JPS63268326A - Wireless data transmission system - Google Patents

Abstract

PURPOSE:To prevent data transmission efficiency from being deteriorated even if the reliability of data transmission is improved by checking the line state periodically and using an error correction code of transmission quality in response to the line state so as to apply data transmission. CONSTITUTION:A line check signal S1 is sent from a calling section periodically to a called station. The called station receiving the line check signal S1 uses a line state deciding means 3 so as to decide the state of the line and the result of decision is returned to the caller station. A transmission mode deciding means 4 of the caller station receiving a return signal S2 representing the result of decision decides the kind of error correction code to be used to send the data transmission to the called station in response to the result of decision and the transmission state of the return signal S2. Thus, the data transmission is applied accurately even with the deteriorated state of the wireless line, the reliability of data transmission is ensured and the limited frequency of the line is utilized effectively without deteriorating the data transmission efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to a wireless data transmission system that transmits data using wireless signals.

[Background Art 1 Several wireless devices that transmit data using wireless signals have already been developed. In such a wireless data transmission system, data is transmitted bidirectionally between a master station A and a slave station B. In other words, the sensor 8 installed in the slave station BflI monitors the operation of the load or detects the operating state,
CPU via Inter 7 Eighth Units) (TFU) 7
Monitoring data etc. are input to I, it is determined whether the lighting devices are on, etc., and this monitoring data etc. is sent from the transmitter/receiver WSe to the master station A via a wireless line. Based on the monitoring data from the slave station B, the master station A uses the control section 9 to perform appropriate control operations. In this conventional system, it often happens that predetermined data sent from the calling station is not accurately transmitted to the called station due to deterioration in the line condition of the wireless line. Therefore, conventionally, the calling station sends data with an error detection code or error correction code superimposed on it, and the called station sends an ACK when the data is normally received by the called station.
(A knowledge) A signal S4 is sent back to the calling station, and a message indicating that the data was not normally received by the called station is sent back to the calling station. It should be noted that when the NAK signal signal is returned, the reliability of the data transmission previously sent by the calling station is improved.

However, wireless lines may deteriorate due to factors such as noise, season, location, and time.

In this case, the called station repeatedly returns the NAK signal, and the calling station repeatedly retransmits the same data, resulting in extremely poor data transmission efficiency over the wireless line, making it difficult to effectively utilize the limited lines. There was an inconvenience that it was not possible. In other words, in the past, the reliability of data transmission and the efficiency of data transmission conflicted with each other.

[Objective of the Invention 1 The present invention has been made in view of the above points, and its object is to provide wireless data transmission in which data transmission efficiency does not decrease even when the reliability of data transmission is improved. The goal is to provide a system.

[Disclosure of the Invention 1 (Configuration) The present invention provides a wireless data transmission system that transmits data using wireless signals, which periodically checks the line status and uses an error correction code with transmission quality according to the line status. Data transmission is carried out using error correction codes that have different transmission quality depending on the condition of the wireless line, which is checked periodically, so that data can be transmitted accurately even if the condition of the wireless line is poor. This improves the reliability of data transmission, and by being able to perform data transmission accurately in this way, data transmission efficiency is prevented from decreasing due to repeated unnecessary retransmissions of the same data. and
This is to prevent data transmission efficiency from decreasing even if the reliability of data transmission is improved.

(Example) An embodiment of the present invention is shown in FIGS. 1 to 3.

This embodiment includes a line check means 2 that controls a transmitting/receiving unit 6 of a calling station to periodically transmit a line check signal S1 to a called station, and a line check signal S1 that is received by the called station.
The line status determining means 3 determines the state of the line at the terminal 1, and any error correction is performed in response to the return signal S2 sent back from the called station to the calling station and indicating the determination result of the line status determining means 3. A transmission mode determiner PU4 determines whether to transmit data to the called station using a code, and a transmission mode designation signal S code is sent from the calling station to the called station by the transmission mode determining means 4 to specify the transmission mode to the called station. and a mode specifying means 5 for transmitting. In the above description, each of the calling station and the called station is provided with one of the means 2 to 5, but it goes without saying that both the calling station and the called station are provided with the respective means 2 to 5. Therefore, the calling station can become the called station. Further, the functions of each of the above-mentioned means 2 to 5 are executed by program processing on the CPUI provided in each of the calling station and the called station. Further, as the error correction code, a Hamming code, a BCH code, a Weiner code, a self-orthogonal code, etc. are used.

A line check signal S is periodically sent to the called station. The called station that receives this line check signal S1 checks the state of the line! ! ! ! The decision is made by the decision means 3, and the decision result by the line state decision means 3 is sent back to the calling station. The transmission mode determining means 4 of the calling station that has received the return signal S2 indicating the determination result determines which fl
u') Decide whether to transmit data to the called station using the correction code.

For example, when the line condition is good, the data is transmitted to the called station using an error correction code with relatively low transmission quality, and when the line condition is poor, the data is sent to the called station using error correction code with high transmission quality. A decision is made to transmit data to the called station using the code. The transmission mode determined by the transmission mode determining means 4 is designated by transmitting a transmission mode designation signal S for designating the transmission mode from the calling station to the called station. When data D such as actual monitoring data is transmitted, the ACK signal described in the conventional example is sent. However, even if the ACK signal S4 and the NAK signal S are sent back, in this embodiment, data transmission is performed using an error correction code according to the line condition, so the called station can send back the NAK signal. Returning S5 is extremely rare and does not reduce transmission efficiency. In this way, according to this embodiment, by periodically checking the line status and transmitting data using an error correction code according to the line status at that time, the reliability of data transmission can be improved. No loss of efficiency.

[Effects of the Invention] As described above, the present invention periodically checks the line condition and performs data transmission using an error correction code with transmission quality according to the line condition. Data transmission can be performed using error correction codes with different transmission quality depending on the condition of the wireless line, and therefore data can be transmitted accurately even in poor wireless line conditions, which increases the reliability of data transmission. As a result, data transmission efficiency can be ensured and data can be transmitted accurately, eliminating the need to repeatedly retransmit the same data as in the past, thereby preventing data transmission efficiency from decreasing. Even if transmission reliability is improved, data transmission efficiency does not decrease, and the limited frequency of the line can be used effectively.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram of the same operation, FIG. 3 is a 70-chart showing the same operation, and FIG. 4 is a block diagram showing a conventional example. FIG. 5 is an explanatory diagram of the same operation. Reference numeral 1 designates the CPU 12 as a line checking means, 3 as a line FI determining means, 4 as a transmission mode determining means, 5 as a mode specifying means, and 6 as a transmitting/receiving section.

Claims (1)

[Claims] (1) A wireless data transmission system that transmits data using wireless signals is characterized by periodically checking the line status and transmitting data using error correction codes with transmission quality according to the line status. wireless data transmission system.