802.11d MAC Functions
What are MAC functions in IEEE 802.11d?
MAC functions control access to the wireless medium and manage communication between devices.
How does 802.11d extend MAC functions?
It adds support for regulatory domain information, allowing devices to adapt to country-specific regulations.
What is the role of the MAC layer in 802.11d?
To coordinate frame exchange, control medium access, and ensure frame delivery within regulatory limits.
How does 802.11d support multi-country operation?
By transmitting country information elements within beacon and probe response frames for compliance.
What is the Country Information Element (IE) in MAC?
A MAC frame element that carries country-specific regulatory rules for channels and power.
How do stations use the Country IE?
Stations use it to configure allowed channels, power limits, and operational parameters dynamically.
Does 802.11d affect MAC frame formats?
Yes, it introduces new information elements but maintains backward compatibility with older frames.
How is channel availability managed at MAC level in 802.11d?
MAC enforces regulatory constraints on channel selection based on received country info.
What MAC functions help prevent interference in 802.11d?
Functions like Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) are supported.
How does 802.11d improve roaming between regulatory domains?
It allows clients to update channel lists and power limits when entering new country zones.
Are there MAC-level security implications in 802.11d?
No direct changes, but regulatory compliance may indirectly affect security policies.
How do access points implement 802.11d MAC features?
By including Country IE in beacon frames and enforcing allowed channel/power rules.
Can clients reject networks with incompatible country info?
Yes, clients can ignore or avoid joining networks that don’t comply with local regulations.
What role does MAC play in power saving with 802.11d?
Power control is adapted per regulatory constraints to optimize transmission power.
Does 802.11d affect frame retry or acknowledgments?
No significant changes; MAC handles these as per 802.11 standards.
How is regulatory info propagated in a WLAN?
Through beacon and probe response frames carrying the Country IE at the MAC level.
What happens if a device ignores 802.11d MAC functions?
It may operate outside legal channel or power limits, causing interference and legal issues.
Are MAC function changes in 802.11d mandatory?
Yes, devices must comply with 802.11d to operate legally in multiple countries.
How does 802.11d enhance device interoperability?
By standardizing regulatory information exchange and channel management at the MAC layer.
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