Please create an account to participate in the Slashdot moderation system


Forgot your password?

Submission + - DARPA begins work on 100Gbps wireless tech with 120-mile range (

MrSeb writes: "DARPA has begun development of a wireless communications link that is capable of 100 gigabits per second over a range of 200 kilometers (124mi). Officially dubbed “100 Gb/s RF Backbone” (or 100G for short), the program will provide the US military with networks that are around 50 times faster than its current wireless links. In essence, DARPA wants to give deployed soldiers the same kind of connectivity as a high-bandwidth, low-latency fiber-optic network. In the case of Afghanistan, for example, the US might have a high-speed fiber link to Turkey — but the remaining 1,000 miles to Afghanistan most likely consists of low-bandwidth, high-latency links. It’s difficult (and potentially insecure) to control UAVs or send/receive intelligence over these networks, and so the US military instead builds its own wireless network using Common Data Link. CDL maxes out at around 250Mbps, so 100Gbps would be quite a speed boost. DARPA clearly states that the 100G program is for US military use — but it’s hard to ignore the repercussions it might have on commercial networks, too. 100Gbps wireless backhaul links between cell towers, rather than costly and cumbersome fiber links, would make it much easier and cheaper to roll out additional mobile coverage. Likewise, 100Gbps wireless links might be the ideal way to provide backhaul links to rural communities that are still stuck with dial-up internet access. Who knows, we might even one day have 100Gbps wireless links to our ISP."

Submission + - Caltech and UVic set 339Gbps internet speed record ( 1

MrSeb writes: "Engineers at Caltech and the University of Victoria in Canada have smashed their own internet speed records, achieving a memory-to-memory transfer rate of 339 gigabits per second (5.3GB/s), 187Gbps (2.9GB/s) over a single duplex 100-gigabit connection, and a max disk-to-disk transfer speed of 96Gbps (1.5GB/s). At a sustained rate of 339Gbps, such a network could transfer four million gigabytes (4PB) of data per day — or around 200,000 Blu-ray movie rips. These speed records are all very impressive, but what’s the point? Put simply, the scientific world deals with vasts amount of data — and that data needs to be moved around the world quickly. The most obvious example of this is CERN’s Large Hadron Collider; in the past year, the high-speed academic networks connecting CERN to the outside world have transferred more than 100 petabytes of data. It is because of these networks that we can discover new particles, such as the Higgs boson. In essence, Caltech and the University of Victoria have taken it upon themselves to ride the bleeding edge of high-speed networks so that science can continue to prosper."

Submission + - New WiFi protocol boosts congested wireless network throughput by 700% (

MrSeb writes: "Engineers at NC State University (NCSU) have discovered a way of boosting the throughput of busy WiFi networks by up to 700%. Perhaps most importantly, the breakthrough is purely software-based, meaning it could be rolled out to existing WiFi networks relatively easily — instantly improving the throughput and latency of the network. As wireless networking becomes ever more prevalent, you may have noticed that your home network is much faster than the WiFi network at the airport or a busy conference center. The primary reason for this is that a WiFi access point, along with every device connected to it, operates on the same wireless channel. This single-channel problem is also compounded by the fact that it isn't just one-way; the access point also needs to send data back to every connected device. To solve this problem, NC State University has devised a scheme called WiFox. In essence, WiFox is some software that runs on a WiFi access point (i.e. it’s part of the firmware) and keeps track of the congestion level. If WiFox detects a backlog of data due to congestion, it kicks in and enables high-priority mode. In this mode, the access point gains complete control of the wireless network channel, allowing it to clear its backlog of data. Then, with the backlog clear, the network returns to normal. We don’t have the exact details of the WiFox scheme/protocol (it’s being presented at the ACM CoNEXT conference in December), but apparently it increased the throughput of a 45-device WiFi network by 700%, and reduced latency by 30-40%."

