Low Power Wide Area (LPWA) connectivity has been optimised for the Internet of Things (IoT). Traditionally, the development path of wide area wireless communication technologies has been driven by a seemingly insatiable desire for bandwidth to support an ever more diverse set of applications for consumers and also enterprise users. But machine-type (IoT) communications are different. Often messages need only be relatively small (even just a few bytes to confirm that a battery is sufficiently charged), and for most applications, latency isn’t an issue unless human interaction is required. It is these types of use cases that LPWA technologies were developed to address.
LPWA technologies are first and foremost wide-area connectivity technologies, so that they can support a connectivity experience that is very similar in nature to traditional cellular services, i.e. a long-range connection to a device. But LPWA technologies differ in that they have been optimised to support machine-type communications: small messages, generally sent infrequently, and where low-latency is not a critical requirement.
In wireless networking, everything is a trade-off, and the constraints of LPWA technologies result in two key benefits which are low power consumption (with a battery life of up to 10 years for connected devices) and low cost connectivity hardware (or modules). Between them, these two characteristics mean that LPWA connectivity can be deployed to support IoT solutions that would otherwise not be economically viable. For instance, a battery-powered domestic smoke detector that is ‘out-of-the-box’ connected and sends out a heartbeat message every day to confirm that the battery is sufficiently charged…until, one day, it doesn’t and the homeowner in question is notified.
By the start of the last decade the potential for this group of technologies was clear and the term Low Power Wide Area (LPWA) was coined by Jim Morrish to help characterise and describe the concept. Spin forwards a decade and most industry observers expect LPWA technologies to be the dominant connectivity solution for wide area wireless connected IoT devices by the mid-2020s. Our own forecasts can be found here on our Forecast Highlights page.
All in all the combination of advantages and disadvantages listed above is a good match for a wide range of IoT solutions. Examples include smart metering, infrastructure monitoring, security monitoring, connected manhole covers, connected fire hydrants, connected post boxes, and so on. The list of assets that can usefully be monitored with a low-cost battery-powered device connected to a wide area network is almost limitless.
Significant demand will also be driven by the ability of LPWA solutions to support ‘out of the box’ connectivity for consumer devices. Contrast the user experience of unboxing a new set of bathroom scales, inserting batteries and having them automatically connect to a LPWA network, with a more involved (and error-prone) process of attaching the same scales to a home Wi-Fi network. From a manufacturer perspective, having devices connect directly to a single homogenous network is far preferable, from a customer service and fault resolution perspective, than each device that they ship needing to connect to a customer’s home Wi-Fi network. Whilst the latter approach might seem like the obvious way to connect, say, a domestic solar panel, it results in an extremely fragmented device estate and a very challenging troubleshooting environment.
Other obvious in-home applications for LPWA technologies include things like connected fire alarms (that can, for example, send alerts when batteries are low), and wide area connected versions of Amazon Dash buttons. Again, the potential is almost endless, and there have even been successful trials of direct marketing campaigns including LPWA-connected enquiry buttons and LPWA-connected shipping labels that send a message when a package is opened.
All told, the potential for LPWA is clear as can be seen from our forecasts. For more details on which applications will see the greatest adoption in IoT using LPWA technologies, see our TAM Forecast Database.
There are three main challenges in the LPWA space: development cycles, application flexibility, and commercial risk. We expand on each below.
Developing a new LPWA solution that is battery-powered and has a long battery life takes work. Developing software applications using typical software development tools, and deploying onto generic hardware, tends to result in very ‘chatty’ solutions with a significant amount of signalling and non-solution-critical communications between a remote device and any central servers. Such solutions are likely to drain batteries quickly. To achieve the 10-year battery life promised by LPWA technology it is necessary to invest more in several areas:
The hardware constraints described above also act to further increase the challenge of developing LPWA applications that must be designed to work within the constraints of a pared-down (or bespoke) hardware environment.
The design process outlined above results in a highly optimised solution designed to maximise battery life. But a consequence of forsaking generic end-device hardware and operating systems in pursuit of battery life is that there is less scope to refine and enhance any resulting application after it has been deployed. Constraints will have been designed-in to end-point hardware, and any significant increase in communications between a remote device and core servers will impact battery life.
Even where generic hardware has been used for end devices (for instance when devices are connected to a power supply), the bandwidth that LPWA connectivity technologies can support is limited, which necessarily limits the potential to enhance solutions once deployed.
Selecting a connectivity partner for any IoT deployment will always entail some level of risk. However, simply as a consequence of the size of the operators, LoRaWAN technologies and Sigfox networks are likely to be higher risk options than either of the 3GPP solutions (NB-IoT and LTE-M).
