1.2

0.9

0.6

0.3

0.0

129

0

1270

1310

133

0

135

0

1370

139

0

1410

143

0

145

0

1470

149

0

1510

153

0

155

0

1570

159

0

1610

1300 1400 1500 1600

Conventional fiber

Full-spectrum (zero water peak) fiber

Loss

, dB/

km

Wavelength, nm

E-band

B R I E F S

AT&T BREAKUP RATIFIED. On 10 July,

AT&T shareholders approved a plan to

reorganize what remains of the phone

giant. The plan calls for its cable opera-

tions to be spun off and then merged into

Comcast. A new tracking stock covering

its consumer long-distance operations

will be created. The remaining AT&T

shares will then be concentrated in a

one-for-five reverse stock split to get

them up to a reasonable price per share.

Separately, AT&T Wireless—spun off

as a separate company last year—is

reported to be in talks with Deutsche

Telekom about a merger with Voice-

Stream Wireless. An AT&T-VoiceStream

merger would create the second-largest

U.S. wireless carrier. But Deutsche Tele-

kom may have some reorganizing to do

itself. Chairman Ron Sommer was under

fire at press time, not least because he

paid $24 billion to acquire VoiceStream

last year.

IT’S A SITE! On 9 July, the U.S. Senate

voted 60 to 39 to approve the establish-

ment of a repository for

nuclear waste at Yucca

Mountain in southern

Nevada. The House ap-

proved the Yucca site in

May. Still, the U.S. Nucle-

ar Regulatory Commis-

sion must grant a license

to set up the repository. Vowing to con-

tinue his efforts to prevent Yucca Moun-

tain from being used in this fashion, Sen-

ator Harry Reid (D-Nev.) [photo] said,

“I’ve just begun to fight.”

NEWS LINKS BROKEN. On 5 July, a

Danish court ordered online news service

Newsbooster.com (Copenhagen) to stop

linking to news stories on the Web sites

of 20 Danish newspapers. They had main-

tained that the links to news stories under-

mined the newspapers’ advertising sales

businesses. Newsbooster, which retains

links to some 4500 newspapers world-

wide, has removed its links to the Danish

newspapers, but plans to appeal. Anders

Lautrup, manager of the site, said, “We’re

deeply shocked. I trust [the court’s deci-

sion] will have consequences for search

engines worldwide.” ––WWiilllliiee DD.. JJoonneess 21

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embedded DRAM project manager atIBM Microelectronics (Hopewell Junction,N.Y.). But they have no plans at present foroffering destructive-read embeddedDRAMs to their customers.

“It’s difficult for a customer to accepta new architecture right away,” saysWordeman. “We need to find the right

application that will motivate the cus-tomer to adopt a new memory.” The newarchitecture is a little more complex thanconventional designs, he adds. But thereis nothing that would prevent it frombeing incorporated into the company’sASIC library in the future.

—Linda Geppert

New Global Standard Set For Metro NetworksThe International Telecommunication Union has removed a barrier to better short-haul communications in urban centers

Coarse wavelength-division multiplexing (CWDM) systems that comply with ITU-T

Recommendation G.694.2 operate on 18 wavelengths, spaced 20 nm apart, between

1270 and 1610 nm. Newer full-spectrum fiber [red] eliminates conventional fiber’s

high loss due to a water-absorption peak around 1400 nm [yellow band]. Those

losses otherwise would make up to 5 of the 18 wavelengths impractical for CWDM.

COMMUNICAT IONS • Yes, thetelecommunications industry is in trou-ble, but some parts are in less troublethan others. Short-haul optical networksin urban areas, for example, have littlecapacity to spare and are ripe to squeezemore into their existing fiber—providingthat the technology for doing so doesnot cost too much. An economicallyattractive approach is to base multiplex-ing systems on channels that are spacedrather far apart, and for some years com-panies have been deploying such sys-tems while a standard was being devel-oped. But there was no guarantee thatthe channel wavelengths they chosewould be in the final standard.

Their period of suspense is over thanksto a standard approved this past June by theTelecommunication Standardization Sec-tor of the International Telecommunica-tion Union (ITU, Geneva). Officially knownas ITU-T Recommendation G.694.2, thenew standard specifies a set of wavelengthsfor use in what are known as coarse wave-length-division multiplexing (CWDM) sys-tems. Unlike dense wavelength-divisionmultiplexing (DWDM), in which wave-lengths are spaced less than a nanometerapart, the new standard for CWDM speci-fies 20-nm spacing. The implications ofthis wider spacing are twofold.

