NFOEC rides a wave of products and papers

NFOEC rides a wave of products and papers


The 1996 National Fiber Optic Engineers Conference, held recently in Denver, focused on Synchronous Optical Network (Sonet) architecture, interfaces and administration; wavelength-division multiplexing (WDM); network testing; and optical fiber amplifiers. Sponsored this year by US West and Bell Communications Research, the 12th annual conference reflected the increased appeal, support and use of fiber optics technology by telecommunications and cable-TV network equipment suppliers and end-users. The conference had more than 2000 attendees, 90 exhibitors and more than 100 technical papers--all record-breaking numbers.

Keynote speaker Solomon Trujillo, president and chief executive of US West--a regional Bell operating company and a telecommunications services supplier to 14 states and 25 million customers--commented, "Applications are going to accelerate because of bandwidth, and fiber optics is the major driver." However, he added that until the Federal Communications Commission clarifies the interconnection rules of the Telecommunications Act of 1996, US West might not invest, upgrade or build infrastructure because of unfavorable interconnection cost issues.

As a guest speaker during the plenary session, Paul Shumate, Bellcore executive director, broadband local access and premises networks, discussed future fiber conditions in a talk aptly named "Fiber `06." Among his predictions was an estimate that total U.S. fiber deployment miles would jump nearly sevenfold, from 16 million miles in 1996 to 110 million miles in 2006. He calculated that this year`s traffic on backbone networks would, in 2006, increase about five times (in Erlangs) and would move at a 20-times-faster bit rate. Similarly, by 2006, access-loop network traffic is expected to jump five times in traffic and 100 times in bit rate and also be able to transfer heterogeneous communications. By 2006, Shumate also envisions that 20 million homes will be wired with fiber, and the market for home gateway gear should top $5 billion.

Interoperability demonstrations

On the exhibitor floor, two interoperability demonstrations drew widespread observation. In the Bellcore booth, Fujitsu Network Communications, Lucent Technologies and Bellcore conducted the first public demonstration of full seven-layer, open systems interconnection, multiple-supplier, Sonet operations communications interoperability (see page 1).

In the other demonstration, Tellabs Operations, Lucent Technologies, Northern Telecom and Fujitsu Network Communications interworked Tellabs` Titan 5500 digital crossconnect system, Fujitsu`s FLM 600 ADM OC-12 Sonet add/drop multiplexer, Lucent Technologies` DDM-2000 OC-3 Sonet multiplexer, Northern Telecom`s s/dms TransportNode OC-3 Express network element and their respective network management systems in the Tellabs booth. The companies performed in concert to show that their Sonet equipment could be mixed and matched, with confidence that the overall network would interoperate reliably.

"Tellabs and Northern Telecom are the first to show how a crossconnect can be managed via reach-through connectivity," says Mike Unger, Northern Telecom group vice president, Sonet transport. "It`s one thing for products to interconnect, but it`s another to have end-to-end network visibility and control that this solution provides."

Taking a leading role in supporting interoperable solutions, Tellabs set out to prove that "plug and play" operations can be achieved when vendors adopt a totally open implementation in compliance with specifications established by the Sonet Interoperability Forum, Bellcore and the American National Standards Institute (ansi). To that end, live video was transmitted between the Tellabs Titan 5500 system and each of the other vendors` add/drop multiplexers via OC-3 and OC-12 fiber-optic transmissions of 155 and 622 Mbits/sec, respectively.

Comments Rich Mosconi, Lucent Technologies vice president of Sonet market development, "Multivendor interworking, or the ability for equipment from different vendors to work together seamlessly within the telecommunications infrastructure, is at the core of what Sonet technology offers network service providers."

Sonet data networking on the Titan system was shown by controlling and provisioning the video sources on each multiplexer. In a practical Sonet network implementation, the data communications channel routing functions let users access remotely located multiplexers and operate, administer, monitor and provision the Sonet network elements by directing messages through the central office, digital crossconnect system.

In Corning`s booth, Northern Telecom demonstrated 20-Gbit/sec transmission over 500 km of Corning smf-ls fiber, using Northern Telecom`s 10-Gbit/sec OC-192 network elements and s/dms Transport Node multiwavelength optical repeater system. However, the company`s products can support WDM OC-48 and OC-192 rates to deliver as much as 80-Gbit/sec capacity.

Studies done by Stentor, Bell Canada and Northern Telecom, and separate trials by Northern Telecom and Corning, show that most of the nondispersion-shifted, fiber-optic cables presently installed in telecommunications networks worldwide can support the high-speed, high-capacity transmissions delivered by Northern Telecom`s s/dms TransportNode OC-192 systems, and that polarization-mode dispersion is not an obstacle.

