SWRU616B September   2023  – April 2024 CC3300 , CC3301 , CC3301MOD , CC3350 , CC3351

 

  1.   1
  2.   CC33xx WLAN Features Guide
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Scope
    2. 1.2 Acronyms Used in This Document
    3. 1.3 CC33xx Specification
  5. 2General Features
    1. 2.1  Supported Rates
      1. 2.1.1 11ax Rates
      2. 2.1.2 11n Rates
      3. 2.1.3 11a/g Rates
      4. 2.1.4 11b Rates
    2. 2.2  A-MPDU and A-MSDU
    3. 2.3  BA Sessions
    4. 2.4  Keep Alive
      1. 2.4.1 STA
      2. 2.4.2 AP
    5. 2.5  Wake on WLAN (WoW)
    6. 2.6  Antenna Diversity
    7. 2.7  Quality of Service (QoS)
    8. 2.8  Security
      1. 2.8.1 Authentication Types
      2. 2.8.2 Encryption Types
    9. 2.9  Wi-Fi Provisioning
      1. 2.9.1 AP Provisioning
      2. 2.9.2 Bluetooth Low Energy Provisioning
      3. 2.9.3 Wi-Fi Protected Setup (WPS)
        1. 2.9.3.1 WPS PBC
        2. 2.9.3.2 WPS PIN
    10. 2.10 Wi-Fi Power Management Modes
      1. 2.10.1 Power Levels
        1. 2.10.1.1 Active
      2. 2.10.2 Power Save Delivery
        1. 2.10.2.1 Legacy Power Save
  6. 3Single Role: Station
    1. 3.1 Scanning
      1. 3.1.1 Active
      2. 3.1.2 Passive
    2. 3.2 Wi-Fi 6
    3. 3.3 Multicast Filtering
    4. 3.4 Preferred Networks
    5. 3.5 Channel Switch
    6. 3.6 Wi-Fi Power Management Modes
      1. 3.6.1 Power Save Delivery
        1. 3.6.1.1 Unscheduled Asynchronous Power Save Delivery (U-APSD)
        2. 3.6.1.2 Target Wake Time (TWT)
      2. 3.6.2 TI Specific Features
        1. 3.6.2.1 Auto Power-Save Mode
        2. 3.6.2.2 Long Sleep Interval
  7. 4Single Role: AP
    1. 4.1 Hidden SSID
    2. 4.2 Maximum Connected Stations
    3. 4.3 Aging
  8. 5Multirole Multichannel
    1. 5.1 AP-STA
    2. 5.2 STA-STA
  9. 6Wi-Fi/Bluetooth Low Energy Coexistence
  10. 7References
  11. 8Revision History

2.2 A-MPDU and A-MSDU

Frame aggregation reduces overhead of the 802.11 protocol and increases data throughput by using a single PHY or MAC header to send multiple frames of data. There are primarily two methods available to accomplish frame aggregation: aggregate MAC service data unit (A-MSDU) and aggregate MAC protocol data unit (A-MPDU).

The main distinction between MSDU and MPDU is how information transmitted through the respective layers.

  • MSDUs transmit information between the upper part of the MAC layer to higher layers.
  • MPDUs transmit information between the lower part of the MAC layer to the PHY layer.

Beyond the difference in transmission between layers, there is also a difference in the frame structure when the units are aggregated.

  • Individual MSDUs each receive an MSDU subframe header to create MSDU subframes. Two or more of these subframes are then inserted into an 802.11 MAC frame with a header and trailer. Once inserted the combined frames are considered an A-MSDU and transmitted using a single MAC header.
  • Unlike MSDUs, MPDUs each have their own 802.11 MAC header and trailer that are then transmitted under the same PHY header.

In frame aggregation these techniques are combined so that multiple MSDUs can be concatenated into a single MPDU and transmitted. These aggregate exchange sequences are implemented through a protocol that acknowledges (ACKs) multiple MPDUs with a single block ACK. For more information on block ACK sessions, see Section 2.3. The CC33x can both transmit and receive data in the A-MPDU format and is able to receive data in the A-MSDU format.

GUID-20230828-SS0I-MSNN-3VDG-9DQ15DZ1M4FL-low.svg Figure 2-1 A-MSDU and A-MPDU Frame Structure