First, keeping the wavelengths so farapart means that tolerances on lasers

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and filters can be relaxed. Laser wave-lengths can be allowed to drift withchanges in ambient temperature withoutfear that they will interfere with oneanother, explains Jerry Shrimpton, a con-sultant for Ciena Corp. (Linthicum, Md.)and what the ITU calls a rapporteur—essentially a leader—of a group studyingcertain issues in optical transport. Bothfinancial and power budgets profitbecause thermoelectric coolers, crucialfor stabilizing wavelengths in DWDMsystems, are not needed.

In addition, with the wider wave-length spacing, CWDM filters are alsoeasier and cheaper to make, becausefewer manufacturing steps are needed tocomply with looser tolerances.

Overall, a system based on CWDMcan cost 40 percent less than if the samenumber of channels of a DWDM sys-tem were used, according to Paul Dick-inson, technical manager of the Cus-tomer Systems Engineering Group atOFS (Norcross, Ga.), formerly the fiber-optic portion of Lucent Technologies(Murray Hill, N.J.).

Robots Stand on Own Two FeetHonda, Sony, and Fujitsu selling the first strolling humanoids

ROBOTICS • The robots of ourdreams walk like us, talk like us, andthink like us. The robots that we’ve gothave the agility of a golf cart and thebrains of a beetle.

Though thinking remains a long-termchallenge, walking and talking have madegreat strides lately. The latest cadre of two-legged robots walks, hops, and skips andin one instance can even dance and carrya tune at the same time. They are the fruitof several years of activity, centered, ofcourse, in Japan, whose popular and tech-nical cultures have long been in thrall tosuch machines.

For any two-legged being, the prob-lem in walking is loss of balance. Andhere, height is no help. Honda’s 120-cm-high Asimo is the tallest robot to ambleadmirably—not only on level ground, butup and down stairs and along slopes aswell. To meet the challenge more easily,the latest robots scale things down:Fujitsu’s new Humanoid for Open Archi-tecture Platform (HOAP-1) is just 48 cmtall, while Sony’s vaudevillian SDR-4X,the singer and dancer, is 58 cm.

Even for this diminutive duo, two-legged locomotion is no stroll in the park.In interviews at Fujitsu’s sprawling researchcenter in Kawasaki, southwest of Tokyo,senior engineers demonstrated HOAP-1for IEEE Spectrum and described how itworks [see photo]. Though small, theandroid uses a 300-MHz Intel MMX Pen-tium chip plus a score of 16-bit microcon-

trollers, each governing an individualmotor that controls motion in a singledegree of freedom in one of the robot’sjoints. There are three degrees of freedomin each shoulder and hip, two in each ankle,and one for each knee and elbow.

The key sensors are a gyroscope andaccelerometers in the upper torso. Theselet the Intel processor keep track of the

Fujitsu’s HOAP-1 ambles along, relying

on 20 motors and microcontrollers and

an Intel MMX Pentium chip.

[Continued from page 21]

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To be sure, the coarse kind of systemprovides far fewer channels: the CWDMgrid explicitly defines only 18 wave-lengths, from 1270 nm to 1610 nm,whereas dense systems squeeze hun-dreds of channels into a single fiberstrand. But the technology is a goodmatch for metropolitan-area networks,which do not need the huge capacity oflong-haul DWDM systems. Still, metro-area networks often cannot afford tothrow away any CWDM capacity, whichis what happens when CWDM is usedwith conventional single-mode fiber and

even with advanced fibers such as OFS’sTrueWave and Corning’s LEAF.

Those fibers all have a water-absorp-tion peak that pretty much incapacitatesfour or five wavelengths in the range of1360–1460 nm, what is known in fiber cir-cles as the E-band [see graph, p. 21]. Los-ing that 100-nm swath of spectrum woulddetract heavily from the value of CWDM.

Fortunately, fibers have been developedto solve the problem. First OFS, and nowothers, have figured out how to make opti-cal fibers without the hydroxyl ion (OH–)that leads to the water absorption, and full-

spectrum fibers like OFS’s AllWave andCorning’s SMF-28e are in commercial use.

