English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The interest in the use of the HF band in telecommunication has increasedsignificantly in the last decade, mainly due to the development of newstandards for military telecommunications in HF, as well as the expansion ofdigital broadcasting in the HF band. More specifically, these new standardsallow the implementation of links of hundreds or thousands of kilometers at alow cost, which suggests a widespread adoption can occur. In Brazil, this typeof communication can be used in remote regions or regions of difficult access,such as the Amazon rain-forest region. In addition to the evolution oftechnologies concerning the physical layer of the HF telecommunication systems,there has been a great development of techniques that use machine learningalgorithms for audio and image coding. It is believed that all these advanceswill enable the use of the HF band for communication services in places withouttelecommunication infrastructure. This work presents recent applications of HFradio for digital links in Brazil, describing the challenges present for thedevelopment of telecommunication systems in the HF band.

Enlaces de r\'adio de longa dist\^ancia utilizando a banda de HF