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in cwna guide on page 188, ch:3...they have mentioned some abot non overlapping channels

"
.802.11 DSSS-30 Mhz spacing(6 channels)
.802.11b HR-DSSS-25 Mhz spacing(5 channels)
.802.11a OFDM-20 Mhz spacing(4 channels)
.802.11g ERP-OFDM-25 Mhz spacing(5 channels)

"

as we have studied that there are only three non overlapping channels in HR-DSSS than how it can be posible of having 6 and 5 non overlapping channels in that

please explain it

Hi Naranjan:

The four bullets at the bottom of CWNAv3 study guide, page 188, are accurate.

The values in parenthesis are not the number of non-overlapping channels, but instead the number of 5 MHz spaces between channel centers of those non-overlapping channels. (What a horrible sentence.)

All 802.11 channels are centered every 5 MHz, whether in 2.4 GHz or 5 GHz bands.

DSSS transmissions must be centered on 2.4 GHz channels at least "six" 5 MHz spaces apart. For instance channels 1 and 7.

HR/DSSS and ERP transmissions must be centered on 2.4 GHz channels at least "five" 5 MHz spaces apart. For instance the universally familiar channels 1, 6, and 11.

OFDM transmissions must be centered on 5 GHz channels "four" 5 MHz spaces apart. Recent amendments allow weaker OFDM transmissions to be centered every channel or every other channel.

I hope this helps. Thanks. /criss

thaks criss for replying i really removed headache of mine and kapil