The ongoing telecom crunch has not only changed the nature of carrier networks, it's changed the way those networks are built and maintained. Carriers feeling the pinch of a tightening market are looking for tools to help them cut the costs of putting in fiber networks and keeping them in peak condition.

This report, the third in Light Reading's series on Test and Measurement in optical networks, describes just what carriers are looking for and how emerging equipment is (or is not) meeting their requirements in the field.

The problem is straightforward: Currently, deploying fiber networks involves lots of dreaded "truck rolls," the dispatching of highly paid technicians by carriers to install single- and multimode fiber and make the necessary adjustments to surrounding devices. These operating costs ramp up quickly and are keeping many of today's carriers strapped.

The tools of the field installer's trade often add to the problem. The gear used in the installation and maintenance of optical networks can be cumbersome, bulky, and often one-dimensional. And it's expensive – not only to buy, but to use.

Because many testers lack remote connectivity and controls, they require technicians, usually highly qualified ones, to travel with the gear to a site and take measurements there. And because so many testers are typically required to get a job done, it's not uncommon for a technician to get to a site, take a few readings, and discover the tool he or she really needs is back in the shop.

Like other areas of test and measurement covered in this series (see Test and Measurement Report, Part 1: Manufacturing and Test and Measurement Report, Part 2: R&D ), field installation and maintenance is changing, however. Old-fashioned test boxes are being replaced by smaller models that do more in less space. These products are coming with new capabilities designed for emerging networks, and they feature Web or wireless links that help make the best use of technicians' time.

This report covers the present state of the market, the key challenges and trends. Read it sequentially, or click to the page that interests you most:

Market Overview
A look at the size and state of the market for field test and measurement gear.

The Challenges
Cumbersome, onsite instruments just aren't cutting it.

The Trends
Speed, versatility, and remote access, for starters...

The Products
A look at the trend-setting vendors of test gear.

— Carl Weinschenk, Senior Editor, Light Reading
http://www.lightreading.comThe focus of this report is the market for fiber optic field test equipment, meaning the instruments used by technicians to install single- and multimode fiber in carrier networks, then to maintain it in peak condition.

Like other areas of the communications test equipment market, this segment's growing respectably, despite the telecom downturn. According to market research firm Frost & Sullivan, fiber optic field test gear comprises roughly 30 percent of a market for physical-layer fiber test instruments that was worth about $1.5 billion in 2001.

These results tally closely with findings from Morgan Stanley Dean Witter & Co., which estimates that the market for field test equipment will average about 25 percent of the overall market for the foreseeable future.

Morgan also notes that test equipment for the optical segment, including field testers for optical networks, is growing fastest of all areas of the communications test industry. Growth will continue through 2005, according to Morgan. In that year, the firm estimates, optical test gear will be the largest segment of the communications test industry, comprising more than 30 percent of total revenues.

So what types of gear are included in this market? There are many different types of instruments used by carrier technicians in their work on optical networks. Key items that may be found in a truck include:

There are many other kinds of field test gear, the functions of which often can be discerned from the name: fault locators, power meters, and light sources, for instance.

Related stories in Light Reading:

The market for field test and measurement gear may be moving along at a steady pace, but challenges loom. Testers need to be revamped to meet carriers' pressing requirements. Myriad, bulky, one-dimensional instruments just aren't cutting it anymore.

There are several reasons for this. First, a central fact of the field instrumentation market, particularly in the case of optical networking, is that it requires enormous amounts of human intervention. And that means costly labor.

According to CIBC World Markets, extending Sonet access to a building in a metropolitan network can cost up to $700,000, between the digging and laying of fiber and the configuration and setup of connections to the Sonet add/drop multiplexers on the required ring. Up to 70 percent of that figure is the labor involved, the dread rollout of trucks laden with highly skilled technicians.

Here’s some more data: Frank A. Maier, operations manager for Agilent’s network test business unit, says that present-day cables often have 864 fibers in them. After installation, each fiber needs to have at least two wavelengths tested in two directions. That’s a lot of testing, and the chore typically takes 72 hours. (Of course, Agilent claims its new field test gear reduces this figure to 9.6 hours. More on that later.)

The work doesn’t stop with installation. On a typical day, says Maier, Agilent RBOC customer Verizon Communications Inc. (NYSE: VZ) receives a million phone calls reporting faults. About 95 percent are dealt with on the phone, Maier says, but the remaining 5 percent – that is, 50,000 fault reports – have to be dealt with by sending an engineer to investigate. To make matters worse, 22 percent of visits end up failing to rectify the fault, so an engineer has to make a return visit.

The bottom line, according to Maier, is that Verizon spends half its operating budget on fixing faults. Now, here’s the amazing bit: Its operating budget totals a staggering $25 billion a year. By that reckoning, improving fault-fixing efficiency by just one percent would save $125 million a year!

