ZyXEL Communications zyair g-260 ユーザーズマニュアル

ZyXEL G-260 User’s Guide

Chapter 2 Wireless LAN Network

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Figure 9   WPA with RADIUS Application Example

The IEEE 802.11b/g standard describes a simple encryption method between the wireless 
stations and AP. Two encryption types are defined: an Open system mode and a Shared key 
mode.

•  Open System mode is implemented for ease-of-use and when security is not an issue. 

The wireless station and the AP do not share a secret key. Thus the wireless stations can 
associate with any AP and listen to any data transmitted plaintext.

•  Shared Key mode involves a shared secret key to authenticate the wireless station to the 

AP. This requires you to enable the WEP encryption and specify a WEP key on both the 
wireless station and the AP. 

Preamble is used to signal that data is coming to the receiver.  

Short preamble increases performance as less time sending preamble means more time for 
sending data. All IEEE 802.11b/g compliant wireless adapters support long preamble, but not 
all support short preamble. 

Select Long Preamble if you are unsure what preamble mode the wireless adapters support, 
and to provide more reliable communications in busy wireless networks. 

Select Short Preamble if you are sure the wireless adapters support it, and to provide more 
efficient communications.

Select Auto to have the ZyXEL G-260 automatically use short preamble when all access 
point/wireless stations support it, otherwise the ZyXEL G-260 uses long preamble.