User's Manual

2.4G Outdoor Router
User Manual
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modulation, and the data rate on each stream. Radios establishing and maintaining a link must
automatically negotiate the optimum MCS based on channel conditions and then continuously adjust
the selection of MCS as conditions change due to interference, motion, fading, and other events.
5.33 What is Frame Aggregation?
Every 802.11 packet, no matter how small, has a fixed amount of overhead associated with it. Frame
Aggregation combines multiple smaller packets together to form one larger packet. The larger packet
can be sent without the overhead of the individual packets. This technique helps improve the efficiency
of the 802.11n radio allowing more end user data to be sent in a given time.
5.34 What is Guard Intervals (GI)?
A GI is a period of time between symbol transmission that allows reflections (from multipath) from the
previous data transmission to settle before transmitting a new symbol. The 802.11n draft specifies two
guard intervals: 400ns (short) and 800ns (long). Support of the 400ns GI is optional for transmit and
receive. The purpose of a guard interval is to introduce immunity to propagation delays, echoes, and
reflections to which digital data is normally very sensitive.