Features

The wireless variant of the ConnectCore 8X SOM integrates a Qualcomm Qualcomm QCA6574 wireless chipset with the following features:

  • Dual Band 5GHz 802.11ac or 2.4/5GHz 802.11n Wireless Local Area Network (WLAN)

    • 20/40 MHz at 2.4GHz

    • 20/40/80 MHz at 5GHz

  • Open, Wi-Fi Protected Access (WPA) and Wi-Fi Protected Access 2 (WPA2) (personal and enterprise) authentications as defined in 802.11i

  • Data encryption using Advanced Encryption Standard (AES) or Temporal Key Integrity Protocol (TKIP)

  • Country and regulatory domain configuration as defined in 802.11d

  • Dynamic Frequency Selection (DFS) support on 5GHz networks as defined in 802.11h

  • Station, SoftAP and Wi-Fi Direct (P2P) concurrent modes

  • IBSS/Adhoc mode is not supported, use Wi-Fi Direct instead

  • Bluetooth (BT) 4.2, ANT+, backwards compatible with BT 4.1, 4.0, 3.x, 2.x and 1.0

  • Bluetooth and WLAN coexistence

MAC addresses

Digi programs one Wi-Fi MAC address during manufacturing of the SOM. This is the MAC address used for client and hotspot modes. The Qualcomm Qualcomm QCA6574 chip supports up to three other virtual MAC addresses that are used for other modes like Wi-Fi direct. You must program these virtual MAC adresses before using these modes (otherwise they have default values).

Program virtual MAC addresses

Use the following commands in U-Boot to program the virtual MAC addresses:

=> setenv wlan1addr 00:01:02:03:04:05
=> setenv wlan2addr 00:01:02:03:04:06
=> setenv wlan3addr 00:01:02:03:04:07
=> saveenv

Fast roaming (802.11r)

Roaming in the context of 802.11 wireless networks occurs when a client with an established association to an access point (AP) migrates the connection within the same Extended Service Set (ESS) to another AP within an area of overlapping coverage. The fast roaming (802.11r) standard introduces a fast transition mechanism which performs the handshake with the new access point before the roaming starts, allowing the client and AP to perform the Pairwise Transient Key (PTK) calculation in advance. This allows fast transitions without reauthentication, and reduces handshaking overheads while providing security and quality of service.

The wireless chip on the ConnectCore 8X supports the fast roaming standard. To use it, you need a group of access points that support the 802.11r mechanisms for fast roaming. You also need to configure them as a mobility domain so they can exchange client station details and perform client pre-authentication prior to the roam.

You can customize the transition between the different access points that compound the wireless infrastructure by tweaking the transition threshold values. These threshold values are saved in the configuration file /vendor/firmware/wlan/qcom_cfg.ini. To customize it:

  1. Modify the file vendor/digi/qcacld-2.0/firmware_bin/WCNSS_qcom_cfg.ini located inside the Digi Embedded for Android source code directory.

    • gNeighborLookupThreshold: When the signal of the current Wi-Fi connection is weaker than this dBm value, the wireless chip performs a background scan to see if there are access points with a better signal.

    • gNeighborReassocThreshold: When the signal of the current Wi-Fi connection is weaker than this dBm value and there is another access point with a better signal, the wireless chip connects to that alternate access point.

      The dBm values in the config files are represented without sign. 
      gNeighborLookupThreshold=66
gNeighborReassocThreshold=71

  2. Build new images following the instructions at Build your development images.