A closed-loop rate adaptive scheme for IEEE 802.11 multi-rate wireless networks

Closed-loop rate adaptive scheme is mutually considered both the rate and CW values. CRAS is a receiver-assisted rate adaptation protocol. It also considers the loss of frames due to collisions. The information about atmosphere energy level of a sender is carried via the DATA packet with one extra byte. It introduces a rate suggestion (RS) chart, that received via continuously observing the atmosphere energy level and obtaining performance. The RS chart is used to guide the receiver to select the most excellent proper rate for the sender. CRAS algorithm maintains high throughput comparable to other adaptation techniques.