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Ubiquiti Networks airFibe5 User Manual

Getting the most from a versatile platform, Design guide

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D

esign Guide

Getting the Most from a
Versatile Platform

The airFiber AF24 is a versatile platform that can be optimized

for a variety of conditions. The user interface is simple and

intuitive, but there are numerous configuration parameters.

The AF24 is a veritable Swiss Army knife when it comes to

versatility and options to address different needs.

airFiber Configuration Interface

Configuration for Ultimate Speed and
Latency Performance

Typically the best speed and lowest latency will be obtained

with the AF24 configured as a full-duplex system using

Frequency Division Duplexing (FDD). The data streams

generated by the AF24 are simultaneously transferred

across the wireless link. The transmitter and receiver are

running concurrently in time. Because of the trade-off

between bandwidth resources and propagation conditions,

this approach is typically reserved for links in areas where

installations are in clear line-of-sight conditions and free of

reflected energy such as that generated by heavy rain or

intermediate objects. Installations that are subject to Fresnel

reflections or highly scattered environments may experience

some level of degradation at great range.
For Full Duplex mode, the TX and RX Frequencies should be

different.

TX

RX

TX

RX

Slave

Master

Frequenc

y A

Frequenc

y B

Full-Duplex Diagram

Configuration for Highest Possible
Availability and Robustness

Links that are installed in environments that are highly

reflective or subject to considerable scattering due to heavy

rain or foliage loss are typically better suited to half-duplex

configurations. In this case the frequency and bandwidth

resources are shared on a Time Division Duplexing (TDD)

basis, and the system can accept higher levels of propagation

distortion. The trade-offs are reduced throughput and slightly

higher latency.

For Half Duplex mode (default), the TX and RX Frequencies can

be the same or different to suit local interference.

TX

RX

TX

RX

Slave

Master

Frequenc

y A

Frequenc

y A

Half-Duplex Diagram

The AF24 radio system has the ability to manage time and

bandwidth resources, similar to other systems utilizing

different modulation schemes that are scaled according

to the noise, interference, and quality of the propagation

channel. The AF24 system also automatically scales its

modulation based on channel quality but has the ability to be

reconfigured from a time/bandwidth perspective to allow for

best possible performance. In many regards the suitability of

the duplexing scheme needs to be taken into account based

on the ultimate goals of the user. Just as channel conditions

have an effect on the modulation scheme selection, there are

effects on duplexing modes to consider as well.

Design Guide

This manual is related to the following products: