Symbol Technologies Spectrum24 AP-4131 - Manual (Page 19)

Introduction
AP-4131 Access Point Product Reference Guide 9
APs with the same Net_ID (ESS) define a coverage area. The MU searches for
APs with a matching Net_ID (ESS) and synchronizes with an AP to establish
communications. This allows MUs within the coverage area to move
about or roam. As the MU roams from cell to cell, it switches APs. The switch
occurs when the MU analyzes the reception quality at a location and decides
which AP to communicate with based on the best signal strength and lowest
MU load distribution.
If the MU does not find an AP with a workable signal, it performs a scan to
find any AP. As MUs switch APs, the AP updates the association table.
The user can configure the Net_ID (ESS). A valid Net_ID (ESS) is an
alphanumeric, case-sensitive identifier up to 32 characters. Ensure all nodes
within one LAN use the same Net_ID (ESS) to communicate on the same
LAN. Multiple wireless LANs can coexist in a single environment by assigning
different Net_IDs (ESS) for APs.