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OPTICAL TECHNOLOGIES, COMMUNICATIONS APPLICATIONS, AND INDUSTRY ANALYSIS WORLDWIDE APRIL 2007

INDUSTRY

Fiber remains medium of choice for data center applicationsBy MEGHAN FULLER

Fiber cabling shipments are expected to experience a 26.3% compound annual growth rate to net $4 billion by 2010, according to new re-search from FTM Consulting (www.igigroup.com). In fact, FTM analysts forecast that fiber cabling shipments will exceed copper UTP cabling shipments by 2008. And the highest growth application is expected to be the data cen-ter. Though fiber has always been a competitive option, new developments in optics and emerging applications have further strengthened the business case for fiber in the data center.

Todays data center de-signers are discovering that traditional building LAN equipment just isnt sufficient for use in the current data cen-ter environment. Traditional LAN equipment simply will not allow designers to achieve the requisite density, scalabil-ity, manageability, and flexi-bility, says Alan Ugolini, data center specialist at Corning Cable Systems (www.corningcablesystems.com).

Hutch Coburn, senior prod-uct manager of enterprise fi-ber infrastructure solutions at ADC (www.adc.com), agrees, noting that LAN traffic may not always be mission criti-cal, but data

TECHNOLOGY

Understanding component specifications for plug-and-play cable assembliesBy DONALD K. HALL

As high-bandwidth applica-tionssuch as 10-Gigabit Ethernet; 2-, 4-, and 10-Gbit/sec Fibre Chan-nel; and InfiniBand 4X-SDR and 4X-DDRhave emerged, link-loss bud-gets have been reduced. At the same time, there has been an increase in the use of fac-tory-terminated cable assem-blies. Early drivers of this latter trend included a move to structured cabling and the modularity benefits fac-tory-terminated assemblies offer: rapid installation, scal-

able growth, and ease of fiber plant maintenance. However, as system designers increas-

ingly find value in the flexibility of network to-

pologies with a high degree of connectivity, a secondary driver has emerged: the abil-ity to minimize connector-re-lated insertion loss through superior factory polish-ing and assembly processes, which helps network design-ers meet the new smaller link-loss budgets.

The principles of passive plant design and installation using factory

APPLICATIONS

Survey details switch to OM3 in enterpriseBy MATT BROWN

Predictions of exponential growth in bandwidth demand were common in the late 1990s. Now, with technology back on the rise, the commu-nications industry is begin-ning to see those predictions realized. With the demand for individual user bandwidth in-creasing, the funneling effect of LAN switching is driving the need for more high-band-width fiber in the enterprise backbone.

To support bandwidth-in-tensive, real-time applica-tions and to accommodate

ever-increasing file size and traffic volume, IT managers are moving toward the higher performance offered by laser-optimized multi-mode optical fiber (OM3). According to research com-missioned by SYSTIMAX So-lutions, OM3 products are expected to become the domi-nant fiber type over the next 5 years, representing 43% of new installs in that period (see Figure 1). Conversely, use of OM1 and OM2 fiber is expected to be cut in half, from 63% in current installs to only 34% of new installs in

that same time frame. The re-search, in which 1,484 IT pro-fessionals from around the

world provided infor-mation on their require-

ments and strategies, not only details this evolution,

but reveals some of the fac-tors shaping cabling technol-ogy purchases in general.

Defining fiber categoriesTo understand the appeal of OM3 fiber, it is helpful to have a basic understanding of all three grades of multimode fiber. OM1 is a

Carriers lean on operations support systems. PAGE 31

Support SOS

RPR packs a punch for campus comms. PAGE 27

In the ring

Check, clean, and calibrate for best test results. PAGE 15

Three Cs

Carried awayWith its AnyWave Optical Net-work strategy, OpVista provides a graceful upgrade path for transi-tioning to high-speed, high-capac-ity Ethernet transport. PAGE 20

page 15

page 31

page 27

Photo 1. Compared with traditional LC panels, the MTP adapter panel enables far greater density, support-ing up to 432 fibers in a 1-U configuration.

CO

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V O L . 2 4 , N O . 4 A P R I L 2 0 0 7ContentsTechnology Applications Industry

www.lightwaveonline.com LIGHTWAVE April 2007 5

15 Achieving precision in optical measurementsBY RICK RACINSKAS, TELLABS

15 TECH TRENDS TODC vendors ready inline

and integrated devicesBY MEGHAN FULLER

19 STANDARDS WATCH Fast progress in ITU for bend-loss

insensitive singlemode fiberBY GERARD KUYT, DRAKA

COMTEQ OPTICAL FIBRE

20 PRODUCT PROFILE OpVista unveils AnyWave

Optical Network conceptBY STEPHEN HARDY

20 PREMIER PRODUCTS Components, installa-

tion and test equipment, systems, and subsystems

FOCUS ON 27 ENTERPRISE NETWORKS RPR simplifies cam-

pus communicationsBY VINAY BANNAI, ADTRAN

27 CASE BY CASE Innovation makes a comeback

BY STEPHEN HARDY

31 OSS vendors grapple with network evolutionBY STEPHEN HARDY

31 ANALYST CORNER Dynamics of the Carrier

Ethernet switch marketBY SEAMUS CREHAN,

DELLORO GROUP INC.

35 PEOPLE Mintera appoints vice president

Calix adds board member

Santur appoints CEO

OSA selects senior director

FOLS elects new officers

38 MARKET WATCH AT&T ranks first in U.S. busi-

ness Ethernet services

Study analyzes Carrier Ethernet over MSPP-based networks

Optical networking mar-ket topped $3.2B in 4Q06

AnyWave Optical Network strategy takes existing networks to Carrier Ethernet-ready page 20

FOCUS ON ENTERPRISE NETWORKS Increases in traffic vol-umes and high expectations for quality of service demand flexible, reliable network performance. This month, articles focus on the need for high-bandwidth fiber in enterprise networks and data centers (both front page), the link between connector-related insertion loss and system performance (front page), and achieving Carrier Ethernet qualities in cam-pus networks using RPR architecture (page 27).

6 update

11 www.lightwaveonline.com

12 Editorial STEPHEN HARDY A shrink-proof industry?

up-front


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updateHOTPICK

LIGHTWAVE (ISSN 0741-5834), a trademark, 2007, is published 12 issues per year monthly by PennWell Corporation, 1421 South Sheridan Road, Tulsa, OK 74112, telephone 918-835-3161; fax 918-831-9497; Web address www.pennwell.com. All rights reserved. No material may be reprinted. Bulk reprints can be ordered from Kathleen Skelton 603-891-9203 voice, 603-891-0587 fax. SUBSCRIPTIONS: 847-559-7520, 7:30am-6pm CST. Subscrip-tion rates in the U.S. and possessions: one year, $144; Canada/international via surface mail, $163; international via airmail, $197. Periodicals postage paid at Tulsa, OK, and additional mailing offices. We make portions of our subscriber list available to carefully screened companies that offer products and services that may be important for your work. If you do not want to receive those offers and/or information, please let us know by contacting us at List Services, Lightwave, 98 Spit Brook Road, Nashua, NH 03062. POSTMASTER: Send address changes to: LIGHTWAVE, P.O. Box 3279, Northbrook, IL 60065-3279 PRINTED IN THE USA GST NO. 126813153 PUBLICATIONS MAIL AGREEMENT NO. 908584 Return Undeliverable Canadian Addresses to P.O. Box 122, Niagara Falls, ON L2E 6S4

DISCLAIMER: The information contained in this publication is for general information purposes and is not intended to be advice on any particular matter. No subscriber or other reader should act on the basis of any matter contained in this publication without considering appropriate professional advice. PennWell Corporation, and the authors and editors, expressly disclaim any and all liability to any person, whether a purchaser of this publi-cation or not, in respect of anything (and the consequences of anything) done or omitted to be done by any subscriber, reader, or other person in reliance upon the contents of this publication.

