  Carrier Sense Multiple Access (CSMA) is widely used as a Medium Access
Control (MAC) in wireless networks due to its simplicity and distributed
nature. This motivated researchers to find CSMA schemes that achieve throughput
optimality. In 2008, it has been shown that a simple CSMA-type algorithm is
able to achieve optimality in terms of throughput and has been given the name
"adaptive" CSMA. Lately, new technologies emerged where prolonged battery life
is crucial such as environment and industrial monitoring. This inspired the
foundation of new CSMA based MAC schemes where links are allowed to transition
into sleep mode to reduce the power consumption. However, throughput optimality
of these schemes was not established. This paper therefore aims to find a new
CSMA scheme that combines both throughput optimality and energy efficiency by
adapting to the throughput and power consumption needs of each link. This is
done by controlling operational parameters such as back-off and sleeping timers
with the aim of optimizing a certain objective function. The resulting CSMA
scheme is characterized by being asynchronous, completely distributed and being
able to adapt to different power consumption profiles required by each link
while still ensuring throughput optimality. The performance gain in terms of
energy efficiency compared to the conventional adaptive CSMA scheme is
demonstrated through computer simulations.
