The Internet of Things is an important part of the new generation of information technology. With the development of information technology today, the demand for communication between people has shifted to the interconnection between people and things and between things and things,WiFi Wireless Module and finally realizes the interconnection of everything. Sensor technology, embedded system technology and communication technology are the three important components of the Internet of Things, and communication technology is the material basis for information transmission and logistics between various units of the Internet of Things. Today I will discuss LORA communication technology and NB -IOT communication technology.
LORA wireless technology
LORA is one of the LPWAN communication technologies. It is an ultra-long-distance wireless transmission scheme based on spread spectrum technology adopted and promoted by Semtech in the United States. It provides users with a simple way to achieve long-distance, long battery life, and large Capacity system, and then expand the sensor network. At present, LORA mainly operates in the global free frequency band, including 314, 868, 915MHz and so on.
LORA communication protocol
The network layer protocol based on LORA wireless technology is mainly the LORAWAN gateway module, which defines the network communication protocol and system architecture. The communication system network of LORAWAN is a star network architecture, Wireless modem which is mainly divided into three types:
1. Point-to-point communication, point A initiates, point B receives
2. Star network polling, point-to-multipoint mode, a central point and N nodes, starting from the node, the central point receives and confirms the completion of the reception, and the next node continues to upload until the N nodes are completed.
3. Concurrent star network is also a point-to-multipoint communication. The difference is that multiple nodes can communicate with the central point at the same time, which saves the power consumption of nodes and avoids the failure of individual nodes to cause network paralysis. Network stability has been improved.
LORA wireless technology uses global free frequency bands. Base stations or gateways have strong penetrating capabilities. The distance connecting sensors in the suburbs can reach 15-30KM. LORA uses an asynchronous protocol, and nodes can communicate in different lengths according to specific tasks. Dormancy, supplemented by a low data rate, makes the battery life up to 3 to 10 years, wide coverage, long use time, and LORA nodes can reach millions. These remarkable features make LORA technology can be applied in demanding In IoT applications with low power consumption, long-distance, and massive connections, such as intelligent transportation, it can accurately provide traffic data such as vehicle speed, distance, and traffic flow; intelligent parking, through real-time monitoring of parking spaces, realizes information transparency and charges Accurate and reduce labor costs; smart bridges can reduce the probability of accidents by timely assessing the status of bridges; urban smart manhole covers can achieve fewer vehicle accidents and casualties by monitoring the position of manhole covers; smart agriculture, through temperature, humidity, Monitoring of wind speed etc. Grasp the production status and increase production; in addition, it can also be used in smart medical care, smart ocean, smart tracking, etc.
この記事をシェア