6 April 2007 LIGHTWAVE www.lightwaveonline.com

Cortina Systems (www.cortina-systems.com) has acquired Immenstar (www.immenstar.com), a privately held semiconductor company that specializes in PON system-on-chip (SoC) technology. According to Cortina, the Immenstar acquisition simultaneously builds on the strength of its existing technology and expands its reach into the access network; the company confirms plans to play in both the EPON and GPON markets with a portfo-lio of products that combine intelligent bandwidth, high density, and low power. Financial terms of the acquisition were not disclosed.north america

JDSU (www.jdsu.com) has announced a definitive agreement to ac-quire Picolight Inc. (www.picolight.com), designer and manufacturer of optical pluggable transceivers. The transaction is expected to close June 30, subject to regulatory approvals. JDSU will acquire Picolight for approximately $115 million in JDSU stock, plus up to an additional $10 million in cash subject to the achievement of certain revenue targets during calendar year 2007. Picolight has been an active player in the devel-opment of 850- and 1,310-nm vertical-cavity surface-emitting lasers (VCSELs).

Carrier Access Corp. (www.carrieraccess.com) has completed the acquisition of IP net-working product assets from Mangrove Systems Inc. (www.mangrovesystems.com) in a cash transaction valued at approximately $8 million. Carrier Access says it has hired 30 former employees of Mangrove to sell, support, and continue R&D of the newly acquired Mangrove products. The acquisition is anticipated to be accretive to Carrier Access earn-ings in 1Q08.

Enablence Technologies Inc. (www.enablence.com) has completed a private placement of 25 million common shares at a price of $0.60 per share for gross proceeds of $15 mil-lion. The syndicate behind the funding round was led by Paradigm Capital Inc. and included Wellington West Capital Markets Inc. and Raymond James Ltd. as syndicate partners. Ac-cording to Enablence chief executive Arvind Chhatbar, the company needs more money to strengthen its position as it enters volume production. In particular, he says the company wants to be in a position to expand its product line or production resources, or enter new

partnerships, without being restrained financially.

Ceterus Networks (www.ceterusnetworks.com) has an-nounced a $20 million funding round led by Intel Capital. Sevin Rosen and ComVentures, both investors since incep-tion, and Aldus Equity, a new investor, also participated in the funding. Ceterus Networks has aimed to create a plat-form for versatile, cost-effective Ethernet service delivery platforms supporting both wireline and wireless service providers in their delivery of new data and voice services. The new funding will help with large customer infrastruc-ture rollouts and market expansion, the company says.

Transceiver supplier OE Solutions Co. Ltd. (www.oesolution.com) has closed a $4.3 million Series C round of funding, led by two Korean venture capitalists, Korean Development Bank Capital and Kibo Technology Advancing Capital. The round brings the companys total funding to date to $16 million. OE Solutions says it will use the funds

to expand its global marketing and sales efforts and to accelerate future product development to meet growing customer demand worldwide.

Alchemy Communications Inc., provider of colocation and managed data center services, has chosen MRV Communications Fiber Driver to increase the bandwidth of its backbone network. Incorporating the DWDM-capable Fiber Driver also will increase the redundancy and efficiency of Alchemys Los Angeles-based fiber-optic network, resulting in a greater return on in-vestment, say MRV representatives.

Tyco Telecommunications (www.tycotelecom.com) has chosen Bookham Inc. (www.bookham.com) to be the lead supplier of 980-nm pump laser mod-ules. Bookhams OceanBright pump lasers will be used in erbium-doped fiber amplifiers (EDFAs), which in turn are incorporated into repeaters that form a critical element of undersea cable systems around the world.

Fujikura Ltd. (www.fujikura.co.jp) and Nistica (www.nistica.com), optical subsystems supplier to telecom system OEMs, have announced a broad cooperative agreement whereby Fujikura will provide full production man-ufacturing facilities and processes for the volume delivery of Nisticas FLEDGE series of tunable filters and ROADM modules, as well as future

Nistica products. In addition, Fujikura will act as a strategic partner for field, warranty, and sales chan-nel support in selected markets. Moreover, Nistica and Fujikura say they will explore jointly developing products in the ROADM market based on Nisticas technology and platform.

TXP Corp. (www.texasprototypes.com), an original design manufacturer (ODM) for the electronics and telecommunications industries, has entered into an agreement to supply its ONT equipment to an un-named provider of communications technology and infrastructure equipment. This agreement comes just 2 months after TXP officially acquired the ONT busi-ness unit of Siemens. The acquisition brought to TXPs portfolio BPON ONTs for single-family units (SFUs), multidwelling units (MDUs), and small business units (SBU); and GPON ONTs for SFUs, Ethernet-only SFUs, and SBUs.

TriAccess Technologies (www.triaccesstech.com) has signed a multiyear supply agreement with Lu-minentOIC Inc. (www.luminentoic.com), a wholly owned subsidiary of MRV Communications (www.mrv.com), to supply the latest version of its TAT6254 Series RF integrated circuit for use in GPON net-works. LuminentOIC plans to incorporate the Tri-Access 6254 RFIC in triplexer transceivers installed within optical network terminals (ONTs). Luminent-OIC will be the lead customer for the next product release in the TriAccess TAT6254 series for GPON applications and has committed to purchasing sig-nificant volumes of this device, say TriAccess rep-resentatives. In addition, as part of this agreement, LuminentOIC has attained exclusive rights to the TAT6254 product series for all BPON applications.


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updateRedfern Integrated Optics Inc. (www.rio-inc.com), developer and manufacturer of optical transmitters, has successfully completed reliability qualification of its PLANEX technology platform, in accor-dance with the requirements of Telcordia GR468-CORE. PLANEX is a planar-based external cavity laser (ECL) packaged in an MSA-compliant transmitter optical sub-assembly (TOSA) form factor for XFP, SFP, and SFP+ transceiver modules.

Privately held American Fiber Systems Inc. (AFS; www.afsnetworks.com) has completed a $10 million transaction to acquire IDACOMM (www.idacomm.com), the communications subsidiary of IDA-CORP. IDACOMM is a fiber facilities-based competitive metro network provider, with operations focused in Nevada and Idaho, specializing in fiber-based transport ser-vices to both carrier and enterprise cus-tomers. IDACOMMs network includes more than 45,000 local and long-haul fi-ber-strand miles with approximately 150 buildings on net and includes the cities of Las Vegas, Reno, and Carson City, NV, as well as Boise, ID, opening up new regional transport business for AFS.

The United States Patent and Trade-mark Office has issued a patent entitled

Method and Apparatus for Testing Opti-cal Networks (US patent no. 7,187,861) to EXFO Electro-Optical Engineering Inc. (www.exfo.com). The patent serves as the basis of EXFOs series of PON power meters, which are widely used by technicians to characterize FTTH net-works, particularly near the ONT at the customer premises where triple-play ser-vices need to be activated. EXFOs pat-ented technology enables pass-through measurements of both downstream and upstream optical power at different wave-lengths, including those of bursty up-stream signals.

emeaADVA Optical Networking (www.advaoptical.com) has been named a supplier of Ethernet last-mile access products in British Telecoms 21st Century Network. The carrier will deploy the ADVA FSP 150 as the Network Termination Equipment (NTE) to interconnect all end customers,

carriers carriers, and BT facilities. The ADVA FSP 150 portfolio, featuring Ether-jack technology, provides Ethernet de-marcation, extension, and aggregation.

The Neuf Cegetel Group (www.groupeneufcegetel.fr) plans to offer fiber-based broadband services beginning this month in Paris. The carrier expects to pass a million homes by the end of 2009 and to connect a total of 250,000 customers. Coverage areas will include Paris and its suburbs, districts of other major cities, and other areas selected on the basis of rollout costs and oppor-tunities to increase market share. The target might be raised if investments can be mutualized with other partner operators. To start the rollout of its program, Neuf Cegetel acquired in early 2007 Mediafiber, which serves around 3,000 FTTH customers in the city of Pau (among around 40,000 homes passed). On February 20, 2007, the group announced an agreement to take a controlling stake in Paris-based Erenis, which has more than 55,000 homes passed and more than 10,000 customers connected.