Fujitsu Network Communications showcased its OC-192 Sonet ring platform, a practical local area network (LAN) interconnection application and a switched-digital video fiber-to-the-curb network.

The OC-192 three-node ring configuration, which supports video trunking, featured the company`s Flash-192 multiplexers. Plugging Fujitsu`s FastLane cards into its FLM 150 OC-3 add/drop multiplexers allows the seamless integration of native LAN interconnect and cell-relay services into Sonet networks. In a switched-digital video demonstration, the company`s Factr access/transport platform delivered various broadband services over a Sonet/Asynchronous Transfer Mode (ATM) network setup.

Alcatel Telecom targeted an end-to-end Sonet network capable of carrying as much as 160 Gbits/sec using standard open interfaces. The company based its network on controlled lasers at the component level, durable erbium-doped fluoride-fiber technology for its optical amplifiers, and the Alcatel 16192 SM Sonet OC-192 or SDH STM-64 multiplexer. Alcatel plans call for achieving the 160-Gbit/sec transport rate through a combination of WDM and time-division multiplexing technologies.

According to Joe Bass, Alcatel Telecom vice president and general manager, lightwave products, "The 16192 SM multiplexer and 16-channel WDM must be used together, not as alternatives, to achieve the highest possible wavelength of 160 Gbits/sec. This type of bandwidth means greater, faster and more-efficient services, particularly in the video and ATM areas."

The Alcatel 1610 OA optical add/drop multiplexer--a fluoride-based optical amplifier--uses novel manufacturing techniques developed at Alcatel Optronics in France. This amplifier is claimed to provide a signal-to-noise ratio consistency that is an improvement over that of silica fiber-based amplifiers across the 1530- to 1565-nm transmission window. Alcatel states that fluoride fiber systems offer flatter gain across the entire transmission window and that silica fiber amplifiers have a fundamental problem with gain slope in the 1530- to 1542-nm range. More than 98% of installed worldwide fiber-optic cables use this transmission window.

On the laser front, Alcatel is developing light sources to provide as many as 32 wavelengths, making possible a 32-channel WDM system that theoretically could deliver 320 Gbits/sec.

Three types of cable

Pirelli Communications Div. introduced three types of fiber-optic cables--unarmored and armored KleenCore cables with MarineCore technology, and FirstLink indoor/outdoor transition cables (see photo). All three types are members of the KleenCore group, do not contain messy petroleum-based core flooding gels and are available in fiber counts of 4 to 288, with as many as 12 fibers per loose tube. Removal of the gels eliminates the additional time associated with cleaning gels from the cable core components during sheath preparation and termination. Consequently, a splicer can save 15 minutes to 2 hours per splice point, depending on the fiber count.

MarineCore water-blocking technology protects the cable core from sea water and other moisture penetration without the use of traditional petroleum-based core flooding gels. Corrugated steel is used to protect the armored cables. Indoor/outdoor cables eliminate the vault splicing needed at the point inside the building where the outside plant cables are traditionally spliced to indoor cables. This capability can save a splicer approximately eight hours when working on a 144-fiber cable.

Says Ray Robinson, vice president and general manager of Pirelli`s Communications Div., "The accelerated growth of competition within the communications industry continues to place pressure on cost reduction. The KleenCore family of cables can lower installation time and the associated costs while giving craftspeople a friendly product."

Lucent Technologies showed its small, polarized LC fiber-optic connector, which employs the RJ-45 push-pull insertion-release mechanism similar to a typical telephone plug. Compliant with Bellcore, ansi, Electronic Industries Association, Telecommunications Industry Association and International Electrotechnical Commission standards, the connector is half the size of ST and SC connectors, provides an antisnag latch, and suits applications where space is limited. Insertion loss is specified at 0.10 dB, return loss at -20 dB maximum and cable retention at 2 lbs. The LC product line consists of multimode and singlemode simplex and duplex patchcords, pigtails, duplex adapters, and a host of support parts.

GRC International in Vienna, VA, displayed additions to its OSU network interface line, which provides demarcation between any two entities within a Sonet network. One addition--a TL1 craft manager--allows Sonet network managers to write provisioning scripts quickly by avoiding the need to draft commands in machine code. Another addition--an OSU derivative product--supports line level automatic protection switching at an OC-3/3c/STM-1 rate, and an automatic protection switching system monitors redundant signals on two Sonet lines and automatically selects the one that is working at an optimal level. q

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