Views: 0 Author: Site Editor Publish Time: 2022-02-18 Origin: Site
LORA transmission technology and lora wireless remote water meter introduction
In the water meter remote transmission scheme, the wireless remote water meter LoRa is a terminal water meter in the wireless remote transmission scheme. The main technology used is LoRa technology. Due to the early start of LoRa technology, after several years of exploration and practice, the wireless remote water meter LoRa technology has been very mature and has been widely used in urban water supply metering and other projects.
In terms of transmission distance and penetration, the wireless remote water meter LoRa is better than the FSK and GFSK transmission methods, but it is still difficult to achieve a concentrator without dead angle signal reception for the entire cell. This is mainly because many manufacturers use LoRa remote When transmitting technology, the influence of its own structure on wireless transmission is ignored. For example, LoRa remote transmission technology is extremely sensitive to structural parts such as metal, and slight changes in design will make the wireless transmission effect worse. However, with the continuous development of technology, This drawback is gradually resolved.
The working mode of wireless remote water meter LoRa is to receive and open the search wake-up signal after sleeping for a period of time. In the whole working mode, the power consumption in the meter reading state cannot be saved, while the breathing state only generates sleep and receiving power consumption. Obviously, controlling the receiving power consumption is the key, and the best way to save the power of the module is to Try to shorten the receiving time. However, if the LoRa spreading factor is adjusted to the highest and the rate is the lowest, the wake-up time (reception time) will be doubled in the case of transmitting the same data, the rate is too high, the distance is short, and the rate is too low , it consumes too much power. Therefore, the selection of the spreading factor in the wireless meter reading of the water meter, that is, the selection of the rate and the receiving time must achieve a balance in a certain sense, and cannot go to extremes.
As for the technical problems encountered in the promotion process of wireless remote water meter LoRa mainly include:
1. The power supply problem of wireless remote water meters: Since most wireless remote water meters are powered by batteries, the power consumption requirements are very strict, and it is unrealistic to replace the batteries frequently. Generally speaking, after the nominal capacity of the battery is estimated conservatively, the actual service life is still more than 6 years to meet the relevant requirements.
2. The accuracy of measurement and the reliability of communication: The accuracy of measurement and the reliability of communication are the most basic requirements of the wireless meter reading system, but at the same time they are not easy to solve. Because wireless communication is easily shielded by some metals, house structures, and some radio waves with similar frequencies of wireless signals.
3. Communication data security: The frequency band channel of wireless communication is relatively fixed, and it is easy to be detected, which requires strengthening preventive measures in terms of data security.
4. Cost of wireless remote water meters: Compared with ordinary mechanical water meters, the price of wireless remote water meters having many functions is that their cost is much higher than that of ordinary mechanical water meters. Because the cost topic is more sensitive, whether it is ordinary users or water companies, etc. Big watch users will pay attention to it. The cost here includes two parts, namely: the cost of one-time modification or installation, the operating cost of the system and the later maintenance cost.