Avanex Corp. (www.avanex.com) has entered into a definitive agreement to sell a 90% interest in its French subsid-iary, Avanex France S.A., including its indium phosphide (InP) and gallium ar-senide (GaAs) semiconductor fabs, to Global Research Co., a socit re-sponsibilit limite, owned by Alexandre Krivine, and to the current management of Avanex France S.A., Didier Sauvage. In addition to the semiconductor III-V fabs, the divested business includes the laser, terrestrial pump, submarine pump, and fiber Bragg grating product lines. Avanex plans to maintain a core development group of about 20 employees in France focused on transmission products. Jo Major, Avanexs chairman, president, and chief executive officer, confirms that the company expects to realize between $12 million and $16 million in annual financial improvements as a result of this divesti-ture beginning in fiscal 4Q07.

Irish ISP Digiweb has deployed an ad-vanced Ethernet-over-optical network within its Dublin Metro network using equipment from both Transmode (www.transmode.com) and Overture Networks


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update(www.overturenetworks.com). The joint Transmode/Overture network provides Digiweb with a new Ethernet-over-WDM backbone network and Ethernet-over-fi-ber/copper access network to support growing demand for the carriers business-to-business and consumer ISP services.

ColorChip (www.color-chip.com), manu-facturer of glass-based planar lightwave circuit chips and modules for FTTH net-works, has completed a $7.4 million fund-ing led by Vertex Venture Capital. Vertex joined existing investors including Bes-semer, Eurofund, Motorola, Polytechnos, and Walden Israel Venture Capital. Ac-cording to Moshe Price, chief executive officer of ColorChip, the proceeds will en-able the company to move from product qualification to mass manufacturing to accommodate the strong FTTH market demands in the US, Japan, Asia Pacific, and Europe.

ECI Telecom Ltd. (www.ecitele.com) has completed the first stage of the construc-tion of a metro optical network for Ukrtele-com JSC, a national telecommunication operator in Ukraine. This first stage cov-

ers Ukraines nine largest regions and will include the deployment of ECIs XDM optical platform to enable Ukrtelecom to meet increasing subscriber demand for next-generation services.

ECI Telecom also has demonstrated what it claims is the industrys first suc-cessful 43-Gbit/sec transmission over 1,000 km via a 10-degree, 50-GHz chan-nel-spaced wavelength-selective switch (WSS) reconfigurable optical add/drop multiplexer (ROADM). According to the company, the demonstration illustrates how bandwidth-tolerant 43-Gbit/sec modulation formats enable signal trans-mission up to 1,000 km through 50-GHz spaced WSS ROADMs, while maintaining high noise tolerance similar to that of 10-Gbit/sec signals. The company says its XDM offering allows carriers to build reconfigurable ROADM-based networks with maximum capacity of 80 channels 40 Gbits/sec (or 3.2 Tbits/sec) and dis-tances suitable for metro, regional, and long-haul applications.

Ericsson (www.ericsson.com) has signed a turnkey contract with the city of Trikala as

equipment provider and prime integrator to implement the citys pioneering plans for the creation of the first Greek Digital City. Per the contract, Ericsson is the sole supplier of switching, Wi-Fi systems, and a 15-km fiber-optic metro network, as well as related telecom services, such as con-sulting, deployment, systems integration, and customer support, until 2008.

Alcatel-Lucent (www.alcatel-lucent.com) has signed a turnkey contract with the East Africa Submarine Cable System (EASSy) consortium to lay the first ever optical submarine cable network landing in East Africa, scheduled for completion by the end of 2008. Based on Alcatel-Lu-cents submarine and terrestrial optical systems, the EASSy submarine network will deliver a regional capacity of nearly 320 Gbits/sec and span nearly 10,000 km, linking eight countries from Sudan to South Africa, via Djibouti, Somalia, Kenya, Tanzania, Madagascar, and Mo-zambique. Governments, public admin-istrations, and businesses will be able to leverage the network to support new applications such as remote medical di-agnosis and international call centers.

By interconnecting with Sea-Me-We 3, Sea-Me-We 4, SAS1, Falcon, and SAT3/WASC/SAFE, the EASSy submarine cable system also will serve as a supporting in-frastructure for these networks.

asiaIndependent Indonesian telecommu-nications provider PT NAP Info Lintas Nusa and Tyco Telecommunications have announced the signing of a con-tract between NAP Singapore-based affiliate Matrix Networks and Tyco Tele-communications to construct an under-sea fiber-optic system. The system will comprise a four-fiber-pair trunk between Singapore and Jakarta with branches to Batam in the Riau Islands Province and Pontianak in Kalimantan on the island of Borneo. The design also facilitates a future connection to Perth, Austra-lia, via an undersea branching unit. Us-ing DWDM, the system will be able to transmit 64 10-Gbit/sec wavelengths on each fiber pair for a total bandwidth of nearly 2.6 Tbits/sec.


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www.lightwaveonline.comfind these features online this month


Verifying Metro Ethernet QoS BY MIRNA MEKIC, JDSU COMMUNICATIONS TEST & MEASUREMENT

Used for delivery of next-generation IP-based services, including triple play, metro Ethernet facilitates the availability of affordable bandwidth on demand and highly secure private network communication. Yet despite the lucrative and strategic advantages it brings, many providers are reluctant to embark on full implementation to bring carrier-grade Ethernet offerings to market. This is due in part to the inherently greater complexity of maintaining carrier-class quality at the node and network levels. This hesitancy also stems from a lack of standardized test and monitoring tools and procedures.

OA&M: Going beyond the standards to enable innovative Carrier Ethernet services BY UMESH KUKREJA, ATRICA

The ability to offer attractive service-level agreements (SLAs) is increasingly important to a service providers success. Recognizing this, Carrier Ethernet has been developed with SLA support as one of its critical, core capabilities. However, comprehensive, effective SLA support requires advanced opera-tion, administration, and maintenance (OA&M) tools that can manage and monitor SLAs and provide reports to end-user customers, ensuring service provider compliance.

PBT vs. MPLS BY PETER LUNK, EXTREME NETWORKS

Provider Backbone Transport (PBT) is an exciting new technology that takes advantage of the recent advances in Ethernet standards. PBT enables a much more economical access and aggregation network that minimizes the need for MPLS outside the core of the carrier network. The deterministic network architecture made possible by PBT delivers all of the advanced services sub-scribers are seeking while maintaining the simplicity and reliability of SONET/SDH networks.

Expanding the bandwidth pipe: Subwave technologies BY KEN DAVISON, MERITON NETWORKS

Gigabit Ethernet bandwidth is being driven deep into the network, and trans-port providers already are seeing requests for Ethernet in ranges from 2.5 to 10 Gbits/sec. Rather than dedicate a wavelength to a single service, subwave grooming techniques now enable carriers to pack wavelengths with as much traffic as possible for more efficient utilization. This article will explore emerg-ing methods for expanding the bandwidth pipe, including ways to switch con-nections at the wavelength, subwavelength, and even sub-subwavelength level, otherwise known as tunnel switching.

Rolling out business Ethernet BY FRED ELLEFSON, ADVA OPTICAL NETWORKING

More and more multiple-systems operators (MSOs) seek to introduce com-petitive, carrier-class, Ethernet-based business services such as voice over IP (VoIP), dedicated Internet access, point-to-point connectivity, and virtual

private networks (VPNs). The commercial business opportunity is tremendous, but the challenges are not inconsequential. This article will explore how an MSO can roll out a consistent, profitable, competitive Ethernet offering to multisite enter-prise customers, even when leveraging disparate legacy networks and technolo-gies in various regions and markets across the nation.

Increasing the fiber in cables diet BY JAMES O. JIM FARMER, WAVE7 OPTICS

While most of the FTTH buzz has surrounded the telcos, cable TV companies are starting to deploy this technology as well, primarily in greenfield applications. This paper shows that it is easy for service providers with hybrid fiber/coax (HFC) net-works to deploy FTTH in greenfield situations, while maintaining their existing HFC networks until end-of-life.

FTTH giving homeowners a raise BY DAVID MEIS, CORNING CABLE SYSTEMS

FTTH is now being touted as a value-enhancing amenity for many homes, as well as for developments. Not only is there talk of FTTH commanding a premium in home selling price, there is also strong emerging evidence that supports this claim.


