Fiber optic cable uses pulses of light to carry network traffic over longer distances. Fiber has high throughput that is naturally resistant to EMI. The signals are sent via laser or Light-Emitting Diode (LED) using a core of glass or plastic. Many times, fiber is used as the backbone on a LAN and comes in two forms:

• Multimode (MMF): This uses multiple light signals, has a higher bandwidth than UTP, and is used to carry backbone traffic in a LAN. MMF can use either glass or plastic, using either LED or laser signals, over a distance to up to 2 km.
• Single mode (SMF): This uses a single light signal. Single mode fiber has a higher bandwidth than MMF and can carry a signal for many miles. SMF must use a laser to produce a bright, coherent light.

Fiber optic has many benefits, but it is more expensive than twisted pair and requires special equipment to manage. As a result, LANs use fiber primarily for backbone traffic and use twisted pair for work areas. 

Today, it is common to see wireless network communication, which uses radio waves to transmit signals. The following section outlines the various ways you may work with analyzing a wireless connection.