Accton Technology Cheetah Wireless-3501C Quick Installation Manual page 23

Setting Wireless Properties
17. The access points and client card drivers have a radio setting for RF Preamble.
Enabling it can boost your throughput. Preamble Type offers a drop-down list with
three options: Auto, Long, or Short. If you are not sure whether all the clients and
access point radios in your wireless network support the Short RF preamble, then
leave this setting on Auto. See "Terminology" on page 42
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