user manual

User Manual
TEW-455APBO High Power Wireless Outdoor PoE Access Point
21
3.2.2 Wireless Advanced Setup
To achieve optimal wireless performance, it is necessary to tweak advance setting per requirements properly,
not necessary higher the better or lower.
The administrator can change the RTS threshold and fragmentation threshold settings for the system. Please
click on Wireless -> Advanced Setup and follow the below setting.
 Slot Time : Slot time is in the range of 1~1489 and set in unit of microsecond. The default value is 20
microsecond.
Slot time is the amount of time a device waits after a collision before retransmitting a packet. Reducing the
slot time decreases the overall back-off, which increases throughput. Back-off, which is a multiple of the
slot time, is the random length of time a station waits before sending a packet on the LAN. For a sender
and receiver own right of the channel the shorter slot time help manage shorter wait time to re-transmit
from collision because of hidden wireless clients or other causes. When collision sources can be removed
sooner and other senders attempting to send are listening the channel(CSMA/CA) the owner of the
channel should continue ownership and finish their transmission and release the channel. Then, following
ownership of the channel will be sooner for the new pair due to shorter slot time. However, when long
duration of existing collision sources and shorter slot time exist the owners might experience subsequent
collisions. When adjustment to longer slot time can’t improve performance then RTS/CTS could
supplement and help improve performance.