LoRa is a Semtech technology for IoT
• Provides long range and low power
wireless technology to connect lowcost, battery operated sensors over
long distances (10 miles range and
> 10 years battery life)
• The LoRa Alliance was formed
in February 2015. Release 1.0
of LoRaWAN specification was
released to public on June 16, 2015
• Applications: smart city, sensor
networks, industrial automation
application
Important Factors in LORA network
The most critical factors in a LORA
are:
• Network architecture
• Communication range
• Battery lifetime or low power
• Robustness to interference
• Network capacity (maximum
number of nodes in a network) Network security
• One-way vs. two-way
communication
• Variety of applications served
What is LORAWAN?
LoRaWAN™ defines the
communication protocol and system
architecture for the network while
the LoRa® physical layer enables
the long-range communication
link. The protocol and network
architecture have the most influence
in determining the battery lifetime
of a node, the network capacity, the
quality of service, the security, and
the variety of applications served by
the network.
Network Architecture
Many existing deployed networks
utilise mesh network architecture. In
a mesh network, the individual endnodes forward the information of other
nodes to increase the communication
range and cell size of the network.
While this increases the range, it also
adds complexity, reduces network
capacity, and reduces battery
lifetime as nodes receive and forward information from other nodes that is
likely irrelevant for them. Long range
star architecture makes the most
sense for preserving battery lifetime
when long-range connectivity can be
achieved.
Network Infrastructure:
The LoRaWAN protocol was defined
specifically for LPWAN applications,
keeping security, scalable capacity,
cost, and ease of deployment
in mind. LoRaWAN gateways
enable public and private network
deployments and are designed for
outdoor or indoor use. The gateways
support bidirectional communication
and can simultaneously process
messages from many LoRa-based
sensor nodes. To keep hardware
infrastructure costs low, most
of the processingcomplexity is
shifted up the chain so that network
management functions and any tasks
that require significant processing
power are handled in the server
layer. The gateways typically act as
packet forwarders and send packets
to a network server via a backhaul
connection that may use Ethernet, WiFi, 3G, or 4G/LTE. Due to the low cost
of gateways compared to cellular
base stations, increasing the capacity
of a LoRaWAN network by adding
additional gateways is fairly easy and
cost-effective. Each sensor message
is picked up by all the gateways
within its range and each gateway
can support
between eight to 64 channels, which
allows millions of messages per day
to be processed by a network.
Network Server:
The network server resides in the
Cloud, and it processes packets from
multiple gateways, directing them
to an application server. Thanks to
innovative features in the network
server, many service providers have
been able to create unique IoT
offerings. Companies offer LoRaWAN
network servers with value-added
features ranging from free initial
connections, to verified support for
several gateways, to multiple IoT
platforms that manage sensor nodes
and integration with other backend
services.
Application Server:
The network server sends packets
to the appropriate application
server, which handles the customer
application and presents data that is
relevant. This helps users to monitor
and track assets, cost savings
and operational efficiency gains.
Additionally, the user may set up rules
to take action on specific events or
a combination of events via a webbased application dashboard. There
are highly-integrated application
servers and dashboards available
which make setting up and managing
a LoRaWAN network fast. As most
business owners and end users are
looking for ease of use and reliable
data that they can take action on,
the IoT applications on smartphones
and computers are designed to have
easy configuration with a simple
visual interface. These applications
also offer integration with large Cloud
service providers such as Amazon
Web Services and Microsoft Azure.
Features of LoRa Technology
Low Power:
LoRaWAN was designed
to reduce the power consumption
and extend the battery lifetime of
connected sensors. In the lowest
power mode, it uses an asynchronous
communication method so the nodes
only “wake up” when they have
data to send, and then go back
into power saving “sleep mode”
directly or once the transmission is
acknowledged. LoRaWAN systems
also use intelligent, Adaptive Data
Rate (ADR) algorithms that enable the
nodes to adjust data rates to best suit
the environment. If a node is close to
a gateway, then it will use less power,
less time on air and higher data rates.
Conversely, nodes located at the
furthest possible points would use
higher power and lower data rate.
This is in contrast to cellular-based
technologies that constantly ping the
network to sync and to competing
LPWAN technologies that do not
support ADR and use a constant data
rate regardless of the environment.
LoRaWAN sleep mode currents
are in the nano amp-range while
active receive and transmit currents
are in the low milliamps, enabling
some applications such as smart
meters to last 20 years on a single
battery. LoRaWAN also supports a
“beaconing mode” named Class-B
and a “continuous receive mode”
named Class-C for applications at
the expense of slightly higher power
consumption.
LoRaWAN’s low power feature
extends battery life in sensors and
makes it a good fit for smart building
applications where sensors may
be located in hard-to-reach places,
such as behind walls, in elevator
shafts or in basements. Smart
building applications can prevent
property damage, minimize time
spent manually monitoring premises,
reduce insurance premiums, as
well as improve response times to
problems, such as water leaks or
heating outages.
