What is the primary transmission medium for DSL Internet service?

The primary transmission medium for DSL (Digital Subscriber Line) Internet service is telephone wires. DSL technology utilizes existing copper telephone lines to deliver high-speed Internet access to homes and businesses. By employing frequency division multiplexing, DSL allows for simultaneous voice and data transmission, using a higher frequency range that won't interfere with voice calls. This enables users to access the Internet and make phone calls at the same time without disruption.

Other mediums like fiber-optic cables and coaxial cables are used in different types of Internet services, such as fiber-optic broadband and cable Internet, respectively. Wireless signals are also a separate technology for connecting to the Internet, often associated with Wi-Fi networks or mobile broadband. Thus, while those other options are viable for different services, telephone wires are specifically integral to how DSL functions.