Webee Wireless N Router with 3G Modem Support, User Manual, Page: 79 / 91

USER MANUAL OF WEBEE WIRELESS N ROUTER
Version:1.1
Firmware Type 2
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packets to be broken into smaller fragments. These small fragments, if corrupted, can be
resent faster than a larger fragment. Fragmentation increases overhead, so you'll want
to keep this value as close to the maximum value as possible
.
6.11.
WHAT IS RTS (REQUEST TO SEND) THRESHOLD?
The RTS threshold is the packet size at which packet transmission is governed by the
RTS/CTS transaction. The IEEE 802.11-1997 standard allows for short packets to be
transmitted without RTS/CTS transactions. Each station can have a different RTS
threshold. RTS/CTS is used when the data packet size exceeds the defined RTS
threshold. With the CSMA/CA transmission mechanism, the transmitting station sends
out an RTS packet to the receiving station, and waits for the receiving station to send
back a CTS (Clear to Send) packet before sending the actual packet data.
This setting is useful for networks with many clients. With many clients, and a high
network load, there will be many more collisions. By lowering the RTS threshold, there
may be fewer collisions, and performance should improve. Basically, with a faster RTS
threshold, the system can recover from problems faster. RTS packets consume valuable
bandwidth, however, so setting this value too low will limit performance.
6.12.
WHAT IS BEACON INTERVAL?
In addition to data frames that carry information from higher layers, 802.11 includes
management and control frames that support data transfer. The beacon frame, which is
a type of management frame, provides the "heartbeat" of a wireless LAN,
enabling
stations to establish and maintain communications in an orderly fashion.
Beacon Interval represents the amount of time between beacon transmissions. Before a
station enters power save mode, the station needs the beacon interval to know when to
wake up to receive the beacon (and learn whether there are buffered frames at the
access point).
6.13.
WHAT IS PREAMBLE TYPE?
There are two preamble types defined in IEEE 802.11 specification. A long preamble
basically gives the decoder more time to process the preamble. All 802.11 devices
support a long preamble. The short preamble is designed to improve efficiency (for
example, for VoIP systems). The difference between the two is in the Synchronization
field. The long preamble is 128 bits, and the short is 56 bits.
6.14. WHAT IS SSID BROADCAST?
Broadcast of SSID is done in access points by the beacon. This announces your access
point (including various bits of information about it) to the wireless world around it. By
disabling that feature, the SSID configured in the client must match the SSID of the
access point.
Some wireless devices don't work properly if SSID isn't broadcast (for example the D-link