A Thorough Look at How Various Low-Power Wide-Area Technologies Simplify or Complicate IoT Device Makers’ Work
To make devices that meet your customers’ needs, IoT device makers need wireless technologies that meet their needs. This article will reveal how various technologies do or don’t do what they should to make it simple for IoT device makers to meet their customers’ needs.
By Ted Myers, CTO and Co-founder of Ingenu
There is a clear market need for low-power wide-area (LPWA) connectivity. LPWA offers the value proposition of a secure, ubiquitous, battery-efficient, professionally managed, out-of-the-box connectivity to unlock massive value for 10s to 100s of billions of Internet of Things (IoT) devices. These devices require reliable, low-cost connectivity that will not sunset. They are their own unique category of devices and, as we will see, a unique advanced technology is necessary to meet their exceptional demands.
The Low Power Wide Area (LPWA) market has been validated by a number of diverse and significant players. Take a look at the valuation of Sigfox, the number of partners participating in the LoRa ecosystem, and the amount of effort the cellular standards bodies are spending attempting to play catch up so they may someday offer LPWA solutions of their own. Third party analyst firms also agree, with reports from companies such as Machina Research stating total LPWA connected devices will exceed 2B by 2023. Everyone believes the opportunity is there for LPWA, but what technology is best suited to address that opportunity? That is what this paper will answer.
The Importance of the Right Advanced Technology
IoT devices are no different from any other connected devices in the following regard: advancements in technology will allow for uses not possible with previous generations. Just as ever advancing silicon technology has contributed to increasing Wi-Fi speeds by a factor of 7000 since the 1990s, or how advanced silicon technology has evolved the 1990s era brick voice-only cell phone into your full featured iPhone or Android device, technology will also enable the evolution of IoT. But, as we will see, determining the right advanced technology to enable the IoT can often be difficult because the marketing spin on these technologies often does not match reality.
In this document we endorse the argument that all LPWA players firmly believe: there is a gap in the existing technology landscape for addressing IoT. Next, we look at the marketing claims for each of the major LPWA approaches (Sigfox, LoRa, Cellular LPWA, and RPMA) and square them against the reality of the technology they are offering. Then we explore the details of the resultant complexity on the end user for each of the LPWA approaches. ABI is a very reputable analyst firm which has released a report entitled Best Fit Uses Cases for LPWANs — ABI Research that affirms much of this resultant complexity.
Based on this research methodology, we show that Ingenu’s RPMA is the right advanced technology for IoT. RPMA allows for user simplicity as well as extreme value in the offered capability. And, as the ABI report explores, this matters in terms of the applicability of the technology to various verticals.
The Gap: Existing Solutions Fail to Bring the Necessary Simplicity for IoT Devices
Several solutions may, at first, seem poised to address the connectivity needs of the billions of IoT devices. However, deep fundamental limitations of these existing solutions preclude mesh networking, existing cellular (2G, 3G, 4G LTE), or private networks from addressing this space. This is something that all the LPWA players (including the cellular industry) agree upon.
Sometimes to take a major step forward, you have to completely change direction…
The above is the phrase Apple uses to advertise its new Mac Pro, but it is equally applicable to many other significant advancements in technology. It is why we have automobiles instead of faster horses, and why we have light bulbs as opposed to brighter burning candles.
The table below explains the deep fundamental flaws of the following solutions in regards to IoT connectivity, deep enough issues that a completely new direction is needed:
• Mesh had its chance and failed to provide the publicly available wide-area connectivity the IoT needs. The smart meter application seems to be optimally suited for mesh (mandated, powered, smart meter endpoints in every house), but even then, the results are disappointing. For a variety of technical and business reasons, mesh will never scale to connecting a significant number of IoT devices.
• Existing cellular is great for the handset, but complicates the connection of most IoT devices. As a result, it has had minimal success addressing the IoT despite its formidable presence. And as for those devices that cellular has managed to connect, they have recently been orphaned by the sunsetting of the 2G spectrum. The cellular industry aggressively joining in to attempt to create their own LPWA solution is an admission that a new approach is needed and that the current cellular systems (2G, 3G, 4G LTE) do not address the requirements of IoT devices.
• Private networks describe short-range connectivity to a home/enterprise gateway. Technologies such as Zigbee, Wi-Fi, Bluetooth, and in some cases LoRa are the typical wireless connectivity mechanism of private networks. In addition to issues around cost and complexity, security is a critical issue with this type of connectivity. As the recent Mirai attack and the attempted hack of a small Vermont utility show, small private networks lack the economy of scale to withstand the sophisticated security attacks that are constantly emerging.
