OTA: LimeSDR Shipping, 6G Cellular, New Osmocom, and More

LimeSDR (cased)

Work to deliver outstanding LimeSDR, LimeSDR Mini, and associated devices continues, but there’s been a major change in the background: Crowd Supply is now in full control of inventory management and distribution, which is going to make future fulfilment considerably smoother at the cost of a moderate delay in the short term.

“Up until now, we’ve been manufacturing LimeSDR products in fits and starts in order to efficiently allocate resources to meet demand in close to real time. While we’ve successfully manufactured and shipped many thousands of units, we are working hard to catch up with the back log of orders,” the LimeSDR team explains in a campaign update. “Indeed, the more we ship, the more demand there is. This, of course, is very welcome, as we now can look to organising a much higher volume production plan.

“As part of this effort, we’re pleased to announce that we’ve extended our relationship with Crowd Supply and, effective immediately, have given them exclusive control over all LimeSDR-related inventory management and distribution. We believe this will free up our production team to focus on manufacturing and developing products at the cutting edge of software-defined radio, and at the same time ensure much better availability of LimeSDR products, predictability of delivery schedules, and overall quality of the customer experience.”

With Crowd Supply placing bulk orders and acting as the sole distributor of LimeSDR parts, the future looks set: ordered boards which have not yet been produced are to be built as part of Crowd Supply’s first quarterly order and will be shipping in mid-July. “Obviously, this is much further out than originally expected and we do apologise for any inconvenience this may cause. Although this is our official delivery date for the orders in hand, we are doing everything we can to expedite delivery by exercising our influence on our supplier partners,” adds the team. “This, we hope, could result in improving the above delivery timeline.”

The Osmocom Cellular Network Infrastructure (CNI) software stack has received a major update this month, totalling around half a year of work on bug-fixing, stabilisation, and specification compliance.

“Those new tagged/released versions contain half a year of work since the previous versions released in early November 2017,” the Osmocom team explains in a news post. “The primary focus was on bug-fixing and stabilisation. Many bugs were introduced during the split of the NITB into individual network elements during 2017, and even more bugs exposed by our ever-growing test coverage, particularly in the Osmocom TTCN-3 test suites. All-in-all, the post-NITB stack has gained a lot in terms of spec compliance, robustness, stability and features during this period.”

The update brings the version numbers to: OsmoTRX 0.4.0; OsmoBTS 0.8.0; OsmoBSC 1.2.0; OsmoMSC 1.2.0; OsmoHLR 0.2.1; OsmoSTP 0.9.0; OsmoSGSN 1.3.0; OsmoGGSN 1.2.1; libosmocore 0.11.0; libosmo-abis 0.5.0; libosmo-netif 0.2.0; osmo-mgw 1.3.0; osmo-sip-connector 1.1.0. All are available now as pew-compiled packages from the official website.

The deadline for participating in the Osmocom Conference (OsmoCon) 2018 has been extended to the 30th of May, ahead of the conference opening in October this year.

“The deadline of the Call for Participation (CfP) to the OsmoCon2018 has been extended by two weeks,” Osmocom explains in its news post on the topic. “This means you still have time until May 30, 2018 to submit your proposal and meet us in October 2018 to talk about your experience, or to share your ideas about Open Source Mobile Communications.”

Details, and a submission form, are available from the OsmoCon 2018 CfP page.

RTL-SDR has brought to our attention an experiment by John Fallows on implementing spatial filtering in GNU Radio.

“This GNU Radio SDR spatial filtering demo shows how you can eliminate local RF interference using coherent sampling on two radio channels with different antennas,” John explains. “Here is a demonstration of ‘noise cancellation’ using digital data in a software defined radio. Actual implementation requires a dual channel SDR with one antenna for the main reception, and the second antenna focused on receiving noise or interference. This demo uses GNURadio to simulate how two IQ data channels can be used to subtract interference.”

The results, demonstrated in real time in an explanatory video, are impressive: while no SDR hardware is involved, instead using simulated signals where a dual-channel coherent SDR would be, the flow diagram’s impact on the noise level is plain to see.