Given figures like these, it's clear that field test equipment must streamline and become less labor-intensive. But for now, many test instruments are contributing to the problem. Here's why:

Installation and maintenance test and measurement gear manufacturers are facing other challenges as the sophistication of the networks grows. Two examples: As simple point-to-point networks give way to mesh and ring/mesh topologies – in which signals can take different paths – it becomes more difficult for test and monitoring gear to keep track of what is within and what is without normal operating parameters. Likewise, the arrival of all-optical add/drop muxes can blindside monitoring gear designed to trigger on the electrical changes that traditionally were part of dropping and adding signals.

Equipment vendors are working to meet these challenges head on. Their efforts are coalescing in several key trends, including faster equipment, test consolidation, miniaturization and modularity of gear, feedback improvements, and innovations in monitoring optical equipment before it breaks. In the next section, we'll look more closely at each of these trends.

Speeding Up



The increased speed of today’s networks calls for several changes to test equipment used in the field. Testers must be faster in order to keep up with the speed of networks.

Gear also needs to be adjustable. As Norman Ireland, director of marketing management at Acterna, put it: “How do you test for multiple signals, given that end users are procuring different speeds, not only very low speed T1 [1.544 Mbit/s] , but also OC12 [622 Mbit/s] and OC3 [155 Mbit/s], STS1 [51.8 Mbit/s], and other interfaces, all wrapped up in an OC48 [2.5 Gbit/s] pipe?”He says the answer is to develop test gear that can fluidly test across all these speeds.

Some say running tests in parallel on the same instrument at the same time is the answer. Parallelism is becoming feasible as the microprocessing power of devices increases. But this means a move to more powerful chips and new designs for test equipment makers.

The use of high-speed connections also calls for new kinds of tests.

As in other areas of test and measurement, the arrival of faster speeds means that chromatic dispersion (CD) and polarization mode dispersion (PMD) become more crucial issues than before.

Presumably, designers and manufacturers paid attention to CD and PMD in the research and development and manufacturing stages. Even if they did, attention must be paid at the installation and maintenance phases as well.

As light pulses travel, a couple of phenomena cause the wavelengths to become misshapen. For one thing, not all photons travel at the same speed. Further, some photons, like recalcitrant teenagers, simply start moving in the wrong direction. These two problems – CD and PMD, respectively – are not issues at slower speeds, because the wavelengths are far enough apart that the destination is reached before the spreading starts causing bit-rate errors. Faster systems mean that the wavelengths are more tightly packed and CD and PMD move from the theoretical to the real.

In general, measuring CD is easier than PMD, sources say. CD is a static measure – the CD at the beginning of a link is the same as at the end – and a dispersion adjusting compensator can handle the problem. PMD is a different animal, however, in that ambient conditions such as temperature and the movement of the fiber lead to flux in PMD. It is still not possible to measure PMD in signals moving through optical amplifiers.

More With Less



Several of the field test equipment trends we cited earlier need to be discussed together. Specifically, these are test consolidation, miniaturization, and modularity.

It’s getting mandatory that optical tests require fewer devices. As we’ve pointed out, the sheer volume of fiber testing is overwhelming, and when extra CD and PMD tests are added for higher-speed lines and DWDM, a carrier can get swamped.

The answer is to put more tests in one instrument, which can be made lightweight and portable enough for field use. This is where the current crop of mini-OTDRs seems to be heading.

Better Feedback



Service providers are demanding that problems be identified before they result in downtime – and that those that do occur be handled immediately.

These requirements necessitate a number of fundamental changes that, collectively, could help transform installation and maintenance from a reactive exercise to a proactive program that catches the majority of problems before they cause outages. Truck rolls, a bottomless cost pit for service providers, will be cut, and those that are performed will be far more targeted and useful.

Among the features that are helping this effort are the following:

Following, in alphabetic order by vendor name, is a sampling of some products that typify the trends in optical field testing.

Acterna Corp. (Nasdaq: ACTR)Acterna released in January 2002 a new version of its Atlas tester that allows remote monitoring of fiber networks and delivery of data to a PC over a secure link. It also enables preemptive testing by placing compact test units at points throughout the network that are connected to a central server.

Acterna also has introduced an optical spectrum analyzer for its MTSe tester that covers both the C and L frequency bands, which are typically used in DWDM gear. The MTSe now provides both OTDR measurements and optical spectrum analysis. The combination of C- and L-band testing with the OTDR functions reduces the number of tests required of field personnel, the vendor says.

