Lime Microsystems has announced an accelerator programme which will see SDR projects receive discounts on components and crowdfunding fees and additional support and promotion — and the programme’s first participant has been confirmed.

“We’re proud to announce the launch of our new Lime SDR Accelerator initiative and its first participant: uSDR, a tiny, single-sided M.2 SDR board that you can operate easily using your web browser,” says Lime Micro’s Ebrahim Bushehri of the new programme. “Through the accelerator, uSDR and other Crowd Supply projects benefit from promotion, discounted parts, and more.”

The programme sees projects based around Lime’s software-defined radio technologies eligible to receive discounts on components purchased through Lime Micro and Mouser. Member projects will also receive a discount on fees charged by crowdfunding and fulfilment platform Crowd Supply, as well as promotional and technical support from Lime Micro.

More information on the accelerator, which is accepting applications now, is available on Crowd Supply.

The uSDR project, which has successfully completed its crowdfunding campaign, has confirmed that work is underway in adding support for Lime Suite to the project.

“Lime RFIC [Radio-Frequency Integrated Circuit technology] – and LMS6002D in particular – plays a significant part in the uSDR design,” the project’s creators, Wavelet Lab, explain. “It gives users the option to work through SoapySDR and their preferred software as an alternative to our web interface. We’ve already started working on Lime Suite compatibility and will have it ready by the time the first orders ship out. Stay tuned!”

The uSDR is a compact M.2-format software-defined radio board built around the Lime Micro LMS6002D chip and promising a full browser-based experience with no need to install any software. For those who do want to dig deeper, though, the Lime Suite compatibility should be ready by the time hardware reaches backers.

More information is available in the project’s latest campaign update on Crowd Supply.

Adrian Musceac has written up a project to build a multi-carrier base station transceiver for DMR, YSF, M17 and more using Multi-Mode Digital Voice Modem (MMDVM) and GNU Radio software linked to a LimeSDR.

“[This] uses a fork of MMDVM (written by Jonathan Naylor G4KLX) created by Rakesh Peter which enables running MMDVM on a Linux host and communication with MMDVMHost via a pseudo TTY instead of actual serial port,” Adrian explains. “Because I did not have dedicated MMDVM hardware for digital voice, but I had SDR hardware, I’ve created GNU Radio flowgraphs (integrated in QRadioLink), and attempted to transmit and receive multiple DMR, Yaesu System Fusion, and M17 channels at the same time using LimeSDR hardware (LimeNet Micro, LimeSDR Mini). Theoretically other modes supported by MMDVM should work as well, but I did not have the necessary radios to test them.

“MMDVM capable hardware generally seem to consist of a Linux computing platform on a low power Arm platform (Raspberry Pi, Pi Zero etc.) which runs MMDVMHost and other user interface and configuration software (dashboard etc.), coupled with a dedicated board carrying the RF chip and the microcontroller running MMDVM. Having multiple MMDVM radio channels requires using multiple such hardware combinations which does not scale very well, both in cost and in maintenance. On the other hand, having a SDR device already available, this function can be accomplished with a single radio, a single power amplifier, a single antenna and a single computing platform.”

The full project write-up, including source code, is available on the QRadioLink website.

Kaushlesh “KD9VFU” Chandel has designed a portable software-defined radio host with a satisfying physical user interface, built to make it easier to access commonly required features on-the-go: The SDRDock.

“Built on a Raspberry Pi platform, SDRDock aims to enhance the SDR experience by integrating all essential hardware components onto a single, streamlined PCB,” Kaushlesh explains of the concept build the build. “With the convenience of 3D-printable enclosures and compatibility with various SDR dongles, this device is both accessible and versatile. What sets it apart is its tactile interface, featuring user-friendly knobs and buttons that transform complex SDR tasks into an intuitive and engaging experience.”

That “tactile interface” takes the form of physical buttons, knobs, and sliders located beneath a colour touchscreen display, allowing for tuning and other commonly-required tasks to be carried out by feel. Inside the chassis is a Raspberry Pi 4 Model B and a 1Ah lithium-ion battery, plus a cooling system and an Espressif ESP32 microcontroller to handle the user interface – plus the user’s choice of software-defined radio dongle.

More information on the project is available on Kaushlesh’s page.

Researchers at the Massachusetts Institute of Technology (MIT) have developed a system for ultra-low-power underwater communication over ranges of more than a kilometer – drawing one-millionth the power of traditional approaches.

“What started as a very exciting intellectual idea a few years ago – underwater communication with a million times lower power – is now practical and realistic,” claims Fadel Adib, associate professor and director of MIT’s Signal Kinetics group, of the team’s work. “There are still a few interesting technical challenges to address, but there is a clear path from where we are now to deployment.”

