LoRaWAN leading technology in the LPWA space

Last week IoT Solutions World Congress was held in Barcelona, and the booth with the most quantity of IoT devices was the stand with LoRaWAN devices. It's imposing. Let's know why LoRaWAN is so famous for IoT.

IoT Glossary Definition

LoRaWAN is an abbreviation for Long Range Wide Area Network. It's a type of Low Power Wide Area Network (LPWAN) that uses open-source technology and transmits over unlicensed frequency bands. LoRaWAN was designed for the Internet of Things (IoT) technology and provided a far more extended range than Wi-Fi or Bluetooth connections. It works well indoors and is especially valuable for applications in remote areas where cellular networks have poor coverage.

The difference between LoRa and LoRaWAN

It's not uncommon to hear LoRa and LoRaWAN used interchangeably, but they're two different things.

LoRa (Long Range) is an LPWAN protocol that defines the physical layer of a network. It's a proprietary technology owned by Semtech (a chip manufacturer) that uses Chirp Spread Spectrum to convert Radio Frequencies into bits so they can be transported through a network. LoRa is one of the technologies that make LoRaWAN possible, but it's not limited to LoRaWAN, and it's not the same thing.

LoRaWAN (Long Range Wide Area Network) is an upper-layer protocol that defines the network's communication and architecture. More specifically, it's a Medium Access Control (MAC) layer protocol with some Network Layer components. It uses LoRa, explicitly referring to the network and how data transmissions travel through it.

The main characteristics

LoRaWAN has two key characteristics that make the technology particularly suitable for specific IoT markets. 

Firstly, it is an LPWA technology meaning that LoRaWAN-connected devices can be battery-powered with battery lives of potentially several years. Also, LoRaWAN networks have the potential to be deployed as wide-area public networks, much as cellular networks are currently deployed today. 

Secondly, LoRaWAN operates in the licence-exempt spectrum, meaning that an end-user or network provider does not need to procure radio spectrum before deploying a network. These characteristics make for cheap and easy network deployment to provide connectivity for battery-powered sensing or actuating devices that can potentially operate for years with minimal maintenance requirements. The trade-off for this flexibility lies in LoRaWAN's limited data rates, which are much lower than today's cellular technologies but are often perfectly adequate for IoT devices. 

LoRaWAN Classes A, B, & C

LoRaWAN has three classes that operate simultaneously. 

Class A is purely asynchronous, which we call a pure ALOHA system. This means the end nodes don't wait for a particular time to speak to the gateway—they simply transmit whenever they need to and lie dormant until then. If you have a perfectly coordinated system over eight channels, you could fill every time slot with a message. As soon as one node completes its transmission, another starts immediately. Without any communication gaps, the theoretical maximum capacity of a pure aloha network is about 18.4% of this maximum. This capacity is due to collisions. Two nodes will collide if they transmit at the same frequency channel with the same radio settings.

Class B systems work with battery-powered nodes. Every 128 seconds, the gateway transmits a beacon. (See the time slots across the top of the diagram.) All LoRaWAN base stations simultaneously transmit beacon messages at one pulse-per-second (1PPS). Every GPS satellite in orbit transmits a message at the beginning of every second, allowing time to be synchronized worldwide. All Class B nodes are assigned a time slot within the 128-second cycle and are told when to listen. You can, for instance, tell a node to listen to every tenth-time slot, and when this comes up, it allows for a downlink message to be transmitted (see above diagram).

Class C allows nodes to listen constantly and send downlink messages anytime. This system is used primarily for AC-powered applications because it takes a lot of energy to keep a node actively running.

Where to use

LoRaWAN networks have been deployed as wide-area private networks, notably to support applications such as smart metering and public space lighting, including street lighting. Deployment of networks for street lighting, in particular, can unlock new opportunities for smart streets.

Some companies have ambitious plans to deploy LoRaWAN as a wide-area public network technology that is rapidly gaining momentum. In this context, it is worth calling out three companies: Everynet, Helium, and Senet. Recently, Everynet has pursued a strategy to roll out such networks, starting in Brazil and following with the USA and Indonesia. The company's networks cover more than 50% of the population of Brazil and more than 40% of the population of the USA, and Everynet will enhance this baseline coverage according to customer demand. The following priorities include several larger European countries.

Meanwhile, Helium claims to offer the largest LoRaWAN network in the world. Hotspots or access points can be deployed by any individual or business and offer coverage as part of the Helium network in return for payment, enabled and administered using distributed ledger - Blockchain - technology. Currently, the Helium network is comprised of around 850,000 LoRaWAN hotspots. Senet positions itself as a carrier-grade network provider and has a two-way roaming agreement with Helium. Senet itself, in September 2022, announced that it had expanded the build-out of its public LoRaWAN network across all five boroughs of New York City.

Forecast for LoRaWAN applying

According to the forecast, by 2030, there will be 6.9 billion wide-area wireless IoT connections, of which 36% will be traditional cellular technologies, while 4.4 billion will be LPWA technologies.

Utilizing the power of LoRaWAN can solve a mix of connectivity challenges for things such as sensors and metering across industries, including smart cities, fleets, automotive, agriculture and industrial.

LoRaWAN is ideally suited for deployment as a campus area network in agricultural contexts, in support of devices ranging from soil-moisture sensors to temperature sensors in greenhouses and from storage tank level monitoring to enabling remotely controlled irrigation systems. In other enterprise contexts, the technology is well-suited to monitor various assets' location and condition, enabling building automation solutions and many other applications.

One of the key scenarios includes deploying networks to support inventory management and monitoring, including stock level monitoring and warehouse management systems which can reduce the load on warehouse employees, freeing them up for other higher-skilled tasks. 

Significant benefits can be gained from monitoring chillers and refrigerators in retail, hospitality, medical and warehouse contexts. In all these cases, a simple LoRaWAN temperature sensor connected to a private network can provide regular temperature readings and help ensure that refrigeration units are maintaining correct temperatures, reducing spoilage and waste.

Pitfalls

LoRaWAN is fine if you want to build on carrier-owned and operated public networks. Service providers like to compete in this space, so many choices exist. And for simple applications, where you don't have a lot of nodes and don't need a lot of acknowledgement, LoRaWAN works. But if your needs are more complex, you will inevitably hit serious roadblocks. Many LoRaWAN users have not experienced those roadblocks because their networks are still relatively small. Try using LoRaWAN to operate a public network with thousands of users doing different things, and the difficulties will most certainly skyrocket.

Also, developing and deploying a system around LoRaWAN is a complex process. It is an excellent misapprehension to think that LoRaWAN "works out of the box" like some Wi-Fi or cellular modems might. You will want to be sure you understand all the architecture and have a good grasp of how the system works before you decide it's the best route for you.

Alternatives 

Symphony Link is an alternative LoRa protocol stack developed by Link Labs. To address the limitations of LoRaWAN and provide the advanced functionality that most organizations need, we built our software on top of Semtech's chips.

Let's discuss it next time.