Internet Wireless Gridlock:
Optical PC Desktops better tan wireless?
Optical advantage?
Is this in part why TI has been weak?
dailynews.yahoo.com
Go optical my friend,
TA
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interactive.wsj.com
E-Business, January 8, 2001
Raft of New Wireless Technologies
Could Lead to Airwave Gridlock
By JARED SANDBERG
Staff Reporter of THE WALL STREET JOURNAL
For months it was driving Howard McCollister nuts.
The 50-year-old surgeon from Deerwood, Minn., had equipped his kids' Apple laptops with wireless antennas called the AirPort. The doodads allow the McCollister siblings to connect to the Internet without a direct phone line. Instead, they receive their Internet link through the air, via a small radio transmitter connected to a phone. The setup ended arguments "about one or the other hogging the phone line," says Dr. McCollister.
But the wireless link kept blinking out, and Dr. McCollister couldn't figure out what was wrong. He upgraded the software and pored over online discussion groups without any luck.
Finally, a friend who is an Apple dealer asked if he had a cordless phone that transmits its calls at 2.4 gigahertz and Dr. McCollister had his breakthrough. Two months earlier, he had bought two of the phones for his kids. It turned out they were creating interference that scotched the computer connection. Confirming the problem, he found a document on Apple's Web site that lists things ranging from 2.4 gigahertz phones to microwave ovens as potential sources of interference.
Brace for mid-air collisions. The high-tech industry is hyping a raft of new technologies that use the airwaves to link personal computers, Palm hand-held devices and other gadgets to the Internet and corporate networks, as well as to each other. Executives say such wireless connections herald a new era of anywhere, anytime computing.
But these technologies communicate in the increasingly crowded 2.4 gigahertz band of the radio spectrum, potentially clogging the airwaves like planes over LaGuardia. Developed to liberate people from their desks and the linguine knots of cables emerging from their computers, some wireless technologies could create airborne entanglements that increase the complexity of computing, instead of reducing it.
"New technology is always more complex at first," says Forrester Research analyst Galen Schreck. "We promise something that is going to be magical, something that will configure itself, but that doesn't emerge until later into the game."
The wireless technologies come in several flavors. One is called Wi-Fi, which also goes by the technical name 802.11b, and is used by Apple. It is aimed at allowing machines inside houses to communicate at high speeds and share Internet connections. A similar technology used by other companies is dubbed HomeRF. Lastly, there's a nascent technology called Bluetooth that is intended to allow hand-held computers, cellphones, pagers, laptops and computer peripherals such as printers to communicate with each other at distances of up to 30 feet. That way, for instance, you could zap a phone number from your cellphone to a friend's Palm.
Typically, interference occurs when two radio signals using the same frequency collide, corrupting both. The receiving antenna simply can't pick out the correct signal and it must be retransmitted, resulting in a loss of speed.
Yet the Federal Communications Commission knew such interference was the likely outcome when it set aside the 2.4 gigahertz spectrum for such uses. Unlike most areas of the radio spectrum, which are licensed for specific applications such as TV signals or cellphones, the 2.4 gigahertz band was designed as a sort of innovation zone, where technology companies and cash-strapped entrepreneurs could test new wireless devices without first seeking a costly government license.
The band has been swamped in recent years by communications companies using it for data networking, resulting in a free-for-all of radio signals. Yet the FCC considers such interference to be the price of doing business in the band. Engineers must build wireless systems robust enough to coexist with such "noise."
"Every one of these devices has a label on it that says they can cause interference and must accept interference," says Julius Knapp, chief of the policy division in the FCC's engineering office. He says most products should work fine. But, he adds, "If you really require high reliability, that's really not what this band was set up for."
Some industry engineers say there's little to worry about. Sure, there will be some collisions, but wireless technology is constantly improving. For example, in the early days of cordless phones users sometimes could hear their neighbor's conversations, while baby monitors could pick up signals from the infant next door.
Anticipating interference, most newer wireless systems use "spread spectrum" technologies, in which the signal hops within a small band of frequencies at lightening speeds, or changes the pattern of transmissions, to reduce the impact of warring signals. Spread spectrum technology, originally conceived during World War II by actress Hedy Lamarr to thwart eavesdropping, essentially prevents the kind of accidental snooping of the past.
