A new, tunable smart surface can transform a single pulse of light into multiple beams, each aimed in different directions. The proof-of-principle development opens the door to a range of innovations in communications, imaging, sensing, and medicine.

The research comes out of the Caltech lab of Harry Atwater, a professor of applied physics and materials science, and is possible due to a type of nano-engineered material called a metasurface. “These are artificially designed surfaces which basically consist of nanostructured patterns,” says Prachi Thureja, a graduate student in Atwater’s group. “So it’s an array of nanostructures, and each nanostructure essentially allows us to locally control the properties of light.”

The surface can be reconfigured up to millions of times per second to change how it is locally controlling light. That’s rapid enough to manipulate and redirect light for applications in optical data transmission such as optical space communications and Li-Fi, as well as lidar.

“[The metasurface] brings unprecedented freedom in controlling light,” says Alex M.H. Wong, an associate professor of electrical engineering at the City University of Hong Kong. “The ability to do this means one can migrate existing wireless technologies into the optical regime. Li-Fi and LIDAR serve as prime examples.”

Metasurfaces remove the need for lenses and mirrors

Manipulating and redirecting beams of light typically involves a range of conventional lenses and mirrors. These lenses and mirrors might be microscopic in size, but they’re still using optical properties of materials like Snell’s Law, which describes the progress of a wavefront through different materials and how that wavefront is redirected—or refracted—according to the properties of the material itself.

By contrast, the new work offers the prospect of electrically manipulating a material’s optical properties via a semiconducting material. Combined with nano-scaled mirror elements, the flat, microscopic devices can be made to behave like a lens, without requiring lengths of curved or bent glass. And the new metasurface’s optical properties can be switched millions of times per second using electrical signals.

“The difference with our device is by applying different voltages across the device, we can change the profile of light coming off of the mirror, even though physically it’s not moving,” says paper co-author Jared Sisler—also a graduate student in Atwater’s group. “And then we can steer the light like it’s an electrically reprogrammable mirror.”

The device itself, a chip that measures 120 micrometers on each side, achieves its light-manipulating capabilities with an embedded surface of tiny gold antennas in a semiconductor layer of indium tin oxide. Manipulating the voltages across the semiconductor alters the material’s capacity to bend light—also known as its index of refraction. Between the reflection of the gold mirror elements and the tunable refractive capacity of the semiconductor, a lot of rapidly-tunable light manipulation becomes possible.

“I think the whole idea of using a solid-state metasurface or optical device to steer light in space and also use that for encoding information—I mean, there’s nothing like that that exists right now,” Sisler says. “So I mean, technically, you can send more information if you can achieve higher modulation rates. But since it’s kind of a new domain, the performance of our device is more just to show the principle.”

Metasurfaces open up plenty of new possibilities

The principle, says Wong, suggests a wide array of future technologies on the back of what he says are likely near-term metasurface developments and discoveries.

“The metasurface [can] be flat, ultrathin, and lightweight while it attains the functions normally achieved by a series of carefully curved lenses,” Wong says. “Scientists are currently still unlocking the vast possibilities the metasurface has available to us.

“With improvements in nanofabrication, elements with small feature sizes much smaller than the wavelength are now reliably fabricable,” Wong continues. “Many functionalities of the metasurface are being routinely demonstrated, benefiting not just communication but also imaging, sensing, and medicine, among other fields... I know that in addition to interest from academia, various players from industry are also deeply interested and making sizable investments in pushing this technology toward commercialization.”

As the world’s 5G rollout continues with its predictable fits and starts, the cellular technology is also starting to move into a space already dominated by another wireless tech: Wi-Fi. Private 5G networks—in which a person or company sets up their own facility-wide cellular network—are today finding applications where Wi-Fi was once the only viable game in town. This month, the Newbury, England–based telecom company Vodafone is releasing a Raspberry Pi–based private 5G base station that it is now being aimed at developers, who might then jump-start a wave of private 5G innovation.

“The Raspberry Pi is the most affordable CPU[-based] computer that you can get,” says Santiago Tenorio, network architecture director at Vodafone. “Which means that what we build, in essence, has a similar bill of materials as a good quality Wi-Fi router.”

The company has teamed with the Surrey, England–based Lime Microsystems to release a crowd-funded range of private 5G base-station kits ranging in price from US $800 to $12,000.

“In a Raspberry Pi—in this case, a Raspberry Pi 4 is what we used—then you can be sure you can run that anywhere, because it’s the tiniest processor that you can have,” Tenorio says.

Santiago Tenorio holds one of Lime Microsystems’ private 5G base-station kits.Vodafone

Private 5G for Drones and Bakeries

There are a range of reasons, Tenorio says, why someone might want their own private 5G network. At the moment, the scenarios mostly concern companies and organizations—although individual expert users could still be drawn to, for instance, 5G’s relatively low latency and network flexibility.

Tenorio highlighted security and mobility as two big selling points for private 5G.