There are, of course, many exceptions to this general rule. For example, Proximus operates a LoRaWAN network in Belgium, and Kyocera operates a Sigfox network in Japan. But this level of scale is nothing compared to the support enjoyed by NB-IoT and LTE-M by mobile operators worldwide.
That’s not to say that selecting either NB-IoT or LTE-M, supported by a mobile operator, is entirely risk-free. Not all mobile operators will be successful in their LPWA endeavours, and those that aren’t may not want to fund the investments necessary to maintain their overall LPWA proposition.
The main LPWA technology contenders are LoRaWAN, 3GPP (cellular) standards NB-IoT and LTE-MTC, and Sigfox. The following sections provide a high-level overview of each. In all cases, development is ongoing to support direct-to-satellite flavours of these technologies.
LoRaWAN is an LPWA networking protocol designed to wirelessly connect battery operated devices to the IoT in campus, regional, national or global networks. Development of the technology is led by the LoRa Alliance. LoRaWAN is an open standard, although Semtech holds the IP for LoRaWAN-supporting chipsets and earns a royalty on each device sale.
The LoRa Alliance includes more than 500 members, including sponsoring members such as Alibaba, Amazon, Cisco, Microsoft, Orange, and Tencent. There are over 160 LoRaWAN public network operators worldwide and numerous Private Networks worldwide, not open to third party monetisation, and including cities and corporate private networks. As of early 2022, LoRaWAN networks connect over 225 million devices worldwide.
While LoRaWAN is ideally suited to private network deployment, the focus of the LoRaWAN ecosystem is shifting to focus more on wide-area connectivity deployment in association with cellular operators and other partners that can support national rollouts. Roaming between public networks is supported (at a technical level, at least, if not always at a commercial level).
In what is likely to be a significant development, in late 2020 Amazon activated the latent networking capabilities in millions of Amazon smart home products in the US to create the Sidewalk network, supported by LoRaWAN which is used to create a mesh network between devices beyond their respective home networks. This mesh of devices will be connected to the internet provided at least one of them is connected to a suitable local area network. Simpler devices may exist only as endpoints on the network. At first all Sidewalk devices will be Amazon products, but third-party manufacturers have also partnered with Amazon and begun to offer devices that will operate on the network. Compatible devices will also be able to continue to operate should their local internet access be interrupted, provided neighbours are still connected (and within LoRaWAN range, which is likely in urban areas). Although high bandwidth applications will experience limited functionality, certain security applications will greatly benefit as alerts can still be pushed to users in the case of local (home) network outages. Effectively, Sidewalk is (almost) a crowd-sourced LPWA network – the only difference between Amazon’s Sidewalk deployment and LoRaWAN public network deployments being some security elements.
The GSMA launched the ‘Mobile IoT Initiative’ in June 2015 to accelerate the commercial availability of LPWA solutions in licensed spectrum. The mobile industry has focused on two complementary licensed 3GPP standards: Long-Term Evolution for Machines (LTE-M) and Narrowband-Internet of Things (NB-IoT). The two technologies are currently deployed in 4G networks and will be homologated into 5G networks as the two components of the massive machine type (mMTC) component of 5G standards. For more discussion of 5G see our dedicated Hot Topics page on 5G IoT.
Of the two technologies, LTE-M has a higher throughput with lower latency, and consequently a higher current draw and lower battery life. LTE-M is also better suited to devices that will not remain stationary. Of the two, it is only NB-IoT that can realistically achieve the 10-year battery lifespan that might be required for certain applications.
Sigfox was founded in 2010, and is headquartered in Labège, near Toulouse, France. The company operates Sigfox networks under its own brand, and also licences the technology to Sigfox Network Operators (SNOs) in individual country territories. The company strategy is to cover individual countries with a single Sigfox network.
Sigfox is the most extreme of the mainstream LPWA providers, having pushed the compromise between available bandwidth for communications and battery life to near the limit. The technology supports extremely limited throughput. An uplink message can have an up to 12-bytes payload, and takes an average of two seconds over the air to reach base stations. Each end-point can broadcast a maximum of 140 messages per day. A downlink message is limited to 8 bytes, and devices can receive up to 4 messages per day.
In many ways, it was Sigfox that created the LPWA space with its vision of billions of ultra-low-cost devices connected worldwide. But vision is nothing without execution and in early 2022 the company filed for bankruptcy protection. Our view is that the Sigfox concept and the currently deployed networks (operated by SNOs) will probably survive, but that's by no means certain at this stage. A restructuring might be just what the company needs to close the gap between vision and execution.
