LoRaWAN is the network's communication protocol and system architecture, while LoRa is the physical radio layer enabling the long-range communication link. The LoRaWAN protocol and network architecture directly influence the battery lifetime of a node, network capacity, quality of service, security, and the variety of applications served by the network.

LoRa is the technology that modulates the data into electromagnetic waves. It uses a transmission method called “Chirp Spread Spectrum,” encoding data in frequency-modulated “chirps.” This transmission method has been used in military and space communication for decades.

In a typical LoRaWAN network, range depends on numerous factors—indoor/outdoor gateways, the messages payload, antenna used, etc. On average, in an urban environment with an outdoor gateway, you can expect up to 2- to 3-km-wide coverage, while in the rural areas, it can reach beyond 5 to 7 km. In some cases, extremely long range is also attainable—ref: 702 km! 

LoRa’s range depends on “radio line-of-sight.” Radio waves in the 400- to 900-MHz range may pass through some obstructions, depending on their composition, but will be absorbed or reflected otherwise. This means the signal can reach as far as the horizon as long as there are no physical barriers to block it. Elevating LoRa devices—placing them on rooftops or mountaintops, for example—will maximise their range. Other factors, such as antenna gain, will also significantly impact range.

One of the unique features of LoRaWAN is its long battery life. To achieve this, devices are generally programmed to go into deep sleep mode when not transmitting messages, maximising battery life. The capacity of its battery still determines the longevity of any node, but going to sleep for extended periods will dramatically extend charge cycles. 

Also, the LoRa signal doesn’t require much power to generate and transmit. That means power consumption is kept at a trickle even when the system is active and transmitting. With a minimal amount of software tinkering, the Strata node from Gumstix idled at 20 mA in “idle” mode and topped out at less than 110 mA during transmission.

The speed at which you can send data over LoRaWAN is extremely low. Don’t expect to send large files such as music, video, or images over this type of network. It’s suitable for tiny sensor data packets that can be used for alarms, triggering, and monitoring purposes. This plays a massive factor in optimising battery life.

Another critical feature of LoRaWAN is its ability to support bidirectional communication. This means that an end device (sensor) can send a message to the network (i.e., sensor data, occupancy, location) and receive messages from the network back to the device. Thanks to this, LoRa devices can be programmed or designed to deliver status indicators to remote locations. 

A good application for this bidirectional long-range capability could be indicating if a bridge has been washed out on a back-country service road or hiking trail at the trailhead so that crews and hikers can plan a new route. A floating switch, or humidity and pressure sensors, would detect if the bridge deck was submerged in water and transmit that data to a cloud service. This service, in turn, would send a trigger signal to the signpost node, which would operate a mechanism to indicate that the bridge is out.

Security has always been an essential aspect of any wireless technology. LoRaWAN utilises two layers of security: one for the network and one for the application. Network security ensures the authenticity of the node in the network, while the application layer of security ensures the network operator doesn’t have access to the end user’s application data. AES encryption is used with the key exchange. 

A bonus is that low-power Chirp Spread Spectrum signals are challenging to detect and intercept.

 For people interested in getting started with LoRaWAN, there’s a global community of over 35,000 people in over 500 cities worldwide using the open free network “The Things Network.” All you need is some end devices, and you can start diving into LoRaWAN in a flash. If you’re in an area with no coverage, you can always set up a base station, thereby providing coverage to yourself and local members of your network. 

Various paid networks can provide dedicated network or application servers offering greater bandwidth, storage, and number of devices; additional privacy, security, and software licensing options.

Yes, that’s it. Not just limited to a few monitoring and alert messages, LoRaWAN, over time, has found applications ranging from smart cities to industrial IoT, manufacturing, and plenty of other verticals. 

The architecture and critical characteristics of the LoRaWAN core technology have expanded into new emerging applications across multiple industries.

A big alliance of companies supports the LoRaWAN standard, called the LoRa Alliance. This support is pretty vital for the future and adaptability across different industries. In a short span of three years, over 500 companies and organisations have become part of the LoRa Alliance.

An exciting feature of LoRaWAN is localisation without the need for GPS. This feature is handy for tracking assets and sensors since it’s very battery-efficient. LoRaWAN sensors can support tracking applications using Differential Time of Arrival techniques to determine the approximate location of the nearest city block. 

This coarse-grained triangulation can be achieved when a device is transmitting to at least three gateways, similar to GPS receivers. With foreknowledge of each gateway’s physical location and by detecting the difference in time between them as the signal arrives, an application can compute the approximate position of the signal’s origin.
Reference IoTHotspots

There are many commercial and development-oriented products, projects, and development options for a wide variety of applications. Commercially available, OTB (out-of-the-box) gateway solutions can be found locally at www.gowifi.co.nz.