Is mioty the next leap in LPWAN technology?

As an IoT expert with a rich background in embedded development, I’ve witnessed the evolution of communication technologies that power our interconnected world. Today, I’m discovering mioty – a promising entrant in the Low Power Wide Area Network (LPWAN) arena. Let’s dive into what makes mioty stand out, how it stacks up against LoRaWAN, and other LPWAN technologies and the scenarios where it can truly shine.

What is mioty?

Mioty is a software based LPWAN protocol designed to tackle the challenges of today’s wireless connectivity. Its design is driven by the mioty Alliance , which is backed by companies like Diehl Metering, Fraunhofer, Texas Instruments, LORIOT, ST Microelectronics, Olympus and more.

The alliance site explains that mioty is built for massive industrial and commercial IoT deployments, offering best-in-class reliability and scalability .

If you are familiar with LoRaWAN, you’ll see a certain resemblance: their architectures consist in low power devices connecting through distant gateways (or base stations), themselves managed by a Network server (or Service Center) which exposes devices and their data securely to applications through an Application Server (or Application Center).

And if you come to think about it, other LPWAN technologies like NB-IoT or LTE-M do propose similar architectures as well. The difference lies in the modulation of the signal between the device and the Gateway or Base Station. There are different types of modulation each designed to address different scenarios.

So many LPWAN technologies… but why?

There are indeed many different LPWAN technologies out there: NB-IoT, LTE-M, Sigfox, LoRaWAN, and mioty (to name only the major ones relevant to IoT scenarios), and it is legitimate to question why there are so many. Why no narrowing it down to just one or two?

To better understand how mioty fits in the LPWAN landscape, it is important to look closer into the broader wireless connectivity ecosystem, and it’ll take a little more than a couple of paragraphs for that, but please, bear with me.

The reason for so many different LPWAN technologies all comes down to the different use cases. Each of these technologies rely on different methods favoring or focusing on different aspects of communication: bandwidth, data rate, range, power consumption. It’s all a question of compromising between these aspects.

Licensed vs. license-free spectrums

While doing my research, I came across different interesting articles explaining the different types of modulation methods used in LPWAN technologies which basically fall under two groups based on their operating spectrum: licensed vs. license-free:

• NB-IoT and LTE-M are derived from 3GPP cellular standards and operate on licensed spectrum.
• LoRaWAN, Sigfox and mioty operate on license-free spectrum but use different modulation technologies (Spread Spectrum, Ultra-Narrowband, and Telegram Splitting respectively), making them vary significantly in terms of network performance criteria. I cover these differences in more details later in the article.

The above diagram maps out all the main wireless technologies used in IoT solutions based on their range and their data rate and power consumption and that gives a general idea of where each stand regarding these criteria, but there is more to wireless than range, data rate and power consumption. Other dimensions need to be considered when picking the best connectivity for a specific use case, like infrastructure requirements, scale and capacity, security, interference resiliency or mobility.

Infrastructure, scale, security

NB-IoT and LTE-M are cellular technologies operating on licensed spectrum and leverage networks that provide more reliable and secure service through established mobile operators and existing broadly deployed infrastructures. This means you don’t have to deploy your own infrastructure to connect your devices, and you can benefit from scalable ones that operators have already deployed and are maintaining worldwide. But operators will not let you in for free, so you need to account for the cost of getting onto these established networks. There are some options to deploy your own private 5G infrastructure, but that means you will need to account for the initial cost of this private infrastructure, as well as the costs for maintenance.

With LoRaWAN and mioty, you can use existing public networks, but there are few of them deployed to date and you will find it hard to get decent pre-existing coverage, which means you will most likely have to deploy and operate your own infrastructure of gateways or base stations.

