AirLive WIAS-3200N v2 - Manual (Page 90)

5 Configure Wireless Connection
AirLive WIAS-3200N v2 User’s Manual
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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 1~255. The default is 1.
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 to occur. The
pros is obvious, the cons is the overhead for transmission. So, in a clean environment,
higher fragment threshold can be an option to increase throughput.
Fragmentation will be triggered by setting the Fragment Threshold, usually in
Byte-length. Only when the frame size is over the Threshold, fragmentation will take
place automatically.
RTS Threshold: TRTS Threshold is in the range of 1~2347 byte. The default is 2347
byte.
The main purpose of enabling RTS by changing RTS threshold is to reduce possible
collisions due to hidden wireless clients. RTS in AP will be enabled automatically if the
packet size is larger than the Threshold value. By default, RTS is disabled in a normal
environment supports non-jumbo frames.
Short Preamble: By default, it’s “Enable”. To Disable is to use Long 128-bit Preamble
Synchronization field.
The preamble is used to signal "here is a train of data coming" to the receiver. The
short preamble provides 72-bit Synchronization field to improve WLAN transmission
efficiency with less overhead.
Tx Burst: By default, it’s “Enable”. To Disable is to deactivate Tx Burst.
With TX burst enabled, AP will send many packets in a burst, without collision
detection and RTS/CTS for each packet. TX Burst have better throughput but cause
interference with other APs in channel.