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Editorial


STEPHEN M. HARDY

Editorial Director & Associate Publisher

[email protected]

One conundrum of the optical communications in-dustry that continues to stump observers and par-ticipants alike is the issue of consolidationor, more precisely, the lack thereof, particularly in the compo-nents/subsystems space. Carriers have consolidated, and system vendors, as evidenced by the Alcatel-Lu-cent merger and the Siemens/Nokia hook-up, have begun to follow suit. At the component/subsystem level, however, everyone appears to agree that too many companies continue to chase too few business opportunities. Of course, people have commented on this fact for at least the last 5 years. Still, even as the week of OFC/NFOEC began with news of three component/subsystem-level acquisitionsFinisars agreements to purchase AZNA and Kodeos, followed closely by Optiums announcement of its acquisi-tion of Kailightthe overall viewpoint remains un-changed. More mergers and acquisitions need to take place before the industry can right size to a rational

number of players.So whats holding things up? The

OSA/Lightwave Executive Forum of-fered some cluesclues that indi-

cated that factors intrinsic to the optical communications field and to the customers it serves may pose high enough barri-ers to consolidation to pre-vent the industry from ever reaching the right number of participants. In fact, these factors, if fully considered,

may change the idea of just what number represents criti-

cal mass.Certainly one can list several fac-

tors that should drive a large number of companies out of the components and

subsystems market in the near term. First, while the market has begun to pick up, its still not healthy enough to support a bubble-era competitive land-scape. (In fact, one could argue the industrys recently concluded problems stemmed in large part from the fact that the bubble itself wasnt large enough to sus-tain the bubble-era competitive ecosystem.) Second, just as their customers seek to reduce operational ex-penses, system houses wish to shrink their own opex by limiting the number of suppliers they must engage. Third, with the market having stabilized now is a good time for VCs and other investors to force their companies to reconsider an exit strategy that might involve being acquired.

Forum participants, who included not only high-

level executives from component compa-nies but observers from the financial and customer arenas, harped in particular on the first two of these motivations for con-

solidation. For example, some of the major compo-nent players justified their support of broad product lines with the explanation that with system houses looking to trim their roster of suppliers, the ability to meet a wide variety of needs was essential for survival. This philosophy has been espoused for some time as the one-stop shop approach to the market, and com-panies such as JDSU, Bookham, and others have at-tempted to implement this philosophy with varying degrees of success.

However, the same panelists emphasized that the key to future fiscal health and success was a focus on the areas where they could maintain a competi-tive differentiation. Needless to say, unless a company has unlimited financial and personnel resourcesand not even JDSU has this kind of weight to throw aroundit cant differentiate everywhere. Thus, ma-jor system houses can reduce their supplier counts to three or four for each of their product lines. But when they aggregate the supplier lists for all of those prod-ucts, theyre likely to find that they still must deal with 10 or more vendors, like it or not. Differentiation and product line expansion clearly conflict, particu-larly in an environment in which R&D dollars cant be spent indiscriminately. Some companies will at-tempt to solve this problem through acquisition, and the recent M&A activity described earlier illustrates relevant examples. (I didnt say M&A would stop, just that it wont result in a market size most people appear to want.) But there are only so many differentiated product lines a single company can support without swamping itself. As one forum participant observed, No one talks about the one-stop shop anymore.

System houses and the customers they serve also must share the blame (if one can call it that) for the unexpectedly large number of component/subsys-tem suppliers that continue to hang on in the market. Thats because the forum participants revealed that these parties continue to insist on customized prod-ucts, even when dealing with areas where standards (or at least multisource agreements) are in place. Again, how many customized variants of each prod-uct can a single supplier support? As long as system houses and their customers require nonstandard products, the market will require a larger number of suppliers to fill the need.

I have said in this space previously that 2007 will see a significant amount of consolidation. I still believe this will be the case. However, I also believe that ob-servers and participants will continue to lament that there are too many companies making components and modules, regardless of how much M&A goes on. And the industry has itself to blame.

EDITORIAL

Editorial Director and Associate Publisher Stephen M. Hardy

603-891-9454 [email protected]

Managing Editor Carrie Meadows


Senior Editor Meghan Fuller


ColumnistsGerard Kuyt

Seamus Crehan

Editorial Advisory BoardDr. Donald Bossi / Aegis Semiconductor

William J. Cadogan / Vesbridge PartnersAndy Chraplyvy /

Alcatel-LucentDonald T. Gall / Pangrac & Associates

Ira Jacobs / Virginia Polytechnic InstituteMichael Lebby / OIDA

Kevin Lefebvre / SUNY ITStan Lumish / JDSU

Stephen Montgomery / ElectroniCastVik Saxena / Comcast

Paul W. Shumate, Jr. / IEEE LEOS

Presentation Manager Cindy ChamberlinSenior Illustrator Dan Rodd

Marketing Director Lisa A. Bergevin603-891-9410 [email protected] Manager Michelle Blake


ATD PUBLISHING DEPARTMENTS

Art Director Meg FuschettiProduction Director Mari Rodriguez

Senior Vice PresidentGroup Publishing Director

Mark Finkelstein603-891-9133

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Tel: 603-891-0123, Fax: 603-891-0587

For subscription inquiries only:Tel: 847-559-7520, TDD: 918-831-9566

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CORPORATE OFFICERS

Chairman Frank T. LauingerPresident and CEO Robert F. Biolchini

Chief Financial Officer Mark C. Wilmoth

ADVANCED TECHNOLOGY DIVISION

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More mergers and

acquisitions need to

take place before the

industry can right

size to a rational

number of players.

A shrink-proof industry?


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Technology Advances in research, development, engineering, and standards

CONTINUED FROM PAGE 1


TECH TRENDS

Cont. on pg 18

Cont. on pg 16Cont. on pg 17

Achieving precision in optical measurementsBy Rick Racinskas

You have your favorite fiber test box and trust it for great measurements performed via more buttons and digits than youve ever used before. Are you getting the performance you paid for or even what the sales rep prom-ised? Probably not.

Fiber is not just copper with a different color jacket. To ob-tain proper measurements, you must treat it with the utmost care within an almost clean-room en-vironment when it comes to con-nections. Consistent, accurate, and repeatable measurements take knowledge, a few tools, and a lot of vigilance. This article re-views some of the primary sources of problems when it comes to ob-taining precise measurements, matched with some suggestions about how to solve them.

Patch cordsThe instrument starts at the far end of the patch cable. Your $50,000 box can behave like a $300

knockoff if you dont have a proper cable. You wouldnt put a $50 probe on a fancy 10-GHz scope, would you? The same principle applies here. A cheap, damaged, or dirty patch cable

will throw power measure-ments way off. If you remate connectors several times and see a 0.5-to-1-dB read-ing bounce, you need to clean or replace them. If all is well, you should see 0.02-dB or less bounce each time. Since it is difficult to clean mating fiber adapters, one idea is to leave a 1-m patch cord on. Choose a refer-ence or a calibrated grade and avoid generics.

Mating most any connec-tor to a typical power me-ter should yield accurate readings due to the size of the photodetector. But

source connections require precision mat-ing to achieve maximum

Photo 1. A simple fingerprint can significantly degrade fiber performance. A quick cleaning can make a lot of difference.

assemblies are essentially the same as when field termination is performed. However, there are some practical considerations that sys-tem designers and installers should be aware of, especially as low-loss cable assemblies are specified. These considerations are directly related to the fact that the assembly manu-facturer is delivering finished components with guaranteed insertion loss and effective modal bandwidth performance when mated to other components. It is therefore important to understand the relationship between cable assembly specifications and expected system performance when multiple assemblies are linked together to form the passive plant.

Common cable assembly typesFactory cable assemblies have been supplied for many years using simplex and duplex con-nectors. Increasingly popular are modular

plug-and-play assemblies, which usually con-tain ribbons in multiples of 12 fibers to take advantage of the high density of MPO-style connectors. The four basic types of plug-and-play assemblies include the following: Trunks. These are cable assemblies of cus-

tomer-specified length terminated on each end with 12-fiber MPO connectors. Fiber counts are typically up to 144 fibers.