Submission + - Increasing wireless network speed by 1000%, by replacing packets with algebra (

MrSeb writes: "A team of researchers from MIT, Caltech, Harvard, and other universities in Europe, have devised a way of boosting the performance of wireless networks by up to 10 times — without increasing transmission power, adding more base stations, or using more wireless spectrum. The researchers’ creation, coded TCP, is a novel way of transmitting data so that lost packets don’t result in higher latency or re-sent data. With coded TCP, blocks of packets are clumped together and then transformed into algebraic equations that describe the packets. If part of the message is lost, the receiver can solve the equation to derive the missing data. The process of solving the equations is simple and linear, meaning it doesn’t require much processing on behalf of the router/smartphone/laptop. In testing, the coded TCP resulted in some dramatic improvements. MIT found that campus WiFi (2% packet loss) jumped from 1Mbps to 16Mbps. On a fast-moving train (5% packet loss), the connection speed jumped from 0.5Mbps to 13.5Mbps. Moving forward, coded TCP is expected to have huge repercussions on the performance of LTE and WiFi networks — and the technology has already been commercially licensed to several hardware makers."

Submission + - First air-to-ground quantum network created, transmits quantum crypto keys (

MrSeb writes: "A team of quantum engineers in Germany have created the first air-to-surface quantum network, between a base station and an airplane flying 20 kilometers (12.4 miles) above. The researchers, led by Sebastian Nauerth of the Ludwig Maximilian University, performed the experiment at an airport near Munich using a specially-equipped plane. The airplane is outfitted with a a photon source (a laser), and a system that can alter the spin (polarization) of the photons very exactly to encode data using the BB84 quantum key distribution protocol. Once the plane is aloft, the base station (a telescope) tracks the plane using a motorized mirror, which is quite difficult as the plane is moving at 300 kmh (200 mph) and is 20 kilometers up in the air. The telescope picks up the transmitted photons, bounces them through a few more mirrors, and then uses a very sensitive photodetector to turn them into qubits. All told, the plane/base station were able to maintain a stable link for 10 minutes, transmitting 145 qubits per second, with a quantum bit error rate (QBER) of 4.8%. This might seem like a small amount of data, but it’s more than enough to securely transmit an encryption key that can then be used to encrypt normal data that’s sent over standard, classical networks."

Submission + - Check your phone bill: You're probably being overcharged for data (

MrSeb writes: "A recent study conducted by UCLA professor Chunyi Peng shows that carriers generally count data usage correctly, but those customers who commonly use their device in areas with weak signal strength or to stream audio or video are often overcharged. Peng and three other researchers used data gleaned from an app installed on Android smartphones on two different carriers. The issue appears to be in how the system is set up to count data usage. Under the current scenario, data is charged as it is sent from the carrier’s network to the end user. What does not exist is a system to confirm whether the packets are received, and thus preventing charges for unreceived data. Peng demonstrated this in two extreme circumstances. In one case, 450 megabytes of data was charged to an account where not a single bit of it had been received. On the flipside, Peng’s group was able to construct an app which disguised data transfers as DNS requests, which are not counted by the carriers as data usage. Here they were able to transfer 200 megabytes of data without being charged. Overall, the average overcharge is about 5-7% for most users. While that does not seem like much, with unlimited plans gone and data caps in style that could pose potential problems for some heavy data users. Could you be going over your data allotment based on data you never received? It’s quite possible."

Submission + - Preventing another Carrier IQ: Introducing the Mobile Device Privacy Act (

MrSeb writes: "Lawmakers in Washington have turned their sights on mobile device tracking, proposing legislation aimed at making it much harder for companies to track you without consent. The Mobile Device Privacy Act makes it illegal for companies to monitor device users without their expressed consent. The bill was introduced Thursday by Massachusetts Democrat Representative Edward Markey, co-Chair of the Bi-Partisan Congressional Privacy Caucus. Much of the impetus for the bill came from last year’s Carrier IQ debacle, where it emerged that the company's software was found to exist on both iOS and Android devices on AT&T and Sprint’s networks. While the company denied any wrongdoing, the software captured keystrokes and sent the details of your device usage back to the carriers. That news set off a firestorm of criticism, including the attention of Senator Al Franken, who grilled the company and received some details on Carrier IQ’s intentions. If passed, the legislation would require the disclosure of including tracking software at the time of the purchase of the phone, or during ownership if a software update or app would add such software to the device, and the consumer gains the right to refuse to be tracked. This disclosure must include what types of information is collected, who it is transmitted to, and how it will be used."

