The regional optical network boom is changing the way the nation lives

In the late 1990s, streets across the U.S. were narrowed to one or two lanes as construction crews carved the earth to lay the fiber optics that would shoulder the burgeoning demand for Internet bandwidth.

Then the dot-com bubble burst, and much of that fresh, new fiber sat dormant and dark. Available at fire-sale prices, the under-utilized fiber in many cases was seized upon by the research and education community to form the foundation of a litany of regional optical networks (RONs) interconnecting colleges and universities within and across various states.

Institutions stepped up their investment in the infrastructures. Some built networks from scratch, and some turned to flexible service providers for powerful managed services. And, today, these innovative RONs are closing gaps. Universities of varying levels of prestige are collaborating on the world’s most vexing scientific problems – often through revolutionary collaborative efforts such as Internet2 and National LambdaRail. The RONs are also being used to bring, for example, telemedicine services to remote areas of the country.

Out of the dark-fiber glut has grown a new digital deal for much of the U.S. The RON boom – born of the dot-com bust – is changing the way the nation lives.

Flexible ROADM portfolio and extended reach
Figure 1: Flexible ROADM portfolio and extended reach.

The technological impact of the RON rise is indisputable. The research and education community’s determination to enable sophisticated, high-bandwidth applications such as grid computing has helped spur on some of optical networking’s most important innovations.

Let’s take a look at this phenomenon in the area of dynamic reconfigurability, exemplified in the U.S.-based Dynamic Resource Allocation over GMPLS Optical Networks (DRAGON) infrastructure. DRAGON was designed to enable collaborative grid computing and other e-science applications among ad-hoc partnerships of government agencies, universities and businesses. The idea is to integrate and release networks very quickly, as necessary for particular projects. Reconfigurable Optical Add/Drop Multiplexers (ROADMs) and Generalized Multiprotocol Label Switching (GMPLS) are key enablers of dynamic reconfigurability.

ROADMs facilitate connections among end points on an optical network without the need for Information Technology (IT) personnel to physically visit equipment. Avoiding truck rolls in this way saves time and money. Tiny mirrors are etched into integrated circuits in a ROADM, and they switch optical telecommunications signals of up to 40 Gbps each among partners connected across the network.

Within the ROADM technology space, there are two basic types of devices: single- and multi-degree. Single-degree ROADMs switch between two devices. Multi-degree ROADMs are necessary in networks such as DRAGON, because they enable switching among four devices or more and “any-port connectivity” across supported topologies. (The DRAGON network, delivered in 2006, was the first in-service deployment of commercially-available, multi-degree ROADM technology, controlled end-to-end across a network by GMPLS.)

The GMPLS control plane provides the intelligence needed by the ROADMs to correctly provision services end-to-end across the network. GMPLS inventories the network, maps network and protection paths and provides a standard User Network Interface (UNI) bridging optical and router infrastructures to enable simplified provisioning of services among partners. Taking into account standardized software platforms and the labels on traffic data packets, the control plane triggers the ROADM’s Micro-Electro-Mechanical Systems (MEMS) arrays of mirrors and directs signals appropriately along defined paths.

In this way, GMPLS intelligently enables bandwidth-guaranteed services, priority-based bandwidth allocation, pre-emption services and other sophisticated services, regardless of the various types of access media that partners employ. This is key because, for the foreseeable future, there will remain plenty of diversity among legacy and next-generation networks that must be seamlessly supported if the potential of collaborative applications such as grid computing is to be realized.

Big bandwidth is a big part of the RON story. Dense Wavelength Division Multiplexing (DWDM) – supporting up to 80 channels of traffic reaching 40 Gbps or more per channel – is at the heart of the Arkansas Research and Education Optical Network (pronounced “ARE ON”), for example. This protocol-agnostic, high-bandwidth transport capability is a requirement for ARE_ON’s demanding applications such as grid computing, transfers of huge, three-dimensional scientific images that previously had to be exchanged by shipping storage discs, and high-definition television (HDTV) for distance learning.

