Lime Microsystems has announced the LimeSDR Mini 2.0, an upgraded version of the smallest member of the LimeSDR range featuring a considerably improved field-programmable gate array (FPGA) – boosting its flexibility.

Since its launch in 2017, the LimeSDR Mini – a single-channel full-duplex software defined radio built on the same Lime Micro LMS7002M as the LimeSDR USB – has found a home in a wealth of projects not requiring dual-channel operation. Ongoing supply chain issues, however, have meant that supplies have been running dry – which is why the LimeSDR Mini 2.0 is on the way.

The core specifications of the board, Lime Micro has confirmed, remain unchanged. The difference: the Intel MAX 10 FPGA, which is in extremely short supply, has been replaced with a Lattice Semiconductor ECP5.

The shift isn’t just about part availability, though: it represents a considerable upgrade, bosting the number of programmable logic gates from 26k to 44k. As a result, those taking advantage of the open nature of the LimeSDR family to program their own gateware will find plenty of room for their own code – offering the potential to add anything from on-device signal detection to pre-processing and filtering.

More details on the new board are available on the Crowd Supply campaign page, where you can sign up to be notified when the LimeSDR Mini 2.0 is available to order.

The Linux Foundation and the GSMA have jointly announced the launch of CAMARA, the telecommunications industry global application programming interface (API) alliance – created with a view to improving interoperability.

“We are thrilled to enter into this next chapter of collaboration with the GSMA,” says Arpit Joshipura, general manager for networking, edge and the Internet of Things (IoT) at the Linux Foundation. “By harnessing existing open source communities within CNCF [Cloud Native Computing Foundation], LF Networking, LF Edge and aligning to GSMA’s OPG [Operator Platform Group] industry requirements, we are poised to address current challenges in API accessibility.”

The CAMARA project aims to develop an open, global, and fully-accessible API for access to operator capabilities regardless of network – meaning that applications written for telecommunications networks will be able to run consistently regardless of where they’re deployed.

“The Operator Platform initiative welcomes new members to join more than 40 leading operators, and 35 ecosystem partners, already working together on requirements and APIs. This type of collaboration with CAMARA is essential in accelerating scale to meet today’s integration demands,” says Henry Calvert, head of networks at GSMA. “We are very pleased to be working with Linux Foundation, and our membership, on developing reliability and resilience in APIs, and simplifying challenges for our developer communities.”

More details on the CAMARA project can be found on the official GitHub repository.

Osmocom’s Harald “LaForge” Welte has announced another experiment in the OCTOI TDMoIP protocol project, successfully carrying out the first ISDN calls over the system.

Designed to carry E1 circuits over IP networks in a more efficient way than previously possible, the “proposed efficient TDMoIP” protocol is under active development. “Yesterday, [we] managed to establish the first successful calls between two ISDN PBX interconnected via the Proposed_efficient_TDMoIP protocol implemented in osmo-e1d using the icE1usb hardware,” Harald writes in the project’s latest update.

“Using this setup we could validate so far: the new, efficient and transparent OCTOI TDMoIP protocol works over public consumer internet access (VDSL on one end/DOCSIS on another end); GPS-locked oscillators on both sides provide stable shared clock for cycle-slip free operation. Contrary to other established TDMoIP protocols, it is both transparent/protocol-agnostic and only transmits those timeslots of a E1 PRI circuit that are in use.”

Harald announced the first successful validation of the proposed last month, connecting two icE1usb USB-E1 interfaces using an intermediate IP network while monitoring the connection for several hours to prove its stability.

Now, Harald says the team is “fairly certain” that the setup can be used as the basis for a large-scale community TDM/ISDN/SS7 network – but warns that there’s plenty of work ahead, and has called for assistance.

More details on the proposed community network are available on the OCTOI wiki, along with information on the TDMoIP protocol implementation.

Vodafone Spain has announced the completion of its first commercial 5G call to use open radio access network (open RAN) technologies – and it was powered by a LimeNET Base Station.

“The open RAN networks will allow the promotion of a solid and diverse ecosystem in terms of suppliers of this technology in our market,” the company announced, in translation, following a live demonstration at the Mobile World Congress event, “by having differentiated software and hardware providers with interoperable components.

“The flexibility provided by this technology is especially important in the case of deployments in rural environments, because it would allow deployments to be carried out more quickly, at a lower cost and with more efficient equipment in energy terms.”

The 5G video call was carried out using off-the-shelf smartphones running on an open commercial network served by a LimeNET Base Station – a LimeSDR-powered small-cell base station device created to speed deployment and increase flexibility by offering a combination of general-purpose processing and software-defined radio capabilities in a single system.

The demonstration comes as Vodafone aims to deploy open RAN technologies across 30 per cent of its European network by 2030, and shortly before the announcement of active open RAN deployments in seven rural UK communities in order to boost 4G coverage in the regions.

“With OpenRAN, we can bring 4G coverage to some of our most remote and rural communities for the first time, helping to give more people a digital connection and closing the digital divide,” Vodafone UK’s chief network officer Andrea Donà says. “As part of our network modernisation programme, we will continue to invest in our network across the UK to ensure it continues to benefit from our best network.”

More information on the demonstration is available from Vodafone Spain’s Twitter posts.

