New Mobile Phones Will Work with Cellular and Wi-Fi
Mobile-phone carriers are preparing to offer a service that would seamlessly and automatically switch cellular calls to Wi-Fi networks once a customer is within range of a participating network.
This dual-mode approach could save consumers service minutes, as some of the time they currently spend using cellular service would be spent using Wi-Fi.
This could be particularly appealing in Europe, where cellular rates are high, said analyst Charles Golvin with Forrester Research. In the US, he noted, the technology could enable users to buy less expensive cellular-service packages that offer fewer minutes per month.
Mobile-phone carriers plan to offer a service that would seamlessly switch cellular calls to a Wi-Fi network once a customer is within range of a participating network. Typically, a network controller would pass calls between a cellular base-station controller and an Unlicensed Mobile Access (UMA) base-station controller, which would package the cellular signals into an IP format. The Wi-Fi service would then use voice-over-IP telephony, sending data packets over an IEEE 802.11 network. Meanwhile, the plan would give cellular customers access to highspeed Wi-Fi networks for video, games, Web access, and other data-intensive services, which could attract subscribers.
And the use of Wi-Fi home networks for telephony might convince some users to give up landlines for mobile carriers' cellular/Wi-Fi services, explained Steve Shaw, director of marketing for Kineto Wireless, which provides Unlicensed Mobile Access equipment for the new approach.
UMA is the protocol—developed by the Third Generation Partnership Project, a consortium of telecommunication companies and organizations—that defines how to package a circuit-based voice call for transmission via an IP network, such as one based on Wi-Fi.
T-Mobile USA may become the first US carrier to offer the cellular/Wi-Fi service, as it already offers at least one dual-mode phone, noted company spokesperson Graham Crow.
US carriers Cingular and Sprint Nextel are also pursuing such an approach, noted Golvin.
European service providers—including Telecom Italia and TeliaSonera—are also working on dual-mode offerings. Orange recently announced availability of its Unique dual-mode service in France, Holland, Poland, Spain, and the UK.
The Wi-Fi aspect of dual-mode services uses voice-over-IP telephony, sending data packets over IEEE 802.11b and g networks. 802.11b has a maximum data rate of 11 megabits per second, and 802.11g provides 54 Mbps, while third-generation cellular promises only up to 4 Mbps.
In a typical dual-mode approach, a network controller seamlessly passes calls between a cellular base-station controller and a UMA base-station controller, which packages the cellular signals into an IP format and tunnels them over the Internet.
Dual-mode users would have to work with a Wi-Fi network that their cell phone carrier either provides or interacts with, such as one in an airport or a coffee shop.
To succeed, said Golvin, the transfers between cellular and Wi-Fi service will have to be truly seamless, and more users will need to have Wi-Fi networks at home or in the office. And, said Shaw, the prices must be reasonable.
However, Golvin added, Wi-Fi isn't as energy-efficient as cellular service and thus could drain mobile-phone batteries quickly.
Using Tags to Make a More Secure OS
As the software underpinning to computers, operating systems are a critical part of overall security. Because of this, many companies have expended considerable time and resources to make OSs safer.
A UCLA researcher is taking a novel approach to this problem. Assistant professor Eddie Kohler and a team of MIT, Stanford University, and UCLA graduate students have designed Asbestos. The OS minimizes unauthorized users' ability to access designated data from either PCs or servers, even in the face of security failures elsewhere on the system.
With a typical OS, said Kohler, programs run by the same computer offer identical access rights. This makes it more difficult for users to individualize or control access to their data.
Asbestos, on the other hand, dynamically provides various data sets with simple, 61-bit tags that specify and carry out different access-control policies. The application that creates the data allocates the tag, which Asbestos implements. The tag states which other users and applications can read the data. Unauthorized users are unable to access the information.
Asbestos tags also provide security for applications by keeping other programs, which could contain viruses or other malicious code, from accessing them.
According to Kohler, Asbestos uses a lightweight tagging process that doesn't require a lot of system memory. For example, the research team's prototype Asbestos-based Web server can store tag-based data for 145,000 users, needing only 5.5 Kbytes per person.
To maximize Asbestos' potential, Kohler said, users would have to determine the most restrictive access privileges that the different parts of their applications require and then identify which tag configurations will enforce them. Developers would then write their applications accordingly.
Initial tests have been promising, according to Kohler. However, he noted, he has no plans to commercialize the technology.
IBM Plans First Petaflops Supercomputer
The US Department of Energy has awarded IBM a contract to build what could be the world's first supercomputer capable of performing 1 petaflops—a million gigaflops.
The DoE's Lawrence Livermore National Laboratory currently houses the world's fastest supercomputer, IBM's Blue Gene/L, which performs up to 280 teraflops. Other research teams—including several in Japan and the US—are also working on petaflops computers.
IBM—along with partners Advanced Micro Devices, QLogic, and Voltaire—plans to build the Roadrunner supercomputer using 16,000 AMD Opteron server processors and 16,000 IBM high-performance Cell processors.
Cell chips—which IBM, Sony, and Toshiba originally designed for use in the PlayStation 3 videogame console—include eight engines capable of rapidly parallelizing and performing calculations, said Dave Turek, IBM's vice president for deep computing.
A master processing unit orchestrates data access and calculations by the floating-point units, making Cell very efficient and powerful, he explained.
Each Cell processor runs at 3.2 GHz and, in Roadrunner, would yield 1 teraflop per node, thereby contributing to the supercomputer's high performance.
Cell technology, which could be used in a range of mathematics-intensive applications, is being fine-tuned for Roadrunner, Turek noted.
In the supercomputer, the Cell chips would handle demanding floating-point and graphics-related computations, while the Opteron chips would boost the system's overall raw performance.
Using Opteron processors is important because they could provide an affordable architecture on which to base other supercomputers, Turek added.
Roadrunner will use InfiniBand—a high-speed, serial, switched-fabric technology—for communications between the Opteron processors. It will utilize HyperTransport—a bidirectional, serial/parallel, high-bandwidth, low-latency bus—for data transmission between Cell-based nodes.
The company will use the Red Hat Linux 4.3 operating system, as well as software for tasks such as cluster management. IBM expects the computer to have 32 terabytes of memory and occupy 12,000 square feet of floor space.
The $110 million project will have three development phases—the first involving construction of an 80-teraflops machine—and is slated for completion in 2008.
The DoE will install Roadrunner—named after New Mexico's official bird—at its Los Alamos National Laboratory, which is located in the state. The agency will use the computer to help safeguard the US nuclear weapons stockpile by simulating a wide variety of conditions, including the effects of aging on materials.
Los Alamos spokesperson Kevin Roark said the DoE accomplishes this by running advanced simulation models on its supercomputers.
In terms of general supercomputing and its value to science and industry, Roadrunner would be a noteworthy advance, said University of Texas associate professor Doug Burger. However, he added, the supercomputer would be complex and thus difficult to program to run optimally. Also, he said, the machine could have trouble running hard-to-parallelize applications.
News Briefs written by
Linda Dailey Paulson, a freelance technology writer based in Ventura, California. Contact her at ldpaulson@yahoo.com.
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