control unit that controls data transmission and reception and data transfer with the control device; 25 is a table that stores relay route data when relaying data; and 26 is an antenna.

FIG. 1 shows an example of a wireless communication system in which a plurality of such units are arranged. 1a, 2a, 3a in the same figure
, 4a, 5a, 6a are wireless communication units; 11,
13, 15, and 16 are control devices serving as data generation points or arrival points, and are units 1a, 3a, 5a, and 6a, respectively.
and data transmission is performed via these. Here, it is assumed that 2a and 4a are not connected to the control device and have only a data relay function. Also, r1,
r2, r3, and r4 respectively indicate the effective range of transmission radio waves from each unit.

FIG. 3 shows an example of the contents of the table 25 in FIG. 2. Figures 3 (a), (b), (c), and (d) are tables (1c, 2c,
3c, 4c), and the left column of the table shows the identification number ID (1, 2, 4c) of the unit that is the final destination of the data.
3, 4, 5), the right column stores the unit ID to which data should be sent directly when sending data to the final destination unit indicated by the data in the left column, and each item in the left column and Each item in the right column is paired.

Now, based on FIG. 1, the operation when transmitting data from the control device 11 to the control device 15 will be explained. When the control device 11 transfers data that is to be sent to the control device 15 with information indicating that the final destination of the data is the unit 5a, the control section of the unit 1a transfers the data to the wireless communication unit 1a connected to the control device 11. Store the data in the internal buffer memory, refer to table 1c, and find the ID of the unit to which the data should be sent directly, which is stored in the right column of the item whose unit ID is 5 in the left column.
(Here, 3) is read out. The control section selects a transmission channel for the unit 3a to which data is to be transmitted, and activates the transmitter to transmit the data on the buffer memory. The transmitter converts the data in the buffer memory into a format that can be transmitted sequentially, performs necessary modulation, and sends the data to unit 3.
Transmit wirelessly using the transmission channel to a.

The control section of the unit 3a demodulates and converts the data transmitted from the unit 1a using an internal receiver, and stores the demodulated data in a buffer memory as received data. When the control section of the unit 3a identifies that the final destination of the received data is the unit 5a, it refers to the table 3c shown in FIG. Read the stored ID (5 in this case) of the unit to which data should be directly transmitted. Then, the control section of the unit 3a activates the transmitter in the same manner as the control section of the unit 1a, and transmits the data in the buffer memory to the unit 5a. The control section of the unit 5a demodulates and converts the data transmitted from the unit 3a using an internal receiver, and stores the demodulated data in the buffer memory as received data. Furthermore, when the control section recognizes that the final destination of the received data is its own unit, it transfers the data from the buffer memory to the control device.

As described above, here, the control device 11
Data can be transmitted from the controller 15 to the control device 15 via the relay unit 3a. The contents of the table 25 in each unit are determined in advance from the range of radio waves from each unit and the distance between each unit after the arrangement of each unit is decided, and is stored in a programmable memory, such as an EPROM. Try to remember it.

FIG. 4 shows an example in which relay routes for transmission to the final destination unit are stored in field format. Note that this data is stored at a specific position in the information string transmitted and received between units. In other words, the unit ID (Ne) of the final destination of the data and the ID of the unit that should receive the data for relaying are arranged in the order (N1,
N2, N3, ...Ne). This is a unit that can effectively transmit data directly via wireless radio waves from the transmitting unit, and the relay unit and its order so that the unit closest to the final destination of the data becomes the receiving unit. This is what was decided. The operation of transmitting data from the control device 11 to the control device 15 will be described below based on such data. First, the control device 11 stores the data to be sent to the control device 15, and at a predetermined position of the data, the ID of the unit that is the final destination of the data (here, 5), and the ID of the relay unit selected based on the criteria described above. (Here, 3, 5) is added and transferred to the wireless transmission unit 1a, the control unit of the unit 1a stores the data in the internal buffer memory, and the first relay unit ID (here, 3) of the data is transferred to the wireless transmission unit 1a. Read out.

