802.11r MAC Timings
What are MAC timings in 802.11r?
MAC timings refer to specific time intervals and delays in frame exchanges and state transitions at the MAC layer during fast roaming.
Why are MAC timings critical in 802.11r?
Precise MAC timings reduce handoff latency, ensuring seamless and fast transitions between access points.
Which MAC timing is most important for fast roaming?
The time taken for FT Authentication and Reassociation frame exchanges is crucial in minimizing roaming delays.
How does 802.11r reduce MAC timing delays?
By enabling pre-authentication and caching keys, reducing the number of frame exchanges needed during handoff.
What is the typical MAC timing for FT Authentication in 802.11r?
FT Authentication exchanges usually complete within a few milliseconds to ensure fast transitions.
What role does the Short Interframe Space (SIFS) play in MAC timings?
SIFS is the shortest waiting time between frames and is used to prioritize control frames during fast transitions.
How is the Distributed Interframe Space (DIFS) relevant to 802.11r timings?
DIFS defines the wait time before a device can transmit data frames, affecting the timing of reassociation.
Does 802.11r define new timing parameters?
Yes, it introduces timing requirements specific to Fast Transition frame exchanges to ensure quick handoffs.
What is the role of the Timeout Interval in MAC timings?
Timeout intervals determine how long a station waits for a response before retrying or failing the handoff.
How does MAC timing affect overall network performance in 802.11r?
Efficient MAC timings reduce packet loss and latency during roaming, improving user experience.
Are MAC timing intervals configurable in 802.11r?
Some intervals, like retransmission timeouts, can be configured to optimize roaming speed and reliability.
How does the MAC timing coordinate with PHY during handoff?
MAC timings align with PHY switching times to ensure minimal disruption during channel changes.
What is the impact of MAC timing on key establishment in 802.11r?
Shorter timing intervals enable faster key exchanges, reducing authentication delays during roaming.
How does the MAC layer handle retransmissions in 802.11r timings?
Retransmissions occur after defined backoff and timeout intervals, which are optimized to minimize delay.
What is the relationship between MAC timing and FT Action frame exchanges?
FT Action frames must be exchanged within specified timing windows to ensure fast and secure handoffs.
How do MAC timing parameters affect power management in 802.11r?
Efficient timing reduces active radio time, helping conserve battery life in client devices.
Are MAC timings standardized globally for 802.11r?
Yes, the standard defines maximum allowable timings, though implementations may vary.
What timing challenges does 802.11r address compared to legacy 802.11?
It reduces handoff delays caused by full reauthentication and key negotiation, common in legacy systems.
How important is synchronization of MAC timings between AP and client?
Proper synchronization ensures frames are exchanged without collisions or unnecessary delays during handoff.
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