By: Sean McClinton
Famous UK mathematician, Clive Humbly is credited with first saying “data is the new oil”. With the cost of putting a spacecraft into orbit coming down dramatically due to falling launch costs and the use of commercial off the shelf technologies, the amount of data generated from space is going up exponentially. However, raw data isn’t worth much until it is refined into data products that customers want and need. The race is on to find ways to monetize that data. When you are talking about moving ever larger amounts of data from space to places around the globe, flexibility, resiliency, and cost savings become critical. Flexibility, resiliency and the ability to save cost can be achieved through more software-defined ground infrastructure. A future part of a software-defined ground infrastructure that is data-centric will be the adoption of “radio frequency over Internet protocol” (RF over IP).
The data value chain begins when a spacecraft transmits data down to the ground. Data from space undergoes a number of changes between the time it is generated on board the spacecraft and when it reaches the end user, such as demodulation and digital conversion. Traditionally, once the data from a spacecraft reaches the ground station, it is converted into digital by the radio after much of the seemingly extraneous information is stripped away from the original signal. But what if you could convert all of the data immediately upon reaching the ground station into digital? “RF over IP” is more of a marketing term. It is more accurate to call this “IF over IP” or intermediate frequency over Internet protocol.
The promise of IF over IP lies in the ability to convert the RF spectrum into a digital signal when it lands at the ground station, avoiding some of the issue of the degrading nature of the RF analog signal being transported over longer distances. Once the RF spectrum is converted to digital, that data can then be routed to multiple locations for processing. The ability to route the data to multiple locations for processing adds resiliency to the overall solution and provides the satellite operator flexibility as to where they wish to process the data. The tradeoff for this conversion is a large (20x) increase in bandwidth consumption. For Earth observation satellites in sun synchronous orbits (SSO), large amounts of data are sent down to often remote ground stations in high northern latitudes with expensive backhaul costs – but that’s changing. The movement to IF over IP also can lead to the adoption of software-defined radios (SDR’s) that can exists anywhere including public and secure government clouds. The adoption of SDR’s in the cloud means that you do not need to deploy and maintain expensive hardware at every antenna site.
As we transition from a world of an analog-defined ground system to a more software-defined ground segment, we start to see the possibility of greater network resiliency and flexibility, analog hardware component cost savings, and the ability to shift to a multi-tenant/multi-mission ground segment. In order adopt this approach today, RBC Signals has partnered with large, public cloud operators at the ground station, with a focus on narrow band. Because of the large expansion of bandwidth required to support the larger data flows, RBC Signals is focused on IF over IP application in narrowband and looks to the future with increased data rate price performance for wideband applications.
While the future of IF over IP won’t arrive overnight, RBC Signals has already begun the transition within our partner and company–owned networks. We have helped customers with our network architecture consulting services start planning for a tomorrow that more fully utilizes IF over IP where the benefits are valued by the mission.