Different services are assigned different wavelengths of light in the color spectrum and multiplexed for secure transport across a fiber strand at native speed in WDM. The technology is fully transparent to bit rates and protocols. Ethernet (10/100/1000/10G), Fibre Channel (1, 2, 4, 8 and 10G), InfiniBand, ATM, SONET...all of these traffic types traverse the same fiber strands in WDM.

Two other key emergent technologies in the RON space are tunable lasers and optical amplifiers. Tunable lasers allow flexible expansion and adjustment of wavelengths, simplifying inventory and sparing of WDM line cards. Only a single card is necessary to tune across as many as 40 wavelengths of traffic. This also saves in cooling costs for the RON operator and fosters a simplified network.

Optical amplifiers are supporting longer- and longer-distance transmission of signals without regeneration or degradation. Optical-amplification distances have expanded from roughly 30 to 60 miles and are being stretched even further, enabling RON operators to more cost-effectively extend services among geographically distributed partners. The benefit of this technological advancement is of particular value in the RON space, as universities frequently hold no property in between two campuses to be connected.

For the most part, research and education institutions have opted to build and deploy these networks themselves. But in some instances, the institutions have turned to network service providers to lease managed services. Level 3, for example, is a carrier that has successfully provided research and educational institutions with services in some areas of their networks.

The key considerations for carriers seeking to capitalize on RON revenue opportunities are flexibility and control. Research and education institutions require plenty of the former, and network service providers don’t want to lose any of the latter.

For carriers, delivering RON services is not as easy as simply deploying 10 Gbps to every user along the network. Needs vary among institutions and even across a given institution. One particular workgroup might need a great deal of dependable bandwidth for four hours every Wednesday evening – and none the rest of the week; an admissions office, on the other hand, might demand significantly less bandwidth but never-compromised service around the clock and calendar. The carriers who accommodate this diversity in needs – and price service attractively – will be the ones who capture RON service revenues.

At the same time, no carrier wants to give up control of its dark-fiber assets. Wide-scale deployment of WDM across optical networking in the last 10 years has fostered expertise and considerable comfort with the protocol among a variety of IT professionals. A carrier that turns over dark fiber to a customer runs the risk that the customer itself would deploy WDM on the connection – preventing the carrier from profiting on the customer’s incremental expansion in bandwidth and service needs.

Today at least, the RON space is not a source of rich revenues for carriers. But the RONs comprise a good market to stay tapped into, as some might one day be converted into broader services businesses supporting more than only universities. In fact, the users and uses of the RONs are already growing more intriguing every day.

Let’s take a look at what has gone on in Georgia. The history of PeachNet – “The Network for Education in Georgia” – goes back to the early 2000s, according to “With the decline in the telecommunications market, excess commercial fiber became available for long-term lease.” The University System of Georgia (USG) Office of Information and Instructional Technology (OIIT) “acquired some of these fiber assets and leased 1,900 route miles of fiber in 2004 to connect 26 of the 35 USG institutions, as well as additional USG sites. By leasing the fiber directly, OIIT is able to move PeachNet services away from commercial telecommunications services. The result is additional bandwidth and levels of redundancies that were previously cost prohibitive.”

PeachNet today supports more than 60 University System of Georgia sites, five private higher-education institutions and more than a half-dozen other government agencies across a 10 Gbps network of 2,400 miles. Georgia’s Barrow County Schools system is one of the most recent additions to the PeachNet user base. With its link through Georgia’s RON, Barrow County Schools educators are considering a host of uncommon opportunities for K-12 students:

• A “global concert series” offered by the Philadelphia Orchestra via Internet2;
• Interactive programs offered by Atlanta’s Center for Puppetry Arts;
• Environmental science programs where students can interact with researchers on the sea floor at Gray’s Reef National Marine Sanctuary; and
• A Georgia State University project in which professors can observe student teachers in Barrow County classrooms as part of their teacher training and skills development programs.

PeachNet is not alone in extending its unprecedented capabilities to non-university users. RONs in Arkansas (, Ohio (, Texas ( and a variety of other states have similar designs for growth.