A commercial storefront business, for instance, might be attracted to the extra security protections that a SIM card can provide compared to password-based wireless network security. Because each SIM card contains its own unique identifier and encryption keys, thereby also enabling a network to be able to recognize and authorize each individual connection, Tenorio says private 5G network security is a considerable selling point.

Plus, Tenorio says, it’s simpler for customers to access. Envisioning a use case of a bakery with its own privately deployed 5G network, he says, “You don’t need a password. You don’t need a conversation [with a clerk behind a counter] or a QR code. You simply walk into the bakery, and you are into the bakery’s network.”

As to mobility, Tenorio suggests one emergency relief and rescue application that might rely on the presence of a nearby 5G station that causes devices in its range to ping.

Setting up a private 5G base station on a drone, Tenorio says, would enable that drone to fly over a disaster area and, via its airborne network, send a challenge signal to all devices in its coverage area to report in. Any device receiving that signal with a compatible SIM card then responds with its unique identification information.

“Then any phone would try to register,” Tenorio says. “And then you would know if there is someone [there].”

Not only that, but because the ping would be from a device with a SIM card, the private 5G rescue drone in the above scenario could potentially provide crucial information about each individual, just based on the device’s identifier alone. And that user-identifying feature of private 5G isn’t exactly irrelevant to a bakery owner—or to any other commercial customer—either, Tenorio says.

“If you are a bakery,” he says, “You could actually know who your customers are, because anyone walking into the bakery would register on your network and would leave their [International Mobile Subscriber Identity].”

Winning the Lag Race

According to Christian Wietfeld, professor of electrical engineering at the Technical University of Dortmund in Germany, private 5G networks also bring the possibility of less lag. His team has tested private 5G deployments—although, Wietfeld says that they haven’t yet tested the present Vodafone/Lime Microsystem base station—and have found private 5G to provide reliably better connectivity.

Wietfeld’s team will present their research at the IEEE International Symposium on Personal, Indoor and Mobile Radio Communications in September in Valencia, Spain. They found that private 5G can deliver connections up to 10 times as fast as connections in networks with high loads, compared to Wi-Fi (the IEEE 802.11 wireless standard).

“The additional cost and effort to operate a private 5G network pays off in lower downtimes of production and less delays in delivery of goods,” Wietfeld says. “Also, for safety-critical use cases such as on-campus teleoperated driving, private 5G networks provide the necessary reliability and predictability of performance.”

For Lime Networks, according to the company’s CEO and founder Ebrahim Bushehri, the challenge comes in developing a private 5G base station that maximized versatility and openness to whatever kinds of applications developers could envision—while still being reasonably inexpensive and retaining a low-power envelope.

“The solution had to be ultraportable and with an optional battery pack which could be mounted on drones and autonomous robots, for remote and tactical deployments, such as emergency-response scenarios and temporary events,” Bushehri says.

Meanwhile, the crowdfunding behind the device’s rollout, via the website Crowd Supply, allows both companies to keep tabs on the kinds of applications the developer community is envisioning for this technology, he says.

“Crowdfunding,” Bushehri says, “Is one of the key indicators of community interest and engagement. Hence the reason for launching the campaign on Crowd Supply to get feedback from early adopters.”

If youre putting together a DIY project that needs a network connection, like a NAS or a home media server, plugging into your main network is the end goal, but could cause some problems if youre still experimenting. DIY projects by their very nature can result in a lot of trial and error, and if youve got other members of your home using your home network, they might not think that restarting the router or needing to assign custom IPs to every new device is quite as interesting as you do. For the most part, you won't need another router for DIY projects, but if it involves networking, it's not a bad idea to do your testing on a separate router.

Many of us have experienced the frustration of weak or inconsistent Wi-Fi signal in our homes. Even with a seemingly adequate setup, dead zones and ...

The post This free app makes it very easy to identify areas with better Wi-Fi appeared first on Gizchina.com.

Without a doubt, coverage and speed are the two most important considerations when choosing a router, but it can be hard to find one with the right balance. While most routers strive for good coverage, some models excel more than others with clever antenna designs and modern technology support like OFDMA and beamforming. If youre willing to go with one of the best mesh systems, you have a lot more options, but if you just want a single router that can do it all, and maybe expand with a mesh later on, youll want something with a bit more power.

Resetting your router can be a quick way to solve some connectivity issues or to get a fresh start, but if your internet connection doesnt come back on, its very frustrating. Your router is part of a large collection of devices that directs data from your connected devices to the right server online and back again, so there are a lot of things that can prevent your connection from working. If youve reset your router, and it wont connect to the internet, there are some quick fixes you can try.

Welcome to another edition of Should You Bother With, where the useless and the utilitarian of PC gaming hardware are sorted into two satisfyingly neat piles. And after the hard science demanded by SYBW’s previous look at Hall effect keyboards, I’m pleased to say that the concept behind this week’s focus can be summed in with as few words as "faster Internet." It’s Wi-Fi 7 – or 802.11be, to its friends.