Harnesses. These are short, 12-fiber cable as-semblies made from interconnect cables that are terminated on one end with a 12-fiber MPO connector and at the other end with simplex or, more commonly, duplex connec-tors. Harnesses mate to trunks via their MPO connectors. Although the simplex/duplex connectors can be mated into a patch panel, they are usually directly mated to an equip-ment port.

Modules. Sometimes

Tunable optical dispersion compensators (TODC) are used within 10- and 40-Gbit/sec optical systems to compensate for signal distortions caused by chromatic dispersion (CD). CD is a form of intersymbol interference (ISI), which is espe-cially detrimental in optically amplified systems. CD causes

a spreading of light pulses as they travel down an optical fiber. Different colors will propagate at slightly different speeds, thereby rendering the receiver unable to differen-tiate one light pulse from the next. TODCs work by intro-ducing either positive or negative dispersion to balance or offset the dispersion in the fiber.

The only TODCs deployed in significant numbers today are thermally tuned fiber Bragg grating (FBG)-based de-vicesand only at the receiver to combat residual disper-sion. Sources interviewed for this article are unanimous in their assertion that TODCs have yet to be deployed for inline applications. And no integrated TODCs (i.e., within

300-pin MSA transponders) have been deployed to date. But TODC vendors are gearing up to offer such devices now.

Residual compensationThere are two key applications for TODCs in the network: 1) residual compensation and 2) bulk or inline compensation (see figure). Residual compensation provides constant, per-channel dynamic

By Meghan Fuller

TODC vendors ready inline and integrated devices

Component specs for cable assemblies

Meghan Fuller is senior editor at Lightwave.

ANDevices uses a PLC-based technology for its small-footprint 10- and 40-Gbit/sec TODC devices.

Fingerprint

Core area

After cleaning


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Equipment cord

Transceiver TransceiverModule Trunk Harness

MPOs

Duplexconnectors

Example system 1

Tx/Rx Tx/Rx

Equipment cord Equipment cord

Transceiver TransceiverModuleIntegrated trunk module

MPOs

Duplexconnectors

Example system 2

Tx/Rx Tx/Rx


Technology


Understanding component specifi cations for plug-and-play cable assembliescalled breakout modules or transi-tion modules, these assemblies offer a space-efficient means of transi-tioning from MPO connectors to simplex/duplex connectors. These cable assemblies are terminated in the same manner as harnesses, but they are usually made from bare op-tical-fiber ribbons rather than inter-connect cables. The fiber portion is protected within a plastic or metal casing that mounts in a connector housing like a patch panel. The sim-plex/duplex connectors are accessed at the front of the module for mat-ing with jumpers or patch cords. The MPO connector is accessed at the rear of the module, where it is mated to a trunk.

Integrated trunk modules (ITMs). These cable assemblies combine the functional attributes of a module and a trunk. They are essentially modules with long interconnect cable tails terminated with an MPO connec-tor. The protective casing mounts in a connector housing like a standard module but is deep enough to pro-vide a means of storing trunk slack, thus allowing the installer to deploy only enough of the trunk to reach the intended MPO connection point. ITMs are especially useful in small data centers and enterprises between the main distribution area and the end equipment or in large data cen-ters between a consolidation point and the end equipment.These components are usually in-

stalled as part of a structured cabling network comprising multiple links per channel. For simplicity, Figures 1 and 2 illustrate the use of each of these components in a point-to-point system.

Those familiar with traditional field-terminated assemblies will quickly recognize that the static functionality of each of these sys-tems can be achieved by terminat-ing bulk cable with simplex/duplex connectors at patch panels. In such builds, calculation of an expected link budget is straightforward and is merely a summation of the fiber loss and connector losses. The fiber loss is calculated by multiplying the fiber length by the fiber attenuation coef-ficient, expressed in decibels per unit length. The fiber attenuation coeffi-cient is wavelength dependent. The

connector loss is simply a maximum loss specification per mated pair, fre-quently taken as 0.75 dB per mated pair in accordance with ANSI/TIA/

EIA-568-B.1. This calculation does not include the connectors mated to the transceiver ports, because the loss of these connectors is accounted for in the transceiver specifications.

The static equivalent of both fig-ures would be a cable terminated with simplex/duplex connectors and joined to the equipment at each end with jumpers mated through a patch panel. The link budget would be 1.5 dB plus calculated fiber loss. However, as noted, the traditional field-termi-nated assemblies, while achieving the desired static functionality, do not of-fer the flexible reconfigurability and scalability of a modular plug-and-play system.

It can be seen that the plug-and-play systems have more connector pairs per link compared to the field-terminated approach. Each break-out module contains two connectors. Each harness also contains two con-nectors, although if mated directly to equipment as in Figure 1, only the MPO connector pair would count in the link budget. There-fore, the link of Figure 1 contains three mated pairs. Although the link of Figure 2 is not directly terminated to equipment on either end, this link also contains three mated pairs, because the ITM is functionally equivalent to a trunk and a module, thus keeping the connector count for the link at three instead of four. If one allows 0.75 dB per connector pair, it can be seen that the link budget for these systems would be 2.25 dB plus fiber loss. In this case, there would ef-fectively be a budget penalty associ-

ated with the increased modularity of the plug-and-play system.

For high-bandwidth systems, es-pecially where multiple links form a

single channel, the total channel loss penalty may be unacceptable, leading a system designer to specify a field-terminated system when the flexibil-ity of a modular plug-and-play system is actually desired. For this reason, manufacturers of plug-and-play com-ponents may offer components with insertion loss specifications requiring connector losses well below 0.75 dB per connector.

To illustrate, consider the example of Figure 1. If the module has a speci-fied insertion loss of 0.5 dB and the MPO pair shared by the trunk and harness has a specified loss of 0.35 dB, one would then calculate a link bud-get of 0.85 dB plus length-dependent fiber loss. Note again that the duplex connector pair shared by the harness and the equipment port doesnt con-tribute to the link-loss budget because the harness is directly terminated into the equipment ports. This link bud-get is well below the 1.5-dB budget calculated for the field-terminated approach. Of course, it would be the

prerogative of the system designer to specify a field-terminated system with maximum connector insertion loss of some value less than 0.75 dB per mated pair. However, the likelihood of achieving these lower insertion losses is very field craft dependent. Because

of the superior control of insertion loss in the factory environment, there is a clear advantage to the specification of factory-built assemblies.

Product certification or QC measurements, when provided to cus-tomers, are usually the only customer-visible as-pect of a manufacturers quality assurance pro-gram. Other aspects may include such controls as dimensional verification of fiber and connector geometry or other pro-

cess monitoring means. The ability of individual cable assemblies to meet performance expectations when con-catenated in the field must be proven as part of the product qualification during development. This is usually done by performing loss measure-ments before and after environmen-tal exposure on randomly mated cable assemblies manufactured under stan-dard process conditions.

ANSI/TIA/EIA-568-B.3, Annex A describes a broadly accepted, stan-dardized procedure for qualification of cable assemblies under defined test conditions. These loss measurements can then be analyzed to ensure con-catenated link performance. Once the cable assemblies have been qualified, QC pass/fail criteria can be set to en-sure that they are manufactured to the same quality level as those that were evaluated during product qualifica-tion. Because individual component quality is assured by the manufacturer, it is not necessary to field-test individ-ual components.

Field testing of linksA final consideration is field link test-ing. Concatenated field links, which usually have simplex or duplex con-nectors at the ends, can be tested end-to-end using standard power-through test sets and well-

Figure 1. In this example, a trunk features a module at one end and harness at the other end. An equipment cord connects the module to one transceiver. The harness connects directly to the other transceiver port.

Figure 2. This system features an integrated trunk module (ITM). Equipment cords connect modules to transceivers.

