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56 NUTS AND BITS—TELECOM HARDWARE, SOFTWARE, AND MORE Lidija Sekaric, now a researcher at IBM’s Watson Research Center in Yorktown Heights, New York, worked with Cornell graduate student Keith Aubin and undergraduate researcher Jingqing Huang on the new nanoguitar, which is about five times larger than the original but still so small that its shape can only be seen in a microscope. Its strings are really silicon bars, 150 by 200 nm in cross-section and ranging from 6 to 12 mm in length (a micrometer is one-millionth of a meter; a nanometer is a billionth of a meter, the length of three silicon atoms in a row). The strings vibrate at frequencies 17 octaves higher than those of a real guitar, or about 130,000 times higher. The researchers recently observed that light from a laser could cause properly designed small devices to oscillate, and this effect underlies the nanoguitar design. The nanoguitar is played by hitting the strings with a focused laser beam. When the strings vibrate, they create interference patterns in the light reflected back, which can be detected and electronically converted down to audible notes. The device can play only simple tones, although chords can be played by activating more than one string at a time. The pitches of the strings are determined by their length, not by their tension as in a normal guitar, but the group has “tuned” the resonances in similar devices by applying a direct current voltage. “The generations of researchers to come can aim to play more complex pieces,” says Sekaric. “This goal would indeed improve the science and technology of NEMS by aiming for integrated driving and detection schemes as well as a wide range of frequencies produced from a small set of vibrating elements.” Most of the devices the group studies don’t resemble guitars, but the study of resonances often leads to musical analogies, and the natural designs of the small resonant systems often leads to shapes that look like harps, xylophones, or drums. The guitar shape was, Craighead Sekaric says, “an artistic expression by the engineering students.” Sekaric notes that “a nanoguitar, as something close to almost everybody’s understanding and experience, can also be used as a good educational tool about the field of nanotechnology, which indeed needs much public education and outreach.” The ability to make tiny things vibrate at very high frequencies offers many potential applications in electronics. From guitar strings on down, the frequency at which an object vibrates depends on its mass and dimensions. Nanoscale objects can be made to vibrate at radio frequencies (up to hundreds of megahertz) and so can substitute for other components in electronic circuits. Cell phones and other wireless devices, for example, usually use the oscillations of a quartz crystal to generate the carrier wave on which they transmit or to tune in an incoming signal. A tiny vibrating nanorod might do the same job in vastly less space, while drawing only milliwatts of power. Research by the Cornell NEMS group has shown that these oscillations can be tuned to a very narrow range of frequencies—a property referred to in electronics as “high Q”—which makes them useful as filters to separate signals of different frequencies. They also may be used to detect vibrations to help locate STORAGE 57 objects or detect faint sounds that could predict the failure of machinery or structures. As the nanoguitar shows, NEMS can be used to modulate light, meaning they might be used in fiber-optic communications systems. Such systems currently require a laser at each end for two-way communication. Instead, Craighead suggests that a powerful laser at one end could send a beam that would be modulated and reflected back by a far less expensive NEMS device. This could make it more economical to run fiber-optic connections to private homes or to desktop computers in an office. 2.14 STORAGE As mobile devices become more capable, they’ll need to store a growing amount of data. Getting tiny mobile units to store vast quantities of information isn’t easy, however, given physical space restraints. But researchers are working hard to pack data into ever-smaller amounts of space. 2.14.1 Tiny Hard Drive Toshiba has developed a 0.85-inch hard disk drive, the first hard drive to deliver multi-gigabyte data storage to a sub-one-inch form factor. The device is suitable for use in a wide range of mobile devices, including palmtops, ultraportable notebook PCs, handheld GPS units, and digital audio players and jukeboxes. With the new drive, Toshiba has achieved a smaller, lighter, high-capacity storage medium in which low-power consumption is complemented by high performance. The drive will have an initial capacity of 2 to 4 GB and deliver enhanced data storage to smaller, lighter more efficient products. Toshiba expects the new drive to bring the functionality and versatility of hard disk drives to a wide range of devices, including mobile phones, digital camcorders, and external storage devices, as well as inspire other manufacturers to develop new applications. The device is scheduled to begin appearing in mobile devices during 2005. Work on the drive has centered on Toshiba’s Ome Operations-Digital Media Network, home to the company’s main development site for digital and mobile products and the manufacturing site for the device. The drive under development is planned to have a capacity of 2 to 4 GB, but Toshiba anticipates achievement of even higher densities in the near future. 