The communications system is based on backscatter technology, using a retrodirective Van Atta array to reduce the scattering of the signal waves in the wrong directions and thus dramatically boost the range of the system – increasing the range by 15 times compared to previous efforts, with the potential for more in the future. “We are creating a new ocean technology and propelling it into the realm of the things we have been doing for 6G cellular networks,” says Fadel. “For us, it is very rewarding because we are starting to see this now very close to reality.”

More information on the work, including links to two open-access papers on the project, is available on the MIT website.

A team at South Korea’s Electronics and Telecommunications Research Institute (ETRI), meanwhile, claims to have come up with something similar – but targeting long-range wireless communications underground, rather than underwater.

“We have conducted successful communication trials between the first and second layers of underground mines using magnetic field communication systems,” says In-kui Cho, director of electromagnetic wave basic technology at ETRI, of the team’s recently-completed field tests. “This greatly reduces the likelihood of communication network disruptions caused by mine collapses.”

The communication system developed by ETRI uses very-low-frequency (VLF) narrowband transmissions in the 20kHz spectrum with a one-meter transmitting antenna and multiple smaller receiving antennas picking up the signal through magnetic induction. In testing, the system was able to transmit data or voice at a 4kb/s rate over a 40m distance within a limestone mine.

“This technology is anticipated to be a groundbreaking mode of reliable communication in complex and unpredictable environments,” claims Seung-keun Park, assistant vice-president at ETRI’s radio research division, “like underground construction, tunnelling, and ocean excavation.”

The project was presented as a poster session at the 20th Annual IEEE International Conference on Sensing, Communication, and Networking (SECON 2023), but has not yet been published publicly.

Software developer and radio amateur Stephen D. has published details of a project to transmit live video footage from a high-altitude balloon over the 70cm band, driven by a Raspberry Pi single-board computer.

“We’re using a [Silicon Labs] RF4463F30 module to transmit FSK [Frequency Shift Keying]-modulated packets in the 70cm band at 1W,” Stephen says of the skybound transmission system. “These packets are LDPC [Low-Density Parity Check]-encoded for error correction. Currently it pegs the [Raspberry Pi 4] CPU at around 50 per cent, “but the hope is to eventually move to GPU transcoding to save some power — and heat!

“The video is encapsulated in an MPEG-TS stream to allow graceful recovery from packet loss. The video is 640×480, 12FPS, with a maximum bitrate of 200kbit/s, though GStreamer seems to exceed this at times. We want to stream the next launch to YouTube. To facilitate this I’m going to add an RTSP [Real Time Streaming Protocol] server to the ground station. I figure I can use existing software to consume this stream and pipe it to the Internet.”

The full project write-up, including sample footage, is available on Stephen’s website.

The Things Network has announced a new world record for longest LoRaWAN transmission distance, with a tracker on board a fishing vessel successfully making a connection over an 832km (517 mile) range.

“After three years, the new world record was set by installing LoRaWAN trackers on a fishing boat Estrela de Sesimbra and on its buoys on the Sesimbra coast, Portugal,” The Things Network writes of the new record. “The tracker was able to make contact with a gateway in the Canarian Islands. Three messages have been received by the ‘cablpa-pitilleros’ gateway connected to The Things Stack Community Edition.

“The remarkable point of this record is that it is achieved at sea level. Reaching extended distances with LoRaWAN at sea level eliminates potential variables introduced by varying altitudes, providing a standardized and objective measure of the technology’s capabilities. We do have to note that this is an exceptional achievement. The majority of The Things Stack-operated devices range between 25 and 100 meters (75-300 feet) from the gateway.”

The full write-up is available on The Things Network website; a visualisation of the record-breaking transmission is available on the site’s mapper.

The UK Department for Science, Innovation, and Technology (DSIT) has announced the winners of its Open Networks Ecosystem competition, including one project involving Lime Micro and partners: HiPer-RAN, which received nearly £8 million in funding.

“The HiPer-RAN (Highly Intelligent, Highly Performing RAN) project aims to develop an open platform able to host diverse, software-based intelligence that accounts for the whole RAN architecture,” the project’s organisers explain. “The platform will look to deliver measurable benefits at a system level, contributing to the acceleration of open-interface products and solutions, as well as to the development of an internationally recognised UK telecoms ecosystem.

“HiPer-RAN tackles 2 fundamental challenges. Firstly, the development of interoperable, efficient, and reliable software for automation operating at different time scales. Secondly, the efficient translation of intelligence into quantifiable and measurable gains, enabling high-performance, energy efficient, and low latency operation at a system level. As such, HiPer-RAN not only focuses on the challenging task of developing efficient and reliable intelligent software applications (such as xApps or rApps), but also on the efficient integration of such applications into actual RAN developments to enable measurable gains.”

