SWRU423A July   2015  – May 2016 WL1801MOD , WL1805MOD , WL1807MOD , WL1831MOD , WL1835MOD , WL1837MOD

 

  1.   WiLink 8 WLAN Features Guide
    1.     Trademarks
    2. 1 Introducion
      1. 1.1 Scope
      2. 1.2 Acronyms Table
      3. 1.3 WiLink 8 Specification
    3. 2 General Features
      1. 2.1  Supported Rates
        1. 2.1.1 11b Rates
        2. 2.1.2 11a/g Rates
      2. 2.2  High-Throughput (HT) Features
        1. 2.2.1 11n Rates
        2. 2.2.2 MIMO at 2.4 GHz
        3. 2.2.3 40-MHz BW Operation
        4. 2.2.4 A-MPDU and A-MSDU
        5. 2.2.5 RIFS
        6. 2.2.6 BA Sessions
        7. 2.2.7 Greenfield
      3. 2.3  Quality of Service (QoS)
      4. 2.4  Protection Types
        1. 2.4.1 General
        2. 2.4.2 Protection Methods
      5. 2.5  Suspend and Resume
      6. 2.6  WoW (Wake on WLAN)
      7. 2.7  Set TX Power
      8. 2.8  5-GHz Antenna Diversity
      9. 2.9  Wi-Fi – Bluetooth/Bluetooth Smart Coexistence
      10. 2.10 Wi-Fi – ZigBee Coexistence
      11. 2.11 Accurate Synchronization Over Wi-Fi
    4. 3 Single Role: Station
      1. 3.1  Scanning
        1. 3.1.1 One-Shot Scan
        2. 3.1.2 Connection Scan
        3. 3.1.3 Background Scan
      2. 3.2  Connection
        1. 3.2.1 Manual (Via Commands)
          1. 3.2.1.1 Connection Time
          2. 3.2.1.2 Connection Success Rate
          3. 3.2.1.3 Connect to Best BSSID of the Configured SSID
        2. 3.2.2 Automatic (Via Profiles)
        3. 3.2.3 Wi-Fi Protected Setup (WPS)
          1. 3.2.3.1 WPS PBC
          2. 3.2.3.2 WPS PIN
      3. 3.3  Disconnection
      4. 3.4  DHCP Client
      5. 3.5  Security
        1. 3.5.1 Authentication Types
        2. 3.5.2 Encryption Types
        3. 3.5.3 Broadcast Key Rotation (BKR)
      6. 3.6  Filtering
        1. 3.6.1 Beacon Filtering
        2. 3.6.2 Multicast Filtering
      7. 3.7  Auto ARP
      8. 3.8  Preferred Networks (Profiles)
        1. 3.8.1 Hidden Network
      9. 3.9  Power-Save Mode
        1. 3.9.1 Active
        2. 3.9.2 Auto Power-Save Mode
        3. 3.9.3 Forced Power-Save Mode
      10. 3.10 Power-Save Delivery Protocols
        1. 3.10.1 Legacy
        2. 3.10.2 U-APSD
      11. 3.11 Keep-Alive Mechanism
      12. 3.12 Smart Config
      13. 3.13 Regulatory Domain
      14. 3.14 DFS Slave (Channel Switch)
      15. 3.15 Roaming
        1. 3.15.1 Roaming Mechanism
          1. 3.15.1.1 Mechanism Enabling
          2. 3.15.1.2 Roaming Candidates List
          3. 3.15.1.3 A Decision to Roam
          4. 3.15.1.4 Connection to a Better AP
        2. 3.15.2 Roaming Triggers
          1. 3.15.2.1 RSSI Level Delta
          2. 3.15.2.2 APs Disappearing
    5. 4 Single Role: AP
      1. 4.1  Connection
      2. 4.2  Hidden SSID
      3. 4.3  Security
      4. 4.4  Regulatory Domain
      5. 4.5  AP Scan
      6. 4.6  Automatic Channel Selection (ACS)
        1. 4.6.1 40-MHz Operation
        2. 4.6.2 ACS Whitelist and Blacklist Channels
      7. 4.7  Maximum Connected Stations
      8. 4.8  Aging
      9. 4.9  DFS Master
        1. 4.9.1 DFS Standards
        2. 4.9.2 DFS Mechanism
        3. 4.9.3 WiLink8.0 DFS Master Capabilities
      10. 4.10 Access Control
        1. 4.10.1 Blacklist
        2. 4.10.2 Whitelist
      11. 4.11 Extreme Low Power (ELP)
    6. 5 Single Role: P2P
      1. 5.1 P2P Device
        1. 5.1.1 Searching Phase
        2. 5.1.2 Negotiation
        3. 5.1.3 Group Formation
      2. 5.2 PSP Client
      3. 5.3 P2P GO
    7. 6 Single Role: Mesh
      1. 6.1 Supported Modes
        1. 6.1.1 Mesh Point
        2. 6.1.2 Mesh Portal/Gate
        3. 6.1.3 Mesh Access Point
      2. 6.2 Hardware and Software Requirements
        1. 6.2.1 Hardware requirements
        2. 6.2.2 Software Requirements
      3. 6.3 Capabilities
    8. 7 Multi-Role
      1. 7.1 General Overview
      2. 7.2 Limitations
    9. 8 Performance
      1. 8.1 Single-Role
      2. 8.2 Multi-Role
      3. 8.3 AP and mBSSID (Dual AP) Fairness
        1. 8.3.1 AP Fairness: 1-to-10 Stations Throughput Distribution
        2. 8.3.2 mBSSID Fairness: 10 Stations Throughput Distribution
      4. 8.4 Bluetooth WLAN Coexistence
        1. 8.4.1 WLAN Single Role – Bluetooth Performance
  2.   Revision History

2.2.4 A-MPDU and A-MSDU

There are two methods available to perform frame aggregation: aggregate MAC protocol service unit (A-MSDU) and aggregate MAC protocol data unit (A-MPDU). The main distinction between MSDU and MPDU is that the former corresponds to the information that is imported to or exported from the upper part of the MAC sublayer from or to the higher layers, respectively, whereas, the later relates to the information exchanged from or to the PHY by the lower part of the MAC. Aggregate exchange sequences are made possible with a protocol that acknowledges multiple MPDUs with a single block ACK.

A-MSDU: The principle of the A-MSDU (or MSDU aggregation) is to allow multiple MSDUs to be sent to the same receiver concatenated in a single MPDU. This improves the efficiency of the MAC layer, specifically when there are many small MSDUs, such as TCP acknowledgments. The main motivations for aggregation at the MSDU layer are:

  • Ethernet is the native frame format for most clients
  • Because the Ethernet header is much smaller than the 802.11 header, the multiple Ethernet frames can be combined to form a single A-MSDU.

WiLink8.0 supports A-MPDU for both TX and RX and A-MSDU for RX (see Figure 1).

a_mpdu_agg2.gifFigure 1. A-MPDU Aggregation

The decision of using A-MSDU versus A-MPDU is a tradeoff between probability of error and retransmission costs in an A-MSDU, versus MAC frame header overheads in an aggregate with A-MPDU. In most real-world systems, the later wins and most systems implement A-MPDUs.