Is LoRaWAN the Solution to Cellular IoT Challenges?
Source: Ken Lynch, Iotforall.com, 2022
A decade ago, hopes were high for cellular networks driving the growth of massive IoT. In fact, Cisco and Ericsson each predicted the market for connected devices would reach 50 billion devices by 2020, according to a recent report by Enterprise IoT Insights. But the overall IoT market has grown more slowly than predicted back then, with only 12.4 billion total IoT devices now in circulation more than a year after the timeframe for these predictions ended. However, LPWAN solutions such as LoRaWAN can easily adapt to IoT application needs and will have a greater impact on massive IoT.
Massive IoT is made up of large numbers of low-complexity, low-cost devices connected to networks that support relatively low throughput speeds. This combination of sensor-enabled devices and networks purpose-built for IoT is transforming how businesses operate, how public infrastructure is monitored, and how organizations approach sustainability initiatives. So, it’s easy to see why hopes were high for cellular networks 10 years ago. After all, cellular connectivity was dominant for other types of devices. Operators already had the infrastructure in place, so why wouldn’t it be easy to use it to power massive IoT? It always seemed like the growth of massive IoT was only a few years away. Then a few more. Always just over the horizon.
Cellular IoT Challenges
It turned out IoT deployments at scale needed technologies that didn’t exist when these predictions were made. Among other challenges, there was a mismatch between infrastructure costs, device battery life requirements, and availability. Cellular operators sought to use technologies that weren’t purpose-built for IoT to connect the billions of devices forecasted.
Of the IoT devices currently deployed, 2G and 3G represent the majority of cellular IoT connectivity, with 53.1 percent using one or the other. That’s problematic as carriers are in the process of sunsetting those legacy technologies, with their replacements still struggling to gain traction. This year, carriers like AT&T and T-Mobile are shutting down their 3G networks, and 2G networks have already sunset across most of the world, with pockets of Europe to follow. 47 percent of users weren’t notified of network shutdowns, creating an uncertain path forward.
Cellular Low Power Wide Area Network (LPWAN) technologies have grown in recent years as use case requirements have become clearer, but even in their most dominant regions, challenges continue to lie ahead. Take China, for example. It is the top and fastest growing market for NB-IoT and Cat-M1, with 100 million cellular LPWAN chipsets sold in the region in 2020, according to internal estimates by Sequans. The rest of the world only accounted for 5 million NB-IoT chipsets in their estimation. In China, data plans and investments in infrastructure enabled the technology to proliferate, but, even there, hardware providers are struggling to turn a profit.
Let’s take a look at three cellular IoT challenges and how LoRaWAN may be able to provide the solution.
#1: Costly Connectivity
Infrastructure cost, in particular, has been one of the biggest barriers to large-scale IoT deployments using cellular networks. Cellular requires costly infrastructure to support it, including towers that can cost more than $100,000 to erect, expensive gateways, and extensive labor required for network deployment and ongoing management. Because of the inherent deployment model of cellular networks, operators are unable to build out networks on-demand unlike unlicensed LPWAN solutions such as LoRaWAN, which can easily adapt to IoT application needs. LoRaWAN hardware also has a lower bill of material (BOM) cost, which leads to lower overall infrastructure and solution costs compared to cellular-based solutions.
That’s even before considering functionality differences in critical areas such as end device power consumption and its associated costs in massive deployments. The communication profile of NB-IoT’s most common use cases, such as asset tracking, smart metering, and wearables, results in high power consumption for cellular devices. Supporting more power-hungry devices inevitably leads to battery drain, which is accentuated by NB-IoT’s inherently “chattier” nature.
Once devices are deployed, firmware updates for cellular devices typically deplete significantly more battery life compared to LoRaWAN devices, making LoRaWAN a more viable solution for projects that need to last longer in the field.
According to Semtech, LoRaWAN operates at three to five times less power than NB-IoT overall. Batteries using NB-IoT don’t last as long either, as ABI Research found that LoRaWAN devices’ battery life lasts more than five years longer on average, providing more useful life, depending on the use case. A group of researchers from the University of Bologna, University of Trento, and Integrated Systems Laboratory found that LoRaWAN battery life can be up to 10 times longer than NB-IoT’s in certain applications, according to their experimental data using sensors developed to monitor structural integrity.
#2: Spotty Coverage and Fewer Options
Because of delayed rollouts of NB-IoT and CAT-M1 deployments, cellular IoT solutions have not been deployed at scale. LoRaWAN, however, is rapidly growing because of the flexibility in deployment models and growing interoperability between network operators, which will combine to offer global coverage in the very near future.
There are now more than 160 countries with public LoRaWAN networks, according to the LoRa Alliance, compared to 64 countries with NB-IoT or LTE-M operators, according to the GSA. The lack of networks paired with interoperability issues makes it significantly harder to manage deployments across locations using cellular IoT technologies. On the other hand, LoRaWAN networks are experiencing significant growth. With the integration between various terrestrial networks and satellite connectivity, along with advancements such as the LoRa Alliance’s LR-FHSS transmission data rate, collaborations like the Multimodal IoT Infrastructure Consortium (MMIIC) are providing a path to 100 percent worldwide coverage in 2022.
Further, certified cellular end devices have been slow to market and are being negatively impacted by the sunsetting of 2G and 3G as previously mentioned. Conversely, the LoRa Alliance offers a robust device certification program, providing end users with confidence that sensor-enabled end devices are compliant with the LoRaWAN specification. End device compliance ensures correct behavior on the network, reducing support costs and preventing product failure later when it is more expensive to fix. This type of policy and regulation will go a long way in ensuring the reliability of end devices that are expected to last for decades in the field. Some operators are even giving up on NB-IoT, as NTT DoCoMo and Dish Network both did over the last year as they shifted focus to Cat M1, LTE-M, and 5G respectively. There’s a lot of confusion about which cellular technology will win, and it’s anyone’s guess – even among mobile network operators.