At Sigfox, our main objective is to provide our customers with the best network possible. We don't develop or sell end-to-end solutions, but we rely on our ecosystem to deploy them.
Because an IoT project involves many different types of companies and skills, you can get help from specialists on every topic you need to focus on. Take a look at our partners website to find the best partners for you.
While Sigfox is the right technology for numerous 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. The 12 bytes payload (maximum, but flexible) of a Sigfox message is also perfectly suited for the vast majority of IoT use cases we see today, allowing devices to transmit relevant data to the Sigfox Cloud.
However, this technology is optimized for a lightweigh use cases. This means that some projects are not currently meant to use the Sigfox technology, because they require high bandwith and constant connection to the Cloud.
2) Legal limitations
As the current version of Sigfox uses public radio frequencies (aka ISM bands), we have to comply with the sharing rules in place in the different regions of the world 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-using 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, acquistion time and the battery voltage.
The Sigfox network has been designed and optimized to be very cost-effective for our customers. From the hardware you need 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
Because the technology is free for semiconductor companies to implement in their solutions, the cost of modules and all the other radio solutions is low in comparison to competing technologies. Starting at less than 2€ for certified modules, you will be able to create connected devices for a relatively small investment.
Since electrical consumption is very low, battery costs are also lowered compared to other solutions, which impacts greatly the overall material costs.
2) Network costs
The total cost of ownership of your solution also integrates the network subscriptions. Our business model is based on yearly subscriptions paid by customers to connect to our service.
As the the technology itself is very long range, we have optimized our deployment costs by lowering the number of antennas needed to cover entire areas, impacting directly the price of the solution we offer to our customers.
Today, the price of the 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-case deployed with the Sigfox technology. It can be achieved through a number of different methods. Let's look at the 3 most common ones, from the least precise to the most precise:
1) Sigfox Location
The location computation is based on the data from the Sigfox infrastructure, coming 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, but on the signal strength (RSSI - Received Signal Strength Indicator) using a probability model.
While this method is not made to be very precise, 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 2 main advantages:
- No additional hardware is required.
- Battery consumption is not impacted.
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, they are then matched to a Wi-Fi hotspot database in order to position the asset.
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,
- Extra hardware is not required,
- Precision: 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 coordonates 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 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 here on the Partners 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 WiFi for indoor use. It all depends on what you need 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.
In order to help our customers reach their objectives faster, we have created a professional services team called the IoT Agency.
This team is dedicated to assist companies developing their own solutions. They specialize in hardware, radio, project management, web applications etc.
If you wish to hire the IoT Agency experts to develop your projects, please contact us.
Some of the devices developed for other technologies might already be compatibe with our network out of the box, with just a firmware upgrade.
If you’re using one of the compatible chipsets for other purposes today (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.
The compatible chipsets are:
- Texas Instruments: CC1120, CC1125, CC1310, CC1350
- Silicon Labs: EFR32, EZR32
- Semtech: SX1272, SX1276
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.