Sigfox: Repurposed Technology
Since Sigfox was late to get started in their technology development and did not have the capital or team in place to begin an intense technology development, they decided to roll out a system based on an existing technology called Ultra Narrow Band (UNB). What Sigfox did that no other company had done was to market the vision of LPWA connectivity very effectively. That has been rewarded by the market with a high company valuation. That’s a testament to the size and excitement of the LPWA market that a technology that has a relatively small range of applicability (as we will demonstrate) would have such a valuation.
The Marketing Spin
Simplicity is a key message of Sigfox. You see it everywhere in their marketing message and it’s in their tagline: “Driven by simplicity we unlock the power of the IoT and give life to the physical world.” That sounds really good. Who doesn’t appreciate simplicity?
Sigfox argues that “The majority of IoT-connected devices do not send huge data loads: they can function perfectly well using ultra narrow band technology.” They are making a valid distinction between IoT devices and an iPhone, for example, and concluding that UNB “technology” (which has been around so many decades its hard to consider it a technology at all) does a better job than cellular in matching these device’s needs. That distinction has merit, but is cellular the right technology comparison point?
The Technology Reality
Did Steve Jobs spend most of his time praising the technology simplicity of the iPhone, or preaching about the user simplicity the iPhone enabled? Obviously the iPhone represents user simplicity which typically is realized by complicated technology under the hood. The technology that delivers a simple, enhanced user experience is typically not simple at all.
As for the Sigfox framing of cellular technology yielding too much complexity, that argument amounts to a clever straw-man argument against technology. Cellular was never designed to support these IoT devices. I know I can outrun a riding mower, but that shouldn’t be an indictment of all motorized vehicles. It is similarly specious to claim that more complex technology, in general, cannot advance IoT devices just because cellular (the wrong technology fit) cannot. The right comparison is against the technology that actually was meant to address the IoT device. We will go on to show that the right technology is RPMA.
End User Complexity
So what is the result of Sigfox short-circuiting any real technology development? One critical aspect that suffers is security. Security for IoT devices is rightly under increasing scrutiny due in part to the Mirai attack. Sigfox takes a cavalier attitude on the subject in claiming that the devices they target do not require very strong security or that they will figure it out over time. I think most people believe that security for all endpoints is critical because, on aggregate, 10s or 100s of billions of devices represent a large attack space. And as for “figuring it out over time”, that is somewhat like NASA sending astronauts to the moon on Apollo 11, and then turning its attention to solving the problem of how to get them back to Earth, or the ‘return problem.’ RPMA, by contrast, has solved the ‘return problem’.
As seen in the table below, Sigfox ultimately falls short in several metrics that are important to device makers using LPWA wireless connectivity. One of these is battery life. Ironically, Sigfox claims that because their approach is so simple, their battery life is superior. But as the ABI report summarized in the Battery Life entry in the table below, advanced technology actually increases battery life significantly. As illustrated by the table only a small fraction of devices that could benefit from LPWA connectivity are addressable by Sigfox because of the user complexities introduced by the Sigfox solution.
LoRa: Not Enough Technology
Semtech acquired the LoRa technology from Cycleo, a small French startup, for around $5 million. Semtech then put a strong marketing effort around the technology including the creation of the LoRa Alliance to promote other company’s participation in the LoRa ecosystem. A few cellular operators are deploying LoRa as a Wide Area Network.
The Marketing Spin
Unlike Sigfox, Semtech has a new approach through the LoRa waveform that they market as a compelling technology for LPWA. Additionally, Semtech attempts to claim that their standardization activity presents opportunities for competition and collaborative innovation. And with various cellular carriers adding LoRa to their offering, Semtech claims the LoRa technology has significant traction.
The Technology Reality
Though LoRa is well marketed, Semtech wound up commercializing a version of Chirp Spread Spectrum (CSS) that had minimal performance benefit over existing low-technology approaches such as Sigfox’s UNB as detailed in Chirp Spread Spectrum: The Jell-O of Non-Coherent M-ary Modulation. Fundamentally, the LoRa waveform has adequate capacity for a Local Area Network (LAN), but will have challenges supporting a successful Wide Area Network (WAN). Also, there are significant problems around the selectivity of the LoRa waveform that can cause poor interactions between public and private LoRa networks.
Most of the carriers deploying LoRa are not overly concerned about these scalability issues because they tend to be committed to the NB-IoT/LTE-M roadmap.
Says Luc Bretones, VP at Orange,
At the end of the day, I don’t know how many years LoRa will have before a regular network will take over.…With NB-IoT we will learn from the work we did with LoRa.