Submission + - FCC to review the relative value of low, high, and super-high spectrum licenses (

MrSeb writes: "The FCC is reviewing the rules it has for spectrum license ownership, particularly on how much spectrum any one company can hold. The FCC is considering this rework because the rules do not currently account for the properties of different frequencies of spectrum. There are three main classes of spectrum for cellular wireless networks: low band, high band, and super high band — but at the moment, they are all valued equally. Given that low band spectrum is valued favorably against high band and super high band spectrum in the market, and that AT&T and Verizon have by far the most low band spectrum, it makes sense for the FCC to adjust its rules in order to more accurately determine how much spectrum any one company needs."

Submission + - Is the Batman stock market heist possible? (

MrSeb writes: "Like most of the world’s population, I recently saw Batman: The Dark Knight Rises. Putting aside the obvious question of just how Anne Hathaway squeezed into that leather outfit, I had to wonder: Is the stock market heist actually possible? If you haven’t seen the movie (spoilers ahead!), here’s a basic outline of the scene: Bane, Batman’s nemesis in the movie, attacks Gotham Stock Exchange with a bunch of armed flunkies. Bane coerces a trader into unlocking his terminal, and then uses Bruce Wayne’s fingerprints (which he obtained earlier) to bet all of Wayne Enterprises’ stock on bad futures. The futures don’t pan out (obviously), and the next morning his company is bankrupt. The feds try to interrupt the heist by cutting the stock exchange’s wired connection, but there’s a backup wireless link that the baddies use instead. There are two key points that don’t quite ring true: Can you simply walk into a stock exchange and execute a bunch of trades? — and, does a stock exchange only have one or two links to the outside world? Is it easy to cut them? After doing a little research, the answers surprised me."

Submission + - Facebook invests in 55-terabit intra-Asia submarine cable system ( 1

MrSeb writes: "Facebook has joined a consortium that will build by far the fastest intra-Asia submarine fiber optic network, the Asia Pacific Gateway (APG). Facebook is the only American company involved with the venture, which will see 10,000km (6,000 miles) of prime fiber laid between Malaysia and Japan (pictured above), with branches landing in almost every country along the way (Singapore, Thailand, Vietnam, China, Taiwan, and South Korea). When the cable goes online in 2014, at a cost of around $450 million, it is slated to use 40Gbps channels, for a total capacity of 55 terabits per second, or a transfer speed of 6.9 terabytes (138 Blu-ray discs) per second. When the various routers and repeaters are upgraded to 100Gbps-per-channel, the cable will have a total capacity of well over 100Tbps. The prime reason for building the cable, other than making money, is to provide more redundancy between the US and Asia. Currently, almost every connection from Asia to the US is routed through Singapore or Japan. If there is congestion at one of these sites, or a cable is cut, then the other (highly populous) countries in south east Asia are in trouble. It is perhaps no surprise that China Telecom and China Unicom, two of the world’s largest telecoms companies, are involved in the laying of APG. Facebook's involvement is almost certainly due to the fact that the social network's growth has almost stagnated in Europe and North America, while Asia is only just starting to climb on the Facebook bandwagon."

Submission + - 'Twisted' OAM beams carry 2.5 terabits per second (

MrSeb writes: "American and Israeli researchers have used twisted, vortex beams to transmit data at 2.5 terabits per second. As far as I can discern, this is the fastest wireless network ever created — by some margin. These twisted signals use orbital angular momentum (OAM) to cram much more data into a single stream, without using more spectrum. In current state-of-the-art transmission protocols (WiFi, LTE, COFDM), we only modulate the spin angular momentum (SAM) of radio waves, not the OAM. If you picture the Earth, SAM is our planet spinning on its axis, while OAM is our movement around the Sun. Basically, the breakthrough here is that researchers have created a wireless network protocol that uses both OAM and SAM. In this case, Alan Willner and fellow researchers from the University of Southern California, NASA’s Jet Propulsion Laboratory, and Tel Aviv University, twisted together eight ~300Gbps visible light data streams using OAM. For the networking nerds, Willner’s OAM link has a spectral efficiency of 95.7 bits per hertz; LTE maxes out at 16.32 bits/Hz; 802.11n is 2.4 bits/Hz. Digital TV (DVB-T) is just 0.55 bits/Hz. In short, this might just be exactly what our congested wireless spectrum needs."