Robust Long-Range Coverage:
Depending on the environment and
the presence of any obstructions,
LoRaWAN can cover distances up to
30 miles in rural areas and more than
2 miles in dense urban environments
with link budgets ranging from 158
dB to 168 dB. This coverage distance
Wide area networks Technology Trade-offs
can compete with existing cellularbased technologies, and it is enabled
by LoRa’s unique spread-spectrum
modulation scheme. Moreover,
spread-spectrum techniques are
more robust than narrowband
schemes in noisy channel conditions
and better at mitigating interference.
LoRa’s long-range capability, in
addition to its native geolocation, lowcost and low-power characteristics,
makes it ideally suited for a range of
smart city applications. A successful
trial in street lighting showed that
a single LoRaWAN gateway could
cover up to 20,000 streetlights with
the farthest streetlight being 10 miles
away from the gateway. Significant
energy and costsavings can be
gained when cities implement smart
street lighting infrastructure, where
lights are automatically dimmed or
even switched off during low traffic.
This is just one example of a smart
city use case enabled by LoRa’s
long-range capability. LoRaenabled
smart sensors can monitor a variety
of municipal infrastructure, such as
bridges, tollbooths, parking lots,
manhole covers, historic buildings,
trash containers, water reservoirs,
and help to reduce traffic congestion,
lower operational costs, and schedule
preventive or repair maintenance
work.
Low Cost:
LoRaWAN sensors and
gateways (base stations) typically
cost less than competing LPWAN
technologies for a number of reasons.
First, there are no wireless spectrum
license fees because they operate in
unlicensed spectrum, and the LoRa
Alliance ensures that the protocol is
royalty free. Next, LoRaWAN’s longrange star network architecture allows
a mix of in-building and outdoor
gateways and sensors that can be
flexibly deployed to minimize capital
expenditure (CAPEX) and operating
expenditure (OPEX) for network
operators. Finally, the LoRa Alliance
ecosystem allows for competition
on every level in the value chain that
creates more cost-effective solutions
for consumers and business owners.
Abstract
Cellular-based technologies, in
contrast, operate in licensed spectrum
and incur intellectual property (IP)
royalties due to 3GPP heritage. Even
if these technologies are expected
to be deployed on existing LTE base
stations, where the existing hardware supports it, licenses will apply. And,
LTE primarily covers urban areas
using the expensive LTE frequency
spectrum. The required software
upgrades, which would incur an
investment for the cellular operators,
often require hardware upgrades of
the gateways incurring additional cost.
LoRa (Low Range)
LoRaWAN’s cost efficiency makes it
particularly suited for utility companies.
Utility companies were among the
first adopters of LPWAN technology
because their battery-powered
meters are located in underground,
difficult to reach places, and they
were looking for more efficient ways to
monitor energy, water and gas usage.
This required a connectivity solution
with very low power and long-range
capability that is also at a low cost,
which LoRa technology, operating in
an unlicensed industrial, scientific and
medical (ISM) radio frequency band,
could provide.
Geolocation:
LoRaWAN provides
secure geolocation data for outdoor
fixed and mobile assets without using
expensive, power-hungry Global
Positioning System (GPS) on the
sensor nodes. LoRa uses Differential
Time of Arrival and other hybrid
techniques to determine location
without using extra processing
power and without added cost to
the end node.
WHY LoRa IS A GAME CHANGER FOR SMART CITY APPLICATIONS
Location is estimated
by algorithms in the Cloud using a
packet’s time of arrival from a sensor
node to multiple gateways that are
precisely time synchronised.
Technical Benefits
LoRaWAN’s modulation and
bandwidth are also suitable for
connecting fast moving objects, unlike
narrowband solutions that offer limited
mobility support. In use cases where
movement is involved, geolocation
capability becomes necessary to
track assets and optimize operations.
LoRa enables location determination
ranging from 65 to 650+ feet, which
can be further enhanced through
machine learning and Big Data
analytics. If the power consumption
allows for the use of Wi-Fi, BLE,
GPS, then other technologies’ hybrid
end node designs will support use
cases that require enhanced location
accuracy.
Business Benefits
Today, the LoRa geolocation solution
helps improve asset utilisation and
reduce operational expenses by
up to 50% in some cases. Smart
sensors enable logistics companies
to track the location of containers as
well as their condition by monitoring
vibrations, opening/closing of
container doors, and temperature
or humidity.
Conclusion
This helps logistics
companies better manage inventory
levels, optimise land use and improve
efficiency. In agriculture, geolocation
provides valuable input to determine
where to irrigate to achieve an
increased yield. For example, potatoes
grow 20% better when properly
irrigated. Moreover, cattle location and
status information increase operational
efficiencies and drive down mortality
of cows and their calves.
