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.