Other projects named as funding recipients are: the 5G MoDE (Mobile oRAN for highly Dense Environments) project in Reading, 5G SWaP+C (Size, Weight and Power + Cost) in South Wales and Ipswitch, ARIANE (Accelerating RAN Intelligence Across Network Ecosystems) in London, the BEACH energy-efficient shared network project in Worthing, the Cambridgeshire Open RAN Ecosystem (CORE), Dorset Open Networks Ecosystem (DONE), Energy-efficient Composable Optical Topologies for Assembled Processing (ECO-TAP) in Leeds and London, FoFoRAN (Factory of Future) in Blackburn, the Liverpool City Region High-Density Deployment (HDD) project, NAVIGATE HDD in London, the ONE4HDD “HDD on Wheels” project, ON-SIDE (Open Network Shared Spectrum Innovation and Design Environment) in Glasgow, One Western O-RAN in Bath, PerceptRAN in Cambridge and Edinburgh, Project AURA in Bristol, Ipswich, and Northampton, REACH in Blackpool, SCONDA (Small Cells ORAN in Dense Areas) in Glasgow, and the Sunderland Open Network Ecosystem.

A full list of winners and the grant funding given to each is available on GOV.UK.

Radio ham Helge “LA6NCA” Fykse has designed “the simplest QRP transceiver that can be made,” fitting entirely into a mint tin and being powered by a low-cost Arduino Pro Mini microcontroller.

“I have designed a super simple transceiver. It only has a few parts,” Helge explains of the build. “The aim of the project is for me to be able to communicate several hundred kilometres away. I assemble everything in a small tin box. The antenna tuner can be replaced for the 80, 60 and 40 metre band. The oscillator is in use on both the receiver and the transmitter. It changes the frequency [by] 600Hz when in Rx mode. Then you will hear the tone of the station you are communicating with.

“A relay sends the oscillator’s signal either to Rx or Tx. The transmitter consists of two transistors that deliver their signal to the antenna tuner. The receiver receives its signal from the antenna tuner. It uses a mixer whose output has the audio signal which is a mix product between the oscillator and the antenna signal. The output of the mixer is connected to an amplifier with a gain of 2000. This then goes on to a CW filter. The antenna tuner filters the signal and delivers a 50 ohm signal.”

The full project write-up, including schematics, is available on Helge’s website, with more information in a supporting video on YouTube.

Pseudonymous developer “Aang23” has released a new version of the SatDump satellite data processing tool, adding a range of new features and fixing a selection of bugs.

“It’s been 285 days since SatDump 1.0.3 was released,” Aang23 writes by way of background. “A lot has changed since then – new features have been added and numerous bugs were squished! That’s why we decided to finally release SatDump version 1.1.0.”

The new build includes support for scripting through the Lua language, the ability to generate Level 1b products for selected calibrated instruments – “this is a big deal,” Aang23 explains, “as raw counts from these instruments are not linear to temperature or even albedo” – automatic tracking based on pass prediction, cloud overlays, CCSDS LDPC, Inmarsat STD-C, and TUBIN X-Band decoding, support for FengYun-3G, FengYun-3F, METEOR-M 2 and 3, GEONETCAST, GOES RAW, STEREO-A, DSCOVR EPIC, Lucky-7, ELEKTRO-L 4, decimation capabilities, projectable instruments, and a remote SDR system – “still an early feature,” its creator warns, “[which] could evolve significantly in the future.”

Full release details are available on the SatDump website, with source code published to GitHub under the reciprocal GNU General Public License 3.

Finally, KrakenRF Inc. is preparing to launch a lighweight dish antenna designed for L-band weather satellite and hydrogen-line reception: the Discovery Dish.

“The Discovery Dish is a 65cm diameter aluminium satellite dish and active filtered feed designed for receiving GOES HRIT, GK-2A LRIT, FengYun LRIT, NOAA HRPT, Metop HRPT, Meteor M2 HRPT and other weather satellites that operate around 1.69GHz,” the project’s creators explain. “The dish is designed to weigh under one kilogram, and it splits into three petals, making it easier to ship worldwide. The 1.69GHz feed contains a built-in LNA right at the feed point, as well as filtering, which means that there is almost no noise figure loss from cables or connectors.

“To amplify the weak signals transmitted by weather satellites, Discovery Dish incorporates the Qorvo QPL9547 high-linearity, ultra-low-noise amplifier in a small 2x2mm surface-mount package. The 1.69GHz active feed that comes with the dish can be swapped out for an optional 1.42GHz feed optimized for hydrogen line observation and radio astronomy experiments. This will be one of the easiest radio astronomy projects to set up, making it great for radio astronomy beginners and educational institutions.”

Full project details are available on the Discovery Dish Crowd Supply page, where the crowdfunding campaign will launch soopn; the pictured prototype is a single-piece version, not reflective of the finished three-part foldable version which will be shipped to backers.