Cont. on pg 24


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Needs for TODC in the network

Rx

TODC

TODC

Tx

TODCTODC

Source: Alcatel-Lucent

ODC ColorlessColorless

May ormay not becolorless

NonadjustableODC

1. Residual compensation, constant dynamic adjustment Necessary for bit rates 40 Gbits/sec2. Bulk compensation, set-and-forget adjustment Eases installation and inventory

Some popular uses for TODC:


Technology

TECH TRENDS

CONT. FROM PAGE 15

adjustment at the receiver. It is necessary at data rates of 40 Gbits/sec and above, contends Christopher Doerr, distin-guished member of the technical staff at Bell Labs (www.bell-labs.com). If the link is long enough, say, 300 km, even environmental temperature changes in the fiber are enough to require a change in the TODC setting, he notes.

Therefore, each wavelength needs a tunable dispersion compensator at 40 Gbits/sec. That said, even though the tunable compensator is not used to compensate the dispersion on many channels at a timeits only a sin-gle channel at a timethe light still needs to be colorless, mainly for in-ventory purposes, adds Martin Guy, vice president of product manage-ment and technology at TeraXion (www.teraxion.com).

Wenhua Lin, vice president of tech-nology and new products at ANDe-vices (www.andevices.com), says she has seen some variation in the ways in which system vendors are deploying TODC technology for residual disper-sion. We see a lot of new applications where people are using the TODC combined with other things, like a transponder, she confirms. Usu-ally, the TODC is a separate unit or line card before the receiver, but now system vendors want to integrate the TODC into the transponder. While such integrated devices are not really taking off right now, Lin confirms that system vendors currently are weighing how to use TODC technol-ogy most efficiently in the network.

Inline compensationIn todays 10-Gbit/sec networks, a light signal can travel up to 65 km without dispersion compensation, reports Haim Laufer, senior vice president of sales and marketing for Civcom (www.civcom.com). Using chirp or a different mod-ulation scheme extends that distance to 80 km, after which some form of inline dispersion compensation is required.

The sources interviewed for this story say that TODC is just starting to emerge as a replacement for the in-cumbent inline compensation technol-ogydispersion-compensating fiber (DCF)for 10-Gbit/sec long-haul and metro systems. TODC for inline appli-cations has not been used in the past for several reasons. First, the relatively recent emergence of reconfigurability

places new requirements on the network in terms of tunability. Second, inline dispersion compensation is a bit more challenging than residual compen-sation, admits Bell Labs Doerr. With inline, you need to be able to tolerate cascading effects, he ex-plains. Residual compen-sation, by contrast, can have a smaller disper-sion [window] because you only have to pass through once, and theres no cascading.

System vendors also may be slow to adopt TODC technology for inline applications because the incumbent DCF technology is so thoroughly en-trenched. DCF is specialized fiber that has high levels of negative dispersion over relatively short lengths. While it is a widely used, proven technology, DCF is bulky, difficult to install, and suffers from high attenuation. The attenuation requires the use of addi-tional amplification, which, in turn, adds to the overall cost of the system. Moreover, DCF is not tunable. For each distance you have to compen-sate, says Laufer, you need a differ-ent product.

TODCs, on the other hand, provide set-and-forget adjustment. The big advantage is its easier for the cus-tomer to install a system because they dont have to measure their link dis-persion very accurately, says Doerr.

Once [a TODC] is installed, they can tweak the amount of dispersion theyll need. Doerr also cites the advantage of tunability for inventory reduction; assuming they integrate the TODC component directly on a line card, sys-tem vendors could use the same card at every node.

Doerr confirms that Alcatel-Lu-cent is currently working to integrate TODCs for inline compensation into some of its commercially available products. While he recognizes that

the cost of tunable optical dispersion compensation has to come down for it to really be disruptive and take over inline, Doerr believes the benefits of TODC outweigh the additional cost, even in the near term. He compares the use of TODC versus DCF to auto-matic versus standard transmission in a car. Most drivers are willing to pay a bit more for automatic transmission, he says, because it is convenient and

requires less training. It is the same with TODC versus DCF; with the proper feedback signal, TODC can au-tomatically set the dispersion, whereas DCF requires skilled craft to install.

A further benefit of TODC technol-ogy is that the same device can be used for both residual and inline compen-sation, depending on where it is de-ployed in the network. If it is placed near the optical amplifier, [the cus-tomer] probably wants to target it for DCF replacement, says Lin. If they use the TODC before the receiver, then they want to use it for residual disper-sion compensation. But a single unit can do two functions.

As TODC technology improves going forward, Doerr imagines that inline compensation could eventu-ally eliminate the need for residual compensation. Such an implementa-tion would be more cost-effective, he says, because you could eliminate the per-channel cost penalty of residual compensation.

Technology smorgasbordEach vendor playing in the TODC market uses a different material tech-nology and tuning mechanism; some are already commercially available, while others are still in development.

TeraXion claims to be the market leader in dispersion compensation with its FBG-based devices. TeraXion couples its FBG with a thermal gra-dient platform. Basically, we change the thermal gradient on the fiber, and that changes the dispersion level, says Guy. He notes that the same un-derlying technology is used for both TeraXions static or fixed dispersion compensators, which are widely de-ployed for both residual and inline compensation, and its tunable com-pensators. The vendor simply adds a tuning mechanism to the grating. Its a natural choice to move from a static dispersion compensator to a tun-

able dispersion compensator using a proven technology, which is the fiber Bragg grating, he contends. TeraX-ions 10- and 40-Gbit/sec TODCs are commercially available.

While some cite the FBGs size as a shortcomingit is too large to be integrated into a 300-pin MSA tran-sponderGuy reports that TeraXions customers have not been asking for transponder-based devices. I would say our customers are mainly integrat-ing our components directly on their line cards, he says.

TODCs also can be made from et-alons, which are based on bulk optics made into an optical cavity that in-duces multiple beam interference be-tween two mirrors. Etalons feature one of two tuning methods: They are either tuned by changing the space between the mirrors or by adjusting the temper-ature. Civcoms etalon-based TODC, for example, is thermally controlled. Laufer reports that Civcoms TODC is small enough to fit in a standard, 300-pin transponder. The vendor currently offers both the dispersion compensa-tion component as well as the com-ponent integrated within a 300-pin transponder, enabling system vendors to achieve distances between 170 and 350 km, says Laufer.

Fujitsu (www.fujitsu.com), mean-while, has commercially available 10- and 40-Gbit/sec dispersion com-pensators based on virtual image phased array (VIPA) technology. In a VIPA-based device, dispersion com-pensation is accomplished via a thin glass plate coated on both sides with a reflecting film and a reflecting mirror. Industry insiders report that such de-vices achieve the largest dispersion of any TODC to date but currently have a large footprint and high insertion loss.

ANDevices employs a planar light-wave circuit (PLC) approach in which a cascade of multiple Mach-Zehnder interferometers

Residual compensation provides constant, per-channel adjustment at the receiver, while inline dispersion compensation provides a more compact, tunable alternative to the incum-bent technology, dispersion-compensating fiber.

Cont. on pg 19


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Technology


results. Remember you are lining up tiny lenses in three dimensions close to millionths of an inch. Youll also need a good bulkhead adapter. A cheap, worn-out one wont do. Pick up a nice ceramic adapter and keep it capped. For critical measurements, always clean the adapters first using only a fiber-grade stick cleaner. Clean transceivers as well, but be carefultoo much force or excess cleaning liq-uid may damage the internal lens.

Laser sources and other similar gear can become unstable as the connector tip takes a beating. Often a factory re-polish will restore performance. Add-ing a sacrificial patch cable is a cheaper solution. The idea is to reduce instru-ment matings and provide a connector that is easier to clean and inspect.

Dont store cables tightly wound or take measurements that way. They will take that shape and cause nonlin-ear losses, especially at the 1,490/1,550-nm wavelengths. Verify cables by gently moving them during measurements. Replace them after a few hundred in-sertions. Always clean both ends!

Whats wrong with generic patch ca-bles? Plenty. If you need precision in a lab or production environment, they may add 0-1 dB of unstable loss. The Purchasing Department may treat patch cables as cheap commodities, but they are not all the same. Only about one-third of generics are usable for lab purposes. So after cleaning and hand-testing each one, where is the savings?

