Installation guide

Spatial streams, the act of transmitting information out of more than one antenna port concurrently, require
that the AP have at least two or more transmitters and support elements of 802.11n, for example, support of
multiple spatial streams. In the 802.11a/b/g days data rates were actual Mbps rates such as 2, 11, 54 Mbps
etc., and was done with one transmitter.
The AP 3500 series has two transmitters per band so it supports 802.11n data rates up to 300 Mbps using two
spatial streams.
With 802.11n the different rates are called Modulation and Coding Scheme (MCS) index value. The value
also defines how many streams are used. The AP 3500 supports up to 300 Mbps (MCS rate 15 configured
with a bonded channel and short guard interval (GI). See Figure 30. The MCS values correspond to actual
data rates.
Figure 29  AP 3500i/e is a 2x3:2 system (supports up to 2 transmit chains)
Note: 2x3:2 means two transmitters, three receivers supporting 2 spatial streams.
Figure 30  Modulation and Coding Scheme: 2SS Bonded Channel Supports up to 300 Mbps