Albrecht Lohofener has updated his broadly-supported DAB and DAB+ decoder for software defined radios, including the LimeSDR family – and in the software’s latest version has added compatibility with Microsoft’s latest Windows 11 operating system.

Forked from the dab-rpi and sdr-j-dab/qt-dab projects, aims at accessibility. Its system requirements are low enough that it’s capable of running on low-cost single-board computers like the Raspberry Pi 2 or low-cost smartphones, yet it also supports high-DPI and touch-capable displays – and, in its latest release, Microsoft’s Windows 11.

A key feature of the software is its broad support for SDR hardware, including the LimeSDR family via SoapySDR. Fully open-source, the software is provided as source code and also as pre-packaged binaries for Windows, macOS, 64-bit Linux, and Android – after a brief hiatus on building for the latter.

More details on the project are available on the website, while the latest release and full source code are available on the project’s GitHub repository under the reciprocal GNU General Public Licence 2. Al has also published a tour of the software to YouTube, for those interested in checking out its capabilities prior to installation.

A semi-pseudonymous electronics engineer going by “Keegan” has built a gateway system designed to provide real-time communication between smartphones outside network coverage areas – by sending messages over a LoRa connection instead.

“I started this project because I often travel in convoy with friends to remote areas where sending a simple WhatsApp message is impossible due to non-existent cell phone signal,” Keegan explains. “This makes it difficult to let friends know which turn to take or when we are stopping for a break without them being able to physically see us take a turn or pull over.

“Each of these devices, one for each vehicle or group of people, creates a Wi-Fi hotspot that any Android compatible phone can connect to with the accompanying Android app. Groups of people can then communicate, in group chat fashion, with a maximum of 8 Android devices per Wi-Fi hotspot.”

Rather than software-defined radio, Keegan’s approach uses an off-the-shelf SX1278 LoRa transceiver boasting an ideal-conditions range of 10km (around six miles) combined with an Espressif ESP8266 microcontroller module to act as the Wi-Fi hotspot.

More details can be found on Keegan’s project page, along with links to the GitHub repositories for hardware and software designs.

Radio ham Helge “LA6NCA” Fykse has put together a novel transmitter for 80m CW, blending a mixture of modern and vintage technology into a compact package.

“I have designed a new transmitter for 80 meter CW,” Helge writes of his project. The oscillator consists of a modern SI5351 and [the] output stage consists of a tube 12A6. The whole project started when I got 223 pieces of tube 12A6. What should I use them for? I want[ed] to design a transmitter with both old and new technology. Modern oscillator and old amplifier.”

Housed in a repurposed IKEA drawer with a Plexiglas front, aluminium chassis, and 3D-printed mounts, the transmitter includes a hand-wound coil, a custom capacitor created using copper tape stuck to Teflon, the 12A6 vacuum tube and SI351 connected to an Arduino-compatible ATmega328 microcontroller.

Full build details, and a schematic, can be found on Helge’s website.

The UK government has announced changes to the law which, it claims, will make it easier for networks to deploy rural radio access networks and speed up the rollout of 5G connectivity – yet still minimise environmental impact and preserve rural scenery.

“We’ve all felt the frustration of having the ‘no bar blues’ when struggling to get a phone signal, so we’re changing the law to wipe out mobile ‘not spots’ and dial up the roll out of next-generation 5G,” claims Julia Lopez, the government’s Digital Infrastructure Minister, of the changes.

“Phone users across the country will benefit – whether they are in a city, village or on the road – and tighter rules on the visual impact of new infrastructure will ensure our cherished countryside is protected.”

The new rules will relax the requirements on masts, allowing units up to five metres taller and two metres wider than are allowed under current legislation. They will also allow upgrades to existing masts without prior approval, for masts up to six metres above building height to be installed in unprotected areas without prior approval, reduce the required distance between building-based masts and public roads, and allow for deployment of equipment cabinets near masts without prior approval.

“Building the mobile networks that provide the connectivity on which we all rely is both complex and challenging,” says Mobile UK chief executive Hamish MacLeod of the announcement. “The industry welcomes the reforms to planning regulations proposed by the Government. They will enable operators to deploy mobile networks more efficiently to meet ambitious targets for rural and urban coverage, including next-generation 5G.”

The latest Code of Practice document is available on GOV.UK now.

And finally, Hackaday has brought an interesting field station to our attention – housed in a tent originally designed for ice fishing.

“This was the first Winter Field Day that justified a reason to purchase an ice fishing tent,” writes Steve “K2GOG” Bossert of his unusual radio shack. “The tent manufacturer claims you can set this up in under a few minutes and pack it up even quicker.”

Designed for warmth, the tent houses a range of equipment – from a Lenovo laptop to an Icom IC-705 radio and a home-brew battery pack running from LiPoFe4 cells and offering an impressive 12aH of energy storage – with a 40m off-centre-fed dipole antenna mounted to a fibreglass mast.

“This antenna system works great and easily stows in a bag designed for audio equipment,” Steve explains. “Many other accessories for additional HF and VHF antenna also fit in this bag along with a few 25 and 50 foot RG-8X feedlines.”

Steve’s full write-up, and a video of the tent, is available on his blog.