Agilent Technologies Inc. (NYSE: A)Agilent's new Modular Network Tester – introduced at this year's CeBIT trade show – combines a user-defined mix of OTDR, optical spectrum analyzer, dispersion tester, and video microscope. The differentiator for this tester, according to the company, is that the various modules clip together without a chassis. So if a field tech needs to run two tests, they carry just the modules for those tests clipped into a single unit. There are no empty receptacles in the chassis to lug around.

Agilent has also enhanced its multirate J2126A and 2127A transmission test sets. The new configuration allows service providers to buy test equipment geared to a particular speed and add capabilities for other speeds as required. For instance, the 2126A can be purchased for networks of 622 Mbit/s and upgraded to 2.5 Gbit/s via software. The 2127A has an optional "extended chassis" that handles all tests up to 10 Gbit/s.

Anritsu Corp.Anritsu's new MW9076 family of mini-OTDRs measure CD from one end of a fiber, according to the company. The four-model family displays results in 10 seconds, has two-color displays, and samples data at rates of 0.15 seconds.

Anritsu's MD1230A Data Quality Analyzer can monitor virtually all physical interface and network layers, the vendor says. It is intended to provide comprehensive protocol testing. Any combination of five interface modules, from 10 Mbit/s to 10 Gbit/s, can be installed in each MD1230A cabinet. As many as eight units can be cascaded via Ethernet and controlled by one of the MD1230As.

Digital Lightwave Inc. (Nasdaq: DIGL)Digital Lightwave has expanded its Network Access Agent (NAA) product to include management of multiple NAAs in the field. This is a graphical user interface-controlled, Java-based package that enables remote dial-in, network-wide configuration control, test access, and security, the vendor says. Digital Lightwave also has added a Gigabit Ethernet module to its Network Information Computer (NIC) and NAA testers. The module enables these units to test at both the packet and physical layers during the same test session.

EXFO Electro-Optical Engineering Inc. (Nasdaq: EXFO) EXFO's FG-7000 Fiber Guardian and OG-5240 can be accessed locally or set up to report alarms to a pre-specified location. Both devices issue alerts when operations fall outside user-defined parameters. The Fiber Guardian performs real-time physical layer tests on as many as 32 fibers. The Optical Guardian monitors optical level parameters in DWDM or CWDM networks.

EXFO's FTB-8000 is a test unit designed to work with the vendor's FTB-400 tester platform, integrating 10-Gbit/s protocol, optical, and physical-layer testing in one box. Its ability to test as low as DS0 (64 kbit/s) makes it appropriate for metro and access networks. The unit supports Sonet/SDH, T-carrier, PHD, 10/100 Ethernet, and gigabit Ethernet.

EXFO's FTB-5240B OSA module works in the vendor's portable universal test system, based on PC architecture. Other modules for the test system include OTDRs, multiwavelength meters, PMD analyzers, OLTS and ORL testers, and optical switches. The battery-operated FTB-5240B has a built-in reference source and can withstand a 30-inch drop test, the vendor claims.

EXFO also offers a number of portable CD and PMD analyzers. The FTB-5800 measures CD in networks and fiber links in DWDM, long-haul, and ultra-long-haul systems. The FTB-5500 PMD Analyzer performs tests on similar systems. When used in conjunction with EXFO's FLS-100P M2100 light source, it can measure links longer than 250 km, the vendor says.

Ixia(Nasdaq: XXIA) Ixia's IxActivate uses a simple GUI to turn up new services. The system can test Ethernet frame error rates, throughput, latency, packet loss, virtual LANs, and failover time, according to the company.

Luciol Instruments SAThe new PMD option in Luciol's u-CD1 enables the simultaneous measurement of CD and PMD, according to the company. It generates graphical reports.

NetTestNettest has added Single and Multistream IP Performance Test Suites to its interWatch Performance and Verification System. The IP tests end-to-end SLA (service-level agreement) verification and multistream IP QOS (quality of service) measurements across ATM, packet over Sonet, gigabit Ethernet, and MPLS.

PerkinElmer Inc. (NYSE: PKI) Perkin Elmer's Chromos12 is a field-deployable CD and PMD tool that enables end-to-end dispersion measurement over long-haul networks. The company says the units are unique in that they measure through optical and electrical amplifiers. The unit uses a single fiber to perform measurements.

Sunrise Telecom Inc. (Nasdaq: SRTI) Sunrise Telecom's SunSet Modular Testing Toolkit (MTT) includes Layer 1 and Layer 2 BERT and throughput tests; a variety of optical interfaces; 1310nm or 1550nm transceivers; and non-intrusive monitoring of customer traffic, the company says. The vendor's SunLight Optical Handheld Testers offer an optical power meter, a laser light source, a loss test set, and an automated optical attenuator. The units support multiple wavelengths, require no warmup time or other delays, support singlemode, multimode, and high power measurements, and generate multiple reports.