This paper addresses an analytical model that may be applied to
different Wireless Sensor Networks (WSNs) Medium Access
Control (MAC) protocols using different efficient transceivers.
Our model accounts for the impact of several simultaneous
factors, including periodic receive/transmit and sleep cycles,
the length of the transmitted packet and data rate. The Sensor
Block Acknowledgement MAC, a new innovative WSNs
MAC protocol that uses a Block Acknowledgement scheme
to achieve energy efficiency, is proposed as well. Our implementation takes into account the average delay, which can be
clearly reduced when a Block Acknowledgement Scheme is
used. In terms of energy consumption and average delay the efficient radio transceivers that operate in the 2.4GHz band have
better results that the ones that use the 900MHz band. Adaptive
listening (AL) enables radio transceivers to stay alert after
the communication between two neighbour nodes before going
to sleep, allowing for energy saving when synchronisation is
involved.