802.11ac MAC Functions ========================= .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the MAC layer in 802.11ac?** The MAC (Medium Access Control) layer in 802.11ac manages wireless medium access, frame delivery, and coordination for high throughput Wi-Fi networks. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What are the primary functions of MAC in 802.11ac?** Functions include medium access control using CSMA/CA, frame aggregation, retransmissions, error checking, and QoS support. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does MAC handle medium access in 802.11ac?** It uses CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) enhanced with frame aggregation and block acknowledgments to optimize throughput. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What role does MAC play in frame retransmission?** MAC retransmits unacknowledged frames and manages block acknowledgments for efficient error recovery. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does MAC implement collision avoidance?** By employing interframe spacing, random backoff timers, and RTS/CTS mechanisms to minimize collisions in dense networks. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the purpose of ACK and Block ACK frames in MAC?** ACK confirms reception of single frames, while Block ACK acknowledges multiple frames aggregated together. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does MAC layer handle frame aggregation?** MAC supports A-MSDU and A-MPDU aggregation to combine multiple frames, reducing overhead and increasing throughput. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the NAV (Network Allocation Vector) in MAC?** NAV is a virtual carrier sensing timer used to indicate when the medium is reserved, helping avoid collisions. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does MAC manage power saving in 802.11ac?** MAC coordinates power saving modes allowing devices to enter sleep states and wake as needed for efficient energy use. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the role of RTS/CTS in MAC?** Request to Send (RTS) and Clear to Send (CTS) frames reduce collisions, especially in hidden node scenarios. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does MAC prioritize traffic?** Using Enhanced Distributed Channel Access (EDCA), MAC classifies traffic into categories like voice, video, and best effort for QoS. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What types of frames are managed by MAC in 802.11ac?** MAC manages management, control, and data frames to maintain wireless communication integrity. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does MAC deal with errors?** MAC uses CRC checks to detect frame errors and schedules retransmissions as needed. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is MAC responsible for addressing?** Yes, MAC handles physical addressing using MAC addresses for source and destination identification. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does MAC coordinate with the Physical layer?** MAC passes frames to the PHY layer for modulation and handles received data bits for frame reconstruction. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is Distributed Coordination Function (DCF) in 802.11ac?** DCF is the fundamental MAC access method using CSMA/CA for channel contention. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11ac MAC support Point Coordination Function (PCF)?** PCF is optional and less commonly used, providing contention-free periods controlled by the access point. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does MAC support MU-MIMO in 802.11ac?** MAC schedules and manages simultaneous transmissions to multiple users using MU-MIMO technology. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does MAC support roaming between access points?** MAC handles authentication, association, and reassociation processes to enable seamless client mobility. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Where are MAC functions defined for 802.11ac?** In the IEEE 802.11ac amendment to the 802.11 standard, which builds on the original 802.11 MAC specifications. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow Topics in this section, * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`mac_functions Basic Setup on Ubuntu using IPv4 ` * :ref:`Reference links ` .. _mac_functions_step1: .. tab-set:: .. tab-item:: Learnings in this section * In this section, you are going to learn .. _mac_functions_step2: .. tab-set:: .. tab-item:: Terminology * Terminology .. _mac_functions_step3: .. tab-set:: .. tab-item:: Version Info * Version Info .. _mac_functions_step18: .. tab-set:: .. tab-item:: mac_functions Basic Setup on Ubuntu using IPv4 * setup .. _mac_functions_step17: .. tab-set:: .. tab-item:: Reference links * Reference links