I've been doing some reading up on 802.11n now that it's supported and testing with 2 x TP-Link 802.11n cards I'd purchased a while back.
I've also posted some info on the tests I've been doing here: http://www.air-stream.org.au/blog/omega ... -and-cards
Mikrotik Controllable Options
HT Extention Channel - none, above control, below control
User selects a control (primary) channel (frequency) and sets if the bundled(bonded?) channel is above or below the selected channel.
HT AMPDU Priorities
AMPDU allows bursting 802.11 frames up to 64KB and is performed in the hardware. Not quite sure what these settings do yet
HT Guard Interval - any, long
Short GI is 400 nanoseconds vs. the traditional GI of 800 nanoseconds. Short GI reduces the symbol time from 4 microseconds to 3.6 microseconds to improve throughput by 10%.
HT MCS - Currently unchangable
MCS selects, based on RF channel conditions, the best combination of 8 data rates, bonded channels, multiple spatial streams, different guard intervals and modulation types (noting that 802.11 b/g adapts to channel conditions by selecting the highest of 12 possible rates from 1 to 54 Mbps)
Antenna Selection - Not sure if this should be enabled for use with 802.11n Given the Tx/Rx Chain settings?
HT TX/RX Settings - I'm still not entirely sure how the Tx and Rx chain pairing works, but I know that the card I have has 2 antenna sockets although I see only a small increase between having 1 or more selected.
Improvements we might be seeing available in Router OS:
Preamble Mode: long, short, both, greenfield (new)
Greenfield preamble cannot be interpreted by legacy stations. It is shorter than the mixed mode or legacy mode preamble and improves efficiency of the 802.11n networks with no legacy devices.
Would any mikrotik reps care to correct me here or add any further comments?
Pics of my testing