With those fibers well established andthe new ITU Recommendation ensuringstable technical specifications, the stage isset for rapid growth in metro-area net-working. Worldwide, according to a reportfrom Gartner Dataquest (a subsidiary ofGartner Inc., Stamford, Conn.), the opticalmetro network market is expected to climbfrom US $1.1 billion in 2001 to $4.3 billionby 2005. This may not solve all the indus-try’s problems, but it’s a step in the rightdirection. —Michael J. Riezenman

robot’s center of gravity and move the legsto keep the robot strolling smoothly. Thereare also sensors in the heel and toe of eachfoot to sense force, according to YuichiMurase, a hardware designer on the teamof eight engineers who built HOAP-1.These tell the main processor which foot issupporting the robot’s weight at any in-stant and help it determine when to lift theother leg. In a demonstration, HOAP-1not only walked up some stairs but alsohopped nimbly from one leg to the otherand swayed from side to side, like a bellydancer on a storm-tossed boat.

At maximum output, with all thosemotors and processors going at once, therobot consumes over 150 W. When pow-ered only by its on-board nickel-metalhydride batteries, HOAP-1 can walk forabout 20 minutes at most. Thus the pre-ferred mode of operation is to tether it toa more robust power supply, with centralprocessing duties handled by a morepowerful, 700-MHz Pentium processor.

HOAP-1 runs a standard, real-timeversion of the Linux operating system,says Fumio Nagashima, who led soft-ware development. For walking, it usesa neural-network–based program. Fujitsuhas sold a couple of dozen of the robotsfor 5 million yen or so apiece (aboutUS $42 000), mostly to Japanese uni-versities experimenting with robot ambu-lation and control. For that price, Fujitsualso throws in a simulator and other soft-ware development tools.

Beetle-brained but mellifluous

More talented than the Fujitsu’s HOAP-1,Sony’s SDR-4X adds sight, speech, hear-ing, and eight more degrees of freedom,

mostly in the neck, body, and arms. Therobot, controlled by two 64-bit centralprocessors (Sony won’t say who makesthem), also has an array of entertainingfeatures, mostly linked to two color videocameras and seven microphones embed-ded in its head. The cameras and micro-phones are coupled to software for obstacleavoidance and image and voice re-cognition—the robot recognizes the facesand voices of 10 people, Sony claims.

Among the robot’s phrases, uttered ina high-pitched squeak, is “Please holdstill for a minute while I memorize yourface.” The robots can even dance andsing in four-part harmony, says Sony,which already sells a $1500 toy roboticdog called Aibo.

While Fujitsu’s Nagashima speculatesabout using the descendants of HOAP-1some day for tedious farming chores,Sony is aiming SDR-4X squarely at homeentertainment. But probably not in yourhome, unless this article finds you tryingto decide whether to buy a new high-endGerman road machine or an unbeliev-ably expensive toy.

Sony won’t say what the robot will costwhen it is released to the market at the endof this year, but promises that it will cost asmuch as a luxury car. So, if you are willingto forego that vacation home, for about thesame pr ice you can be among the first toenjoy “Sweet Adeline” sung by your very-own quartet of beetle-brained but melliflu-ous mechanical marvels.—Glenn Zorpette

NETWORKING • A digital assis-tant intended to be shared and so helpclose the digital divide in a poor coun-try will soon also be helping readers inthe schools of a wealthy nation. Anuncomplicated handheld computer[see photo, p. 27], Simputer reads Webpages aloud in Indian languages. As ithappens, it has now been chosen byGraffitiWorkz Inc. (Ellsworth, Maine),a commercial library portal, to supplyU.S. schools with access to a library ofrecently released digital titles—for asubscription, of course.

The first batch of Simputers rolledout in India in April, to be deployed inpilot projects there, and a newer versionwas released last month.

Developed by engineers from the Indi-an Institute of Science and from EncoreSoftware Ltd., both in Bangalore, Sim-puter is a Palm-like device, only sturdierand with more memory and a more pow-erful processor on board. The initial ver-sion is based on Intel’s StrongArm micro-processor and GNU/Linux software.

Its browser-like interface, which isindependent of the underlying network

Indian Handheld Bridges Digital DivideA handheld device born in Bangalore stirs interest in Maine