[Show abstract][Hide abstract] ABSTRACT: This paper introduces a light-weight mobility-aware medium access control protocol for wireless sensor networks (MA-MAC). In many respects, the protocol is similar to preamble based, low power listening MAC protocols. It defines a duty-cycle to let nodes sleep when they have no packets to transmit. During active communication, the protocol estimates mobility by evaluating the received signal strength of incoming ACK packets and initiates seamless handover by embedding neighbour discovery requests in data packets. Neighbour nodes randomly wake up from their sleep to participate in a handover process. Moreover, at the beginning of each active cycle, they first listen for handover request before they transmit. A prototype was developed and tested with TinyOS and Micaz platforms. The paper reports the experiment results.