How is digital signal characterized in DSL services?

Digital signals in DSL (Digital Subscriber Line) services are characterized by their ability to efficiently utilize traditional copper telephone lines. This distinctive feature allows DSL to deliver high-speed internet access while running alongside existing voice services over the same lines. Unlike fiber optic cables, which are made of glass and can transmit data at faster speeds and greater distances, DSL relies on the existing infrastructure of telephone lines, which is why it can be widely deployed without the need for extensive new installations.

In the context of DSL, digital signals are advantageous because they can be modulated in such a way that they coexist with analog telephone signals on the same infrastructure. This simultaneous operation enables users to make voice calls while accessing the internet, highlighting the compatibility of digital signals with traditional copper wire technology.

While considering the other options, one can see that the speed of digital signals is not inherently slower than analog signals; in fact, digital technologies often provide faster and bandwidth-efficient alternatives. The statement regarding fiber optic cables does not apply directly to DSL since DSL is specifically designed to utilize copper wiring. Lastly, while digital signals can reduce interference compared to analog signals, they do not carry data without any interference—other forms of noise can still affect transmission, though digital modulation techniques may help mitigate some issues.