  M2M communications are projected to be one of the fastest growing technology
segments of the IT sector in the next years. Sensor and actuator networks
connect communication machines and devices so that they automatically transmit
information, serving the growing demand for environmental data acquisition.
IEEE 802.11ah Task Group addresses the creation of a new standard for giving
response to the particular requirements of this type of networks: large number
of power-constrained stations, long transmission range, small and infrequent
data messages, low data-rates and non-critical delay. This article explores the
key features of this new standard under development, especially those related
to the reduction of energy consumption in the MAC Layer. In this direction, a
performance assessment of IEEE 802.11ah in four typical M2M scenarios has been
performed.
