Deconstructing the divide: extending broadband xDSL services to the periphery

One of the major challenges to providing full-rate digital subscriber line (xDSL) access to residential customers in rural or remote locations is the use of existing copper infrastructure. First, copper is not particularly good for moving high frequencies over extended distances. Second, much of the existing copper in the United States is of diminished quality. Third, digital loop carriers, bridge taps, load coils, and ambient interference negatively impact data transmission. Because of these problems, the geographic reach of xDSL services is limited. To combat this limitation, providers are installing remote digital subscriber line access multiplexers (RDSLAMs). RDSLAMs seek to maximise the amount of demand covered for a peripheral neighborhood and aggregate this data traffic onto a fiber optic connection for transport back to the central office (CO) for switching. Although this is more feasible than constructing a new CO, acquiring the rights of way and installing fiber is expensive. The purpose of this paper is to examine the complexities associated with locating RDSLAMs in a competitive telecommunications market through the use of an integer programming modelöthe remote access hierarchical assignment problemöand a geographic information system. Pertinent policy and technology related issues in residential broadband deployment and their impacts on high-speed services such as xDSL are highlighted. DOI:10.1068/b32058 (1) Broadband refers to telecommunication services with connection speeds greater than 200 kbps both upstream (consumer to provider) and downstream (provider to consumer). The popularity of broadband-access technologies also continues to grow. In August 2004 Nielsen NetRatings (2004) announced that broadband penetration for the United States finally broke the 50% barrier for active residential users. Gillett et al (2004) suggest that technological progress and the mass-market acceptance of broadband technologies such as cable and digital subscriber lines (xDSL) have helped the costs associated with deploying infrastructure to decrease. This, in turn, implies that effective facilities-based competition is now possible in most US markets (Grubesic and Murray, 2004). In the recently issued fourth report on the availability of advanced telecommunications capability in the United States, the Federal Communications Commission (FCC, 2004a) reports that several important developments in last-mile broadband technologies have occurred.(2) First, the FCC (2004a) notes that, unlike the telephone market, the increasingly competitive nature of the residential broadband market has motivated providers to offer increasingly faster service at the same or lower retail prices. For example, figure 1 illustrates the percentage of advanced service lines according to technology for December 2004. The two leading broadband platforms are coaxial cable and asymmetric digital subscriber lines (ADSL). Although the price for cable modem service has not decreased significantly, many providers, such as Time Warner and Comcast, have implemented a twofold increase in download speeds to residential users, with rates approaching 3 ^ 5 Mbps. Similarly, local telephone companies such as Cincinnati Bell and SBC are now offering faster downstream transmission speeds for ADSL subscribers, increasing from 640 kbps to 1.5 Mbps. These types of changes and/or improvements in the market suggest that facilities-based competition for broadband is clearly improving. A second important development in last-mile technologies is the steadily increasing popularity of wireless access options, such as wireless fidelity (Wi-Fi). This is a generic term that refers to any of the 802.11 standards developed by the Institute for Electrical and Electronics Engineers (Newton, 2001). Wi-Fi hot spots are locations at which users can access broadband connections in public spaces (such as a local park) or a private business such as a coffee shop or restaurant. In many cases Wi-Fi hot spots actually use terrestrial broadband technologies (for example, cable and xDSL) when allocating bandwidth to wireless users (Grubesic and Murray, 2004). (2) `Last-mile' technology is a generic term for any telecommunication platform that delivers voice, data, or video to a home or business. Cable ADSL Other wireline Wireless Fiber 82.7%