Submission + - Move over, quantum cryptography: Classical physics can be unbreakable too (

MrSeb writes: "Quantum cryptography? Pah! That’s for newbies, according to researchers from Texas A&M University who claim to have pioneered unbreakable cryptography based on the laws of thermodynamics; classical physics, rather than quantum. In theory, quantum crypto (based on the laws of quantum mechanics) can guarantee the complete secrecy of transmitted messages: To spy upon a quantum-encrypted message would irrevocably change the content of the message, thus making the messages unbreakable. In practice, though, while the communication of the quantum-encrypted messages is secure, the machines on either end of the link can never be guaranteed to be flawless. According to Laszlo Kish and his team from Texas A&M, however, there is a way to build a completely secure end-to-end system — but instead of using quantum mechanics, you have to use classical physics: the second law of thermodynamics, to be exact. Kish’s system is made up of a wire (the communication channel), and two resistors on each end (one representing binary 0, the other binary 1). Attached to the wire is a power source that has been treated with Johnson-Nyquist noise (thermal noise). Johnson noise is often the basis for creating random numbers with computer hardware. For details of how the system works, read the article."

Submission + - Japanese researchers transmit 3Gbps using terahertz frequencies (

MrSeb writes: "Researchers at the Tokyo Institute of Technology have developed a new wireless transmission system that works above all currently regulated spectrum frequencies. The new system works at the range of 300GHz to 3THz (terahertz), which is the Far Infrared (FIR) frequencies of the infrared spectrum. That spectrum is currently totally unregulated by any country or standards organization in the world, making it ripe for development of new technologies. So far the Japanese researchers have transmitted data at 3Gbps, but in theory speeds of up to 100Gbps should be possible."

Submission + - Chinese physicists achieve quantum teleportation over 60 miles (

MrSeb writes: "Chinese physicists are reporting that they’ve successfully teleported photonic qubits (quantum bits) over a distance of 97 kilometers (60mi). This means that quantum data has been transmitted from one point to another, without passing through the intervening space. Now, before you get too excited, we’re still a long, long way off Willy-Wonka-Mike-Teevee-style teleportation. It’s important to note that the Chinese researchers haven’t actually made a photon disappear and reappear 100 kilometers away; rather, they’ve used quantum entanglement to recreate the same qubit in a new location, with the same subatomic properties as the original qubit. The previous record for transmitting entangled qubits was 16 kilometers, performed by another Chinese team back in 2010 — and perhaps most excitingly, the researchers seem confident that their system will scale up from 100km to distances capable of reaching orbital satellites, at which point we'll actually be able to build a global quantum network for all of our cryptographic needs."

Submission + - Smartphones set to become the fastest spreading technology in human history (

MrSeb writes: "According to some numbers compiled by Michael Degusta, smartphones might just be the fastest-spreading technology in human history. The only technologies that come close is the adoption of television between 1950 and 1953, and the recent emergence (and rapid growth) of the tablet market. While his numbers are entirely US-centric, they are representative of other Western world countries. What about the rest of the world, though? Well, mobile phones (and now smartphones) are kind of unique in this regard. Historically, the adoption of advanced technologies is usually closely linked to a country’s GDP — but mobile phones have completely bucked that trend. In 2001, there was just one billion mobile phone subscribers — most of them in developed countries. Today there are six billion subscribers, and 73% of those (4.4 billion!) are in developing countries that account for just 20% of the world’s total GDP. In short, in just 10 years, mobile phones have almost reached saturation point in countries where people earn just a few dollars per day (and we have cheap ARM CPUs to thank for that!) Smartphones, with their larger screens and processors, are obviously more expensive than feature phones at the moment, but it’s only a matter of time until they’re cheap enough for worldwide adoption. In the first quarter of 2012, worldwide, 36% of all mobile phone shipments were smartphones, compared to 25% the year before."

Slashdot Top Deals

All the simple programs have been written.