Communication System Introduction

I. Introduction

The UAV communication system is a communication method that uses radio waves to transmit control information, images, video, and other data. A typical UAV communication system consists of transmitters, receivers, antennas, and power supplies. The transmitter encodes control information, images, and video into electrical signals and transmits them through antennas; the receiver then captures these electrical signals and reconstructs them into the original control information, images, and video.

II. UAV Video & Data Transmission

UAV Video Transmission (First Person View) refers to the real-time transmission of flight video to ground stations or control device displays, enabling operators to view the drone's perspective in real-time. This communication method typically employs wireless video transmission technologies such as 5.8GHz or 2.4GHz band video transmission devices, along with corresponding antennas and receivers. Through video transmission, operators can better understand the drone's flight status, environment, and target area conditions, thereby enhancing flight safety and operational efficiency.

UAV Data Transmission (Telemetry) involves real-time transmission of flight parameters and status information to ground stations or control devices. This data may include position, altitude, speed, attitude, battery level, and other critical parameters. Through data transmission, operators can monitor these parameters in real-time and make necessary adjustments. Data transmission typically uses wireless telemetry modules and specific communication protocols to send data to ground stations or control devices.

The combination of video and data transmission provides comprehensive flight monitoring and control capabilities. Video transmission offers intuitive environmental awareness, while data transmission supplies detailed flight parameters and status information to support informed decision-making. These two communication methods play vital roles in UAV applications, ensuring safer and more controllable flight operations.

III. WiFi HaLow Protocol

The UAV communication system employs the Wi-Fi HaLow protocol, a low-power, long-range communication technology based on the IEEE 802.11 wireless LAN standard. Utilizing the 900 MHz frequency band, Wi-Fi HaLow offers superior penetration and coverage compared to traditional 2.4 GHz and 5 GHz Wi-Fi technologies.

While maintaining the MAC and PHY layer architecture similar to conventional Wi-Fi, HaLow introduces key optimizations for low-power and long-range communication needs. These include adaptive transmission rate and modulation technologies that dynamically adjust based on environmental conditions and device capabilities, ensuring efficient and reliable communication.

Key Features:

1. Multi-channel concurrent transmission: Enhances efficiency and reliability through simultaneous data transmission across multiple channels
2. Flexible connection topologies: Supports point-to-point, star, tree, and mesh configurations to meet various application requirements
3. Real-time performance: Enables instant transmission of captured images to ground control stations while receiving flight adjustment commands (altitude, speed, direction, etc.)

III. UAV Communication Networking Methods

Common wireless networking architectures include Star and Mesh topologies. While internet topology is complex, it can be functionally divided into edge and core components.

Star Topology: Central node-based structure with all other nodes connected to the central hub. Widely used in current LAN configurations due to low latency and simple management.

Implementation: Network access through main router (AP) → distribution to sub-routers (STA) → connection to various hosts and devices (flight control computers, etc.)

Advantages:

• Simple implementation
• Easy maintenance

Disadvantages:

• Central node dependency (AP failure causes network outage)
• Bandwidth allocation decreases with added nodes

Mesh Topology: Decentralized network where all nodes can act as both routers and terminals, enabling multi-path communication between any two nodes.

Characteristics:

1. Full node interconnectivity: Multiple connection paths between any nodes
2. Self-configuration: Automatic network setup and centralized management
3. Self-healing: Automatic route discovery and redundancy maintenance
4. High utilization: Eliminates central node congestion through distributed architecture

Disadvantages:

• Increased latency from multi-hop forwarding

Point-to-Point Networking: Direct communication between two devices using identical frequencies and modulation schemes without central control.

PPP Protocol: The most widely used point-to-point data link layer protocol. PPPoE (PPP over Ethernet) extends PPP functionality to Ethernet networks, commonly used in broadband access solutions. This combination enables secure data transmission and effective link management across various network scenarios.

Essential Communication System Components:

1. Source system
2. Transmission system
3. Destination system

Optical fiber transmission offers the widest bandwidth, minimal signal attenuation, and strongest anti-interference capability among transmission media.

FTP (File Transfer Protocol): Standard protocol for bidirectional file transfer over internet, enabling file copying between local computers and server storage spaces.