In other words, most carriers deploying LoRa as a public network are only doing it as a stopgap to remain relevant in the LPWA market, not as a technology that they will remain committed to in the longer term. As for the appeal of standardization, there are certainly many participants in the LoRa Alliance that gravitate to the notion of an open ecosystem. However, with only a single supplier of LoRa silicon (e.g. Semtech), the LoRa Alliance has an appearance of a standards body, but is a closed ecosystem in reality.
End User Complexity
So what is the result of Semtech’s modest investment in technology development? Similar to Sigfox, the various complications noted in the table below mean that only a small fraction of IoT devices may benefit from LoRa connectivity. Also, the lack of commitment from various cellular carriers cast doubt on whether the LoRa system will be supported as the cellular carriers turn their attention to deploying the 3GPP roadmap of NB-IoT/LTE-M.
Cellular LPWA: Very Impressive, but Mismatched Technology
LTE is the latest, state-of-the-art, wireless technology that delivers unparalleled broadband speeds to consumer devices such as a smartphone. It is also the technology that the cellular industry is attempting to leverage to address the IoT opportunity. But cellular technology, and more specifically LTE, was not designed to support IoT devices. As a result, evolving LTE for the IoT results in an imperfect solution and ultimately improper fit for IoT devices. It is akin to taking the latest, most advanced sports car and trying to use that as a basis to build a long haul semi-truck.
The Marketing Spin
The cellular network exists and has been around for years. Cellular technology is very mature. The carriers are stable companies. With a flip of a switch, the existing infrastructure will now be able to service IoT devices everywhere.
The Technology Reality
There are a variety of institutional reasons why the cellular industry is constrained in the value they can offer to IoT devices:
• Technology Constraints have forced LTE to be the predominant path forward due to Intellectual Property Right (IPR) considerations. This means the companies involved will sacrifice user needs to their bottom line. LTE is a scheduled protocol in FDD spectrum which is the right approach for high data rate cellular links, but an unscheduled protocol in TDD spectrum (e.g. RPMA) is the best technology choice for LPWA devices.
• IoT Priority Constraints mean that voice/data constraints lead to sunsetting and loss of priority for IoT devices. IoT devices cannot compete with the revenue generation of voice and data on cellular networks. Therefore, decisions that are required to be made to improve the delivery of high speed data to its customers will always tend to be at the expense of the IoT devices. That is what we are seeing today, for example, with the re-purposing the 2G spectrum for 4G needs which has already orphaned 30 million devices in the US alone.
End User Complexity
The result is that, in regards to LPWA, the cellular operators and vendors are doing what is simple for them as a play against the other LPWA competitors. The end user is not the main consideration, and as a result, is subjected to a significant amount of complexity. As the table below summarizes, cellular LPWA inherits many of the same problems that have kept the IoT devices from every reaching historical projections on existing cellular networks.
RPMA: The Right Advanced Technology
Ingenu (formerly On-Ramp Wireless) began an intensive technology development in 2008 to provide secure, very low-cost, low-power, feature-rich, and robust connectivity before any other LPWA provider. RPMA is the only technology purpose built for IoT devices and designed from the ground up to operate in free spectrum while having immense capacity for the small frequent data transactions that define the IoT space. With RPMA, there was one objective: satisfy our customers. We have an insurmountable eight-year and 400 person-year lead on developing a technology that provides the required simplicity for the IoT market.
The Marketing Spin
For a long time, Ingenu had no marketing spin. Ingenu was too busy developing RPMA and solving our demanding customers’ problems. Obviously, Ingenu does benefit from effectively conveying its message around simplicity. The big difference is that the end-users benefit because RPMA does actually provide unique and compelling value proposition.
The Technology Reality
RPMA had the benefit of early deployment of demanding, yet patient customers. The feedback and lessons learned led to the evolution of the RPMA technology. The initial customer engagements in the utility and oil and gas space drove the maturity of the technology in a way only possible through failing fast in the real world and improving at each iteration. As a result, RPMA was integrated into several families of electric meters both domestically and internationally along with 60 other device partners. Today, the Machine Network™, the public RPMA network, is being built at an extremely rapid rate with 30 US markets currently covered and a total of 100 marketsby end of 2017.
End User Simplicity
As the table below summarizes, RPMA provides the right technology to make it simple for IoT device makers to meet the needs of their customers. RPMA is real technology that brings true simplicity to IoT device makers.
End User Value
Since RPMA is advanced technology designed from the ground up to address IoT devices, there are attributes that allow the RPMA system to offer significantly more value than competing LPWA systems.
