Справочник Пользователя для National Datacomm Corporation 1022S01

 

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setting of the 

 control is fixed because of the 

 setting, it is 

shown in gray characters and the control is disabled. 

When the 

 control is set to 

, the 

 control offers 

five settings: 

, 

, 

, 

, and 

. 

Using a fixed, high speed throughout a network can improve security by reducing the effective 
range. Fixed, low speeds may be necessary for interoperation with some pre-802.11b devices. 
The 

 setting lets the adapter adjust communication speed according to signal quality; this 

setting thus offers the best combination of throughput, range, and resistance to interference. 

The 

 control is a drop-down list that offers three settings: 

, 

, and 

. You can learn from the 

 panel’s 

 

section if a network is in ad-hoc or infrastructure mode; the network installer or operator can tell 
you if an ad-hoc network is high-speed (22 Mpbs). You must choose the setting that agrees with 
the actual operating mode of the network. High-speed ad-hoc mode can only be used by devices 
in the same product family as your adapter. 

Depending on which part of the world you are in, there can be up to 14 “channels” in the radio 
frequency band used for wireless networking (2.4 to 2.4835 GHz in most countries). A channel 
consists of 23 exact frequencies spaced 1 MHz apart for a total spread of 22 MHz. Such spreading 
is required by regulatory agencies to reduce interference among devices operating in this band. 

On an infrastructure network, each access point (AP) is set to use a fixed channel, and stations 
automatically detect the channel used by the AP that provides the best signal quality. The 

 control is therefore disabled when the 

 control is set to 

. 

An ad-hoc network operates on a fixed channel that will be shown in the 

 panel’s 

 section. To join a given ad-hoc network, you must select the correct channel from the 

 control’s drop-down list. The settings offered in the list depend on the regulations of the 

country in which the adapter was purchased. 

APs with overlapping coverage areas, or different ad-hoc networks operating in the same area, 
should use channel settings that are at least four, and preferably five channels apart (for example, 
1, 6, and 11) to avoid interference and obtain the best possible performance. 

The 

 control is a drop-down list that offers three settings: 

, 

, and 

. 

In Continuous Access mode, your adapter’s receiver is always on. 

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 AP (or, on an ad-hoc network, the current coordinating station) that it is going to 
do so. The AP (or coordinating station) will “buffer” (temporarily store) communications