Developments to Watch
WILL THE OFFICE PHONE SOON CUT THE CORD?
IN A FEW YEARS, YOUR DESK-top phone may lose its cord. Today, cellular office-phone systems are rare due to their high operating expense. But cell-phone suppliers are starting to come up with differential pricing schemes, with calls made from an office being nearly free.
In the vision of Sweden's L.M. Ericsson, a set of channels is designated for in-building use. Calls would be picked up by an antenna in the building and relayed to the wired network. The same channels could be used simultaneously in dozens of other buildings because the signals are low-power and will not interfere with each other. Walk outside during a conversation, however, and the system would switch to a channel for long-range calls--with the charges mounting accordingly.
Telia Mobitel, the No.1 mobile-phone operator in Sweden, recently began testing a tiered pricing plan in cooperation with Ericsson. Some 27% of all Swedes already have mobile phones. Telia hopes the availability of cheap in-building use will nudge the subscription rate past 50%.EDITED BY OTIS PORT By Peter CoyReturn to top
SUPERCOMPUTERS MAY RUN ON WORMS
CAN ELECTRONIC WORMS chew through silicon and spit out a new breed of computer? That's the goal at Virginia Polytechnic Institute & State University. Researchers Peter M. Athanas and Ray A. Bittner Jr. are building a so-called Wormhole system that promises affordable desktop systems faster than any supercomputer.
The trouble with today's computers is that they are compromise tools. They would be a lot quicker if software programs were converted into special-purpose chips. But then everyone would need multiple computers, because hardware optimized for analyzing X-ray images, say, would be woeful at batting out nursing schedules. So Athanas favors a new option: teaming field-programmable gate array (FPGA) technology with just-in-time data and instructions.
FPGA chips have generic circuits that can be repeatedly tailored with electronic stitches to fit almost any task. Usually, that's done offline because it takes a while. But the Virginia Tech team has built a superspeedy FPGA. When it's fed a worm--a string of data specifying a new circuit pattern plus a series of tasks--the chip instantly rewires itself and begins crunching. So, Wormhole computers would need fewer chips to do almost anything faster.EDITED BY OTIS PORTReturn to top
NEW CHIP RECIPE: ADD NITROGEN, BAKE AT 900C
ENGINEERS HAVE LONG dreamed of semiconductor chips that could handle both optical and electrical signals. But silicon hasn't been practical for processing pulses of light. And the semiconductor materials that are--such as gallium arsenide--are expensive or very fragile. Now, hybrid optoelectronic chips have just moved closer to reality.
Researchers at Rochester Institute of Technology have found a way of enabling silicon to see the light. In telecommunications, this could end the need for the cumbersome equipment that converts laser pulses zipping through optical fibers into the electrical signals required by silicon-based switching systems.
The key is a tough new form of porous silicon. Fragility has always plagued porous silicon, a curious form of silicon that's mainly air--but is good for optical signals. But after acid eats away most of the silicon, creating a delicate spongelike structure, the material is too flimsy to withstand chipmaking operations.
The Rochester team, led by researcher Philippe M. Fauchet, set out to make porous silicon stronger. As disclosed in the Nov. 28 issue of Nature, this turned out to be easy: Bake silicon wafers in a standard chipmaking oven at 900C--but in nitrogen, not air. The heat boils off hydrogen atoms, leaving the porous silicon ready for reinforcement with two layers of silicon oxide. Next, Fauchet's team hopes to boost the light-emitting efficiency of this new kind of porous silicon.EDITED BY OTIS PORTReturn to top