Drone Swarm Communication over TDMA MANET and Satellite

Overview

This simulation models a tactical drone swarm communication system with TDMA-based MANET radios and satellite links. Each drone has two communication interfaces: one for MANET connectivity over the C-band, and one for satellite communication over the X-band. The scenario represents a real-world military setup, in which communication occurs on both interfaces at the same time.

The central command server transmits Command & Control (C2) data to all drones through the satellite link at 25 kbps. Each drone sends Telemetry and Status Reports to the server every 3 seconds at 50 kbps, also through the satellite link. At the same time, the drones exchange Intra-swarm Coordination data over the TDMA-based MANET, on direct or multi-hop paths.

The drones follow predefined mobility paths, and the network updates the MANET routes automatically to keep the drones connected. We analyze the end-to-end latency and throughput as mobility changes the topology.

Network Scenario

Figure 1: 5 drones, 1 satellite, 1 satellite gateway, 1 server. Each drone has a TDMA radio interface and a satellite interface. Link-4 is a logical TDMA ad hoc link.

Network Setup

• Communication Range: 150 km for TDMA radios
• Network: 5 drones, 1 satellite, 1 Gateway, 1 Central Server
• X-Band Satellite Communication
  • The server transmits Command & Control (C2) data to the drones at 25 kbps through the satellite link.
  • The drones transmit Telemetry & Status Reports to the server at 50 kbps, every 3 seconds, through the satellite link.
  • Forward and return satellite communication use the X-band.
• C-Band MANET communication
  • Node N1 transmits Intra-swarm Coordination data to Node N5 at 10 kbps over the TDMA link.
  • Drone Communication Range (MANET): 150 km.
  • TDMA-based MANET communication uses the C-band.
• Drone Mobility Configuration
  • N5 and N9 move northeast at 0.4 m/s and 0.9 m/s.
  • N7 and N8 move east at 0.4 m/s and 0.9 m/s.
  • N6 moves southwest at 0.4 m/s.
• Mobility Configuration: File-based mobility for predefined flight path

  

  Figure 2: Initial Position and Velocities. NetSim assumes that nodes have appropriate Doppler compensation mechanisms

Routing Transitions Due to Mobility

Table 1: Time Intervals and Routing Paths Between N5 and N9

System Parameters: Satellite

Table 2: Satellite System Parameters

System parameters: MANET

Table 3: MANET System Parameters

Understanding the multi-hop Routes taken through Animation

Animation

Results

On analysing NetSim’s packet trace log file we observe the multi-hop routes as shown in the table below:

• 0s to 191s: Direct communication (N5 → N9)
• 198s to 318s: Multi-hop communication (N5 → N6 → N9)
• 324s to 900s: Multi-hop communication (N5 → N7 → N9)

Throughput vs Time

Figure 3: Throughput remains stable initially due to direct communication. A drop occurs at 191-198s because of mobility and a path change. Another drop occurs at 319-324s because of a second path change.

Latency vs Time

Figure 4: Low latency initially due to direct communication (up to 190s). A latency peak occurs at 191-198s because of mobility and a path change. Another peak occurs at 319-324s because of a second path change. Latency remains higher afterward due to multi-hop communication.

Satellite communication: Latency. QPSK vs QAM

Figure 5: Average latency for the QPSK is greater than the average latency of 16-QAM.

The simulation results show that 16-QAM gives a much lower average latency than QPSK, especially in the Drone-to-Server direction. With 16-QAM, the average latency meets the target of less than 1 second (1000 ms). The overall mean latency is 700.68 ms across five applications, so 16-QAM is suitable for time-sensitive telemetry from drones.