It is expected that by 2020 we will have about 25 billion devices connected to the internet. To give you an idea that it is more than three times the population of earth today. With the concepts of IoT and Industry 4.0, Connected Vehicles, and Smart Cities spreading rapidly, this is most likely to happen. We already have a handful of wireless protocols like BLE, Wi-Fi, Cellular, etc but these technologies are not ideal for IoT sensor nodes since they need to transmit information to long distances without using much power. This lead to the rise of LoRa Technology, which can perform long-range transmissions with low power consumption.
What is LoRa?
The term LoRa stands for Long Range. It is a wireless Radiofrequency technology introduced by a company called Semtech. This LoRa technology can be used to transmit bi-directional information to long distances without consuming much power. This property can be used by remote sensors that have to transmit its data by just operating on a small battery.
Typically Lora can achieve a distance of 15-20km (will talk more on this later) and can work on battery for years. Remember that LoRa, LoRaWAN, and LPWAN are three different terminologies and should not be confused with one another. We will discuss them briefly later in this article.
Understanding LoRa Technology
In any typical IoT solution provided for warehouse management or field monitoring, there will hundreds of Sensor nodes deployed on the field which will monitor the vital parameters and send it to the could for processing. But these sensors should be wireless and should operate on a small battery so that it is portable. Wireless solutions like RF can send data to long distance but requires more power to do so thus cannot be battery operated, while BLE, on the other hand, can work with very little power but cannot send data to long distance. So this is what brings in the need for LoRa.
In LoRa we can achieve high distance communication without using much power, thus overcoming the drawback of Wi-Fi and BLE communication.
But how is it possible?
That is because LoRa comes with its drawbacks. To achieve high distance with Low power LoRa compromises on Bandwidth, it operates on very low bandwidth. The maximum bandwidth for Lora is around 5.5 kbps, this means that you will be able to send only a small amount of data through LoRa. So, you cannot send Audio or Video through this technology, it works great only for transmitting less information like sensor values. The below chart shows where LoRa lies compared with Wi-Fi, Bluetooth, and Cellular devices.
Many people compare LoRa with Wi-Fi or Bluetooth, but these two do not stand anywhere near LoRa. Bluetooth is used to transfer information between two Bluetooth devices and Wi-Fi is used to transfer information between an Access Point (Router) and Station (Mobile). But LoRa technology was primarily not invented to transmit data between two LoRa modules.
LoRaWAN is a protocol specification built on top of the LoRa technology developed by the LoRa Alliance. It uses an unlicensed radio spectrum in the Industrial, Scientific, and Medical (ISM) bands to enable low power, wide area communication between remote sensors and gateways connected to the network. This standards-based approach to building an LPWAN allows for quick set up of public or private IoT networks anywhere using hardware and software that is bi-directionally secure, interoperable, and mobile, provides accurate localization, and works the way you expect. Its protocol stack is shown below
How much distance can be communicated with LoRa?
The Official Information on LoRa claims that it could achieve a distance of 715km line of sight. That is when there is no obstacle between the Node and Gateway. Few people have even practically achieved communication between 212km Ground to Ground and even up to 702km using weather Balloon.
Features of LoRa-
Geo-Location: It enables GPS-free, low power tracking technology.
Low Cost: Reduces costs three ways: infrastructure investment, operating expenses and end-node sensors, A LoRa base station cost a few hundred dollars and set themselves up with a network. It easy to plug into the existing infrastructure and offers a solution to serve battery-operated IoT applications.
Standardization: LoRa Alliance develops global standards and improved global inter-operability speeds adoption and roll-out of LoRaWAN-based networks and IoT applications.
Low Power: Its protocol designed specifically for low power consumption extending battery lifetime up to 20 years.
Long Range: Single base station of LoRa provides deep penetration in dense urban/indoor regions, plus connects rural areas up to 30 miles away.
High Capacity: It supports millions of messages per base station, ideal for public network operators serving many customers.
Secure: Embedded end-to-end AES-128 encryption mechanism.
Low connection cost: LoRa Technology operates in the unlicensed ISM band, which means no or very low spectrum costs (there may be a very low connection fee if using an external service provider).
LoRa Operational Specifications:-
University Institute of Engineering and Technology, Panjab University