Today we’re going to take an in-depth look at a current campaign on Crowd Supply: LimeSDR. This nifty piece of technology has tremendous potential to impact a number of fields and markets. But what is it? Software-Defined Radio (SDR) is a fairly new technology that uses software to define how a radio works and what signals it can broadcast and receive. What’s so great about that? Let’s step back for a moment and talk about what we mean by “radio.”
Technically speaking, a radio is much more than a box that picks up the NPR pledge drive, smooth jazz, and crudely shouted car commercials and/or political opinions. In fact, broadly speaking radios are everywhere: wifi uses radios in routers and laptops for communication with the internet, your Bluetooth headset uses a radio to talk to your cell phone, which itself uses radio to communicate to the cell tower, astronomers use radio waves to search the universe while air traffic controllers use RAdio Detection And Ranging (RADAR) systems to search for the 5:37 flight from Dulles. All of these technologies, and many more, are based electromagnetic waves. They differ by using different frequencies (how often a wave comes) and amplitudes (how big a wave is), and they have different protocols for encoding and decoding signals, but at their core they all use radio transmitters and receivers.
Traditionally, radios are a one-trick pony, restricted to pre-defined bandwidths and protocols. A Bluetooth radio cannot talk to a Wi-Fi router; they speak completely different languages. With software-defined radio, a single piece of hardware is configured by software to use the frequencies, amplitudes, and encodings of almost any given protocol, be it FM or RADAR. Software-Defined Radios are polyglots, they speak many languages.
Turns out, this can be incredibly useful, with applications in the sciences, military and civil agencies, education, development, and exploration. SDRs can be used to create local cell networks, a mesh of wireless sensors, to scan the stars or, yes, pull in some smooth jazz for your picnic. You can think of it as analogous to how computers have changed from large, single-purpose mainframes to desktops and laptops that can run all sorts of different applications, from graphics to spreadsheets.
LimeSDR takes advantage of all this potential by taking an open source approach. By allowing free and open access to all the hardware and software specifications, open source encourages experimentation and refinement, better allowing LimeSDR to take advantage of the enormous potential of this technology. The LimeSDR software model is built around “apps” that can configure the hardware to function as all different sorts of radios. It’s also built around the open source Ubuntu operating system, which means it is both affordable and accessible as a development platform.
At time of posting, the LimeSDR project is more than 65% funded, with just under three weeks left to go in the campaign. The campaign has gotten backers from across the world, as befits a technology with so much potential to help us all explore and communicate.