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[[Image:MACAW.JPG|thumb|450px|An example to illustrate the principle of MACAW. It is assumed that only adjacent nodes are in transmission range of each other.]]
Assume that node A has data to transfer to node B.
# “Request To send” frame (RTS) from A to B▼
# “Clear To Send” frame (CTS) from B to A▼
# “Data Sending” frame (DS) from A to B▼
# DATA fragment frame from A to B, and ▼
# Acknowledgement frame (ACK) from B to A.▼
Node A initiates the process by sending a ''Request to Send'' frame (RTS) to node B. The destination node (node B) replies with a ''Clear To Send'' frame (CTS). After receiving CTS, node A sends data. After successful reception, node B replies with an acknowledgement frame (ACK). If node A has to send more than one data fragment, it has to wait a random time after each successful data transfer and compete with adjacent nodes for the medium using the RTS/CTS mechanism <ref name="MACAW"/>.
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Before sending a long DATA frame, node A sends a short Data-Sending frame (DS), which provides information about the length of the DATA frame. Every station that overhears this frame knows that the RTS/CTS exchange was successful. An overhearing station (node F), which might have received RTS and DS but not CTS, defers its transmissions until after the ACK frame should have been received plus a random time <ref name="MACAW"/>.
To sum up, a successful data transfer from consists of the following sequence of frames:
▲# “Request To send” frame (RTS) from A to B
▲# “Clear To Send” frame (CTS) from B to A
▲# “Data Sending” frame (DS) from A to B
▲# DATA fragment frame from A to B, and
▲# Acknowledgement frame (ACK) from B to A.
MACAW is a [[non-persistent]] [[slotted]] protocol, meaning that after the medium has been busy, for example after a CTS message, the station waits a random time after the start of a time slot before sending an RTS. This results in fair access to the medium. If for example node A, B and C have data fragments to send after a busy period, they will have the same chance to access the medium since they are in transmission range of each other.
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