Collisions due to interference at MAC layer limit the throughput of Ad Hoc networks using IEEE 802.11 protocol at medium and high load conditions. The proposed MAC layer MAC-CPI-A (Collision Prevention due to Interference) protocol prevents collisions due to interference completely. In the proposed protocol every node refrains from beginning its transmission if any node within its `maximum interference range’ is currently engaged in a data transfer.
The `maximum interference range’ for all nodes is pre-computed as a function of average distance between a transmitter and its receiver, the minimum acceptable Signal to Interference and Noise Ratio (SINR), path loss exponent, the carrier sensing range of a receiver and the maximum noise around a receiver. If the sudden change in signal received by a node is more than a `significant’ value defined by the `maximum interference range’, then the node infers that another node within its `maximum interference range’ has begun its transmission. A scheme for generation of a new signal indicating a sudden increase or decrease in received signal of greater than `significant’ value has been detailed.