For example, commodity ferrules are drilled out to larger holes for ease of assembly. This process causes the fiber to be off-center and creates ex-cess loss and inconsistency. Some are not crimped properly, so twisting the connector will cause stress attenua-tion. The problem here is that remat-ing them will cause inaccuracies due to the mechanical misalignment. You may find most patch cables are dirty right out of the bag, so check them. A better grade comes with factory test data. Remember the Reagan Cold War doctrine: Trust but verify.

You can buy a quality patch cable with very low insertion loss (IL) for about $20. For calibration labs and pre-cise requirements, use a tuned, more expensive master-grade cable, which is available from a variety of suppliers. Label and treasure these cables, as they may get borrowed permanently to fix

unexplainable problems elsewhere.

Other potential problem sourcesThere are other potential sources of problems that deserve a quick review.

Caps: Caps are a major source of problems. They may be dirty and will outgas onto the surface. Clean them and store extras in a clean bag. Al-ways cap fiber ends. Just the electro-static charge on the ferrule alone will attract airborne contaminants.

Instrument adapters: After a num-ber of insertions, instrument adapters can become a hotbed of contamination, so clean them. For lab use, I have gone as far as using an ultrasonic cleaner to get my repeatability back.

Optical inspection: The critical core area on a singlemode connector is 9 m wide, or 0.0003 inches. One human hair is huge by contrast. A speck of dirt, residue, or even smoke you cant see may cause serious atten-uation, backreflection, and even per-manent damage. Simply cleaning the connector may not be enough. Use a 400X scope with a clean adapter on it to inspect your work before mating. The connector may be scratched or even burned by EDFA power levels.

One important note is that negli-gible dirt may not be measurable for insertion loss, producing, lets say, 0.5 dB. But it can reduce your backre-flection by 10 to 30 dB. This is bad news for AM video systems or single-wavelength data. Even worse, you may change to passing data by simply re-mating the connectors once or twice. Your RF and reflection measurements may be compromised. Back at your customers site, the dirt is now opti-mized and your FAIL LED is just waiting for the tech to leave.

Cleaning and calibrationFrom the discussion so far, its clear that cleaning is an essential aspect of ensuring precision measurements. However, the methods (or lack of meth-ods) for cleaning I have witnessed are amazing. I have seen canned air, shop air, window cleaner, rubbing alcohol, clothing, etc., used to clean the micro-miniature, highly precision-polished fiber ends. Would you do this to your expensive eyeglasses?

A simple, consistent (preferably dry) cleaning method is the key to low losses

and accurate measurements. I dont rec-ommend most wet cleaners due to added complexity and because they require a dry wipe to remove film or water spots from evaporation. Using alcohol known as IPA is dangerous. The use of flux bot-tles is another common contamination problem because the alcohol readily ab-sorbs water and after a while may look more like brandy due to dirt.

Whats the best cleaning method? It depends. In general, labs and produc-tion lines need a light cleaning for dust, but the field and service centers may need a heavier and repeated cleaning. Proper cleaning is worth another ar-

ticle in itself [which you can look for in JuneEd.]. For now, your best bet is to see the effects of incorrect cleaning for yourself with a 400X scopethen change that procedure or supplier.

If you havent established a serious fiber inspection and cleaning proce-dure yet, please start now. You have one for ESD, yet fiber cleanliness can be a much more critical and costly is-sue. Westover Scientific has released a free informative video on this topic called Inspect Before You Connect! (Download at www.westoverfiber.com/Support/downloads.php.) The major telecoms estimate that 65% to 75% of optical field issues are attrib-uted to dirty fiber. So either inspect and clean proactively or hire more field staff.

Its particularly tempting to skimp on cleaning in the field. A list of ratio-nalizations might look like this:1. It was cleaned at the factory.

Achieving precision in optical measurements2. I dont need to clean it unless

the link fails.3. I dont do the fiber optics. Im only an

installer.4. My cleaner is empty right now.5. I only had a one-hour class on it.6. Lookits not dirty!

All of these excuses are dangerous to accept. Fibers in the field are the most susceptible to contaminants such as dirt, gels, oils, etc. Clean both ends prior to mating during an in-stallation. One industry secret is how many boards are returned and tested as NTF (no trouble found) once the fiber is simply cleaned.

I can underscore the impor-tance of cleaning in the field from my own painful experience with several FTTH service calls. The installers redid my coax need-lessly, but I simply cleaned the fi-bers and my movie channels are HD-grade for the first time. They needed an optical power meter instead of the cable-TV one they used. I then ended up teaching a class on cleaning and inspection in my dining room.

Had you been in my dining room at the time, you might have seen something like Photo 1, which shows what a simple fingerprint (with clean hands, no less) looks like under 400X magnification. You cant see this level of contamination with

the naked eye. After cleaning, the core area is well defined and ready for low-loss connections.

These issues dont stop with your own staff. Take Joes Discount Cali-bration, who comes to your door with offers of big cost savings. It takes real care and skill to do fiber calibrations. Do they clean the lens, adapters, etc.? Do they use reference-grade patch ca-bles? Are they trained in fiber?

Some vendors will just sticker your box and cal the dirt out for you. Your readings will vary accordingly and may be worse than before. If you clean the lens now, your readings will be higher and off. Quality gear should not require regular tweaks if kept clean. Take before and after measurements. Visit the calibration house. Their gear should be better than yoursyou may be surprised what some use. See if they know how to clean and inspect fiber per written procedure; it makes

Photo 2. This fingerprint dirt was captured by Westover Scientifics FiberChek2. Such computerized systems can provide a quick, simple pass/fail test per a soon-to-be-global standard.


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TECH TRENDS

CONT. FROM PAGE 17

a huge difference. Have a third party or instrument handy for comparison. Stick to a reputable service or use fac-tory calibration otherwise.

Production issuesYou say youve outsourced the fiber manufacturing and now you dont have to worry about it? Here are a few points to consider.

If your vendor uses video inspec-tion systems, its easy to tweak the brightness and contrast down to get the yield up. Critical core area dam-age or contamination may never be spotted. Are you really expecting pro-duction-level folks to measure a 27.2-m blob in Region B as a pass/fail per your procedure? A preferred method is to use a computerized, nonsubjec-tive USB-based system (see Photo 2). Besides offering good results, theyre great news for those involved with fi-ber inspection who dont like grease pencils on screens.

There are other factors to consider when working with an outside vendor. Are they using a reputable calibration

house that knows fiber? Are they re-placing patch cords when they wear out? Are they cleaning each time? You will find that most contract manufacturers wont spend the money on replacement patch cords or cleaners unless required. Proper long-term measurements dic-tate repeatable conditions. Only audits and enforcement will keep your mea-surements accurate.

TrainingI am amazed at how little proper hands-on training takes place. I have seen in-credible yield changesfrom 50% to more than 90%by simply training employees on production lines. Show-ing a fingerprint on a large monitor leaves a lasting impression.

Even expensive equipment will give you erroneous results if not used correctly. Generally, engineers spec-ify nice gear for measurements, but they trust someone else will write the procedures, do the proper training for the techs and installers, and en-force the process for long-term qual-ity. But it just doesnt happen often.

We have ESD audits and procedures due to heightened industry aware-ness. Its time for more fiber aware-ness from management on down.

Getting peak performance from your optical test gear requires knowl-edge and diligence. I hope I raised your awareness of what it takes to make accurate lab, field, and service measurements. The best part is that being meticulous in your measure-ments will increase your companys quality and bottom line. Plus it gives you time to enjoy all those new movie channels fiber provides.

Rick Racinskas is a senior engineer at Tellabs (www.tellabs.com), where he supports global manufacturing for the companys access products. Racinskas has more than 20 years of experience in fiber-optic design, test, and manufacturing. He holds five patents, a bachelors degree in engineering technology from the University of South Florida, and is a member of the international Electronics Manufacturing Initiative (iNEMI). He can be reached at [email protected].

Fast progress in ITU for bend-loss insensitive singlemode fiberBy Gerard Kuyt

A relatively new ITU-T SG15 group (Question 10; chaired by Piet Matthijsse of Draka Comteq) is devoted to optical fibers and cables for the access network to and in buildings and homes. This group has prepared

a new standard for fibers opti-mized for use in the first mile. Aimed at reducing installation cost, the optimization involves reduced bending loss, thereby allowing the fiber to be used in smaller enclosures, cabi-nets, and easily installable in-door cables.

