The Internet of Things can be simply explained as the communication process between the terminal (hardware) and the IoT service platform, and between the IoT service platform and the terminal (hardware). The communication process generally adopts TCP/IP, UDP/IP and other methods to transmit messages or instructions, and instructions (messages) usually need to be processed by sticking packets and breaking packets. The following chapters mainly discuss the content related to the in-vehicle Internet of Things.
1. What are the characteristics of in-vehicle IoT communication?
a. There are many types of communication commands
Communication commands can be roughly classified into OTA, EMS itinerary, cold chain, multimedia, event, terminal parameter setting/query, etc. Each category includes specific instructions of varying numbers, such as OTA-type remote upgrade request instructions, remote upgrade request response instructions, and so on.
b. Communication command structure is not unified
In order to win more markets and seize more truck resources, the current in-vehicle Internet of Things companies not only use/promote the in-vehicle terminals developed by the company, but also use terminals that are popular in the market or required by countries (regions) to be installed in the customer's in the car.
For companies to access various types of in-vehicle devices, the IoT back-end service platform must identify and adapt protocols, and parse data according to different protocol specifications.
c. Communication
In-vehicle IoT customers are generally sensitive to positioning information and expect to understand the vehicle's driving trajectory in real time and clearly. Therefore, the vehicle terminal needs to report the positioning information frequently, and the general interval is about 5 to 10 seconds.
d. Communication network status is complex
When the vehicle is driving in areas such as roads, bridges, and tunnels with poor mobile communication signals, the equipment may be offline and the positioning information may be lost. Although basically all vehicle-mounted terminals currently support base station positioning, they still cannot 100% solve the problem of inability to locate.
2. Choice of Communication Architecture
Both Mina and Netty are the leaders in actual production applications, and they are also network application architectures with high performance and high scalability in the Java field. We currently use Mina as the basic communication architecture of the in-vehicle IoT service platform.