2.14.2 Optical Storage A new optical storage medium, developed jointly by engineers at Princeton University and Hewlett-Packard, could profoundly affect the design and capabilities of future mobile devices, including mobile phones and PDAs. 58 NUTS AND BITS—TELECOM HARDWARE, SOFTWARE, AND MORE The discovery of a previously unrecognized property of a commonly used conductive polymer plastic coating, combined with very thin-film, siliconbased electronics, is expected to lead to a memory device that’s compact, inexpensive, and easy to produce. The breakthrough could result in a single-use memory card that permanently stores data and is faster and easier to use than a CD. The device could be very small because it would not involve moving parts such as the laser and motor drive required by CDs. “We are hybridizing,” says Stephen Forrest, the Princeton electrical engineering professor who led the research group. “We are making a device that is organic—the plastic polymer—and inorganic—the thin-film silicon—at the same time.” The device would be like a CD in that writing data onto it makes permanent physical changes in the plastic and can be done only once. But it would also be like a conventional electronic memory chip because it would plug directly into an electronic circuit and would have no moving parts. “The device could probably be made cheaply enough that one-time use would be the best way to go,” Forrest says. Hewlett-Packard researcher Sven Möller made the basic discovery behind the device by experimenting with a polymer material called PEDOT, which is clear and conducts electricity. The material has been used for years as an antistatic coating on photographic film and more recently as an electrical contact on video displays that require light to pass through the circuitry. Möller found that PEDOT conducts electricity at low voltages but permanently loses its conductivity when exposed to higher voltages and currents, making it act like a fuse or circuit breaker. This finding led the researchers to use PEDOT as a way of storing digital information. A PEDOT-based memory device would have a grid of circuits in which all the connections contain a PEDOT fuse. A high voltage could be applied to any of the contact points, blowing that particular fuse and leaving a mix of working and nonworking circuits. These open or closed connections would represent “zeros” and “ones” and would become permanently encoded in the device. A blown fuse would block current and be read as a “zero,” whereas an unblown one would let current pass and serve as a “one.” The memory circuit grid could be made so small that, based on the test junctions the researchers made, 1 million bits of information could fit in a square millimeter of paper-thin material. If formed as a block, the device could store more than one gigabyte of information, or about 1,000 high-quality images, in one cubic centimeter, which is about the size of a fingertip. Developing the invention into a commercially viable product will require additional work on creating a large-scale manufacturing process and ensuring compatibility with existing electronic hardware, a process that might take as few as five years, Forrest says. The technology offers numerous potential mobile device applications. Extensive and detailed street map databases, designed for use with GPS and other location-oriented services, could be easily inserted into even the smallest mobile devices and consume very little power. Other possible applications STORAGE 59 include easily accessible music and e-book libraries, shopping and attraction directories, and powerful software applications. Funding for Forrest’s research came in part from Hewlett-Packard as well as from the National Science Foundation. Princeton University has filed for a patent on the invention. Hewlett-Packard has an option to license rights to the technology. 2.14.3 Nanoring Memory Recent nanotechnology research at Purdue University could pave the way toward faster computer memories and higher density magnetic data storage, all with an affordable price tag. Just like the electronics industry, the data storage industry is on the move toward nanoscale. By shrinking components to below 1/10,000th the width of a human hair, manufacturers could make faster computer chips with more firepower per square inch. However, the technology for making devices in that size range is still being developed, and the smaller the components get, the more expensive they are to produce. Purdue chemist Alexander Wei may have come up with a surprisingly simple and cheap solution to the shrinking data storage problem. Wei’s research team has found a way to create tiny magnetic rings from particles made of cobalt. The rings are much less than 100 nm across—an important threshold for the size-conscious computer industry—and can store magnetic information at room temperature. Best of all, these “nanorings” form all on their own, a process commonly known as self-assembly. “The cobalt nanoparticles which form the rings are essentially tiny magnets with a north and south pole, just like the magnets you played with as a kid,” says Wei, who is an associate professor of chemistry in Purdue’s School of Science.