TRENDnet TEW-455APBO User Manual page 26

User Manual
TEW‐455APBO High Power Wireless Outdoor PoE Access Point
RSSI Threshold: RSSI Threshold is in the range of ‐128~127.The default value is 24.
RSSI is defined as Received Signal Strength Indication, when the received signal strength from peer is
below this threshold, the peer will be consider as disconnected. Set the threshold higher will make
roaming happen earlier, set lower will allow weak signal peer to connect. In normal condition, the longer
the distance, the lower the signal strength between peers. You could consider lowering RSSI to increase
the wireless coverage. Increase the RSSI Threshold to have a more stable, but smaller coverage area.
Beacon Interval: Beacon Interval is in the range of 1~5000 and set in unit of millisecond. The default value
is 100 msec.
Access Point (AP) in IEEE 802.11 will send out a special approximated 50‐byte frame, called "Beacon".
Beacon is broadcast to all the stations, provides the basic information of AP such as SSID, channel,
encryption keys, signal strength, time stamp, support data rate.
All the radio stations received beacon recognizes the existence of such AP, and may proceed next actions if
the information from AP matches the requirement. Beacon is sent on a periodic basis, the time interval
can be adjusted.
By increasing the beacon interval, you can reduce the number of beacons and associated overhead, but
that will likely delay the association and roaming process because stations scanning for available access
points may miss the beacons. You can decrease the beacon interval, which increases the rate of beacons.
This will make the association and roaming process very responsive; however, the network will incur
additional overhead and throughput will go down.
DTIM Interval: The DTIM interval is in the range of 1~15. The default is 15.
DTIM is defined as Delivery Traffic Indication Message. It is used to notify the wireless stations, which
support power saving mode, when to wake up to receive multicast frame. DTIM is necessary and critical in
wireless environment as a mechanism to fulfill power‐saving synchronization.
A DTIM interval is a count of the number of beacon frames that must occur before the access point sends
the buffered multicast frames. For instance, if DTIM Interval is set to 3, then the Wi‐Fi clients will expect
to receive a multicast frame after receiving three Beacon frame. The higher DTIM interval will help power
saving and possibly decrease wireless throughput in multicast applications.
Fragment Threshold: The Fragment Threshold is in the range of 256~2346 byte. The default is 2346 byte.
Each Wi‐Fi packet can be divided into smaller packets, marked with a sequential fragment number and re‐
assemble in the receiving ends. The purpose is to make a short frame, instead of long frame, transmitting
by radio in a heavy noisy environment. Because of sending smaller frames, corruptions are much less likely
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