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Wireless spectrum is always at a premium—if you’ve ever tried to connect to Wi-Fi in a crowded airport or stadium, you know the pain that comes from crowded spectrum use. That’s why the industry continues to tinker with ways to get the most out of available spectrum. The latest example: Qualcomm’s FastConnect 7900 chip, which the company unveiled Monday at Mobile World Congress in Barcelona.

Qualcomm touts the FastConnect 7900 as a provider of “AI-enhanced” Wi-Fi 7, which the company views as an opportunity to create more reliable wireless connections. The chip will also better integrate the disparate technologies of Wi-Fi, Bluetooth, and ultrawideband for consumer applications. In addition, the chip can support two connections to the same device over the same spectrum band.

The FastConnect 7900 comes as the wireless industry renews its focus on reliability with Wi-Fi 7, the wireless tech standard’s latest generation. The emphasis comes in addition improving throughput and decreasing latency, something to which every Wi-Fi generation contributes.

(Wi-Fi is a range of wireless networking protocols based on the IEEE 802.11 set of standards. The IEEE is IEEE Spectrum‘s parent organization.)

AI-Enhanced Wi-Fi

“[Wi-Fi’s] a bit like the wild, wild West,” says Javier del Prado, vice president for mobile connectivity at Qualcomm. “It’s all sorts of devices out there, congestion, devices that come in and go off, access points that do this, access points that do that—it’s very difficult to guarantee service.” Del Prado says that AI is the “perfect tool” to change that.

Key to the FastConnect 7900’s capabilities is the chip’s ability to detect what applications are in use by the device. Different applications use Wi-Fi differently: For example, streaming a video may require more data throughput, while a voice chat needs to prioritize low latency. After the chip has determined what applications are in use, it can optimize power and latency on a case-by-case basis.

Using AI to manage wireless spectrum connections isn’t a new problem or solution, but Qualcomm’s chip benefits from running everything on-device. “It has to run on the device to be effective,” says del Prado. “We need to make decisions at the microsecond level.”

Put another way, using the Wi-Fi connection itself to transmit the information about how to adjust the Wi-Fi connection would defeat the purpose of AI management in the first place—by the time the chip receives the information, it’d be way out of date.

Also important: The chip doesn’t suck power—in fact, it saves power overall. “These are fairly simple models,” says del Prado. “It’s not a 5 billion parameter AI. It’s a much smaller model. The key performance indicators are the speed and the accuracy.”

Del Prado says that the chip’s power consumption is negligible. In fact, because of its ability to optimize power depending on what applications are running, the chip saves its device up to 30 percent in power consumption.

Wi-Fi and Bluetooth and Ultrawideband, All in One

Outside of cellular, Wi-Fi is the most common way our phones connect with the world. But it’s not the only tech—Bluetooth is used for things like wireless earbuds, and ultrawideband (UWB) also sees some use for applications like item tracking (think Apple’s AirPods) and locking and unlocking cars remotely. All three technologies rely heavily on proximity and distance ranging to maintain wireless connections.

“There are all these use cases that use proximity and that use different technologies,” says del Prado. “Different technologies bring different benefits. There’s not always a single technology that fits all use cases. But that creates complexity.”

Qualcomm’s FastConnect 7900, del Prado says, will hide that complexity. “We make it technology-agnostic for the consumer.”

Sharing Spectrum Bands

One final trick the FastConnect 7900 offers is an ability to host two Wi-Fi connections on the same band of spectrum. Here, the chip is building on previous FastConnect generations. “We already introduced what we call ‘hybrid-simultaneous’—this is the capability of doing multiple channels simultaneously on the 5- and 6-gigahertz bands,” says del Prado.

New to the 7900 is audio over Wi-Fi, says del Prado. Qualcomm is calling it “XPAN,” and it’s a separate channel for audio only in those 5-GHz and 6-GHz bands.

This matters because those spectrum bands can deliver a much higher audio quality to the device compared to, say, Bluetooth, which operates in the 2.4-GHz band. By carving out a separate channel just for audio, says del Prado, the 7900 chip can provide that much better audio quality without it succumbing to the strain that typically emerges when multiple connections demand the same wireless signal. “That’s something that cannot be done with Bluetooth today, because it’s bandwidth-limited,” says del Prado.

Qualcomm is already sampling the FastConnect 7900 to its customers—that is, manufacturers of phones and similar devices. Del Prado estimates that the first products with the chip will hit the market in the second half of the year. “When the new round of premium Android phones hits the market later this year, those should support this functionality.”

If your Wi-Fi isn't giving you excellent coverage with consistent and reliable speeds, you're missing out. Even one of the best Wi-Fi routers can struggle on its own if you have thick walls or a big house. Mesh systems can work around these obstacles with multiple nodes instead of having to use brute force in every direction.