Power Saving Mechanisms in IEEE 802.11g protocol
What are power saving mechanisms in IEEE 802.11g?
Techniques that allow Wi-Fi devices to reduce energy consumption by entering low-power sleep states.
How does Power Save Mode (PSM) function in 802.11g?
Devices alternate between awake and sleep states, waking periodically to check for buffered data.
What role do beacon frames play in power saving?
Beacons inform sleeping devices about buffered unicast or multicast data using TIM and DTIM fields.
What is the Traffic Indication Map (TIM)?
A field in beacon frames that indicates which stations have buffered unicast frames waiting.
What is the Delivery Traffic Indication Message (DTIM)?
A special beacon interval that notifies clients about multicast or broadcast traffic delivery.
How does the access point buffer data for sleeping stations?
It queues frames addressed to sleeping clients and delivers them when clients wake up.
Can power saving increase latency?
Yes, since devices sleep, data delivery may be delayed until the client wakes.
Is power saving mode mandatory for 802.11g devices?
No, it is optional but widely supported for battery-powered devices.
How does power saving affect throughput?
It may reduce throughput due to sleep intervals and delayed frame delivery.
What is the difference between TIM and DTIM intervals?
TIM is for unicast buffered frames; DTIM additionally signals multicast/broadcast.
Can devices selectively disable power saving?
Yes, devices can turn off power saving to prioritize performance.
Does power saving work with QoS features in 802.11g?
Basic power saving is compatible, though advanced QoS mechanisms may require specific support.
How do clients know when to wake up from sleep?
They wake based on beacon intervals that indicate buffered data.
Can power saving save battery in mobile devices?
Yes, it significantly extends battery life by reducing radio usage.
Are power saving settings configurable?
Yes, users or device drivers can configure power saving behavior.
How does the AP inform clients about multicast traffic?
Through DTIM beacon intervals signaling multicast data availability.
Can power saving cause packet loss?
Generally no, but delayed reception can affect real-time apps.
Does 802.11g power saving differ from 802.11a?
The concepts are similar but adapted for their respective PHY characteristics.
What happens if a client misses a beacon?
The client may miss notifications of buffered data, requiring re-association or retransmissions.
How do power saving and roaming interact?
Clients maintain power saving states during roaming to ensure battery efficiency.
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