IoT wireless remote transmission

Overview

Wireless remote transmission is a series of solutions based on GPRS, 4G, and NB-IOT related technologies to transmit meter flow signal information to the Internet or designated terminal equipment.

At present, our company has two remote transmission systems based on the Internet and the local area network.

The Internet method is a set of programs in which the signal is transmitted to the network server through the DTU device, and then the user accesses the instrument information through the Internet. The advantage of this scheme is that it is not limited to the location, density and quantity of meters, and new meters can be added unlimitedly, and each meter is independent of each other, and no intra-network interference will occur. The disadvantage is that due to the limitation of the mobile network, it needs to be used within the scope of network support, which will incur traffic charges every year. Due to package restrictions, the transmission time interval is generally longer.

The 315/433Mhz free wireless frequency band adopted by the local area network collects instrument information within a centralized range, and users directly access the instrument information in the network through the Internet of Things. The advantage of this scheme is that a limited number of instruments can be centrally managed in a small area, no annual fee is required, and the collection speed is faster.

GPRS-based wireless remote transmission scheme

 The user transmits traffic or other information to the server via GPRS, and then accesses the server data via the Internet, which can be displayed on the user's PC, mobile phone applet, etc. The user can monitor and read the meter at any time, which solves the problem of meter reading.

Data transmission is achieved through standard modbus485, realizing equipment monitoring, real-time curves, historical curves, comparison curves, historical details, statistical analysis of data reports, etc. According to the different needs of users, the corresponding hardware can be selected to realize remote recharge and remote switch valve.

At present, data transmission generally uses DTU. Generally, there are many types of DTU. This platform can support 2G, 3G, 4G, 5G, and NB networks. However, depending on the level of network popularity, 2G and 4G networks are generally preferred. NB networks are generally used in ultra-low power consumption modes, and the transmission frequency is very low, such as once a day or once a month for applications, and the network coverage is not all areas.

DTU needs an Internet of Things card for traffic communication. Generally, we only use mobile Internet of Things cards. (2G has been withdrawn from the network except for mobile, so in order to stabilize the product sequence, we mainly use mobile products). Customer adaptation, some products can also be provided by customers with phone cards.

LAN wireless remote transmission solution

Our company uses LoRa communication technology for the local area network. LoRa mainly operates in free frequency bands around the world, including 433, 868MHz, etc. LoRa is one of LPWAN communication technologies, an ultra-long-distance wireless transmission scheme based on spread spectrum technology. This solution changes the previous compromise between transmission distance and power consumption, and provides users with a simple system that can achieve long-distance, long battery life, and large capacity, and expand the sensor network. Access to server data via the Internet can be displayed on the user's PC, mobile phone applet, etc. The user can monitor and read the meter at any time, which solves the problem of meter reading.