Eddie MacDonald is continuing his development of plugins for the popular SDR# software package, including a new tool designed to assist with managing the use of other plugins.

Following on from his earlier plugins – a tuning dial, night mode toggle, Fast Fourier Transform (FFT) capture, and a quick-access toolbar – the SDR# Plugin Manager does exactly what it says on the tin: provides a convenient interface for installation, removal, and editing of SDR# plugins – including Eddie’s own.

More information on the plugin, along with Eddie’s other plugins and a new tool for changing the colour of the spectrum chart, can be found on Eddie’s SDRPlugins.com website.

SDRplay has warned the radio community to be on the alert for a batch of RPS1A and RPS2pro devices which were stolen from a manufacturing partner and which have cropped up on auction site eBay.

“It has come to our attention that a consignment of RSPs that was recently stolen from our manufacturing partner have appeared for sale on eBay,” the company explains in a forum post which provides a list of affected device serial numbers. “If you have any of the following devices and have purchased them from a non-approved reseller of SDRplay products, please contact admin@sdrplay.com and also contact the seller requesting a refund as the devices appear to have come from a stolen consignment of goods.

“Please be aware that we have now black-listed the above serial numbers and these devices will not work at all or will only work with a very restricted range of software. Anyone with any of these devices will not receive any form of support or technical assistance from SDRplay.”

The full list of serial numbers affected by the theft can be found on the SDRplay forum.

IEEE Spectrum’s Samuel K. Moore has published an interesting article on making radio chips which can withstand extreme environments, based on the work of the University of Arkansas and the KTH Royal Institute of Technology.

“There are still some places the Internet of Things fears to tread. Researchers at the University of Arkansas and the KTH Royal Institute of Technology, in Sweden, are building a radio for those places,” Samuel writes. “This month, in IEEE Electron Device Letters, they describe a mixer, a key component of any wireless system, that works just fine from room temperature all the way up to 500ºC. It’s the first mixer IC capable of handling such extremes.

“IEEE Fellow and Arkansas professor of electrical engineering Alan Mantooth specializes in electronics for extreme environments. Of several projects ‘one of the more sexy is trying to put a rover or some sort of instrument on [the surface of the planet] Venus that will last for more than two hours, which is the current record.’ An high temperature for average day on Venus reaches 467ºC. But it’s a sulfuric heat.”

Other environments where Mantooth and colleagues may deploy their mixer IC include the inside of a natural gas turbine generator running at 1,000ºC and the inside of a diesel combustion chamber.

Consumer radio reception in the United Kingdom has hit a milestone this year, with more listeners using DAB than analogue FM for the first time – a breakthrough that could spell the end for FM broadcast stations.

Figures released by the UK’s Radio Joint Audience Research (RAJAR) for the first quarter of 2018 showed digital listening hitting 50.9 percent – up from 47.2 percent a year prior – and taking a majority share for the first time. Arqiva reports from the Tuning In commercial radio conference where the Minister of State for Digital and the Creative Industries Margot James highlighted the 50 percent mark as “an important milestone for radio” and hinted that regulation may come to the now-minority FM bands.

The UK would not be the first country to close down FM broadcast stations: Norway ended national FM radio broadcasts in 2017 following an uptick in digital listening, though some stations in the region continue to broadcast without a licence in protest of the move.

The Australian arm of cellular communications provider Vodafone has launched its first massive multiple input multiple output (massive MIMO) trial in Parramatta, using the 1.8GHz spectrum.

“The projected growth in the Massive MIMO market indicates the potential and untapped opportunities for the telecommunications industry to improve its network offerings. Rather than focusing on stunts around 5G, Vodafone is investing in technologies that will help deliver real benefits to our customers now,” crowed Vodafone’s chief technology officer Kevin Millroy of the launch. “The sites selected for the 4.9G trial are in high-density, high usage areas where we can really exercise the benefits we saw during the field demonstration.”

The live trial follows field testing of frequency division duplex (FDD) massive MIMO on the 1.8GHz spectrum in 2017, when Vodafone demonstrated a sustained throughput of 7171Mb/s across eight client devices. The Parramatta site will be joined by four other sites in Australia, the company has confirmed, with Sydney’s Chinatown and Haymarket next on the list.

