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

3.15.1.2 Roaming Candidates List

When a station is connected and the roaming mechanism is enabled, it starts to scan periodically; this process is called a background scan. The scanning interval is defined during connection, and depends on a customer's needs. The characteristic value is 10 seconds. During each scan instance, the station only scans one channel. The purposes of the scan are to detect APs with SSID, like the currently connected SSID of the AP, and to reveal its RSSI. Once an AP with the same SSID is detected, its channel is scanned during each scan period, in addition to the regular one-by-one channel scan to get the updated RSSI level information. The scan may be active, using probe requests and receiving probe responses, or passive, by listening to AP beacons, depending on driver configuration and other aspects. All channels are scanned according to a regulatory domain configuration.

If the RSSI level of the current connected AP decreases below the defined RSSI level threshold, the station invokes a one-time scan instance on all channels within one scan interval. The purpose is to detect a roaming candidate AP with a higher RSSI level, to avoid a performance degradation and a potential disconnect. Then, it continues the one-by-one channel scanning.