Satellite Communication

Overview

NetSim satellite library simulates end-to-end, full stack, packet level communication between terrestrial nodes via a Geostationary satellite. (LEO and MEO satellites are currently under development)

The Satellite MAC layer protocol supported in NetSim is TDMA for forward link and MF-TDMA for return link. In the earth-to-space link NetSim supports are Ku band (12 – 18 GHz) and X-Band (7.9 - 8.4 GHz) while in the space-to-earth link NetSim supports Ka band (24 – 60 GHz) and X-Band (7.25 - 7.75GHz).

The satellite can be thought of as a relay. It operates on the bent-pipe principle, sending back to Earth what comes in, with only amplification and a shift from uplink to downlink frequency.

Standard and architecture

  • Based on ETSI EN 302 307 V1.2.1 (August 2009) and ETSI EN 301 545-2 V1.2.1 (April 2014), the simulation follows DVB-S2 / DVB-RCS2 standards for a single-satellite system.
  • Supports transparent payload (bent pipe)
NetSim Satellite Communication

Specifications

    Network components

    UT node, UT Router, Satellite, Satellite Gateway, Remote server.

    Link Specifications

    • Feeder Link

      • Connects the Gateway and Satellite

    • Service Link

      • Connects the Satellite and UT

    Mac layer models include

    • Superframe, frame and slot structure
    • Access protocol:
      • Forward: TDMA
      • Return: MF-TDMA

    PHY layer models include

    • DVB-S2/DVB-RCS2, per ETSI EN 302 307 V1.2.1 (Aug. 2009) and ETSI EN 301 545-2 V1.2.1 (Apr. 2014).
    • Channel model: Free space path loss with Loo Markov and Rayleigh fading model.
    • MODCODs per table 12 from ETSI EN 302 307 DVB-S2.
    • Antenna gain to Noise temperature.

    All the choices of transport protocols, and all types of applications in unicast mode can be run. In NetSim, the satellite communication network library interfaces with Internetworks library. This means users can connect Satellite gateway and User Terminals to Remote servers.

    Modulation and coding schemes (MODCODs) supported

    • QPSK with coding rates: 1/3, 1/2,1/4, 2/5, 3/5, 2/3, 3/4, 4/5, 5/6, 8/9, 9/10
    • 8PSK with coding rates: 3/5, 2/3, 3/4, 5/6, 8/9, 9/10
    • 16APSK with coding rates: 2/3, 3/4, 4/5, 5/6, 8/9, 9/10
    • 16QAM with coding rates: 3/4, 5/6
    • 32APSK with coding rates: 3/4, 4/5, 5/6, 8/9, 9/10

    Propagation Delay

    NetSim computes the distance between the ground nodes and the satellite and divides it to the speed of light to obtain the propagation delay.

    Measurements and Analytics

    • Throughput, Latency, Error ... and more.
    • Packet Trace
    • Radio measurements: Logs Time, Tx Power, Rx power, Pathloss, fading loss, Noise, SNR, etc.
      • RadiomeasurementLog
      Ratio measurement log
    • Satellite Log

      • The log shows the formation of return and forward superframes for Satellite, including frame length, slot length, bandwidth, and carrier details.
      It also records the sequential start and end times of frames within the superframe along with UT–gateway associations.

Satellite Communication Protocol Stack

Satellite-protocol-stack

Useful Links

Satellite Communication Documentation (Documentation)