802.11h MAC Timings
What are MAC timings in 802.11h?
MAC timings refer to the time intervals and delays defined at the MAC layer to support features like DFS and TPC in 802.11h.
How does 802.11h affect the Channel Availability Check (CAC) timing?
CAC requires a mandatory monitoring period (usually 60 seconds) where the MAC must detect radar signals before a channel can be used.
What is the purpose of the Non-Occupancy Period in MAC timing?
After radar detection, the MAC enforces a non-occupancy period (often 30 minutes) during which the channel cannot be used.
How does MAC timing impact channel switching delays?
MAC layer introduces delays for safe channel switching to ensure compliance with DFS and avoid interference with radar.
What is the Channel Switch Announcement (CSA) timing?
CSA timing defines how long a device must continue transmitting on the current channel after announcing a switch before moving.
Does 802.11h MAC adjust interframe spacing?
Yes, MAC may adjust interframe spacing (like SIFS or DIFS) to prioritize control frames related to DFS and TPC.
What is the impact of MAC timing on beacon intervals?
Beacons may carry DFS and TPC info, so timing may be adapted to ensure clients receive updated regulatory info promptly.
How does MAC timing manage radar pulse detection intervals?
MAC uses predefined time windows to monitor radar pulse patterns reliably before triggering DFS procedures.
What timing constraints exist for Transmit Power Control (TPC) adjustments?
TPC changes are applied dynamically but within MAC timing rules to avoid sudden power fluctuations that might disrupt connections.
How long must the MAC wait before reusing a channel after radar detection?
The MAC enforces a non-occupancy period, typically 30 minutes, before the channel can be used again.
Are there MAC timing differences between indoor and outdoor 802.11h operations?
Timing parameters may vary depending on regional regulations and deployment scenarios.
How does MAC timing handle simultaneous radar detections?
MAC sequences the handling of channel switches with appropriate timing to avoid network disruptions.
Does MAC timing impact how quickly a device can join a network on a DFS channel?
Yes, the CAC period must be completed before a device can use a DFS channel, potentially delaying association.
What role does MAC timing play in managing client communication during channel switches?
MAC coordinates timing to ensure clients receive channel switch announcements and can switch channels smoothly.
Are MAC timing parameters standardized or configurable?
Many timing parameters are standardized but some vendor implementations may allow limited tuning.
How does MAC timing support regulatory compliance audits?
MAC logs timing events like CAC and channel switches to demonstrate adherence to regulations.
Can MAC timing cause temporary network performance degradation?
Yes, channel switch delays and CAC monitoring can cause brief interruptions or latency spikes.
Does MAC timing affect power-saving mechanisms?
DFS and TPC timing constraints may override power-saving timers to prioritize compliance.
How critical are MAC timings for successful 802.11h deployment?
Precise MAC timing is essential to balance regulatory compliance, interference avoidance, and network performance.
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