AT&T charts network growth over installed fiber plant
george kotelly
With its communications service demands increasing dramatically, the leading U.S. long-distance carrier, at&t, is planning to add more Synchronous Optical Network (Sonet), dense wavelength-division multiplexing (dwdm), and Asynchronous Transfer Mode (atm) capacity during this year than the total capacity of all of its networks just six years ago. However, this expanded capacity is apparently going to be accomplished by connecting network equipment to the existing singlemode fiber plant--not by installing new fiber-optic cabling. According to industry analysts, at&t is also striving to achieve competitiveness with long-distance carrier rivals mci Communications Corp. and Sprint Corp., which have already deployed numerous Sonet backbone, point-to-point, and ring networks.
Frank Ianna, at&t vice president and general manager for network and computing services, in Bedminster, NJ, says that the company plans to spend $5 billion of this year`s $8 billion to $9 billion capital expenditures budget on expanding and upgrading atm, Sonet, and restoration networks, and introducing new telecommunications, data, and Internet services. The main goal, however, centers on meeting users` needs for increased bandwidth via the inherent high capacity of Sonet networks and wdm technology. Ianna presented at&t`s plans to more than 700 members of at&t`s Voice Networking Forum, made up of representatives of large corporations.
During 1996, at&t installed 11 Sonet rings and by year-end, will have 30 Sonet rings operational as well as coast-to-coast Sonet connectivity. Moreover, by year-end 1998, at&t plans to have more than 50 Sonet rings in service. These rings are projected to transport 2.5-Gbit/sec data rates and incorporate 8-channel wdm equipment for a total network backbone throughput of 20 Gbits/sec.
According to Dan Sheinbein, at&t vice president of network architecture, the company has installed more than 40,000 fiber route-miles in the continental United States. But at year-end 1998, he says, there will not be a significant increase in fiber route-miles because the company will be using the existing singlemode fiber in the ground. Instead of installing new fiber, at&t is putting in new equipment and electronics at the network endpoints to provide higher capacity and standardization and achieve lower cost and rapid restoration.
Explains Sheinbein, "The number of additional route-miles is not going to dramatically change, but the company is increasing the capacity of each route-mile. To accomplish that, at&t is going to use dense wavelength-division multiplexing [dwdm] equipment, deploy more point-to-point rings, seek open standards, and purchase multivendor equipment."
Richard F. Tomlinson, president of Connecticut Research Inc., a telecommunications market research firm in Glastonbury, CT, explains that "at&t`s intention to wring more capacity out of its core network fiber in 1997 through the aggressive application of Sonet and dwdm may sound like bad news for fiber-optic cable vendors. However, there will still be plenty of fiber deployed for local applications by local exchange carriers, competitive local exchange carriers, and interexchange carriers.
"As noted in a recent report on local telecommunications competition, competitive local exchange carrier route-miles increased by 76% in 1996. While 1997 fiber deployment may moderate slightly as switch installation is emphasized, the pace remains strong," Tomlinson says.
"In addition, a surge of fiber deployment is anticipated from an unexpected source. The construction of new wireless systems, which were licensed in recent Federal Communications Commission auctions, has begun in earnest. One aspect of this construction is the need to move existing microwave links in the 2-GHz regime that interfere with the pcs [Personal Communi cations Services] allocated spectrum.
"Most of these links belong to electric utilities, which have slowed their network investments while awaiting resolution of the compensation issues. A recent survey of electric utility capital spending plans found that many utilities are expected to use the payments from pcs companies to deploy Sonet-based fiber networks rather than new digital microwave systems. This pent-up demand, combined with rising utility strategic interest in telecommunications is forecast to result in increased capital spending by utilities for fiber cable and Sonet electronics in the latter half of 1997 and continuing through 1998," adds Tomlinson.
By installing the latest-generation Sonet technology for network upgrades, at&t expects to provide users with the flexibility, reliability, and performance capabilities needed to deliver the next generation of voice, data, and multimedia services.
According to Ken Kelly, senior analyst at Northern Business Information, a telecommunications market research company in Englewood, CO, "Deploying dwdm equipment with its Sonet ring backbone architecture allows at&t to increase the capacity of its installed singlemode fiber-optic cable plant. This strategy makes sense because the company will not have to do a wholesale fiber changeout to get the eightfold increase in its fiber capacity with dwdm. Also, the increase in capacity is accomplished without having to upgrade to OC-192 [10-Gbit/sec] and dispersion-shifted fiber technologies.
"In addition, the company can provision each channel only as it needs the capacity. This deployment will keep the company at the forefront of technology and increase its network`s capacity," says Kelly.
Ianna says, "Network reliability is our primary goal. Our target is to complete the maximum number of calls possible on the first attempt. To meet our customers` communications needs today and tomorrow, we are currently designing, engineering, and building the network infrastructure that will carry us well into the next millennium."
The expansion of self-healing Sonet ring networks is therefore a top priority for at&t, which expects to restore network communications traffic within milliseconds after a service outage.
The company also plans to deploy more atm switches because the growth for those services has been high. Ianna even sees circuit-switched voice traffic moving onto an atm network in five or six years.
at&t`s plans for local networking, which would involve putting in digital subscriber line technology, are currently under review and discussion. The plans depend on negotiations with the regional Bell operating companies and local exchange carriers. q