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What are RTS and CTS packets?
RTS/CTS (Request to Send / Clear to Send) mechanism is a reservation scheme used in the wireless networks. It is used to minimize frame collisions created due to the hidden node problem. The attacker nodes modify the duration field value of the RTS packets to reserve the channel for additional time.
What is CTS packet?
Clear to Send (CTS) is a control frame employed in the medium access control (MAC) layer protocol IEEE 802.11 RTS/CTS. The protocol uses the concept of Multiple Access with Collision Avoidance (MACA) in wireless networks.
How does RTS CTS data and ACK packets interact?
Upon correctly receiving the RTS, node B responds with another small packet called Clear- to-Send (CTS). After receiving the CTS, node A sends the DATA packet to node B. If node B receives the DATA packet correctly, it sends an Acknowledgment (ACK) back to node A.
What is the time duration of NAV CTS )?
Duration of the CTS frame is the duration field of RTS, adjusted by subtraction of aSIFS & time required to transmit the CTS frame. Here is the frame capture of CTS frame. In this case duration is set to 80μS ( 124-44, indicate CTS frame require 44μS ).
How does RTS CTS relate to CSMA?
Moreover, the RTS/CTS mechanism for CSMA/CA protocol was adopted in the IEEE 802.11 to reduce the collision probability caused by hidden nodes terminals9. So applying the CSMA/CA – RTS/CTS to each channel part should improve the performance in terms of throughput and collision probability.
Is RTS CTS required?
With hardware flow control (also called RTS/CTS flow control), two extra wires are needed in addition to the data lines. They are called RTS (Request to Send) and CTS (Clear to Send). These wires are cross-coupled between the two devices, so RTS on one device is connected to CTS on the remote device and vice versa.
What is the packet size threshold for RTS / CTS?
RTS/CTS packet size threshold is 0–2347 octets. Typically, sending RTS/CTS frames does not occur unless the packet size exceeds this threshold. If the packet size that the node wants to transmit is larger than the threshold, the RTS/CTS handshake gets triggered. Otherwise, the data frame gets sent immediately.
How does the CTS and RTS connection work?
The CTS features a time value that will alert other stations to hold access to the medium while the station that initiates the RTS transmits the data. The RTS/CTS connection provides a framework for the shared medium.
When does the RTS and CTS handshake occur?
Typically, sending RTS/CTS frames does not occur unless the packet size exceeds this threshold. If the packet size that the node wants to transmit is larger than the threshold, the RTS/CTS handshake gets triggered. Otherwise, the data frame gets sent immediately.
How does the receiving station send out the RTS packet?
In the first mechanism, the transmission station will send out the actual packet after waiting for the silence period, while in the latter, the transmission station sends out an RTS packet to the receiving station and waits until the receiving station transmits a CTS packet before sending the actual packet data.