“The nanoparticles link up when they are brought close together. Normally you might expect these to form chains, but under the right conditions, the particles will assemble into rings instead.” The magnetic dipoles responsible for nanoring formation also produce a collective magnetic state known as flux closure. There is strong magnetic force, or flux, within the rings themselves, stemming from the magnetic poles each particle possesses. But after the particles form rings, the net magnetic effect is zero outside. Tripp developed conditions leading to the self-assembly of the cobalt nanorings, then initiated a collaboration with Dunin-Borkowski to study their magnetic properties. By using a technique known as electron holography, the researchers were able to observe directly the flux-closure states, which are stable at room temperature. “Magnetic rings are currently being considered as memory elements in devices for long-term data storage and magnetic random-access memory,” Wei says. “The rings contain a magnetic field, or flux, which can flow in one of two directions, clockwise or counterclockwise. Magnetic rings can thus store binary 60 NUTS AND BITS—TELECOM HARDWARE, SOFTWARE, AND MORE information, and, unlike most magnets, the rings keep the flux to themselves. This minimizes crosstalk and reduces error during data processing.” When you turn on your computer, it loads its operating system and whatever documents you are working on into its RAM, or random-access memory. RAM is fast, enabling your computer to make quick changes to whatever is stored there, but its chief drawback is its volatility—it cannot perform without a continuous supply of electricity. Many people have experienced the frustration of losing an unsaved document when their computer suddenly crashes or loses power, causing all the data stored in RAM to vanish. “Nonvolatile memory based on nanorings could in theory be developed,” Wei says. “For the moment, the nanorings are simply a promising development.” Preliminary studies have shown that the nanorings’ magnetic states can be switched by applying a magnetic field, which could be used to switch a nanoring “bit” back and forth between 1 and 0. But according to Wei, perhaps the greatest potential for his group’s findings lay in the possibility of combining nanorings with other nanoscale structures. “Integrating the cobalt nanorings with electrically conductive nanowires, which can produce highly localized magnetic fields for switching flux closure states, is highly appealing.” he says. “Such integration may be possible by virtue of self-assembly.” Several research groups have created magnetic rings before but have relied on a “top-down” manufacturing approach, which imposes serious limitations on size reduction. “The fact that cobalt nanoparticles can spontaneously assemble into rings with stable magnetic properties at room temperature is really remarkable,” Wei says. “While this discovery will not make nonvolatile computer memory available tomorrow, it could be an important step towards its eventual development. Systems like this could be what the data storage industry is looking for.” Wei’s group is associated with the Birck Nanotechnology Center, which will be one of the largest university facilities in the nation dedicated to nanotechnology research when construction is completed in 2005. Nearly 100 groups associated with the center are pursuing research topics such as nanometer-sized machines, advanced materials for nanoelectronics, and nanoscale biosensors. 2.15 MORE EFFICIENT BASE STATIONS As mobile devices get better, researchers are also looking to improve the technology that handles users’ calls. For example, Cambridge, Massachusetts-based Vanu has created the Vanu Software Radio, a software-based system that promises to replace a mobile phone tower’s room full of communications hardware with a single computer. The system is designed to making personal communications more affordable, particularly for small, rural communities. The software is also capable of running emergency communications—such as MORE EFFICIENT BASE STATIONS 61 police, fire, and ambulance channels—on the same device as the civilian system, eliminating the need for a separate network of emergency communications towers. “Rural customers are the first application of the technology, but large carriers are watching to see what happens,” says John Chapin, chief technology officer at Vanu. Vanu scientists developed and tested the software with funds from the National Science Foundation, the federal agency that supports science and engineering research and education. Although not yet commercially available, the technology is beginning to attract the attention of service providers nationwide. “When the telecom industry crashed, Vanu technology caused wireless operators to look at deployments differently,” says Sarah Nerlove, the NSF Small Business Innovation Research program officer who oversees Vanu’s awards. “Vanu was an ideal fit for their changing needs.” Mobile phone towers dot the landscapes of cities and suburbs, providing millions of Americans with access to wireless communications. At the base of each tower is an air-conditioned shelter filled with expensive equipment called a base station. “As technology advances, all of that equipment continually needs to be overhauled or replaced,” says Chapin. Besides replacing much of a base station’s hardware with a single server, radio software can aggregate equipment from many stations into a single location that communications engineers call a “base station hotel.” Vanu Software Radio performs all of the functions of a global system for mobile communications (GSM) base station using only software and a nonspecialized computer server. The servers run the Linux operating system on Pentium processors, further simplifying the technology and reducing cost. Vanu is demonstrating the technology in two rural Texas communities: De Leon in Comanche County and Gorman in Eastland County. When the test ends, sometime in 2004, the