Communication technologies in the Internet of Things include long-distance communication and short-distance communication. This article will talk about short-distance communication networking technology. As the wireless communication technology of the Internet of Things continues to innovate, we commonly see short-distance wireless communication technologies such as Zigbee, WiFi, Bluetooth, and LoRa.
1. LoRa communication technology
It is a kind of LPWAN communication technology. It is an ultra-long-distance wireless transmission solution based on spread spectrum technology adopted and promoted by Semtech Company in the United States. This solution changes the previous trade-off between transmission distance and power consumption, providing users with a simple system that can achieve long distance, long battery life, and large capacity, thereby expanding the sensor network. Currently, LoRa mainly operates in free frequency bands around the world, including 433, 868, 915 MHz, etc.
standard:
Frequency: 433, 868, 915 MHz
Communication distance: 3-8km
Data rate: 30kb/s~180kb/s [depending on the product itself and communication distance]
Security: high
Application scenarios: oil fields, remote meter reading
Advantages: low power consumption, long communication distance, supports multiple networking methods
Disadvantages: spectrum interference. As the deployment of LoRa devices and networks increases, there will be certain spectrum interference between them.
2. ZigBee communication technology
The name ZigBee comes from the eight-character dance of bees. Bees rely on flying and zig-zagging their wings to communicate the location of pollen to their companions. In this way, they form a communication network in the group. ZigBee technology is suitable for automatic control and remote control fields and can be embedded in various devices.
Standard: 802.15.4
Frequency: 868MHz-868.6MHz, 902MHz-928MHz and 2.4GHz-2.4835GHz
Data rate: 20kbps, 40kbps and 250kbps
Communication distance: 20-350m
Security: Medium
Application scenarios: industrial automobiles, agriculture, medical care, smart home
Advantages: low power consumption, low cost, low latency, large network capacity, short distance, support Mash network
Disadvantages: weak ability to penetrate walls, higher cost, poor self-organizing network capability, poor anti-interference performance
3. Wifi communication technology
Short-range wireless communication technology WiFi connections are often a priority for many developers, especially given the popularity of WiFi in home environments within local area networks. In addition to being clearly stated, the existing infrastructure is extensive and provides fast data transfer and the ability to process large amounts of data.
Standard: Based on 802.11n
Frequency: 2.4GHz, 5GHz frequency band
Data rate: 600 Mbps maximum, 150-200Mbps (typical).
Communication distance: 20-300m
Security: low
Application scenarios: smart homes, smart buses, subways, parks
Advantages: wide coverage, easy to use, low cost
Disadvantages: limited communication distance, high security risks, poor stability, high power consumption, and poor networking capabilities
4. Bluetooth communication technology
Short-distance wireless communication technology Bluetooth uses short baud high frequency (UHF) radio waves and uses frequency hopping technology to resist signal fading; fast frequency hopping and short packet technology can reduce co-channel interference and ensure transmission reliability; forward error correction Coding technology can reduce the impact of random noise during long-distance transmission; FM modulation can be used to reduce the complexity of equipment, etc.
Standard: Bluetooth 4.2 Core Specifications
Frequency: 2.4 to 2.485GHz
Communication distance: 10-300m
Data rate: 1Mbps
Security: high
Application scenarios: mobile phones, smart homes, wearables
Advantages: low power, low latency, support for complex networks, intelligent connection
Disadvantages: short transmission distance, average transmission rate, incompatible protocols between different devices, poor networking capabilities, and radio wave interference issues at the 2.4GHz frequency
Keywords in this article: LoRa communication technology, industrial-grade LoRa RTU