The most common problem in wireless communication is packet loss. Whether it is a simple and primitive 433MHz communication or a sophisticated 5G signal, there will be network packet loss. Solving the problem of packet loss is also a necessary job for wireless engineers. Packet loss in wireless communication networks is inevitable, but what to do when encountering packet loss is what this article will talk about.

The most important thing in wireless communication is to design a communication protocol that can meet the application requirements, and the communication protocol includes these elements: what frequency band the wireless signal uses, what modulation method is not interfered, who the wireless signal is sent to, and how to ensure that the wireless signal reaches the target , What should I do if multiple identical devices are used at the same time, how does the receiving end judge whether the received signal is received repeatedly or missed... In fact, these are all about solving a problem-network packet loss.

network packet loss

Therefore, any commonly used wireless communication protocol must be divided into several logical layers, each logical layer. For example, common lora modules, WiFi modules, ZigBee modules, Bluetooth modules, and wireless module communication protocols all have two common logical layers—PHY physical layer and MAC link layer. Among them, the PHY layer defines the frequency band, modulation method and transmission method. The MAC layer defines who will send the signal, who will receive the signal, and when to send the signal.

The basic PHY physical layer nd MAC link layer solve the common physical packet loss problem, but the application scenarios of wireless devices are very complex, so various communication protocols are added with logical layers such as the network layer to ensure the stability of communication For example, the TCP protocol on the Wi-Fi protocol is designed to ensure stable transmission. For example, the PHY layer and MAC layer of ZigBee have implemented some processing mechanisms to reduce packet loss.

Fault-tolerant handling of packet loss is the key to wireless communication design. Although the existing mature communication protocols have taken many measures to reduce the packet loss rate, if packet loss occurs, there must be a fault-tolerant mechanism to deal with it, otherwise it is only one in a thousand Or a packet loss of one in ten thousand will bring disastrous consequences to the entire wireless system.