IEEE 802.11ah: Energy efficient MAC protocols for long range wireless LAN

IEEE 802.11ah enables new use cases such as smart grid and smart metering for 802.11 with an increased transmission range that reaches up to 1 km at 150 kbps. However, such a large outdoor network creates more hidden nodes due to a much higher path loss between stations than between a station to an access point (AP). 802.11ah has adopted a slotted medium access scheme and an AP assisted medium access scheme to mitigate the hidden node problem to enable energy efficient medium access for a large outdoor network. This paper presents details of the protocols being developed in the standard and evaluates the gains of the protocols.