I would like to know more about the tx x rx : streams notation. As I understand 3x3 : 2, for example, means that 3 antenna are available to transmit/receive at any one time and that 2 different pieces of information can be simultaneously transmitted/received using those 3 antenna.
I'd like to understand more how spatial streams are defined. If there are 3 transmitters and 3 receivers the AP can send three spatial streams but since WiFi is only half duplex, will it send three streams to one device or one stream to three devices ? I believe an iPhone 5 is a single stream device, some laptops support two streams.
For SU MIMO I assume its three streams to ONE device. Not until .ac is out that supports MU MIMO will the device send to three devices.