[0013] The control section is a unit 3a to which data is to be transmitted.
Select a transmission channel for the transmitter and activate the transmitter to transmit the data on the buffer memory. The transmitter converts the data in the buffer memory into a format that can be transmitted sequentially.
It undergoes necessary modulation and is wirelessly transmitted via a transmission channel to unit 3a. The control section of unit 3a is unit 1a.
The data transmitted from the receiver is demodulated and converted by the receiver and stored in the buffer memory as received data. Furthermore, when the control section of the unit 3a recognizes the ID of the unit next to its own ID (in this example, 5) among the ID group of the relay units, the control section of the unit 3a performs the same process as the control section of the unit 1a, and stores the data in the buffer memory. is transmitted to the unit 5a by activating the transmitter. The control section of unit 5a is unit 3
The data transmitted from a is demodulated by the receiver,
The data is converted and stored in the buffer memory as received data. Further, when the control section recognizes from the received data that the final destination of the data is its own unit, it reads the data from the buffer memory and transfers it to the control device 15 .

In this manner, by using field format data, data can be transmitted from the control device 11 to the control device 15 via the relay unit 3a. Note that the ID and order of the relay units stored in each transmission data are determined in advance by each control device based on the arrangement of each unit, the range of radio waves, and the distance between each unit.

By the way, in such a system,
If you replace the control device or remove the control device and install a relay-only unit in its place, the spatial position of the unit and the resulting wireless communication The environment may change significantly. Under such circumstances, the previous relay route may become unusable, or direct wireless communication may become possible between units that were previously unable to communicate directly. In the former case, conventionally, after replacing the unit or replacing it with a relay-only unit, the installation position of the unit, the direction of the antenna, or the surrounding radio wave environment must be adjusted so that the previous relay route can be used. If this is not possible, the relay route is changed, but in the latter case, the existing relay route is generally used as is.

This will be explained with reference to FIG. In the figure, 1a to 5a are wireless communication units, r1 to r4
indicate the radio wave reach ranges of the wireless communication units 1a to 4a, respectively. Here, from the wireless communication unit 1 to the unit 5a
Assume that routes b1, b2, and b3 were used as routes for transmitting data to the unit 3a, and unit 3a was replaced with unit 6a for some reason. the result,
Assuming that the radio range of the new unit 6a is r5 and unit 6a can communicate directly with unit 5a, the route for transmitting data from unit 1a to unit 5a is better than the route used so far. Using routes b4 and b5 will reduce the number of relays. Therefore, in this invention, if a new relay route with fewer relays appears after replacing the unit or replacing it with a relay-only unit, by using that route, data transmission with fewer relays can be performed. In other words, data transmission with less transmission delay time is realized.

An example of feed data used to implement the embodiment shown in FIG. 6 is shown. As in FIG. 4, this is stored at a specific position in the information string transmitted and received between units, and as shown in data 20a in FIG.
The unit ID (Ne) of the final destination of the data and the ID of the unit that should receive the data for relaying are in order (
N1, N2, N3,...Ne). now,
If the relay route when the control device 11 transmits data to the control device 15 is set as b1, b2, b3 as shown in FIG. Information (20b) indicating a relay route such as
) is stored at a specific position in the transmission data string, and the data is transferred to the wireless communication unit 1a. As a result, unit 1
a transmits data to the unit 2a indicated by the first relay unit ID. The unit (here 2a) that received the data transmitted by unit 1a is the unit 4a whose unit ID is next to its own unit ID in the relay route instruction field in the received data.
Send data to. Unit 4a has its own unit ID in the relay route instruction field of the received data.
The data is transmitted to unit 5a, which is the unit ID located next to . When the unit 5a recognizes that it is the final destination unit of the received data from the relay route instruction field of the received data, it transfers the received data to its control device 15.

