What Is The Purpose Of The Distributed Coordination Function In An Ieee 802.11 Wlan Environment?

What is the purpose of the Distributed Coordination Function in an IEEE 802.11 WLAN environment?

• For collision detection, the full-duplex mode is used by the DCF.
• It gives them access to a client to detect whether or not the channel is clear before transmission. 
• For the transferal of the data through the half-duplex method, DCF is used.
• It can permit the client to change the transmission channels.

Answer: The purpose of the Distributed Coordination Function in an IEEE 802.11 WLAN environment is that It gives access to a client to detect whether or not the channel is clear before transmission.

What is DCF (Distributed Coordination Function)?

Along with the IEEE 802.11 based WLN the distributed coordination function is the important component of the media access control (MAC), which also includes the WIFI. The algorithm which implies the DCF is the backoff algorithm along with the carrier sense multiple access and collision avoidance.

For a DIFS interval and the transmission, listening to the channel status the distributed coordination function needs the station. During the DIFS interval if the channel is busy the station will discard the transmission. in the network when the various stations need the wireless medium, and the several stations sense that the channel is busy and their access is discarded and they found that the channel is free all f them try t send the transmission and the channel may squeeze due to the load and the collision of signals occur .to prevent this the DCF act as the backoff which forces the station to allow its permit to the channel for an extra time.

The length of the DCF backoff period is determined with the help of the following equations:

• DCf has the extra virtual carrier sense mechanism which can exchange the RTS (request-to-send) and the CTS (clear-to-send) frames of the source and destination in the period of the interval of the data packets or frames transmission.
• An acknowledgment mechanism is present in the DCF which ensures when the data is sent toward the destination, the destination needs to send the ACK frames to tell that the source of the transmission is successful.
• The terminal problem either is hidden or the exposure is not thoroughly solved by the DCF only it can reduce the problem burden with the help of the RTS and CTS and gives the advice to use the larger carries sensing range.
• DCF by the default setting of the hardware WIFI is recommended in the IEEE 802.11 metrics.
• The message who has a little knowledge is handled by the 802.11 DCF and it can also use an effective amount of time. Such as the ACK can only take 60 μs for the complete transmission it has also contained a sufficient amount of airtime for the transmission of 3240 bits during the speed of 54 Mbit/s.
• PCF (point coordination function) is the feature that is defined by the IEEE 802.11 standard for extra access act as the network coordination which permits the access point for the management of channel access.