One crucial enabling aspect is the capacity of the RPMA network which allows for large data usage at very low connectivity costs. Using real-world conditions and the benchmark of 32-byte messages:
· An RPMA access point can receive 535,117 messages per hour.
· A Sigfox base station can receive 523 messages per hour.
· A LoRa base station can receive 2,645 messages per hour.
Based on this and other enabling aspects of the technology, RPMA is uniquely able to offer an IoT Device Bill of Rights. IoT devices may not be high throughput devices, but we strongly believe that they have certain unalienable rights which RPMA uniquely addresses. No device should not have access to these rights:
IoT Device Bill of Rights
· Two-Way Data. From our experience, one-way systems have almost no commercial value and downlink capacity is quite an important characteristic of an LPWA system.
· Reliable Delivery. If a data transaction cannot be acknowledged, then that transaction wasn’t particularly useful. RPMA performs an acknowledgement of every data transaction.
· Flexible Packet Sizes. We quickly realized that constraining transactions to exclusively small payloads (like 12 bytes) was unappealing to all the customers we were talking with at the time.
· Network Responsiveness. Consider a switch that you would like to actuate at a particular time, it is not okay to wait potentially several hours until the node polls the network to flip this switch.
· Authentication. Sending rogue data is a standard attack that a nefarious agent can use to create tremendous problems in a system. To prevent this requires an industry-standard “digital signature” that only the valid originator of that data can provide.
· Broadcast Capability. 20+ years is a long time to commit to a particular factory-installed firmware image. All customers we have ever talked to require the ability to do firmware downloads which can be particularly challenging for LPWA systems that inherently do not support high data rates. Other examples of the benefit of a broadcast channel include sending simultaneous commands to a large number of streetlights (e.g. turn on) or to utility load shedding devices to simultaneously turn off hundreds of thousands of pool-pumps and hot-water heaters during periods of peak demand.
Comparing Value: Sigfox, LTE-M/NB-IoT, and RPMA
We looked at the data model associated with 30 applications that are currently or soon to be RPMA enabled. The average transaction size was ~60 bytes. [Note that 3GPP models to a 32 byte average which makes their effective results in the table below even less favorable]. We compared against Sigfox and a projection of what LTE-M/NB-IoT pricing may look like based on some market research. Based on our understanding of pricing, the following 3 plans are similarly priced at around $1 per month: Sigfox Platinum, RPMA @ 1 MByte/month, LTE-M/NB-IoT @ 1 MByte per month. The assumptions are as follows:
• Sigfox numbers seem to be ~$1 per month for their highest end platinum plan which is 140 x 12 byte messages per day with only 4 downlink messages.
• LTE-M/NB-IoT is projected to have a similar access fee of $1 per month as LTE M2M plans.
•Based on simulations performed in 3GPP in regards to NB-IoT/LTE-M in regards to packet aggregation, we carried the existing kbyte rounding billing policy of LTE through to NB-IoT/LTE-M as well.
Clearly RPMA offers incredible relative value based on the magnitude of the numbers in the table. Please note the following regarding the numbers in the table above:
• This table compare apples-to-apples, there are 4 columns depending on the type of data. For Sigfox in particular, there is complexity in building an industry standard authentication scheme. There is also a limit in the platinum plan on how many downlinks per day and that number is 4.
• For cellular LPWA, the simulations only have 50% of the uplink traffic acknowledged. It would be hard to imagine how they enforce that other than more complicated pricing which is why we entered “<80” for reliable traffic.
• RPMA has a very simple pricing model that offers a symmetric link that is acknowledged and authenticated at every tier.
• For the large majority of LPWA devices that do not need the large 1 MByte RPMA data plan, cheaper plans are available.
What it Means: Based on Simplicity and Value, RPMA Has Much Broader Applicability than any other LPWA Technology
The ABI report Best Fit Uses Cases for LPWANs — ABI Research starts to get to the specifics of the user experience. The figure below shows the applicability of the various LPWA approaches to four verticals: Transport and Logistics (upper left), Smart Cities (upper right), Smart Buildings (lower left), and Industrial (lower right). The rows are the various user needs that when addressed provide simplicity and value. The darker blue cells mean “meets or exceeds”, medium blue is “use case dependent”, and lightest blue as “no match”. As you can see RPMA (the rightmost column in each vertical) is significantly bluer than the other LPWA approaches. This means that RPMA will be the right LPWA solution for the vast majority of the 10s to 100s of billions of IoT devices.
Want to know more?
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