Received signal strength indicator

However, because signal strength can vary greatly and affect functionality in wireless networking, IEEE 802.11 devices often make the measurement available to users.

In an IEEE 802.11 system, RSSI is the relative received signal strength in a wireless environment, in arbitrary units.

Vendors and chipset makers provide their own accuracy, granularity, and range for the actual power (measured as milliwatts, which can be expressed in terms of decibels relative to one milliwatt) and their range of RSSI values (from 0 to RSSI maximum, in arbitrary signal units "asu").

[8] However, RSSI still represents the most feasible indicator for localization purposes as it is available in almost all wireless nodes and it does not have any additional hardware requirements.

Received signal power level assessment is a necessary step in establishing a link for communication between wireless nodes.

However, the accuracy of these algorithms can be affected by environmental factors, such as signal interference, obstacles, and the density of nodes in the area.

[citation needed] Factors like diffraction, reflection, scattering, and antenna type can significantly influence RSSI values.