When it comes to the scale, the number of IoT devices that can be connected to a single gateway (or base station) will vary a lot for both licensed spectrum technologies (depending on a multitude of factors, some controlled by the operators themselves and others inherent to the environment such as the density of base stations deployments or the number of cellular devices) as well as for license-free spectrum technologies (depending on the density of the gateway deployment and of physical obstacles like buildings). It’s also hard to compare the 2 directly, so here are some numbers that can give you an idea of what to expect with each of these technologies:

• NB-IoT and LTE-M depend on the 5G connection density requirement of 1 million connections per 1 km2, which includes all other 5G cellular devices around such as smartphones, and other sim-equipped mobile devices.
• An 8-channel LoRaWAN gateway supporting 1.5 million packets per day could potentially handle over 62,000 nodes if each node sends 1 packet per hour (lowest sensitivity mode, SF7).
• A single channel mioty base station can handle over 1 million devices with a capacity of 3.5 million messages per day (full sensitivity for all messages).
• A Sigfox base station can process up to 70,000 frames (or messages) per day. That’s the only number I could find which is understandable considering the specific architecture of the technology.

From the security perspective, cellular options use 256-bit 3GPP encryption, which is more robust than the AES 128-bit encryption commonly used by license-free spectrum technologies. Additionally, while LoRaWAN, SigFox and mioty do use device authentication like Cellular technologies, their open nature, lack of centralized control and less secure device onboarding make them more vulnerable.

Range, Interference Resiliency, and Penetration

When picking wireless communication technology, you need to know how far from a gateway or base station your devices can be and the type of antennas and amplification you’ll need to put on your hardware. Like any wireless signal, LPWAN ones will each be more or less susceptible to interferences, capable of penetrating physical obstacles and resilient to signal degradation over long distances.

Cellular networks are designed to handle interference effectively, considering they operate in licensed bands which are regulated. On the other hand, license-free bands are exposed to interference from other devices, affecting overall reliability. Furthermore, some of the modulation methods like the Spread Spectrum are more prone to collision and require compromising on on-air time, or energy consumption to make sure not too many packets get lost due to interferences. I will discuss the specifics of the different modulations used in the license-free spectrum.

When it comes to penetration, cellular technologies will penetrate buildings and obstacles better due to higher transmit power and optimized modulation schemes while technologies operating on license-free spectrum may struggle in dense urban environments.

Interference and penetration capabilities are not the only factors determining the range capacity of a wireless technology as the use cases and infrastructures differ vastly between licensed and license-free spectrums. For example, if you want to rely on existing 5G infrastructures from operators, you will consider coverage rather than range: it will be more a matter of “Will I have coverage where my devices will be, rather than how far from my gateway can my devices be, or how dense should my gateway/base stations deployment be?”.

If you want to deploy your own 5G infrastructure, then the below numbers might make some sense to compare:

• NB-IoT and LTE-M will support a range of approximately 1km in urban areas and up to 10km in rural areas (with no physical obstacles like buildings)
• LoRaWAN offers a range of about 3km in denser urban areas and up to 10km in rural areas.
• Mioty averages 5km in urban environments, while it gives you up to 15km in rural areas.

Data Rate and Mobility

Comparing data rates is easier: NB-IoT and LTE-M provide higher data rates (up to 1 Mbps for LTE-M), suitable for firmware updates, voice, and richer data. While license-free technologies have lower data rates (typically in the range of 0.3-50 Kbps), suitable for sensor data, alarms, and basic telemetry.

Finally, IoT devices are often mobile, whether on an asset you are tracking within a building or travelling across continents, or on a motorized vehicle moving around your mine, excavation site, farm, or even embedded on a bullet train. Once again, not all LPWAN technologies are equal and as a matter of fact we do have differences within the 2 main groups (licensed and license-free spectrum technologies).

• In the licensed spectrum group, NB-IoT happens to be pretty bad in mobile scenarios, not handling handovers between cells very well, and that’s even one of the main reasons for LTE-M existence which has been designed with mobility in mind.
• In the licensed-free spectrum group, LoRaWAN and Sigfox are not suited for highly mobile devices due to longer connection setup times. Mioty on the other hand happens to be a champion for mobile scenarios (more details on this below).

