New Technology Promises to Boost Wireless Adoption
A company has developed a modulation/demodulation technology that promises to reduce long-range wireless communications' energy consumption and thereby improve mobile devices' battery life. The energy efficiency of xG Technology's xMax system could increase the adoption of wireless approaches such as WiMax and third-generation (3G) cellular.
xMax technology promises lower power usage for data transmissions. This would greatly benefit wireless systems, which operate on limited battery resources. The data is carried in xMax's side wave, whose emitted signal power is too low to interfere with other wireless technologies. The emitted power is well below the signal-interference limit that the US Federal Communications Commission has set for such transmissions. The key issue is the traditional tradeoff in wireless systems among network bandwidth, transmission distances, and a device's power consumption. This tradeoff can cause data transmissions via WiMax or energy-hungry 3G cellular to quickly drain devices' battery power, making them less useful.
To save energy, xMax uses a modulation technique that reverses the standard approach in radio-based communications, said Joseph A. Bobier, xG's president of operations. Like other radio-based approaches, xMax's modulation technique produces a side wave that carries the transmitted data.
Normally, communications technologies try to move as much power as possible to the side wave to provide a stronger signal for receivers to work with, explained Bobier.
xMax, which xG is testing in South Florida, provides very little power to the side wave. However, xG has de-signed a wavelet pass filter that lets the receiver use the side wave's peak power and extract the relatively weak incoming information pulse.
Thus, Bobier said, xMax can use 1,000 to 100,000 times less power than comparable transmission technologies. This greatly benefits wireless systems, which operate on limited battery resources.
Because the side wave uses little power, it can operate at low frequencies without interfering with or risking interference from other signals in the same range. The side wave can be widened or narrowed, depending on how much data will be transmitted.
In addition, xMax systems can broadcast the side wave at various frequencies. Currently, xG Technology is concentrating on the sub-GHz spectrum range that pagers and TVs use. The company is conducting testing in the 150-MHz range, a portion of the spectrum that is largely available now that paging is no longer very popular.
xMax will work with any wireless or nonoptical wired system. xG hopes to license the technology to manufacturers of fixed wireless systems' base stations, cell phones, public-safety radio networks, and coaxial cable and satellite systems.
xMax's longer range would require fewer base stations than other wireless systems, making it less expensive to implement for providing Internet access. This would be an important consideration in sparsely populated areas that don't typically generate much revenue for service providers.
It's premature to speculate whether xMax will experience widespread adoption, said Mike Roberts, principal analyst at Informa Telecoms & Media, a market research firm. "History has shown that most new telecom technologies fail to deliver as advertised," he added.
Roberts also said that providers will have to weigh the technology's benefits against the risks of implementing a proprietary solution and determine whether xMax will work with existing infrastructures.
Vulnerability-Assessing Worms May Be on Their Way
Security experts are expressing concern about a new type of worm that checks computers for vulnerabilities and then sends the information back to the author. The hacker could then either attack the machines or take them over to mount attacks on other systems.
These vulnerability-assessing worms currently are not very common, noted Bruce Schneier, founder and chief technology officer of Counterpane Internet Security. However, he said, their numbers may increase soon because virus writers appear to be changing the focus of their work from code that causes immediate, widespread problems to low-volume, hard-to-trace, long-lasting malware with narrower goals such as assessing vulnerabilities. This will make it easier for hackers to use malware to gain information that will make their exploits dangerous, rather than just attention getting.
The new worms are a type of bot, according to Bruce Hughes, senior antivirus researcher with security vendor Trend Micro. Like other types of malware, he said, they infect systems via assorted vulnerabilities, such as backdoors created by earlier attacks.
The worms typically enter a machine in an internal network and then scan the network to find more vulnerable computers, according to Mikko Hypponen, chief research officer for security vendor F-Secure. They sometimes also attack an off-site Internet-connected corporate laptop, which then brings the malware back to the home network, he noted.