technology will remain as a cellular infrastructure run by Mid-Tex Cellular. Although the software currently runs on large servers, the product can also be used on a variety of ordinary desktop computers. This attribute will allow service providers to install the software on low-priced systems. Even an offthe-shelf PC can run the software, notes Chapin, although it wouldn’t be able to handle a large number of customers. The software’s portable design also allows it to easily adapt to hardware upgrades. The software has carried phone calls since it was installed in the Texas towns in June 2003. Vanu’s researchers are now tracking how many calls are successfully handled through the system, how well mobile phones can communicate with other mobile phones, and how well mobile phones can communicate with landline phones. In the years ahead, large carriers could use the software to establish base station hotels or to upgrade and condense their existing equipment. Additionally, the technology will allow service providers to more efficiently use their portion of the radio frequency spectrum and to quickly adjust to frequency and bandwidth modifications. 62 2.15.1 NUTS AND BITS—TELECOM HARDWARE, SOFTWARE, AND MORE Boosting Mobile Phone Range A new base station remote control system aims to increase the range of mobile phones and also potentially save service operator costs related to operating and repairing defective base station units. The recent explosive growth in mobile phones has been accompanied by a parallel growth in the underlying networks of base stations used to connect calls. This trend has created headaches for network administrators charged with keeping an increasing number of base stations active at all times. Now, a new power and management device is designed to allow administrators to manage base station operations remotely, reducing repair times, lowering costs, and improving range. The system was developed by Amper Soluciones, a Spanish company with expertise in telecom network management systems, and Ascom Energy Systems, a German company that specializes in industrial power plants. “Base stations for mobile phone networks are normally located in places where access is quite difficult,” says Juan Carlos Galilea, Amper Soluciones’ technical and technological support director. “With our system, the operator can remotely determine the real problem in the base station and monitor other systems, such as alarms and communication lines, as well as air conditioning, an external beacon, and even whether the door is open.” Some of the detected problems can be solved remotely, whereas others can be solved by maintenance staff on site. The control unit is built into a small cabinet and offers at least 25 percent more power in the same volume than existing units, says Galilea. The extra power increases the range of the base station, and the small size means that the station can be installed in awkward locations, such as gas stations or church spires. A battery subsystem can maintain operation even with a power loss. The unit’s remote management strengths show through in daily station maintenance, says Galilea. He notes that administrators can monitor their base stations continually and fix any problems as they arise. Galilea stresses the importance of using software simulations to speed up the design process. Rather than build complete prototypes, the project partners used computer simulations to adjust the density of elements in the power system and keep the operating temperature under control. “Simulations and then mechanical prototypes were used to determine the final structure. This allowed us to reduce development costs,” he says. The partners now aim to supply the unit to network operators in Europe and around the world. Chapter 3 Connections in the Air— Wireless Technologies The mobile revolution is being propelled forward by the simultaneous evolution of a set of key technologies in areas such as phone networks, wireless local area networks (WLANs), personal-area networks (PANs), and software infrastructure. Gartner, a technology research firm based in Stamford, Connecticut, reports that core technologies are evolving quickly with little prospect of significant stability before 2005. New developments in areas such as screens, fuel cells, and software for tasks such as speech recognition will continue to drive evolution in the long term. Wireless technology is the primary driving force behind the most powerful and world-altering telecommunications trends. Gartner reports that wireless networking will become ubiquitous with several different technologies and protocols coexisting in the home and office. By 2007, more than 50 percent of enterprises with more than 1,000 employees will make use of at least five wireless networking technologies. “All organizations should develop a strategy to support multiple wireless networking technologies,” says Nick Jones, a research vice president for Gartner. “Organizations developing consumer products for mobile networks should look for ways to add value by interacting with other home devices that might become networked, such as televisions, set-top boxes, game consoles, and remote-control light switches.” Telecosmos: The Next Great Telecom Revolution, edited by John Edwards ISBN 0-471-65533-3 Copyright © 2005 by John Wiley & Sons, Inc. 63 64 3.1 CONNECTIONS IN THE AIR—WIRELESS TECHNOLOGIES WIRELESS LAN “HOTSPOTS” Today’s WLANs represent just the beginning of what will eventually become a wireless world, connecting people to people and people to machines. Existing wireless “hotspots”—WLANs