The regional fiber-optic build-out: choices and challenges

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The CapRock regional network will serve users in five states, many of whom live in rural areas.

It doesn't matter whether a telecommunications provider is constructing a fiber-optic network specifically to serve a particular region or as part of a national network-the carrier will face decisions that can mean the difference between a successful build-out and a failed enterprise.

One competitive local exchange car rier (CLEC), Dallas-based CapRock Communications, undertook the challenge of constructing a 5500-route-mi fiber-optic network connecting most of the primary, secondary, and tertiary markets in a five-state Southwest U.S. region. The company's goal was to provide competitive local, long-distance, data, Internet, and other telecommunications services to areas previously under-served. And because it is being built with added capacity, it will allow national carriers to purchase sections of the fiber-optic network to complete links in their national build-out.

The fiber network will ultimately connect Texas, Louisiana, Arkansas, Oklahoma, and New Mexico (see Figure). It will use TrueWave cable from Lucent Technologies (Norcross, GA), powered by Nortel Networks' OC-48 (2.5-Gbit/sec) Synchronous Optical Network (SONET) terminals over a dense wavelength-division multiplexing (DWDM) optical-networking system. The network's meshed SONET ring configuration can withstand a fiber cut by switching traffic to a protection channel, restoring service within 50 msec with no interruption to the customer.

The most expensive undertaking of any fiber network is the actual laying of the fiber. Because putting fiber underground limits future expansion of the network, advanced planning must be well conceived with an eye toward potential growth in the future. With that in mind, CapRock chose to "futureproof" its network by installing three innerducts and a minimum of a 96-strand fiber cable that provides extra capacity and allows capabilities to be added as necessary.

CapRock is building its network to be scalable yet cost-effective by initially installing OC-48 over the DWDM system, with deployment of the more expensive OC-192 (10 Gbits/sec) only where bandwidth demand dictates. As the price of OC-192 drops, it will be increasingly employed into the network. Using DWDM also allows for the deployment of an overlay Asynchronous Transfer Mode (ATM) network to handle the ever-increasing demand for data services.

The company's bandwidth projections show a large and growing demand for more traditional services such as DS-1/DS-3 private-line services. Although an ATM network can provide those services, the interfaces are more expensive. CapRock has elected to use more cost-effective SONET equipment and separate the two technologies. A customer needing traditional private-line service will receive it on a SONET network, while data and Internet services will ride the ATM network.

The main reason for deploying SONET instead of an ATM or Internet protocol network is quality of service. As the growth of traditional services slows and newer technologies mature, the existing SONET network will be capped and new technologies deployed on one of the 32 DWDM wavelengths.

The desire to bring sufficient service to smaller towns without incurring unreasonable expense dictates how the fiber is deployed. CapRock currently has 800 mi of fiber in the ground connecting the south Texas cities of San Antonio, Laredo, McAllen, Harlingen, Corpus Christi, Victoria, and Houston. DWDM allows CapRock to drop bandwidth off of the DWDM backbone to cost-effectively service the smaller towns along the route.

Most fiber network traffic will travel along "express" routes connecting large cities like San Antonio and Houston. The utility of DWDM allows CapRock to create a "bypass" using a second OC-48 line to directly connect the smaller towns between the main nodes without continually having to drop traffic off in each of the rural towns.

After examining a particular market, some CLECs and regional Bell operating companies (RBOCs) may find it more cost-effective to connect links in their networks by purchasing sections of existing fiber-optic networks from other telecommunications providers rather than laying their own networks. By linking into major metropolitan hubs and using the infrastructure already in place, these regional or national suppliers could more quickly expand their networks and offer immediate services in untapped rural markets where there is less competition.

Because many areas in those types of networks are extremely sparse in terms of population, maintaining a high-quality network, as well as monitoring and maintaining a physical plant, can also be a challenge. To provide prompt service in the event of an emergency or breakdown, CapRock deploys personnel no more than one hour's drive from key points of the network.

Reaching licensing agreements with rural governments presents obstacles of its own for carriers expanding into the rural market. In major metropolitan areas, city government officials deal with carrier franchise agreements on a regular basis and know what those companies require to enter the market. That is not the case in smaller communities, some of which are unaccustomed to dealing with telecommunications issues.

The key to dealing with the smaller communities is education. By providing sample franchise and license agreements, explaining thoroughly the nature of its business, and demonstrating the value the service will offer to the community, its businesses, and residents, a carrier can speed the approval process.

Most carriers install their fiber cable along railroad rights-of-way. One of the critical decisions CapRock made was to remain as diverse as possible from other carriers by using state highways. The philosophy behind the move is that railroads are increasingly charging more for right-of-way access, and it can be difficult to monitor lines because many stretches of railroad are not easily accessible. If a derailment occurs or a bridge washes out, getting physical access to repair the cable can be difficult and time-consuming.

CapRock officials determined that by using state highways, the company could reduce access costs and more easily monitor its line on a daily basis to eliminate potential problems. If a fiber cut, washout, or some other crisis arises, it is easier-and less expensive-to get equipment and personnel to the scene.

The terrain that a network traverses and the weather patterns of the region are sometimes overlooked when companies are planning to deploy a network. They are often major factors contributing to whether the project is completed on time and under budget. But sometimes, Mother Nature can throw a kink into even the best-laid plans, as evidenced when "100-year" floods soaked south Texas and affected CapRock's 1998 build-out schedule.

In Texas, there is a saying that if you don't like the weather, just wait a few minutes and it will change. CapRock was witness to those extremes. The south Texas region was in the midst of a severe drought when the rains came, and the ground was extremely dry several feet down.

Even though the rain came in monumental amounts, it saturated only the top 2 or 3 ft. Crews had trouble installing fiber, which is normally buried 4 to 5 ft underground, because they could gain no traction. As a result, they had to wait for the soil to dry sufficiently before they could resume work.

A telecommunications provider concentrating on a regional build-out should consider all of these aspects before construction of the network begins. A company adding to its national footprint should take all situations and cost factors into account and determine if it makes more sense economically to build its own network or buy fiber from a company with a network already in place. q

Dan Jones is vice president of fiber facilities at CapRock Communications Corp. (Dallas).

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