European Space Agency

WSH – Wideband Software Hub

Objectives

This project demonstrates the feasibility (both technical and business) of a software-defined gateway/teleport implementation scalable to support handling of 5 GHz instantaneous RF bandwidth based on cloud technology and generic processing hardware. The enabling core technology module is the efficient implementation of DVB-S2/S2X software modulation and demodulation based on x86 CPU, without reliance on FPGA or GPU resources. The project demonstrates the implementation of a symmetric duplex 250 MHz RF bandwidth in each direction. The forward link is a single 250 MHz DVB-S2X, while the return link capacity of 250 MHz is divided across DVB-RCS2 TDMA channels and DVB-S2/S2X SCPC channels. The SCPC channels are dynamically allocated with seamless reconfiguration maintaining IP traffic flow without loss in the transition between changing transmission plans.

Challenges

The key challenges in this project are:

  • Development of efficient modulation and demodulation executed on general x86 for DVB-S2/S2X
  • Supporting changing transmission plans for the multiple return link DVB-S2/S2X SCPC carriers
  • Seamless demodulation of the changing SCPC return link carriers without loss of IP packets
  • Implementation of the hub demonstrator with cloud technology applying container-technology, scalable to support 5 GHz instantaneous RF bandwidth 

Benefits

Emerging satellite payloads will require flexible ground structure. The current analogue L-band distribution technology will be replaced by the distribution of digitized RF streams over standards-based Ethernet links. Software defined modulation and demodulation enables cloud implementations of ground segment processing.

By avoiding custom hardware, gateways and ground stations can be architected purely with generic digitizers and generic computing hardware, where all application specific functionality resides in Virtual Network Functions executed in containers in the generic cloud hardware.

Features

The Wideband Software defined Hub is a demonstrator of how a software-defined satellite gateway/teleport would operate:

  • Digital distribution of RF signals. The RF segment is digitized at the antenna and distributed as I&Q samples to the various users of the RF segment, replacing today’s L-band analogue distribution technology
  • Cloud compatible signal processing by software modulation and demodulation executed on general purpose x86 CPUs
  • Demonstration of core VSAT hub functionality with Virtual Network Functions (software modules) executed in a cloud technology environment running in VMs and containers
  • Demonstration of end to end IP traffic with a fully software based terminal emulator implementation
  • A key module in the solution is the DVB-S2/S2X modulator and demodulator software that is implemented with very efficient algorithms. This enables the modulator and demodulator modules processed on general processing hardware to be cost-effective in some market segments compared to traditional FPGA-based solutions. 

System Architecture

The System architecture is shown in the Figure. All software-defined satellite gateway/teleport and terminal functions are implemented in cloud compatible modules and executed on Virtual Machines in containers. The architecture therefore allows scaling to support a large RF segment (5 GHz).

The RF output is generated by a digitizer from the software modulator providing an I&Q stream output. The receiver chain has a digitizer that digitizes the received RF stream as I&Q samples before the I&Q stream is passed to general processing hardware where the demodulation and decoding is performed in cloud compatible environment.

Plan

March  2020: Kick-Off

May     2020: System Requirements Review

Aug     2020: Critical Design Review

April    2021: Test Readiness Review

June   2021: Factory Acceptance Test Review

Sept   2021: Site Acceptance Test Review

Oct     2021: Final Presentation

Current status

The project kicked-off on March 2nd 2020.

Status date

Thursday, March 12, 2020 - 07:33