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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

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