Windows Mobile 5 Switching Connections from GPRS to WiFi RRS feed

  • Question

  • Hi,


    I wonder if someone can shed some light on an issue I am seeing.

    • I am connected to WiFi
    • I call a web service web method, this is successful
    • I then move out of WiFi range, WiFi is disconnected
    • I then call the web service web method again
    • The device connects to GPRS, the web method call is successful
    • I then move back into WiFi range
    • The device reconnects to WiFi
    • I then call the web service web method again
    • The device uses the GPRS connection rather than WiFi connection
    • I then wait 21 minutes and 15 seconds and the WiFi and GPRS are still connected
    • I then call the web service web method again and this now uses WiFi rather than GPRS

    My Questions are :-

    1. I am wondering firstly what makes the device use one connection over another?
    2. Why does the device not start using the WiFi straight away when the device is reconnected to WiFi?
    3. Is there a set time after a reconnection that the WiFi connection will be used over the GPRS connection?

    Any further information about how the Windows Mobile 5 OS handles connections would be very useful.


    Thanks for your time and I look forward to your replies.


    Paul Diston

    Wednesday, November 12, 2008 4:54 PM


  • Hi Paul,

    Connection Manager (CM) is a networking component available on Microsoft Pocket PC and Windows Mobile (WM) OS.  CM computes the “best” path for each of the Connection Requests (CRs),  it will choose the connection path that is likely to have the highest bandwidth.  In your case, WiFi typically has higher bandwidth than GPRS plus VPN.


    For more information:




    For why not using WIFI connection when it is reconnected to WIFI, as far as I know, I don't think it has a time to set it. I think it should be there is some caches or CM is computing the best path.


    Best regards,

    Guang-Ming Bian - MSFT

    Friday, November 14, 2008 3:51 AM