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The following sections offer a brief background of the broad and diversified telecommunications market. The first section summarizes the current service providers (with a focus on local and interexchange carriers) and uses the Internet as an example of telecommunications services offered outside of the traditional carrier envelope. The second section describes the generic services currently available and focuses on the interoperability relationships in today's environment necessary for user-to-user communication. Interoperability today typically occurs at the lowest common denominators of service; the third section therefore provides an example of future services available to the NII. Interoperability among service providers in the realm of advanced services appears to be a significant challenge.

Telecommunications Service Providers

The telecommunications infrastructure is composed of an extensive set of physical communications facilities owned by a relatively small set of telecommunications companies. The LECs and the IXCs provide most of the bulk of the actual physical facilities that deliver telecommunications services. However, a broader definition of infrastructure is offered here that includes a large set of service providers that leverage the physical infrastructure to deliver service. This latter group includes the carriers themselves but also involves many organizations that build services based on specific markets or communities of interest. The Internet is the most prominent example of this latter group, where several thousand networks make up the Internet and only a small subset of the LECs and IXCs actually provide Internet services. In addition, new elements of infrastructure have emerged in the areas of cable infrastructure and wireless media. Although many of the cable and wireless providers have become tied to traditional carriers, their presence implies a strong potential for telecommunications evolution. With the exception of the Internet, the existing infrastructure offers limited interoperability, principally between a federally mandated tier of service providers and at the lowest common levels of information transport.

Local service implies that a service provider is principally restricted to offering connectivity within local access transport areas (LATAs). The local service area continues to be dominated by the regional Bell operating companies (RBOCs). However, many local service providers include traditional service providers and an emerging class of competitive access providers (CAPs). The traditional service providers offer RBOC-like services in independent areas of the country and include a broad spectrum, from large providers such as GTE and Sprint Local (both over 100 years old) to small providers such as Splitrock Telephone Co. of South Dakota. Traditional services offered by the RBOCs and other local providers have increasingly featured voice services, private lines, and a gradual influx of local data services. CAPs, such as Metropolitan Fiber Systems and Teleport Communication Group, have focused on the provision of dedicated access between high-density customer locations (e.g., government and business offices) and the IXCs. The CAP focus can be attributed to the strong business opportunity for local access and the large investment required to reach private residences. CAPs have also gradually increased their portfolio of services offered to include data services. The most prominent upcoming change in the local service area is the likely removal of restrictions on the RBOCs for the delivery of services beyond the local area.

The IXCs, or long-distance carriers, provide telecommunications services between the LATAs. The divestiture of the RBOCs by AT&T in 1984 created the opportunity for new long-distance service providers and has resulted in the creation of several prominent competitors of AT&T, principally MCI and Sprint, and a strong cadre of growing service providers, such as Willtel and LCI. The resulting competition has brought rapid technology evolution, new services, and lower costs to long-distance services. The long-distance infrastructure has also become highly robust and diverse, currently including multiple high-capacity networks with independent control structures. For example, a typical span in a major carrier network may consist of several active fiber pairs, each carrying in excess of 1 gigabit per second (Gbps) of capacity. The IXCs make up multiple cross-country (east to west and north to south) routes that, taken together, represent hundreds of Gbps of capacity. The IXCs support many telecommunications services, dominated by voice (especially for the top three providers) and private line. In addition, the IXCs offer various public services for data or video-based services.

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