Repeater

A repeater is a device that solves a simple physical problem: signals weaken as they travel along a cable. After a certain distance, the signal becomes too weak to be reliably interpreted. The repeater catches that weakened signal and regenerates it — it does not just amplify the existing signal, but recreates it fresh, then sends it onward.

The textbook specifies that data signals can normally travel only about 100 metres over a cable before they start losing strength. Beyond that limit, the signal degrades and becomes unreliable. A repeater is an analog device — it works directly with the electrical or optical signals on the cable, not with the data packets or digital content. Its job is purely physical: take the weak incoming signal, clean it up, and put a strong copy back onto the cable.

Key points to remember:

• A repeater does not understand or interpret the data — it only regenerates the signal waveform.
• It is used to extend the physical reach of a network beyond the natural cable limit (roughly 100 metres for typical copper cables).
• Because it works at the physical layer of networking, a repeater has no intelligence about addresses, errors, or traffic — it simply forwards every signal it receives, good or bad.