Once in a system, the worms look for and report buffer-overflow and other vulnerabilities. "The worms do not scan for the vulnerabilities in the same way a commercial vulnerability scanner does," said Hughes. Instead, the worm scanners are much simpler and smaller and look only for targeted weaknesses, explained Hypponen. According to Hughes, they launch multiple attacks, based on various potential vulnerabilities, until finding one that works.
Once the worm infects a computer and scans the machine, it sends vulnerability information to the hacker via Internet relay chat. "They set up IRC servers on infected computers and access information via routes jumping from one machine to another," explained Hypponen.
And the malware writer can cause more problems by remotely altering the code in much the same way that vendors remotely install updates or patches on their software, noted Schneier.
Virus writers also use techniques such as entry-point obfuscation and encrypted communications to make the new worms hard to detect and trace, he explained. The worms will thus stay in place longer and find more vulnerabilities.
Swarmcasting Software Turns PCs into Broadcast Stations
A team of US university students has developed software that lets any computer with a broadband Internet connection broadcast streaming video or audio, effectively turning it into a miniature media-distribution station.
The Alluvium software could let parents broadcast their children's soccer games, enable small-scale filmmakers to distribute their work more easily, and help organizations communicate with members or employees. The technology was developed at the University of Texas' ACTLab (www.actlab.utexas.edu), a group of participants with art, technology, and other backgrounds.
The researchers built Alluvium as a way to stream data via swarmcasting technology. With swarmcasting, rather than use large amounts of bandwidth sending an entire download to each requesting customer, the content owner's server sends parts of the file to different customers, who then send it to others. All of the participants share pieces until everyone has the complete file. Alluvium then enables the streaming of the swarmcasted data to viewers.
The system works somewhat like the BitTorrent P2P tool for distributing large files such as video to multiple points without heavy bandwidth demands. A difference between Alluvium and BitTorrent is how they download files. Alluvium puts a file's parts in order before downloading them, thereby letting recipients view the file as it streams in. BitTorrent doesn't send files in order. Viewers thus can't watch the file until all parts arrive and the system puts them in the proper sequence.
Researcher Brandon Wiley, an ACTLab teaching assistant, said Alluvium doesn't encourage piracy because it is designed for broadcasting free content from individual computers to multiple recipients on a set schedule. This differs from peer-to-peer file sharing, which lets users contact one another at any time to access content, potentially including copyrighted material.
Wiley explained that his team designed the tool to give independent content producers a way to promote and distribute their work. He said the easy-to-use approach could democratize Internet television by letting even an individual with just a broadband connection broadcast material.
The developers recently posted the first full beta version of the open source Alluvium software on their Web site. They hope to begin all-day broadcasts of experimental films, documentaries, and other video from various sources on their ACTLab TV station for the Web (http://actlab.tv) in the near future.
Calculator Takes a Natural Approach to Problem Solving
A UK researcher has developed a new calculator interface that is more intuitive to work with than traditional button-operated calculators and thus reduces user errors.
The interface—developed and patented by University of Swansea doctoral candidate Will Thimbleby—lets users write mathematical problems onto a screen as they would on a piece of paper, explained Harold Thimbleby, Will's father, who initiated the concept.
Doctoral candidate Will Thimbleby solves problems on his calculator interface. He says the interface is more intuitive to work with than traditional button-operated calculators and thus reduces user errors. "Calculator use is taught in schools at the moment. One of the ideas behind our work was that this is a waste of time when we could be teaching mathematics instead," explained Harold Thimbleby.
The new device—which was written in Java and uses handwriting-, character-, and expression-recognition software modules—works with standard mathematical notation. Users can correct, alter, or move numbers or commands simply by utilizing a pen.
The calculator has been built as an interactive whiteboard but could work on any computer that runs Java.
Harold Thimbleby said the calculator reduces errors because users write calculations in a standard, familiar format. They don't have to arrange equations in a counter-intuitive way so that the calculator can understand it.
The system also allows a wider range of calculations than traditional devices, such as logarithmic equations. The device also works on complex, real, and imaginary numbers; problems with single unknowns; and factorial calculations, all of which would be difficult or impossible to solve on a conventional calculator, Harold Thimbleby explained.
He said he tested the device with users and found that they made fewer errors than with a traditional calculator.
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