[0018] Here, direct radio waves effectively reach from unit 1a, but since the radio waves do not directly reach unit 5a, it is not used as a relay unit in data transmission from unit 1a to unit 5a. Consider a case where the unit 3a and its control device 13 are removed and a relay-only unit 6a having only a relay function is installed instead. After the relay unit 6a is installed, the relay unit 6a first transmits test data to all other units that make up the communication system, that is, units 1a, 2a, 3a, 4a, and 5a, according to the operator's instructions. to find out which units it is possible to communicate directly with. If it is determined that the relay unit 6a is capable of direct wireless communication with the units 5a and 1a, assuming that the radio wave range of the relay unit 6a is r5, the operator can select the route for data transmission between the units 1a and 5a. b4, b5 can be used, and the previous relay routes b1, b2,
It is determined that the number of relays is smaller than b3, and relay route instruction information 20c as shown in FIG.

After performing such processing, when transmitting data from the control device 11 to the control device 15, the control device 1
1 stores the information indicating the changed relay route in a specific position of the transmission data as shown in FIG. 6(c) and transfers the data to the wireless communication relay unit 1a. Data is transmitted to the unit 3a indicated by the ID. Unit 3a, which has received the data transmitted from unit 1a, transmits the data to unit 5a, which is the unit located next to its own unit ID in the relay route instruction field of the received data. When the unit 5a recognizes that it is the final destination unit of the received data from the relay route instruction field of the received data, the unit 5a transfers the received data to its control device 1.
Transfer to 5. In this way, data can be transmitted with fewer relays than before by using the relay route that has become available by replacing the wireless communication unit.

[0020]

[Effects of the Invention] According to the present invention, when data is finally transmitted to a unit that cannot be directly reached by radio waves, the next unit that relays the data is within the range that radio waves can reach. Moreover, since the units closest to the final destination unit of the data are selected in sequence, the number of relays can be reduced and data transmission delays can be reduced. In addition, the communication path between units that has become newly capable of direct wireless communication by replacing the unit can be used as a new route, so even in such cases, the number of relays can be reduced and transmission delay time can be reduced. It is possible to make it smaller.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram for explaining an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of the wireless communication unit in FIG. 1.

FIG. 3 is a configuration diagram showing an example of the table in FIG. 2;

FIG. 4 is a configuration diagram showing an example in which a relay route for transmitting to a final destination unit is stored in field format.

FIG. 5 is an explanatory diagram for explaining when a unit is replaced.

FIG. 6 is an explanatory diagram for explaining another embodiment of the invention.

FIG. 7 is an explanatory diagram for explaining a conventional example.

[Explanation of symbols]

1a Wireless communication unit 1c Relay route table 2a Wireless communication unit 2c Relay route table 3a Wireless communication unit 3c Relay route table 4a Wireless communication unit 4c Relay route table 5a Wireless communication unit 6a Wireless communication unit 11 Control device 13 Control device 15 Control device 16 Control device 21 Receiver 22 Transmitter 23 Buffer memory 24 Control section 25 Table 26 Antenna

Claims (2)

[Claims] Claim 1: Consists of a plurality of units, each having the function of transmitting and receiving data wirelessly, each unit being capable of exchanging data with any other unit within the range of wireless radio waves, and transmitting and receiving data wirelessly. When exchanging data with a unit that cannot be directly reached, the units that are within the range of each other's radio waves sequentially relay data and transmit it to the target unit. When the data to be relayed is ultimately transmitted to a unit that cannot be directly reached by radio waves, the next unit to relay the data must be a unit that is within the reach of radio waves and that is within the reach of the final unit of data. A wireless communication method characterized by selecting the closest unit and transmitting data to that unit. Claim 2: Consists of a plurality of units, each having the function of transmitting and receiving data wirelessly, each unit being capable of exchanging data with any other unit within the range of wireless radio waves, and transmitting and receiving data wirelessly. When exchanging data with a unit that cannot be directly reached, the units that are within the range of each other's radio waves sequentially relay the data and transmit it to the target unit, and one unit is replaced with another unit. A wireless communication method characterized by resetting a data relay route when the data is transferred, even if the data can be transmitted using the previous relay route.