ZyXEL Communications NWA3560-N User Manual page 114

Chapter 9 Wireless
Three channels are sit uat ed in such a way as t o creat e alm ost no int erference wit h one anot her if
used exclusively: 1, 6 and 11. When an AP broadcast s on any of t hese t hree channels, it should not
int erfere wit h neighboring APs as long as t hey are also lim it ed t o sam e t rio.
Figure 49 An Exam ple Four- Channel Deploym ent
However, som e regions require t he use of ot her channels and oft en use a safet y schem e wit h t he
following four channels: 1, 4, 7 and 11. While t hey are sit uat ed sufficient ly close t o bot h each ot her
and t he t hree so- called " safe" channels ( 1,6 and 11) t hat int erference becom es inevit able, t he
severit y of it is dependent upon ot her fact ors: proxim it y t o t he affect ed AP , signal st rengt h, act ivit y,
and so on.
Finally, t here is an alt ernat ive four channel schem e for ETSI , consist ing of channels 1, 5, 9, 13. This
offers significant ly less overlap t hat t he ot her one.
Figure 50 An Alt ernat ive Four- Channel Deploym ent
Load Balancing
Because t here is a hard upper lim it on an AP's wireless bandwidt h, load balancing can be crucial in
areas crowded wit h wireless users. Rat her t han let every user connect and subsequent ly dilut e t he
available bandwidt h t o t he point where each connect ing device receives a m eager t rickle, t he load
balanced AP inst ead lim it s t he incom ing connect ions as a m eans t o m aint ain bandwidt h int egrit y.
There are t wo kinds of wireless load balancing available on t he device:
Loa d ba la ncing by st a t ion n u m be r lim it s t he num ber of devices allowed t o connect t o your AP . I f
you know exact ly how m any st at ions you want t o let connect , choose t his opt ion.
For exam ple, if your com pany's graphic design t eam has t heir own AP and t hey have 10 com put ers,
you can load balance for 10. Lat er, if som eone from t he sales depart m ent visit s t he graphic design
t eam 's offices for a m eet ing and he t ries t o access t he net work, his com put er 's connect ion is
delayed, giving it t he opport unit y t o connect t o a different , neighboring AP . I f he st ill connect s t o
t he AP regardless of t he delay, t hen t he AP m ay boot ot her people who are already connect ed in
order t o associat e wit h t he new connect ion.
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NWA3000-N Series User's Guide