IoT has the potential to change the products and services companies offer, and the way organizations operate. Understanding the strategic advantage that IoT can deliver for your business requires a holistic approach.
The Sigfox IoT Agency has guided businesses and organizations of all kinds in their exploration of IoT, and has written a series of articles, starting with "7-Step Process to Explore IoT Potential in Your Organization". A recommended read at this stage!
While Sigfox is the right technology for many projects, some use cases may not be feasible as of today, due to limitations.
1) Message size limitations
The Sigfox protocol is designed to be extremely efficient and allow devices running over our network to have many years of battery life.
Sigfox messages can carry a payload (your own data) of 12 bytes. That's the maximum, but the payload is flexible: you can send any data size between 1 and 12 bytes. You can even send a payload of 0 byte, in case you just need a ping message.
This makes Sigfox perfectly suited for the vast majority of IoT use cases, allowing devices to send relevant data to the Sigfox Cloud.
However, this also means that some projects are not currently meant to use the Sigfox technology, because they require high bandwith and constant connection to the Cloud. The Sigfox technology is optimized for lightweigh use cases.
2) Message frequency limitations
As the current version of Sigfox uses public radio frequencies (aka ISM bands), we have to comply with the sharing rules ("duty cycle") of the different regions of the world. These regulations exist to keep these bands available for everybody.
For instance, in Europe, the ETSI regulation allows devices on these frequencies to send messages for 1% of the time per hour. To be compliant with the regulations in place, Sigfox devices can only send a defined number of messages per day. Our commercial contracts are designed to match this limitation.
The number of messages per day allowed on the Sigfox network is a direct application of the European ETSI regulation:
- There are 3,600 seconds in one hour.
- 1% of 3,600 is 36 seconds, so a device can emit for 36 seconds per hour.
- A Sigfox message takes 6 seconds to send (for RC1 devices).
- Therefore, a device can send a maximum of 6 messages per hour (36/6), which allows a total of 144 messages per day (24 * 6). Sigfox keeps 4 messages for protocol use, which allows for 140 messages per day for your device.
NB: This calculation is just an example of what is done in the EMEA region (Europe, the Middle East, and Africa). Depending on your device's location, limitations can be very different.
To get more details on the Sigfox technology, you can download the Technical Overview available below.
Sigfox messages are small and optimized for sensors, as they require only a small amount of power.
The Sigfox payload is limited to 12 bytes (excluding the payload headers). Although this might seem to be a very restricted payload size, there's actually a lot that can be done with 12 bytes.
The example below shows how you could structure 12 bytes to send a set of GPS coordinates along with speed, acquisition time and the battery voltage.
When considering a technology for your device, it is crucial to understand how much it will cost you, in all its aspects.
The Sigfox network is designed and optimized to be very cost-effective. From the hardware to create a device, to the cost of network deployment, all the details have been cautiously taken care of to offer the most optimal IoT solution on the market.
1) Hardware costs
We made our technology free for semiconductor companies to implement in their solutions. Thanks to this, the cost of modules and other radio solutions is low in comparison to competing technologies. Starting at less than 2€ for certified modules, you can create connected devices for a relatively small investment.
Since electrical consumption is very low, battery costs are also lowered compared to other technologies, further decreasing the overall hardware costs.
2) Network costs
The total cost of ownership (TCO) of your solution must take into account the network subscriptions. Sigfox's business model is based on yearly subscriptions paid by customers to connect to our service.
As the technology itself is very long range, we have optimized our deployment costs by lowering the number of antennas needed to cover entire areas, thus lowering the price of the solution we offer to our customers.
The current cost of Sigfox connectivity depends on two major factors: the number of messages you need to send every day, and the number of devices you want to connect.
When calculating your project's schedule and costs, do not forget to include the need to have a local conformity mark (CE, FCC, ARIB, etc.), and the need to pass a Sigfox Certification (either Sigfox Verified or Sigfox Ready).
Geolocation is one of the most interesting use-cases seen with connected devices. If you're thinking of producing a device that makes use of geolocation, you must consider how it is achieved.
There are a number of technologies that can help your device send coordinates. Each has upsides and downsides: cost, power needs, accuracy, etc.
Let's look at the 3 most common ones, from the least accurate to the most accurate:
1) Sigfox Location
The location computation is based on the data obtained from the Sigfox infrastructure. This data comes from several replicas of the same messages sent by a device and received by different base stations.
The method used is not based on flight time or signal Doppler shift. Instead, Sigfox relies on the signal strength (RSSI - Received Signal Strength Indicator) using a probability model.
