We often talk about LoRa, or Long Range networks, as they relate to IoT devices. More specifically these days, we focus on LoRaWAN. But do you really understand what LoRaWAN is, and more importantly, why it’s important for the IoT? This overview will help you learn both.
What is LoRa?
As mentioned, LoRa stands for long-range. Think range greater than your typical, modern home wireless network. Here in the U.S., LoRa networks typically use spectrum in the unlicenced 900 MHz band. In a best-case scenario, LoRa signals can extend up to 10 miles in flat, open areas, while reaching up to 3 miles in a city. The LoRa Alliance is comprised of member companies that create, modify, and implement the LoRa standards.
But wait, you say: Can’t cellular networks reach far as well? Absolutely! But LoRa differs in a few ways.
For starters, it uses unlicensed spectrum to carry data. Cellular networks use licensed spectrum, meaning a cellular company has paid to “own” those airwaves. And the cost is often in the billions of dollars range. So to use a cellular network, you’ll have to pay the carrier. You do this today for your connected phone or tablet, for example.
By using unlicensed spectrum, network costs are much lower for both the network provider and the devices on that network. So LoRa offers the long range of a cellular network, but without the cost.
LoRa networks also differ in another important way: They’re meant to carry small bits of data and use very little power. The small amount of data is ideal for IoT devices such as sensors: These typically only send a few bits of data and only when the data has changed.
The network for your smartphone? That’s optimized for lots of data, think video streams, and they use much more power. If your phone battery ever died before the end of a day, that’s part of the reason. Stream videos for a few hours over cellular networks and you’ll see that battery life wither away quickly.
Note that there are cellular network implementations specifically for IoT devices that are used to move small amounts of information using less power. Think Cat-M1, for example, which many carriers offer as a service for IoT devices. Connectivity costs are less expensive than cellular data rates but they can add up over time or with thousands of connected devices.
How does LoRaWAN data get to the internet?
So with LoRa, we have low-cost, long-range networks for IoT devices to send their data. How does that IoT data get to the internet where it’s actually useful? That’s where the cellular model is flipped upside down.
Take the example of Helium’s LoRaWAN network. Individuals set up a Helium hotspot which offers a wide range of coverage for IoT devices compatible with the network. These hotspots are physically connected to a home network, which in turn is connected to an ISP for internet access. Devices and sensors on the Helium network send their data to the closest hotspot over LoRa and the hotspot moves the data to a local network and it goes on to the internet.
By connecting the hotspot to a home network with internet access, the hotspot owner is providing the backhaul for the LoRa network.
Cellular networks use the same principle. Your phone’s 4G or 5G data is wirelessly transmitted to a cellular antenna tower. That tower’s backhaul, or pipe to the internet, is typically wired from the base of the tower. Again though, this is costly: Aside from paying for the airwaves, the carrier has to pay for the tower, devices to convert signals from wireless to wired, and the wired connectivity to the internet. LoRa networks help decentralize and minimize those costs.
Helium is just one LoRaWAN example. There are others such as Loriat, MachineQ, Senet, and The Things Network to name a few. Because these providers use the LoRaWAN standard, they can create broader coverage with roaming agreements. Helium and Senet recently worked out a roaming deal, for example. And these network providers don’t rely on someone’s home internet connection for backhaul.
Instead, like cellular networks, they’ve invested in that backhaul connection, which does add some costs for devices connected to the network. It’s still typically less than what a traditional cellular network costs, however. Mainly because these providers aren’t paying for the actual wireless airwaves.
Other companies have tried to go it alone by not adopting the LoRa standard. France-based Sigfox is probably the best example, having started its LoRa efforts in 2010. As of now, Sigfox is in receivership, which is similar to filing Chapter 11 bankruptcy here in the U.S.
Where does Amazon Sidewalk fit into all of this?
Speaking of going it alone, Amazon’s Sidewalk effort is exactly that: An attempt to provide a broad low-power wide-area network (LPWAN) for pre-certified devices. Amazon is expected to open up Sidewalk for device makers in the future. For now, though, you’re mainly looking at Ring-branded sensors, a few other Amazon devices, and devices from select partners. That’s mainly because Amazon isn’t using the LoRaWAN standard.
The overall approach of Sidewalk is similar to those using the standards though. Sidewalk devices send their little bits of data over 900 MHz spectrum but can also use Bluetooth for this purpose. The bridge for that data to get on the internet is currently specific Amazon Echo devices, which are already connected to consumers’ home networks. And from there, the data goes to the internet over the customer’s ISP connection; consumers pay for and provide the backhaul.
So why is Amazon is essentially trying to build its own implementation instead of using the LoRaWAN standard? The company is thinking long-term. Data from devices won’t cost anything to transfer, unlike most LoRaWAN services today. And that data will be aggregated into AWS, which adds customers to the company’s growing cloud service offerings. Think of it as a type of data lock-in approach made appealing by the no-cost data transfers.
It’s an aggressive strategy but with risk. There won’t be roaming agreements for other LoRa networks. And, in the case of Sidewalk, Amazon is trying to use home networks as backhaul, just like Helium. But there’s a key difference.
When you buy a Helium hotspot, you’re doing so with the intention of providing that internet connection for IoT devices. Amazon is just leveraging the millions of Echo devices it already sold to do the same thing. And some Echo device owners aren’t happy about that. Time will tell if Amazon’s approach works or if it opens up Sidewalk to a more standards-based approach.
Regardless of the network approach, LPWANs provide the type of connectivity IoT devices require and they do so at a much lower cost than most other options. And that’s exactly what we’ll need if the expected billions and billions of connected sensors roll out in the coming years.