IoT, the Internet of Things, surprisingly includes so many different protocols.

IoT protocols refer to the protocols used for communication and data transfer between devices in the IoT environment. Based on different functions, IoT protocols can be divided into transport, communication, and industry-specific protocols.

Transport Protocols: Generally responsible for networking and communication between devices within a subnet. For example, Wi-Fi, Ethernet, NFC, Zigbee, Bluetooth, GPRS, 3G/4G/5G, etc. These protocols ensure the security and reliability of data transmitted over the network.

Communication Protocols: These are mainly device communication protocols that run on top of the traditional Internet TCP/IP protocol and are responsible for data exchange and communication between devices. Examples include MQTT, CoAP, HTTP, etc.

Industry Protocols: These are unified standard protocols within a certain industry. For example, the vehicular communication protocol JT/T808, video protocol GB/T 28181, etc.

1. Transmission Protocol, Modbus, OPC-UA, OPC-DA, LoRa,ZigBee

Comparison of Bluetooth, WiFi, ZigBee Protocols

Currently, WiFi’s advantage is its widespread application, having already been popularized in countless households. ZigBee’s advantage lies in its low power consumption and mesh networking capabilities. The strength of UWB (Ultra-Wide Band) no-carrier wireless communication technology is its transmission rate. Bluetooth is advantageous for its simplicity in networking. However, these three technologies all have their shortcomings, and no single technology can completely meet all the requirements of smart homes.

The emergence of Bluetooth technology has made short-range wireless communication possible. Still, its complex protocol, high power consumption, and high cost are not very suitable for industrial control and home networks that require low cost and low power consumption. Bluetooth’s biggest obstacle is its limited transmission range, generally around 10 meters. Its weak anti-interference capability and information security issues also restrict its further development and large-scale application.

WiFi is also a short-range wireless transmission technology, which allows for anytime access to wireless signals and strong mobility, making it more suitable for use in offices and homes. Of course, WiFi also has a fatal flaw. Since WiFi uses radio frequency technology to send and receive data through the air, it is relatively easy for external sources to interfere.

ZigBee, on the other hand, is an internationally recognized wireless communication technology. Each network port can accommodate more than 65,000 ports, making it suitable for use in homes, industry, agriculture, and other fields, while Bluetooth and WiFi networks can only support up to 10 ports, obviously not meeting the needs of families. ZigBee also has the advantages of low power consumption and low cost.

2. Communication Protocols, MQTT, HTTPS, CoAP, TCP, UDP

Comparison between MQTT and CoAP protocols: MQTT is a many-to-many communication protocol used to transfer messages between different clients via an intermediary agent, decoupling producers and consumers. It allows clients to publish while the agent decides routing and copies messages. Although MQTT supports some level of persistence, it is best used as a real-time data communication bus.

CoAP is primarily a point-to-point protocol, used for transferring status information between clients and servers. Although it supports resource observation, CoAP is best suited for a state transfer model, not entirely based on events.

MQTT clients establish a long TCP connection, which usually poses no problem. CoAP clients and servers both send and receive UDP packets. In NAT environments, tunneling or port forwarding can be used to allow CoAP, or like LWM2M, devices may initiate a frontend connection first.

MQTT does not provide support for message type tagging or other metadata to help clients understand; MQTT messages can be used for any purpose, but all clients must know the upstream data format to allow communication. CoAP, on the other hand, offers built-in support for content negotiation and discovery, allowing devices to probe each other to find ways to exchange data.

3. Industry Protocol