User`s manual

3.32 What is Modulation Coding Scheme (MCS)?

MCS is Wireless link data rate for 802.11n. The throughput/range performance of

a AP will depend on its implementation of coding schemes. MCS includes

variables such as the number of spatial streams, 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.

3.33 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.

3.34 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.

3.35 What is Mesh protocol?

A wireless mesh network (WMN) is a communications network made up of radio

nodes organized in a mesh topology. A wireless mesh network can be seen as a

special type of wireless ad-hoc network. A wireless mesh network often has a

more planned configuration, and may be deployed to provide dynamic and cost

effective connectivity over a certain geographic area. An ad-hoc network, on the

other hand, is formed ad hoc when wireless devices come within communication

range of each other. It is often assumed that all nodes in a wireless mesh network

are immobile, but this may not be the case.