Interference in Wireless Networks

Vocabulary flashcards covering interference, channel planning, attenuation, and multipath effects discussed in the lecture.

Interference

Disruption that occurs when multiple wireless networks operate on the same or overlapping frequencies, causing collisions, retransmissions, and slower networks.

Non-overlapping channels (2.4 GHz)

In 2.4 GHz Wi‑Fi, use channels 1, 6, and 11 because they do not overlap in frequency, reducing interference.

Channel overlap

When adjacent channels share spectrum, leading to interference and degraded performance.

Site survey

The process of assessing a location to identify existing wireless usage and plan AP placements and channel selections.

Extended Service Set (ESS)

A collection of APs that provide a single wireless network; requires coordinated AP placement and channel planning.

Channel plan for 2.4 GHz

Strategy to assign channels 1, 6, and 11 across a space to avoid overlap and ensure coverage.

Coverage

The geographic area where the wireless signal is strong enough for reliable communication.

10–15% overlap

A small intentional overlap between adjacent APs to support handoffs while limiting interference.

5 GHz honeycomb pattern

An AP placement pattern for 5 GHz networks aimed at minimizing interference by spacing channels in a grid-like layout.

Two zones away rule

The same channel should not be reused until at least two zones away to reduce interference.

Attenuation

Reduction in signal strength between the transmitter and the receiver due to distance, obstacles, or interference.

Cable attenuation

Loss of signal within the antenna feedline caused by cable quality and construction.

Antenna quality

Quality of antenna components; higher quality, lower resistance components reduce attenuation.

Multipath reception

Signal reflections off walls/objects that take multiple paths to the receiver, often weakening the signal.

RSSI (Received Signal Strength Indicator)

A measurement of the power level of the received signal.

Throughput

The actual data transfer rate on the wireless link, affected by attenuation and interference.

Omnidirectional antenna

An antenna that radiates energy in all directions, used to illustrate multipath effects.

Handoff

The process of transferring a wireless device’s connection from one AP to another as it moves.