In summary, licensed spectrum LPWAN technologies offer robustness, higher data rates, and seamless mobility, while license-free spectrum LPWAN technologies provide long-range coverage, energy efficiency, and cost-effectiveness. The choice depends on specific use cases, deployment scale, and security requirements.

In a nutshell, if you need to connect many battery powered devices, spread across large areas where cellular coverage is not optimal and you don’t need to send a lot of data, then license-free spectrum are what you are looking for.

Now, if you are looking into the latter as your option, you will need to look at the differences between the options available, of which the most common are LoRaWAN, SigFox and mioty. And the differences mostly lie in the modulation technologies used in each of these options.

Different modulation technologies used in the license-free spectrum

I will not dive too deep into the details of the differences between these modulation technologies because smarter people than me have done it way better than I could ever (and I really recommend reading this short article , it is the right level of details if you are new to the domain), but here is an attempt at summarizing and simplifying my understanding.

To start with, you need to know that there are different ways of handling signals modulation when doing low bandwidth communication, the main objective being to minimize energy consumption while sending a small amount of data to longer distances. The ones we are interested in (because that’s what the IoT narrowband technologies are using) are methods called Spread Spectrum, Ultra-Narrowband and Telegram Splitting.

Spread Spectrum

LoRa, the modulation used by the LoRaWAN protocol, is based on Semtech’s proprietary variant of Spread Spectrum called Chirp Spread Spectrum method. If you want to learn more, I recommend this article and this video .

Spread Spectrum involves spreading a narrowband signal across a wider bandwidth, effectively transforming it into a noise-like signal that is difficult to detect and intercept. Basically, data is transmitted in the form of Chirp that are sinusoidal waveforms whose frequency either increases or decreases linearly over time.

Pros:

• Long range (up to 30km in flat unobstructed areas)
• Low power consumption
• Low-cost hardware

Cons:

• Limited data rate
• Bounded jitter and latency = unsuitable for real-time applications with strict timing requirements
• Downlink capacity constraints
• Operates in different frequency bands across regions
• Long on-air time making it susceptible to collisions in crowded spectrums
• Low spectrum efficiency
• Poor co-existence behavior with message overlays in real-world installations where all gateways and devices share the same channels

Ultra-Narrowband (UNB)

It’s the method used by Sigfox and consists in transmitting signals over an extremely narrow bandwidth: small message (up to 12 bytes) at a low data rate.

Pros:

• Minimizes noise levels while maintaining high spectrum efficiency.
• Low power
• Low-cost hardware

Cons:

• Slow data rate = Longer on-air time (up to 2 sec on-air for 12-byte), making it susceptible to collisions in crowded spectrums
• To enhance QoS, UNB networks may employ redundancy by transmitting the same message multiple times, further increasing power consumption per transmission.
• European and US regulations limiting packet size and transmission frequency and necessitating network designs with trade-offs between range and coverage.
• Limited mobility support

Telegram Splitting

That’s the one implemented in mioty and it consists in dividing a signal into small sub-packets transmitted at varied times and frequencies. An algorithm in the base station permanently scans the spectrum for mioty sub-packets and reassembles them into a complete message. Due to sophisticated Forward Error Correction (FEC), the receiver only needs 50% of the radio bursts in order to completely reconstruct the information. This reduces the impact of corrupted or lost bursts due to collisions and increases the resistance to interference.

Pros:

• Long range
• Low-power consumption
• Supports millions of uplink messages per day per base station and each base station can handle 100’s thousands of connections
• Minimal on-air time resulting in ultra-low power usage and minimal collision risk
• Robustness against interference
• Support mobile nodes moving at high speeds
• Low infrastructure cost

Cons:

• Limited data range
• Most recent technology in the fray
• Operates in different frequency bands across regions
• Low bandwidth limits scenarios like OTA updates
• Software based protocol which can be complex to integrate

… So, which one is best for me?

The above details are… a lot of details!

I believe that each of the LPWAN options mentioned above do have legitimate reasons to exist as they each address, or rather focus, on specific aspects of radio transmissions. Depending on your specific use case, one of the options will be a better fit than the others.

