Configuration Guide Configuring FAT APs
 RTS/CTS
To avoid signal conflict that causes data transmission failure, the IEEE 802.11 MAC protocol provides the Request To
Send/Clear To Send (RTS/CTS) handshake protocol. Assuming that STA A needs to send data to STA B, STA A first sends
an RTS frame to STA B. If STA B allows STA A to send the data, STA B sends a CTS frame to STA A. After receiving the
CTS frame, STA A starts sending data to STA B. If multiple STAs need to send RTS frames to the same STA to request for
data sending, only STAs that receive CTS frames can send data, and STAs that do not receive CTS frames suffer from
channel conflict by default and can send RTS frames after a period of time.
If each STA performs RTS/CTS handshake before sending data each time, excessive RTS frames may occupy channel
bandwidth, the user can set a RTS threshold to specify the frame length of data for sending. If the frame length of data sent
by an STA is smaller than the set RTS Threshold, RST/CTS handshake does not need to be performed.
 Beacon
In a WLAN, an AP regularly sends beacon frames. A beacon frame controls information about this AP. STAs can discover
the WLAN by receiving beacon frames.
 Configuring the Preamble Type
A preamble is a set of bits in the header of a packet, used to synchronize transmission signals between the sending and
receiving ends. The user can configure preamble type (long or short) supported by an AP. The time for transmitting frames
with long preamble is long and the time for transmitting frames with short preamble is short.
 Configuring the Timeslot Type
In a WLAN, to avoid channel contention caused by multiple STAs that send data at the same time, the STAs need to check
whether channels are idle before sending data. If detecting that a channel is idle, an STA does not send data immediately but
waits for a backoff time. A backoff time is a random integer multiple of a slot time (an operation time unit in the MAC protocol).
Assuming that a random value is 3, the system automatically decreases the value by 1 after each slot time. The STA starts
sending data when the value is equal to 0. Therefore, reducing slot time can reduce the overall backoff time and thus
increase network throughput.
 Configuring the Channel Bandwidth
802.11n binds two bandwidths of 20 MHz into one bandwidth of 40 MHz. In actual operation, the bandwidth of 40 MHz can
be used as two bandwidths of 20 MHz (one primary bandwidth and one secondary bandwidth). During data sending and
receiving, the two bandwidths can be used as one bandwidth of 40 MHz or two separate bandwidths of 20 MHz. In this way,
the rate can be doubled, which can improve the throughput of a WLAN.
 Configuring the Prevention Interval
802.11n provides a mechanism for shortening the prevention time and enabling a short prevention interval. The prevention
time is shortened from 0.8 us to 0.4 us.
 Configuring the Country Code
To Next Page
Loading...
Need help?
General
