INTELLIGENCE IN OPTICAL NETWORKS
Architecting the Services Optical Network
Eve L. Varma, Sivakumar Sankaranarayanan, George Newsome, Zhi-Wei Lin, and Harvey Epstein Lucent Technologies
ABSTRACT 80 percent per year. Reliance on silicon alone cannot match this traffic growth. In this new millennium, the most valuable Demand for access technologies such as cable commodity will be information, as seen by the modems, digital subscriber line (xDSL), and surge in demand for faster access technologies wireless data is rapidly increasing. Indeed, some such as cable modems, xDSL, and wireless data. analysts consider that data will eventually make The tremendous growth in data traffic, particu- up 99 percent of the content sent over telecom- larly that associated with the Internet, is chang- munications networks. Network operators have ing the way it is carried over public and private been finding that their more aggressive projec- networks. Together with the rapid advances in tions of traffic growth have tended to be wrong, optical networking technology and the spawning and furthermore, that this demand for traffic of a new category of wavelength services stimu- occurs in often unexpected locations. The sup- lated by new high-speed data requirements, this porting network infrastructure needs to be inher- is dramatically changing network architectures ently scalable to handle this traffic, and and the relationship between network service sufficiently flexible to respond to forecast uncer- providers and their customers. Incumbent carrier tainties. At the same time, it is worth bearing in globalization and new carrier entry require sup- mind that the exponential growth in IP-based port for a broader set of business models and data traffic has not yet translated into a corre- range of service interfaces. The growth and sponding increase in revenue [1]. Higher-volume expansion of networks imply a greater need for lower-revenue service mixes are driving the need more scalable solutions and more automation for increased profitability reflected in near-term for network maintenance. An intelligent optical concerns with cost per bit, high-capacity fiber, core optimized for service optical networking, and cost of spare equipment. It is clear that net- the services optical network, needs to take the work operators will need to dramatically best aspects of both the transport and data net- increase, and maximally share, backbone net- working domains to meet the above needs. This work infrastructure capacity. Moreover, lowering article focuses on architecting the services opti- the cost per bit is not just equipment first cost, cal network to meet the challenges of optical but requires efficient and optimized network data networking, and includes a snapshot of sup- design to reduce operation cost. porting standardization activities. At the same time, the services offered, how quickly these services can be provided, and effi- NTRODUCTION ciency in supporting those services are key differ- I entiators for network operators. Within the Transport networking has steadily grown more backbone/core network in particular, aggressive complex as a consequence of more sophisticated business models and limited network operator customer needs, the convergence of data and staff are driving the need for immediate availabili- transport communications domains, the rate of ty, rapid deployment, and automated provisioning. traffic growth, and conditions imposed by exter- This growth of bandwidth and need to pro- nal market and regulatory forces. Telecommuni- vide new sources of revenue to network/service cations increasingly relies on a diverse network providers have led to two major thrusts: of networks, with widely varying topologies, • Development of the infrastructure for the deployed services, and underlying business mod- optical transport network (OTN), a scalable els. At the same time, traffic is growing at an multiservice-capable and client-transparent unprecedented rate of 200 percent per year, transport infrastructure based on dense while the capacity of silicon is only growing by wavelength-division multiplex (DWDM)
80 0163-6804/01/$10.00 © 2001 IEEE IEEE Communications Magazine • September 2001 Carrier Carrier's Carrier Carrier Carrier's Carrier CustomerA carrier C A Customer A carrier C A Customer Or
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