Test of Time
As equipment manufacturers and service providers rush to build next-generation networks, new approaches to optical tests and measurement are gaining ground.
Under pressure from carriers, manufacturers need to quickly move concepts from prototype to mass production. Carriers have their own set of pressures from customers eager to deploy complex enhanced services, with high reliability, at faster speeds, in smaller boxes.
Service providers must be able to verify the performance of individual components by bench-testing, then field-testing variables like chromatic dispersion, polarization, attenuation and the geometry of the fiber itself. Finally, the network needs to be monitored, and troubleshooting must be done as a regular part of its operation, checking bit-error rates, service levels, fault isolation, provisioning and power-balancing.
Thats a broad range of requirements. What a field tech needs to do the job on-site is entirely different from what is needed in the lab, where test instruments the size of small refrigerators are not uncommon.
"The primary challenge is the speed at which the measurement needs to be made," says Jennifer Pigg, who follows optical networking at The Yankee Group in Boston. In the all-optic network, plugging in electronic test equipment provides proof of Heisenbergs theorem the act of monitoring can degrade the networks performance.
As dynamic provisioning and other intelligent services move from pipe dream to reality, analysts say, expect test functions to migrate from the lab into the network, integrated into transport equipment.
Lucent Technologies was among the first to explore this market, teaming with Digital Lightwave, a Clearwater, Fla., provider of optical network testing gear.
"They realized that in order to speed up deployment, they need to put the test and diagnostic functions into the transport equipment," says Digital Lightwave engineer Doyle Mills. In January, JDS Uniphase took a minority stake in Avantas Networks, a network testing equipment company based in Montreal.
Last fall, Digital Lightwave added Internet Protocol to the list of technologies analyzed by its portable Network Information Computers and Network Access Agents. Carriers such as 360Networks, Level 3 Communications and Livingston UK have purchased Digital Lightwave testers for installation, maintenance and remote performance monitoring.
Sniffer Technologies, a unit of Network Associates, uses Digital Lightwaves Dense Wavelength Division Multiplexing (DWDM) analyzer in its network management products, allowing technicians to pick out one circuit from the hundreds within an optical fiber and run diagnostics on its physical and applications layers.
Among component manufacturers, the name of the test-and-measurement game is to figure out ways to get a brilliant idea from prototyping to mass production as quickly as possible.
Claiming that test and measurement accounts for 60 percent of the cost of optical manufacturing, Canadian test kit maker Exfo Electro-Optical Engineering is working on a system that automatically tests DWDM components, eliminating the need for manual testing. Exfo, which bought Burleigh Instruments last year for its fiber-alignment expertise, has said it will spend $20 million to triple its manufacturing capacity in Vanier, Quebec.
Another test equipment vendor, Newport, took a similar tack when it bought Kensington Laboratories in February. Newport, based in Irvine, Calif., plans to add Kensingtons robotics and motion-control expertise to its line of test and assembly equipment for semiconductor and optical device manufacturing. "This is particularly important as system speed and material handling features are added to our test and assembly tools," says Newport Chairman and Chief Executive Robert Deuster.
Plenty of test-and-measurement companies are claiming "firsts" in the fast-moving market. GN Nettest, a division of Denmarks GN Great Nordic Group, in January released a test suite for Multiprotocol Label Switching. GN Nettest claims its product is "the first complete MPLS testing solution," covering functional, conformance, emulation and interoperability testing.
Valiant Networks, in San Jose, says it pioneered a vendor-neutral approach with its third-party independent testing lab. Valiants 6,000-square-foot "UltraNOC" provides network design, interoperability testing and other services for service providers and equipment manufacturers. Anritsu Co. of Richardson, Texas, says it is the first to support OC-192 (10-gigabit-per-second) speeds in its testing gear. Luciol Instruments, a Swiss start-up, says it is the first to develop exquisitely sensitive photon-counting technology to measure both glass and polymer optical fiber.
Agilent Technologies says it is the first to focus on testing the optical control plane the protocols and hardware connecting different switches and routers. For carriers eager to move onto all-optical networks and offer bandwidth on demand, the control plane holds the key but each switch vendor uses its own protocol, from Sycamore Networks Broadleaf to Telliums StarNet to Cienas Optical Signal and Routing Protocol. Open optical networking seems a long way off.
While vendors, carriers and the Optical Internetworking Forum fight among themselves over standardization, Agilents optical control plane analysis software sidesteps the problem of competing protocols. It converts and displays everything in hexidecimal code, carrying new protocols on a small bandwidth-control channel, rather than taking up a whole wavelength.
While deployment of all-optical networking will be gradual, Agilent expects plenty of business from optical equipment developers eager to see how well their equipment meets market requirements.