This project demonstrates the feasibility of a software hub implementation scalable to support handling of 5 GHz RF bandwidth based on cloud technology and general processing hardware. The DVB-S2/S2X/DVB-RCS2 modulation and demodulation is performed by processing of digitized I&Q samples on general x86 CPU hardware supporting AVX 512. The hub and test bed developed under the project demonstrates a symmetric duplex 250 MHz RF bandwidth in each direction, compatible deployment in the cloud. The forward link carrier 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 key challenges in this project are:
Demonstration of modulation and demodulation executed on general x86 for DVB-S2/S2X
Implementation of the hub with scalable cloud technology capable of supporting 5 GHz RF bandwidth
Emerging satellite payloads will require flexible ground structure. The industry is approaching a paradigm shift where the current analogue L-band distribution technology is being replaced by wideband digitization of the RF at the antenna followed by channelization and digital distribution of I&Q streams. Key enablers besides the digitizer are the software modulation and demodulation functions implemented for execution in general Intel technology CPUs., avoiding the need for FPGAs or GPUs. The hardware for the gateways and ground stations can then be architected with generic digitizers and general-purpose computing server hardware. All application specific functionality resides in Virtual Network Functions executed in the generic cloud hardware.
The Wideband Software Hub prototype is a demonstrator of a VSAT hub operating in a cloud environment:
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 CPUs (x86, AVX512 instruction set)
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.
The Wideband Software Hub and test bed was successfully demonstrated under the Acceptance Test Review milestone in June 2022
The Wideband Software Hub and test bed has also been validated to operate in the private cloud environment of a major satellite operator
The System architecture is shown in the Figure. The VSAT hub and terminal functions are implemented as VNFs (Virtual Network Functions) in cloud compatible modules. The architecture applies microservices and containers, scalable to support a large RF segment (5 GHz).
The RF output is generated by a digitizer while the software modulator provides the digital RF output as a baseband I&Q stream. 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.
The implementation applies industry standards such as DVB-RCS2, DVB-S2X and Vita-49.2
March 2020: Kick-off
May 2020: System Requirements Review
August 2020: Critical Design Review
March 2022: Test Readiness Review
June 2022: Factory Acceptance Test Review
November 2022: Acceptance Review
The project is completed.