Satellite Communication
GEO · DVB-S2 / DVB-RCS2 · TDMA / MF-TDMA · Bent pipe
NetSim's satellite library is an end-to-end, full-stack, packet-level simulator for communication between terrestrial nodes through a geostationary satellite. It includes link models, antenna models and frequency reuse. The NTN library supports LEO and MEO orbits.
What you can do with it
NetSim simulates satellite networks per the standards, from the radio link up to end-to-end application performance.
Full-stack satellite link
The library simulates end to end, with the full stack and at packet level, between terrestrial nodes through a geostationary satellite.
Forward & return links
The forward link uses TDMA, and the return link uses MF-TDMA, with superframe, frame and slot structure.
Bent-pipe relay
The transparent payload sends back to Earth what comes in, with amplification and an uplink-to-downlink frequency shift.
Link & antenna models
The models include free space path loss with Loo Markov and Rayleigh fading, antenna gain to noise temperature, and DVB-S2 MODCODs.
Standard and architecture
The library models a single-satellite system that follows the DVB-S2 / DVB-RCS2 standards, with a transparent (bent-pipe) payload.
DVB-S2 / DVB-RCS2
- ETSI EN 302 307 V1.2.1 (August 2009) – DVB-S2
- ETSI EN 301 545-2 V1.2.1 (April 2014) – DVB-RCS2
- Modelled as a single-satellite system
Transparent payload
- Supports transparent payload (bent pipe)
- The satellite acts as a relay, amplifying and shifting from uplink to downlink frequency
- Interfaces with the Internetworks library for end-to-end connectivity
GEO, with LEO/MEO via NTN
- Geostationary satellite simulation in the satellite library
- LEO and MEO orbits supported through the NTN library
Specifications
A single-satellite scenario has a gateway, a satellite, user terminals and remote servers. You can configure it from the MAC frame down to the radio.
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
- Superframe, frame, and slot structure
- Forward access protocol: TDMA
- Return access protocol: MF-TDMA
PHY layer models
- DVB-S2 / DVB-RCS2 per ETSI EN 302 307 and ETSI EN 301 545-2
- Channel model: free space path loss with Loo Markov and Rayleigh fading
- MODCODs per Table 12 of ETSI EN 302 307 DVB-S2
- Antenna gain to noise temperature (G/T)
Frequency bands
- Earth-to-space: Ku band (12–18 GHz) and X-band (7.9–8.4 GHz)
- Space-to-earth: Ka band (24–60 GHz) and X-band (7.25–7.75 GHz)
Propagation delay
NetSim computes the distance between the ground nodes and the satellite and divides it by the speed of light to obtain the propagation delay.
Protocols & applications
All transport protocols and all application types in unicast mode can run. The satellite library interfaces with the Internetworks library, so gateway and user terminals connect to remote servers.
Measurements & analytics
- Throughput, latency, error, and more
- Packet trace
- Radio measurements log: time, Tx power, Rx power, path loss, fading loss, noise, SNR
- Satellite log: forward/return superframe formation, frame and slot length, bandwidth, carrier details, and UT–gateway associations
Modulation & coding
Per Table 12 of ETSI EN 302 307 DVB-S2:
- QPSK: 1/4 · 1/3 · 2/5 · 1/2 · 3/5 · 2/3 · 3/4 · 4/5 · 5/6 · 8/9 · 9/10
- 8PSK: 3/5 · 2/3 · 3/4 · 5/6 · 8/9 · 9/10
- 16APSK: 2/3 · 3/4 · 4/5 · 5/6 · 8/9 · 9/10
- 16QAM: 3/4 · 5/6
- 32APSK: 3/4 · 4/5 · 5/6 · 8/9 · 9/10
The radio measurement log records Tx power, Rx power, path loss, fading loss, noise, and SNR per link.
Satellite communication protocol stack
The stack runs from the forward and return links at the satellite, down through the MAC and PHY layers, to the output logs.
- Access protocol: TDMA
- Band: Ku
- Range: 12-18 GHz
- Bent pipe
- GEO Stationary satellite
- Altitude (km): 35786
- Access Protocol: MF-TDMA
- Band: KA
- Range: 20-40 GHz
- Superframe, frame and slot structure
- Forward: TDMA and Return: MF-TDMA
- 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)
- BER model: Model based, Fixed, File based
- MODCODs per table 12 from ETSI EN 302 307 DVB-S2
- Propagation models: Free space
- Fading models: Rayleigh, Markov loo
- Radio measurements
- Packet trace
- Buffer occupancy
- Satellite log
Related product
Satellite link budget & coverage planning
The satellite library simulates the network, and NetSim Astra plans the constellation. Astra computes satellite link budgets and RF coverage over real geography, and shows the constellation on a 3D globe. Use the two together to move from coverage design to end-to-end performance.
- Satellite link budget computation
- RF coverage and footprint studies
- Geographic constellation planning
Useful links
Use the documentation and support to take a satellite project further.