User's Manual

Channel control: This control is enabled only when the network mode (see above) is set to
ad-hoc (either 802.11 or high-speed). An infrastructure WLAN can include many access
points using different channels, and to allow roaming, the adapter must be able to switch
channels automatically. An ad-hoc WLAN uses a single fixed channel, and the adapter must
be set to that channel to join the WLAN. Channel detection is automatic for any WLAN that
appears in the Site Survey listing, so the setting of this control rarely needs to be changed.
The radio band used for wireless networking contains 95 frequencies spaced 1 MHz apart.
These are organized into 14 staggered clusters of 23 adjacent frequencies each. Such a cluster
is called a channel. There is much frequency overlap among channels. When overlapping
channels are used in the same area, this causes interference, which reduces throughput.
Which channels are available can differ from country to country (see appendix E).
On an infrastructure WLAN, access points with overlapping coverage areas should use non-
overlapping channels. Non-overlapping channels are those with numbers that differ by 5 or
more, for example, channels 1, 6, and 11, or channels 3, 8, and 13. An ad-hoc WLAN should
use a channel that has little or no frequency overlap with any other channels being used in the
same area.
Power Saving Mode control: The Power Saving Mode control is a drop-down list that offers
two settings:
Continuous Access Mode and Maximum Power Save.
In Continuous Access mode, your adapter’s receiver is always on. This is the default setting.
Maximum Power Save mode is a “doze” mode in which the adapter turns its receiver off but
“wakes up” at fixed intervals to see if any communications are waiting for it. Before entering
this mode, it tells the access point (or, on an ad-hoc network, the current coordinating station)
that it is going to do so. The access point (or coordinating station) will “buffer” (temporarily
store) communications destined for your machine. The adapter stays “awake” only long
enough to check for and receive waiting communications.
4X Mode control: 4X mode is a means of reducing communication overhead and increasing
throughput by allowing packets to be much longer than is normally allowed. This mode can
be used only on connections to devices from the same product family as your adapter.
When the
4X Mode control is set to On, the adapter uses 4X mode whenever possible.
Detection of whether it can be used or not is completely automatic, so interoperation with
devices from other product families is unaffected. When the control is set to
Off, 4X mode is
never used. The default setting is
On.
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