> #### New features
* Added support for USB interface between the HOST and the concentrator,
for sx1250 based concentrator only.
* Added support for Listen-Before-Talk for AS923 region, using the additional
sx1261 radio from the Semtech Corecell reference design v3.
* Added support for Spectral Scan with additional sx1261 radio from the Semtech
Corecell reference design v3.
* Added support for SX1303 chip, for further Fine Timestamping support.
* Merged the master-fdd-cn490 branch to bring support for CN490 Full-Duplex
reference design. It is an integration of the releases v1.1.0, v1.1.1, v1.1.2
described below.
> #### Changes
* HAL: Reworked the complete communication layer. A new loragw_com module has
been introduced to handle switching from a USB or a SPI communication interface,
aligned function prototypes for sx125x, sx1250 and sx1261 radios. For USB, a
mode has been added to group SPI write commands request to the STM32 MCU, in
order to optimize latency during time critical configuration phases.
* HAL: Added preliminary support for Fine Timestamping for TDOA localization.
* HAL: Updated AGC firmware to v6: add configurable delay for PA to start, add
Listen-Before-Talk support.
* HAL: Added new API function lgw_demod_setconf() to set global demodulator
settings.
* HAL: Added new API functions for Spectral Scan.
* Packet Forwarder: The type of interface is configurable in the
global_conf.json file: com_type can be "USB" or "SPI".
* Packet Forwarder: Changed the parameters to configure fine timestamping in the
global_conf.json.
* Packet Forwarder: Added sections to configure the spectral scan and
Listen-Before-Talk features.
* Packet Forwarder: Added a new thread for background spectral scan example,
to show how to use the spectral scan API provided by the HAL, without
interfering with the main tasks of the gateway (aka Receive uplinks and transmit
downlinks).
* Packet Forwarder: Added "nhdr" field parsing from "txpk" JSON downlink request
in order to be able to send beacon request from Network Server.
* Packet Forwarder: Added chan_multiSF_All in global_conf.json to choose which
spreading factors to enable for multi-sf demodulators.
* Packet Forwarder: Updated PROTOCOL.md to v1.6.
* Tools: added util_spectral_scan, a standalone spectral scanner utility.
> #### Notes
* This release has been validated on the Semtech Corecell reference design v3
with USB interface.
v1.1.2
> Integrated in ***v2.0.0*** from ***master-fdd-cn490*** branch.
* packet forwarder: updated global_conf.json.sx1255.CN490.full-duplex with RSSI
temperature compensation coefficients, and updated RSSI offset for radio 1.
v1.1.1
> Integrated in ***v2.0.0*** from ***master-fdd-cn490*** branch.
* HAL: Updated SX1302 LNA/PA LUT configuration for Full Duplex CN490 reference
design.
* test_loragw_hal_rx/tx: added --fdd option to enable Full Duplex
* packet forwarder: updated global_conf.json.sx1255.CN490.full-duplex for CN490
reference design.
v1.1.0
> Integrated in ***v2.0.0*** from ***master-fdd-cn490*** branch.
* HAL: Added support for CN490 full duplex reference design.
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