The mioty Alliance published a graphic that focuses on the different implementations of these modulation methods putting next to each other NB-IoT, LoRa, Sigfox and mioty and how they compare in terms of capabilities:

Mioty & LoRaWAN in the same sandbox of the LPWAN playground, but mioty might have an edge

Mioty is a new player in the LPWAN arena and as for the others, it has been developed to fill in the gaps that exist between the available technologies, sometime overlapping with several of them. As we have seen above, mioty’s closest sibling is LoRaWAN and the 2 will be compared at length, but there is something to say about how mioty is also stepping on the NB-IoT and LTE-M turfs.

There are some scenarios where LoRaWAN is falling short compared to NB-IoT or LTE-M, but where mioty is closing the gap.

Interference and range: LoRaWAN has low resistance against interference which can cause high packet error rates and loss of data in noisy environments like urban areas. Remember, LoRaWAN and mioty both operate on unlicensed spectrum, meaning, there are interferences with other technologies. Thanks to its telegram-splitting technique, mioty offers superior performance in such noisy environments, and maintains effective communication over long distances. Detailed information about the differences between mioty and LoRa can be found in this study by TU Ilmenau.

Latency and on-air time: mioty offers better latency and lower on-air time. It is certainly the most robust connectivity solution on the market for scenarios requiring very low bandwidth.

Mobility: Some IoT devices are mobile, installed on vehicles or moving machines, and this has an impact on communications. LTE-M was developed to cope with NB-IoT Mobility limitations. As soon as you have a moving system, NB-IoT is no longer recommended. LoRaWAN can also struggle if used on fast moving vehicles, while mioty will maintain communication at speeds exceeding 120 km/h. Think trains or trucks. This allows mioty to compete better with LTE-M in mobility scenarios such as asset tracking.

Energy Efficiency: With extended battery life, mioty devices can last longer than those using LoRaWAN, with the same battery capacity, and both LoRaWAN and mioty do much better by nature than NB-IoT and LTE-M. With a power consumption of 17.8 μWh (end-point, 868 MHz) per message, mioty makes battery life of 20+ years a reality

Scalability and Capacity: thanks to the Telegram Splitting Multiple Access method, mioty can handle a high number of messages with low power consumption. It’s capable of supporting over 1 million devices on a single network and managing 44,000 packets per minute.

Standard : mioty is the only LPWAN technology fully compliant with a non-proprietary industry standard: ETSI TS 103 357 .

Where will mioty shine?

The objective of mioty is to fill in the gaps existing in other LPWAN technologies to better address what the mioty Alliance calls massive IoT. They do list many industries and verticals where the technology can be used and point to resources explaining how. You will find the usual Industrial IOT, Smart City, Smart buildings, Logistics, Agriculture, Mobility, Health and Consumer listed. My perspective is that mioty is definitively a great candidate to address scenarios with massive deployments of low-power simple devices sending little data and requiring a high level of data integrity and low latencies, such as Smart Metering and Process Monitoring. In addition to these scenarios, the mobile capabilities of mioty make it the ideal solution for Asset Tracking when trains or cars and trucks are involved.

Experiencing mioty for the first time

Mioty is a software-based protocol, meaning you don’t need a proprietary chip for testing it. I followed instructions on the mioty alliance site and was able to put together my own mioty base station with a Raspberry Pi and a generic USB SDR (Software Defined Radio) receiver. The instructions point to an open-source project by Loriot called miotyGO that makes it super simple to create your own base station. For the sensor device, I used a Raspberry Pi Pico with an RF transmitter and a BME sensor which was a great opportunity to remove the dust from my soldering iron ??

Here the video of my experiment:

Conclusion

Mioty represents a significant advancement in LPWAN technology, addressing the limitations of existing solutions with its innovative approach to data transmission. For developers and technical decision-makers in the IoT space, understanding the capabilities and applications of mioty is crucial for future-proofing our connected ecosystems.