While this method is not made to be very accurate, it can ensure a quality of service between 1 & 10 km precision, which fits most tracking use cases, such as the arrival of a package in a city or airport.
Relying on regular Sigfox messages to be calculated, this solution has two main advantages:
- No additional hardware required.
- Battery consumption is not affected.
Sigfox-based location is perfect for high volume solutions which don't need extra precision, and where battery life is key. Here is a guide on how to create a geolocation callback on our backend platform.
2) Wi-Fi positionning
Another common method to find the position of a device is through listening to Wi-Fi networks around it. Through Sigfox, these networks are then matched to a Wi-Fi hotspot database in order to position the device.
How does it work?
- The device (equipped with Wi-Fi hardware) "listens" to the different networks around it and recognizes the two strongest ones.
- The device sends the BSSIDs of those Wi-Fi networks through the Sigfox network. A Wi-Fi BSSID is 6 bytes, so 2 BSSIDs are perfect for a Sigfox message.
- Once received on your platform, the BSSIDs are sent to a Wi-Fi hotspot database for matching.
- The hotspot database server answers with an approximate position (25 to 50 meters).
This method has numerous advantages:
- Works indoor,
- Energy consumption is average,
- No additional hardware required.
- Accuracy: 25 to 50 meters.
It also some disadvantages:
- Wi-Fi hardware is required,
- Only works if Wi-Fi networks are available,
- Access to the Wi-Fi hotspots database is rarely free.
You can see a quick implementation example here on Github.
3) GPS positionning
The most common way of obtaining geolocation is through the GPS method. By adding a GPS module to your hardware, you will know the position of your assets very easily.
How does it work?
- The GPS module listens to the satellites in sight.
- Once done, the coordinates are sent through the Sigfox network. A GPS coordinate is usually stored on 6 bytes, so you can send 2 GPS positions within a single Sigfox message.
- The data is then transmitted to your own server and can then be located on a map.
GPS has multiple advantages:
- Highly precise (up to 15 meters).
- Widely used.
- Works almost everywhere on the planet.
It has also its disadvantages:
- High battery consumption.
- Not very efficient indoor.
- Expensive hardware.
You can find an example tutorial of Sigfox + GPS here.
You can see all the tracking solutions already available on the Sigfox Partner Network.
What is the best method for my project?
Because it involves modules, the most fitting method depends on the use-case you're targeting. While the Sigfox network geolocation might be better for some use-cases needing high battery life, some will prefer the GPS method for its precision, or even Wi-Fi for indoor use. It all depends on what your device needs to achieve.
A good solution is sometimes a mix of some of them, and that is why module manufacturers are making available hardware that includes the three technologies on board.
Some of the devices developed for other technologies might already be compatible with our network out of the box, with just a firmware upgrade.
If your device uses one of the compatible chipsets for other purposes (private network, proprietary protocols, etc.), it could be possible to reuse the same hardware and be Sigfox-compatible by adding the Sigfox library and upgrading the firmware.
As the Sigfox network is quite specific, some limitations exist, meaning that not all devices will work out of the box.
In order to be also compatible with Sigfox, your product's PCB and hardware designs must follow certain rules, which might not have been applied in the development of current products.
Your product can be easily made compatible with Sigfox if:
- It uses a compatible chipset, or RF integrated circuit. See below for a list.
- It has 5 to 10 KB of available flash memory space in its MCU, to receive the Sigfox stack.
To assert your product's compatibility, you need to apply to our compatibility program and schedule a 1-hour qualification call with one of our Sigfox experts.
The compatible chipsets are:
- Texas Instruments: CC1120, CC1125, CC1310, CC1350
- Silicon Labs: EFR, EZR, SI446X
- Semtech: SX1272, SX1276
- OnSemi: AX8052
- STMicro: Spirit 2 SPII
- Microchip: ATA8520E
- NXP: OL2385
- M2COM: M2C8001
Other chipsets might be compatible with Sigfox. Contact our team for an assessment.
If our team validates compatibility, you will need to go through a compatibility call with our certification team to certify the use-case.
If you would like to know whether your device is already compatible with the Sigfox technology, you can contact us.
Finding a unique name for your own device is a proud moment. We want to make sure that your chosen name doesn't clash with Sigfox's naming rules.
The main rule is simple: partner products names must not refer to any term that could lead to a confusion with “Sigfox” in any way.
Likewise, do not use the Sigfox name or its butterfly logo in your product (casing, manual, box, etc.). If your product has received a Sigfox certification, you can use the "Sigfox Certified" logo for modules, or the "Sigfox Ready" logo for devices. See the branding guidelines.