Client station arranged to indicate a maximum number of long training field (LTF) symbol transmit or receive capabilities and methods

A client station comprising:

• a plurality of antennas configured for a multiple input multiple output (MIMO) communication;
• a network interface device which comprises a physical layer (PHY) unit configured to:
• transmit to an access point a first data unit which indicates a maximum number of long training field (LTF) symbols that the first device transmits and receives for the MIMO communication;
• receive, from the second device, a second data unit which comprises a plurality of LTF symbols up to the maximum number of LTF symbols the first device receives indicated by the first data unit;
• perform a channel estimation based on the plurality of LTF symbols of the second data unit up to the maximum number of LTF symbols indicated by the first data unit to recover information in one or more fields of the second data unit;
• determine based on the one or more fields of the second data unit that the first device is to transmit a third data unit;
• and
• generate the third data unit with a plurality of LTF symbols up to the maximum number of LTF symbols the first device transmits indicated by the first data unit and transmitting the third data unit to the second device, the third data unit generated and transmitted based on the determination that the first device is to transmit the third data unit.