The telephone network is a ubiquitous and mature medium of communication with high levels of consumer penetration and potential data carrying capacity. DSL (Digital Subscriber Line) is one of the technologies used to provision high speed links to data networks over twisted pair Public Switched Telephone Networks (PSTN). These networks were originally designed to carry voice traffic over twisted pair copper lines (Jones, 2006).
The Line in DSL refers to link between the consumer’s location and the local exchange. The PSTNs usually operate in the frequency range between 300Hz to 3.4 kHz of the total 1.1 kHz of spectrum available for voice communications. DSL usually provides high speed data communication by operating in the unused frequency range of the telephony spectrum above 3.4 kHz. DSL technologies support both bus and star topologies of network deployment and utilize pairs of compatible transceivers to facilitate communication between the consumer site and the telephone exchange (Littman, 2002).