When previously discussed in this column (see Standards Watch, Lightwave, July 2006, page 20), the draft recommen-dation (then temporarily de-noted as G.smx) was planned for consent at the June 2007 meeting. Because of requests from several operators and in-dustry parties, fast progress

was achieved and the new recommendation was con-sented at the November 2006 meeting and given the designation G.657. This fast development endorses the apparent need for a worldwide standard for bend-loss insensitive fiber.

Recommendation G.657 recommends two fiber classes: A and B. Class A is in all aspects compliant with the well known Recommendation G.652.D but of-fers a significantly lower macrobending loss. Its use is defined for bend radii of 10 and 15 mm where the maxi-mum bend loss at 1,550 nm is 0.75 and 0.025 dB/turn, respectively. By comparison, the bend loss for G.652.D fiber is specified at the much higher bend radius of 30 mm only.

G.657 Class B may deviate from G.652.D on mode field diameter and dispersion and is intended for use over re-stricted distances for in-building applications. Class B fibers may have different splicing and connection prop-erties than G.652 fibers because of a lower mode field diameter but can be used at smaller bend radii. The max-imum bend loss at 1,550 nm is 0.5 dB/turn at a 7.5-mm bend radius, and 0.1 dB/turn at a 10-mm radius. This is significantly lower than G.657 Class A fibers.

STANDARDS WATCH

Gerard Kuyt is product line manager at Draka Comteq Optical Fibre in the Netherlands; delegate to ITU-T SG15/Q5 and Q10; and convenor of IEC SC86A/WG1. He can be reached at [email protected].

(MZIs) is integrated into a single chip. When a voltage is applied to tune the phases, light with different wavelengths travels through two MZI arms sepa-rately, resulting in negative and positive dispersion. According to Lin, the same design can be used for single- or mul-tiple-channel TODCs. She says ANDe-vices chose the PLC design to leverage the materials mass- reproducible semi-conductor fabrication techniques, thus lowering costs. Moreover, it features no moving parts and can be easily inte-grated with other devices, she says. The company is currently shipping proto-type 10- and 40-Gbit/sec TODCs.

Bell Labs also employs PLC technol-ogy in the form of silica arrayed wave-guide gratings (AWGs). According to Doerr, Bell Labs uses a high-resolu-tion AWG along with a polymer-based thermo-optic lens that it developed in collaboration with Gemfire Corp. (www.gemfirecorp.com). To get dispersion, you need a linear group delay, which means you need a para-bolic phase distribution, he explains.

The high-resolution AWG spreads the spectrum across the thermo-optic lens, and the thermo-optic lens gives you a parabolic phase. You have a region of the material, and you heat up, lets say, the center more than the edges, creat-ing the parabolic phase. The polymer is useful, he says, because it creates a large index change over temperature.

Besides DCF, all flavors of TODCs also will compete against electronic dis-persion compensation (EDC), at least at 10 Gbits/sec. EDC is performed after the optical-electrical-optical conversion and may be accomplished via adaptive clock and data recovery or adaptive equalization. EDC is not yet commer-cially available at 40 Gbits/sec.

Some industry insiders wonder if perhaps EDC will find its niche as a complementary technology to TODC, which only compensates for chromatic dispersion. EDC can be used to combat polarization-mode dispersion, which is problematic for higher-bit-rate systems. Several sources interviewed for this story note that a hybrid implementation of both ODC and EDC may be the best option. In fact, says Doerr, EDC can be used to clean up the high-order effects (e.g., group delay ripple) introduced by the TODC devices themselves. I think in the future, well see a combination of EDC and ODC, he maintains.


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OpVista has recently unveiled the AnyWave Op-tical Network strategy. OpVista has combined al-ready fielded IP with new technology initiatives to enable companies to transition their existing infrastructures into high-speed, high-capacity Ethernet transport networks.

Its a holistic way to look at the network, then its some additional capabilities we added to the portfolio to do that, describes Dawn Hough, vice president, marketing and business development of OpVista. According to Hough, the cornerstones of the companys new strategy include the reuse of existing infrastructure by providing a graceful upgrade path for cur-rent networks, the ability to provide connectivity anywhere in the network at any time, the addition of network resiliency to Ethernet transport, re-duction of capex and opex, and the creation of a service-independent net-work that can cost-effec-tively support voice, video, and data services for resi-dences and businesses.

OpVista has combined existing and newly an-nounced IP to implement the AnyWave Optical Network concept. For exam-ple, it plans to provide scalable capacity via its ex-isting 10-Gbit/sec Ultra-DWDM technology, plus its new WaveWeaver capability. The Ultra-DWDM technology enables 10-Gbit/sec traffic to ride across networks engineered for 2.5-Gbits/sec by combin-ing four 2.5-Gbit/sec streams into a single 2.5-Gbit/sec transmission window. The new WaveWeaver technology enables companies to add wavelengths to existing 10-Gbit/sec networks that have hit max-imum capacity usage. Wavelengths from the exist-ing 10-Gbit/sec multiplexers operating at 100-GHz spacing feed into the WaveWeaver platform, which adds additional wavelengths at 100 GHz, but offset by 50 GHz from the original grid. The new wave-lengths ride between the existing wavelengths, thus doubling capacity to a maximum of 800 Gbits/sec, based on a total of 80 wavelengths.

Hough reveals that the company also plans to port its Ultra-DWDM technology for 40-Gbit/sec applications, again by transporting multiple 10-Gbit/sec streams into the transmission win-dow normally occupied by a single stream. She

declined to reveal when the technology would be officially released.

For ubiquitous connectivity, OpVista will lever-age its existing broadcast-and-select architecture, which uses broadband couplers and tunable receiv-ers to create a ROADM functionality that can be enabled and expanded without disrupting service or requiring forklift upgrades. Hough asserts that thanks to differences in transponder costs and the fact that carriers wont have to install new modules at every node to add or expand ROADM capability, the OpVista ROADM approach will cost 72% less than a typical network equipped with fixed optical

add/drop multiplexers.Meanwhile, the compa-

nys existing Switched Ring Architecture (SRA) pro-vides the network reliability and resiliency that Carrier Ethernet requires, Hough says. The SRA provides full optical layer protec-tion across any number of nodes; Hough says that one customer has deployed an SRA with 26 nodes across 1,000 km. So if you look at video, and operators trying to minimize their cost for servers and storage, if you can serve a large number of nodes with a single video

stream, youre going to save a lot of your cost in that video distribution, Hough explains.

The company believes its upcoming EtherWave technology will reduce capex and opex by decreas-ing router/switch costs at the network edge. The technology will be incorporated into the companys OpVista 2000 platform. One box can be installed at the service hub and pass up to 80 wavelengths of Gigabit Ethernet to another OpVista 2000 at a re-mote node, which will split the streams for delivery to the customer premises. The architecture reduces or eliminates the requirement for comparatively expensive edge routers. While OpVista has intro-duced the concept within the AnyWave Optical Network announcement, it plans a separate release of the technology around the June timeframe.

Taken together, OpVista is confident that its approach provides both scale and cost savings.

We believe the AnyWave Optical Network con-cept is the most comprehensive, cost-effective way to transform your existing infrastructure into a Carrier Ethernet-ready network, Hough concludes.

By Stephen Hardy

OpVista unveils AnyWave Optical Network concept

OpVistas AnyWave Optical Network concept is designed to enable service pro-viders to use the OpVista 2000 to transform their legacy infrastructure into a Carrier Ethernet network.

XFP connector modulesThe XFP001/2/3-L line of 10-Gbit XFP mod-ules is designed for use with 10-Gbit hot-pluggable optical transceiver modules. The cage and connector comply with the Multi-source Agreement 3.0 (MSA 3.0) standard

and support OC-192/STM-64, 10-Gigabit Fibre Channel, G.709, and 10-Gigabit Ether-net (10GbE) protocols in applications such as blade servers, routers, add/drop mul-tiplexers, and remote base stations and central office equipment. They supply en-hanced electromagnetic i

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