LoRaWAN way of LoRaWAN are shown in Fig.9

LoRaWAN is a radio transmission protocol capable of forms
a smart grid. The setup network uses a star-of-stars topology, with gateways
serving as transparent bridges that transmit information between sensors and
the central server. Gateways connect to the network through traditional IP
bindings, and sensor devices use single-hop wireless communication to one or
more gateways. The structure is similar to one cellular network, but instead of
having a single interconnected network, LoRa (Long Range Wireless Network)
allows the deployment of more independent networks over the same
infrastructure.

Lora can covers 15-20 kilometers. The compromise for such
a distance is a reduced power and a lower bit rate, about 0.3 to 50 kbps.

A.    Basic
architecture of LoRa system

The elements components of the system structure in “end-to-end”
way of LoRaWAN are shown in Fig.9 and these are:

Fig. 1.   
The architecture of LoRa system

1)   Nodes

 Represents the
elements of the LoRa network that monitors and controls the infrastructure devices
which are usually located at distance, the LV-MaxSonar-EZ sensors in this case.

2)   LoRa
Gateway

This is the device that receives data from network nodes
through the LoRaWAN protocol and then is transferred over the Internet to the
main application server. The connection to the application server may be
Ethernet, GSM data, or any other cable or wireless telecommunications
connection that provides an Internet connection. Base stations are connected to
the network server using standard IP connections. In this way, the data uses a
standard protocol that can be connected to any public or private telecommunications
network. Given the resemblance of a LoRa network with a mobile network, the
LoRa base stations can often be integrated into a cellular base station. In
this way, the unused capacity of the cellular station can be used to transmit
the data to the network server.Network server

The network server manages the
network. The network server acts to remove duplicate packets, recognition
programs, and control the data transmission speed. Given the way it can be
deployed and connected, the complexity of implementing a LoRa network is very
low.

3)   Application
server

From the application server, you can access applications
that retrieve data from network nodes through the gateway and display them to
provide the most relevant information for the client. In addition, LoRa allows
bidirectional communication between nodes and the network server, remote
commands can be sent to the nodes, these commands can be related to node
management (remote software update) and control of elements in a system (change
of green time of traffic lights).

In this paper it was used and the TTGO LoRa32 board that is
an ESP32 based board that has both an OLED and a Lora transceiver, here is
presented the SX1276 transceiver for the 868 MHz band. It has a high
sensitivity over -148dBm, + 20dBm output power, high reliability and long
transmission distance. The onboard Wi-Fi antenna, 0.96 inch blue OLED display,
lithium battery charging circuit, CP2102 interface and USB serial chip, make it
the perfect support for Arduino development environment. Operating voltage is
from 3.3V to 7V. It have support for Sniffer software protocol analysis,
Station, SoftAP, and Wi-Fi Direct modes. Data rates are comprised between: 11
Mbps and 150 Mbps and the transmit power is between 15.5 dBm and 19.5 dBm. This
development board has a receiver sensitivity up to -98 dBm.