Edimax EW-7303HPn V2 Specifications download pdf (Page 67)

5.11 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.

5.12 What is Beacon Interval?

In addition to data frames that carry information from higher layers, 802.11 include 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).

5.13 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 bit

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Edimax EW-7303HPn V2 Specifications Page 67