that allow mobile device users to access the Internet—allow mobile device users to Web surf, check their e-mail, and swap files while in public places like stores or airports. By 2025, separate hotspots will merge into a “hotworld,” enabling people to access the Internet from just about any location on the planet. “People will come to expect continuous connectivity in the way they currently expect to find electric lights wherever they travel,” says Martin Weiss, chairman of information science and telecommunications at the University of Pittsburgh. The past few years have been an extraordinary period for the hotspot market. Hotspots offer an inexpensive way for service providers to drive subscriptions for an increasingly mobile but data-reliant workforce. The number of worldwide hotspots grew from under 2,000 locations to over 12,000 locations in 2002, according to the Scottsdale, Arizona-based market research company In-Stat/MDR. In most regions, hotspot deployment growth continued strong throughout 2003. Much of the hotspot growth in 2003 resulted from carriers and other large players entering the market. Several European service providers are expected to become more active in the hotspot market in 2003, and providers in the Asia Pacific region will continue to demonstrate a high level of interest. The North American market will be largely impacted by the realization of Project Rainbow. Project Rainbow, a nationwide hotspot network, is supported by AT&T, IBM, and Intel-backed Cometa Networks. The arrival of 802.11.b “Wi-Fi” wireless has given today’s PC users a small taste of what a true “smart home” will be like. Tomorrow’s home networks will go beyond file and Internet access sharing to provide wall-to-wall control over home entertainment, information, communications, and environmental and security systems. “We are all going to have a home server, just like the furnace in the basement,” predicts Brian Costello, president of Supernova, an Internet consulting company located in Addison, Illinois. “Our computing devices will be tied into that server, along with our refrigerator, microwave, and heating, cooling, and security systems. 3.2 WLANS TO COME Beyond today’s Wi-Fi 80211.b technology, additional 80211.x standards promise to make wireless communication faster and more robust and efficient; these are important considerations for enterprises that are increasingly finding their present wireless LANs strained to the breaking point. Already available, 802.11a supports data rates of up to 54 Mbps. Widespread use, however, has been hampered by incompatibility with 802.11b technology (the standards use WLAN FOR EMERGENCY COMMUNICATIONS 65 different frequency ranges); thus a new standard was developed: 802.11g. This technology provides 802.11a-level data rates along with full 802.11b backward compatibility. The first 802.11g products started appearing in 2003, and the market is expected to shift into top gear by 2005. As prices begin falling, the new standard is expected to gradually edge out 802.11b technology. In the near future, support is likely to begin appearing for 802.11f, a standard that provides interoperability between access points manufactured by various vendors, enabling portable device users to roam seamlessly between networks. And the alphabet soup doesn’t stop there. An array of additional 802.11x standards, covering everything from quality of service (802.11e) to security (802.11i) to network performance and management (80211.k), are also expected to enter the mainstream over the next 12 to 36 months. Also on the horizon is 802.16. The WiMax standard enables wireless networks to extend as far as 30 miles and transfer data, voice, and video at faster speeds than cable or DSL. It’s perfect for ISPs that want to expand into sparsely populated areas, where the cost of bringing in DSL or cable wiring is too high. The future also looks promising for the up and coming low-rate Wireless PAN (WPAN) technology, 802.15.4, and ZigBee. The ZigBee specification, now in development, will define the network, security, and application interface layers, which can be used with an 802.15.4 solution to provide interoperability. ZigBee Alliance members are definitely determined to carve out a piece of the wireless pie for themselves. According to In-Stat/MDR, quite a bit hinges on the ability of the ZigBee Alliance to deliver a final specification in a timely manner, including completed, successful interoperability tests. If these milestones are not achieved in a reasonable amount of time, other competing wireless technologies could take hold in these markets, such as a yet-to-be-determined low-rate UltraWideband WPAN alternate PHY or a potential Bluetooth “Lite” version. Therefore, there is an impetuous to move forward according to schedule. According to Joyce Putscher, director of In-Stat/MDR’s converging markets and technologies group, “the heightened interest in 802.15.4/ZigBee wireless connectivity could slowly make ‘The Jetsons’ home of the future a reality; however, I doubt we’ll see that automated meal maker any time soon.” 3.3 WLAN FOR EMERGENCY COMMUNICATIONS Hotspot technology also promises to help public service, emergency services and rescue workers exchange information and collaborate on tasks more effectively and efficiently. Today, first responders would like to be able to send messages simultaneously to all the emergency workers at the scene of a disaster if necessary, but lack of interoperability among various types of radio equipment prevents them from doing so today. In the future, first responders converging on a