Because most of these new wireless devices operate at relatively short ranges, any interference should be confined to a localized area. What's more, most of the anticipated uses won't require a constant connection to the network, so they won't always be sending out a signal that could cause interference. For example, when a user is browsing the Web from a wireless laptop, the computer doesn't need to keep a constant connection to the wireless Internet link.
Bluetooth is aimed at connecting gadgets when they are near each other. For example, a user may point to a phone number on the screen of Bluetooth-enabled Palm; the Palm would then wake up a cellphone in the user's briefcase, which would allow the user to communicate through a wireless Bluetooth headphone.
When there is a signal overlap, the technologies are designed to "degrade gracefully" and retransmit any lost data, engineers say. "There's no doubt that because they share the same spectrum, they're going to collide," says Tod Sizer, a researcher at Lucent Technologies Inc.'s Bell Labs and the chairman of the Bluetooth Coexistence committee. But Mr. Sizer is optimistic that equipment makers will devise fixes that will prevent users from noticing the interference.
Yet technology has proven time and again that anticipating its use can be a tricky. A few weeks ago, Sony Corp. unveiled a television set in Japan called the Airboard. Resembling the screen of a laptop computer, it uses Wi-Fi to allow consumers to roam their homes while watching the tube. Networking giant 3Com Corp. has a radio, dubbed the Kerbango, that the company says will use Wi-Fi to deliver Net-based wireless music. And at San Francisco's 3Com Park, hand-held computers using Wi-Fi are being deployed to allow 49ers football fans to chat by typing and to call up player statistics.
These are just the kinds of data-intensive applications, often requiring a constant connection, in which interference could pose problems. Suddenly, there could be a hiccup in a TV picture or a pause in a song.
Similarly, no one predicted that Wi-Fi would be used as an instrument for techno-ideologues. Some people in cities such as San Francisco and London are putting antennas on their rooftops to link their in-home wireless systems, in effect creating neighborhood networks. That allows them to share their Internet connections or resources such as digital music files stored on their home PCs. Anyone with a $150 wireless Wi-Fi card can join in over the air.
Matt Westervelt, a 28-year-old system administrator for Real Networks Inc., has been working since July on a home-grown wireless network in the Seattle area. With some of the same grass-roots idealism that gave rise to the Internet, Mr. Westervelt is hoping to free people from the grip of Internet services and their monthly fees, as well as the government and its regulators. "We're in control of it," he says. "We're not leasing someone else's network."
Governments may not stop these networks, but buildings, street lamps and wet trees might. Outdoor usage of Wi-Fi is particularly prone to interference, including from some street lamps that emit radiation. And as more neighbors use the network, the potential for interference multiplies.
Some fans of these public-access wireless networks even envision them being used for voice calls, totally cutting out the phone system. But wireless guru Harvie Branscomb says that anyone trying to offer phone service over such networks won't get the kind of quality of traditional cellular networks. "They probably never will," says Mr. Branscomb, who was contracted five years ago by a Sun Microsystems Inc. executive to build one of the first public-access wireless networks, in Aspen, Colo.
Most users are more concerned about garden-variety interference involving the new wireless networks. The most problematic collisions will occur when, say, two Bluetooth devices are communicating near a laptop that is connected to a somewhat distant Wi-Fi transmitter. Under this scenario, the Bluetooth devices could cause problems for the laptop as it tries to communicate with the wireless network.
"Then the performance degradation is almost catastrophic," says Manpreet Khaira, founder and chief executive of wireless start-up Mobilian Corp. (www.mobilian.com1) He says customer-service centers of companies that sell these devices "are going to be overloaded" with complaints.
Now, companies such as Mobilian and Intersil Corp. (www.intersil.com2) are trying to create transmitters that will co-exist peacefully. Standards bodies that determine requirements for the technologies also are calling for suggestions to solve the problem. Stephen Schellhammer, a senior director at Symbol Technologies Inc. and head of such a standards group, is optimistic. Still, he's aware that the technologies are being used in ways no one would have originally conceived. "No one can predict everything," he says.
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