802.11aq MAC Timings
What are MAC timings in IEEE 802.11?
MAC timings refer to the time intervals and delays defined at the MAC layer for coordinating wireless communication.
Why are MAC timing parameters important?
They ensure fair medium access, collision avoidance, and synchronization between devices for reliable communication.
What is the Distributed Interframe Space (DIFS)?
DIFS is a waiting period after a medium becomes idle before a station can transmit a new data frame.
How does Short Interframe Space (SIFS) differ from DIFS?
SIFS is shorter and used between related frames like data and acknowledgment to prioritize quick responses.
What is the role of Arbitration Interframe Space (AIFS) in 802.11e/aq?
AIFS replaces DIFS for different traffic categories to enable Quality of Service by assigning varied waiting times.
What is the purpose of Slot Time in MAC timing?
Slot time is the basic unit for contention window backoff and collision avoidance during medium access.
How is Contention Window (CW) related to MAC timings?
CW defines the range of random backoff slots a device waits before attempting transmission to avoid collisions.
What is the Backoff Time in MAC protocols?
Backoff Time is a randomized waiting period within the Contention Window to reduce the chance of simultaneous transmissions.
How does MAC timing affect collision avoidance?
Proper timing intervals and randomized backoffs reduce the probability of two devices transmitting simultaneously.
What timing parameters are used between RTS and CTS frames?
The SIFS interval is used to prioritize the CTS response right after the RTS is received.
How does MAC timing impact power saving?
Timings govern when stations wake up or sleep, coordinating with beacon intervals to optimize battery use.
What is the Role of Beacon Interval in MAC timing?
It defines how often access points send beacon frames to synchronize and manage client communication.
How does Timing Synchronization Function (TSF) relate to MAC timings?
TSF synchronizes all stations’ clocks in a WLAN to ensure coordinated access and frame timing.
What is the impact of interframe spaces on Quality of Service (QoS)?
Differentiated interframe spaces (like AIFS) enable prioritization of time-sensitive traffic in 802.11e/aq.
How are timing parameters adjusted in high traffic conditions?
Contention windows may increase to reduce collisions by extending backoff times during congestion.
Does MAC timing vary between 2.4 GHz and 5 GHz bands?
Yes, parameters like slot time and SIFS can differ due to propagation characteristics and regulatory requirements.
How does MAC timing influence roaming performance?
Efficient timing coordination helps reduce handoff delays and ensures smooth transitions between APs.
What is Extended Interframe Space (EIFS)?
EIFS is a longer wait time used after detecting erroneous frames to allow the network to recover.
How are MAC timings standardized across devices?
IEEE 802.11 defines strict timing parameters to ensure interoperability and synchronized medium access.
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