ByTechLab has published a write-up of a “mostly” 3D-printed discone antenna design, designed to receive signals between 85MHz and 850MHz.

“For a long time I wanted to listen in to some unencrypted radio frequencies (for example air band). When I discovered the RTL-SDR dongle I have bought it almost instantly. For such a low price, it has incredible possibilities. You can listen to signals that you are receiving ,decode them and observe their spectrum in range of about 500kHz to 1.75GHz,’ explains ByTechLab of the reason for their creation. “Unfortunately, as you can guess, the RTL-SDR without a good antenna can’t do much. I was looking for an antenna that would be relatively easy to build, lightweight and broadband (so that I don’t have to change the antennas every time I want to listen in to different frequencies).

“The antenna was designed in the way so that it can be built with use of 3D printer and some other tools that you probably already have. Unfortunately, as it turned out later, the antenna was not as easy to build as I thought it will be (there were a few problems that are already corrected in the final version of this project). The whole project was supposed to last about one day, unfortunately everything took me about 3 days. I am very happy with this antenna – it works exactly as expected.”

The files for the antenna have been published on GrabCAD, under a Creative Commons Attribution Non-Commercial Share-Alike licence.

ARRL reports on successful reception of signals from DSLWP-A1 and DSLWP-A2, two microsatellites launched by China as part of the Chang’e 4 mission to the far side of the moon.

The two satellites, which were deployed earlier this month, carry amateur radio and educational payloads – and signals have already been received. “Following deployment, signals from the DSLWP satellites were received by radio amateurs in Brazil, Chile, and the US, as well as by many others around the world,” the ARRL writes.

“An open telecommand protocol on the spacecraft is designed to allow radio amateurs to send commands to take and download images. DSLWP-A1 downlinks are 435.425 MHz and 436.425 MHz; DSLWP-A2 downlinks are 435.400 MHz and 436.400 MHz. They will use 250/500 bps GMSK using 10 kHz wide FM single-channel data, with concatenated codes or JT4G. JT4 uses four-tone FSK, with a keying rate of 4.375 baud; the JT4G sub-mode uses 315 Hz tone spacing and 1,260 Hz total bandwidth.”

The National Oceanic and Atmospheric Administration, meanwhile, is having a few problems with its latest GOES-17 satellite and is investigating performance issues with its imaging unit.

“The GOES-R Program is currently addressing a performance issue with the cooling system encountered during commissioning of the GOES-17 Advanced Baseline Imager (ABI) instrument,” a NOAA spokesperson explains. “The cooling system is an integral part of the ABI and did not start up properly during the on-orbit checkout.

“A team of experts from NOAA, NASA, the ABI contractor team and industry are investigating the issue and pursuing multiple courses of possible corrective actions. The issue affects 13 of the infrared and near-infrared channels on the instrument. The three ABI channels with the shortest wavelength are not impacted.”

The fault does not impact weather monitoring from the GOES constellation, which still has GOES-16 and GOES-15 as active monitors and GOES-14 as an on-orbit spare.

Finally, IEEE Spectrum’s Michael Koziol has written of researchers’ work on cellular 6G technologies, even as 5G awaits full deployment.

“This is the year 5G deployment is finally picking up steam,” Michael writes. “But that’s precisely why ComSenTer, a multi-university research effort into the fundamentals of what 6G might look like, is already turning its attention to the next next generation of wireless. 5G will utilize higher frequency spectrum than previous generations in order to improve data rates. Insomuch as anyone has an idea of what 6G might look like, it’s a good bet that it will take that same tack.

“[Mark] Rodwell [ ComSenTer’s director and University of California at Santa Barbara professor] envisions a base station that could emit up to a thousand beams simultaneously. ‘What you’re looking at is four surfaces, each capable of 250 simultaneous beams,’ he says. If each beam provided 10 gigabits per second, a single base station could transfer 10 terabits every second.”

Michael does admit, however, that “it’s not guaranteed that 6G will ultimately look anything like ComSenTer’s vision.”

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