Roaming; Load Balancing - Black Box LW0050A Manual

APPENDIX C: Wireless LAN Concepts
C.2 Roaming
When any area in the building is within reception range of more than one Access
Point, the cells' coverage is said to overlap. Each wireless station automatically
establishes the best possible connection with one of the Access Points. Overlapping
coverage areas are an important attribute of the wireless LAN setup, because this
enables seamless roaming between overlapping cells.
Roaming allows mobile users with portable stations to move freely between
overlapping cells, constantly maintaining their network connection. Roaming is
seamless: You can keep working while moving from one cell to another. Multiple
Access Points can provide wireless coverage for an entire building or campus.
When the coverage areas of two or more Access Points overlap, the stations in the
overlapping area can establish the best possible connection with one of the Access
Points, continuously searching for the best Access Point. In order to minimize
packet loss during switchover, the "old" and "new" Access Points communicate to
coordinate the process.
C.3 Load Balancing
Congested areas with many users and heavy traffic load per unit may require a
multi-cell structure. In a multi-cell structure, several co-located Access Points
"illuminate" the same area, creating a common coverage area, which increases
aggregate throughput. Stations inside the common coverage area automatically
associate with the Access Points that is less loaded and provides the best signal
quality. The stations are equally divided between the Access Points in order to
equally share the load between all Access Points. Efficiency is maximized because
all Access Points are working at the same low-level load. Load balancing is also
known as load sharing.
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