Blink software modem breaks 10Gb/s limit

Blink has really picked up speed.

The Blink wide-band satellite software modem has been built from the ground up for speed and it shows at every step of the way. The last test results we published had been in late 2022, when it became clear that Blink is something different, achieving a continuous throughput of 4.2 Gb/s processing a 1.2 GHz carrier - on a single server.

What does that mean? Blink was able to easily support 2 X-band channels concurrently on a single machine, with capacity to spare. No other commercially available software modem was even close to that.

We have been optimising the code for about a year, so we decided to run those tests again and see where we were. The results are in:

Blink runs at 10 Gb/s.

Besides breaking through a psychological barrier, this is a significant result in a number of ways.

For a start, the bandwidth that Blink can support on a single server in real time is approximately 2.5 GHz. This means that users could e.g. handle 2 nearly full-size Ka-band carriers, or 4 carriers of 600+ MHz wide, all on a single server. This is a significant capability in the light of a long list of large agency and commercial missions announcing Ka-band-class channels, up to 4 times wider than those used in the currently dominant X-band.

Further towards the horizon, V-band and optical space-to-ground communications are expected to push the envelope with regard to throughput. Blink’s current performance already makes usage in those bands feasible. What’s more, the 27% yearly GPU performance upgrades suggest that by the end of 2026, Blink will be able to support 5 GHz or 20 Gb/s carriers and much higher throughput with receiver-friendly modulation schemes like on-off keying (OOK), in wide use in optical communications, even if the software were not optimised further.

For decades, software modems were interesting but hampered by throughput and therefore constrained mostly to TT&C, where their numerous benefits could shine through: speed of development, ease of use, rapid evolution, deployment and scaling, seamless fit in a virtualised ground segment, configuration and state management, reliability and ease of integration. A few years ago, software modems demonstrated that they can do more than TT&C. With Blink in particular, wideband payload reception became a reality, but claims to high throughput were always made with the awareness that traditional, hardware modems are the undisputed champions of high-throughput data reception. With Blink’s latest performance upgrade, this is no longer the case: it may well be that no other, currently commercially available modem - software or hardware - can receive a single 10 Gb/s signal. This is a remarkable achievement for any modem and possibly the first time in space industry history that the title goes to a pure-software modem.

So what’s next?

Most, but not all digitisers are too bandwidth-limited to feed Blink with the kind of bandwidth needed to achieve peak throughput. We are therefore working on evaluating and integrating high-performance COTS digitisers to have solutions ready for a wide array of ground station operators, including those aiming at the very highest end of performance. 2024 is going to be an interesting year!

If you wish to learn more about Blink....

... simply contact us! Our team is more than happy to support your project and to provide you more information.