router - How to check wifi networking standard of current connection

Both my router and my wireless networking card support the standards 802.11a/b/g/n but as I'm only getting speeds around 30-40 Mbit/s I suspect that it's the g standard being used instead of n. Now, I'd like to verify this somehow, so my question is: Is there a way (like a network diagnistics tool or the like) to find out which standard is currently used in the communication between computer and router?

Answer

On Windows (tested on Win7, should be compatible with Vista back to Windows XP):

C:\Users\kuba>netsh wlan show interfaces

There is 1 interface on the system:

    Name                   : Wireless Network Connection 2
    Description            : DW1520 Wireless-N WLAN Half-Mini Card
    State                  : connected
    Network type           : Infrastructure
    Radio type             : 802.11g         <-- the currently negotiated value
    Authentication         : WPA-Personal
    Cipher                 : CCMP
    Connection mode        : Auto Connect
    Channel                : 11
    Receive rate (Mbps)    : 54
    Transmit rate (Mbps)   : 54
    Signal                 : 82%
    Profile                : xxxx

    Hosted network status  : Not started

On many Linux flavors (including Debian) use iwconfig. Although it doesn't display a string such as "802.11n", it does display Bit Rate:54 Mb/s among other settings.