In: Electrical Engineering
What are RTS and CTS packets?
RTS (Request to Send) & CTS (Clear to Send) was used to avoid frame collisions in the hidden node problem and was used by the 802.11 networking protocol as an optional mechanisam. Modern RTS & CTS includes acknowledgments and does not solves exposed node problem which was solved earlier.
It means Request-to-send and Clear-to-send . when stations are communicating each other it will be used inorder to avoid collision.
Mechanisms of RTS and CTS:
When a node wants to transmit data to another node, it sends out a RTS 'Request to Send' packet. The receiver node replies with a packet called CTS 'Cleared to Send' packet.After the transmitter node receives the CTS packet, it transmits the data packets. Encoded within the RTS/CTS packets is a duration field. The duration field is set such that the data transmission can be completed within the designated time period. If a transmiiter node does not receive a CTS packet it enters into an exponential back off mode.