Cisco Aironet 1600 Deployment Manual page 39

Cisco Aironet Access Point Deployment Guide
Figure 51: AP 3500i/e — 2x3:2 System (Two Transmitters, Three Receivers, Supporting Two Spatial
Streams)
Spatial streams, the act of transmitting information out of more than one antenna port concurrently,
requires that the AP have at least two or more transmitters and support elements of 802.11n (for
example, support of multiple spatial streams).
With 802.11a/b/g, data rates were actual Mbps rates like 2, 11, and 54 Mbps and were done with one
transmitter. The AP 3500 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 the Modulation and Coding Scheme (MCS) index value, and
the value defines how many streams are used. The AP 3500 supported up to 300 Mbps (MCS rate 15)
configured with a bonded channel and short guard interval (GI). (See Figure 52.) The MCS values
correspond to actual data rates.
Note: 2x3:2 means two transmitters, three receivers supporting two spatial streams
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