Power Saving Mechanisms in IEEE 802.11ah protocol
What is the main goal of power saving in 802.11ah?
To extend battery life of devices by reducing power consumption during idle times.
How does 802.11ah achieve power saving?
By enabling devices to enter sleep states and wake only when needed to transmit or receive data.
What is the Target Wake Time (TWT) in 802.11ah?
A mechanism that schedules specific wake-up times for devices to minimize idle listening.
How does TWT improve battery efficiency?
By allowing devices to sleep longer and wake only during agreed communication windows.
What role do beacon frames play in power saving?
Beacons inform devices about buffered data and timing, helping them decide when to wake up.
What is the Delivery Traffic Indication Message (DTIM)?
A special beacon signal that indicates pending multicast/broadcast data for sleeping devices.
How does 802.11ah reduce energy usage in IoT devices?
By optimizing sleep schedules and minimizing unnecessary transmissions.
What is the difference between 802.11ah power saving and older Wi-Fi standards?
802.11ah is designed for longer range and ultra-low power use, especially for IoT applications.
Can 802.11ah devices negotiate their wake times?
Yes, through Target Wake Time agreements between AP and stations.
How does power saving affect network latency?
It can increase latency slightly due to scheduled wake periods but balances battery life with performance.
What is the role of Traffic Indication Map (TIM) in 802.11ah?
TIM signals which stations have buffered unicast data awaiting delivery.
Do all devices in 802.11ah support power saving?
Power saving features are optional but highly recommended for battery-operated devices.
How is multicast traffic handled in power saving mode?
Multicast data is buffered and delivered during DTIM intervals when devices wake up.
What mechanisms coordinate sleep and wake cycles?
APs use beacons, TIM, and TWT to schedule device wake-ups.
How does power saving work in dense 802.11ah networks?
Efficient scheduling and grouping of devices reduce collisions and power use.
What is the impact of power saving on throughput?
Throughput may be slightly reduced due to devices being asleep but overall efficiency improves.
Are power saving mechanisms compatible with security protocols?
Yes, power saving operates alongside security features without compromise.
Where can I find detailed specifications on 802.11ah power saving?
In the IEEE 802.11ah standard document, especially sections on MAC layer power management.
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