While Sigfox is a very good technology for numerous projects, some use cases may not be feasible as of today.
1) Small messages
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 interesting data to the cloud.
However, this technology is optimized for a specific kind of use case, meaning that some projects requiring high bandwith and constant connection are not really adapted for the Sigfox technology today.
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.
In Europe, the ETSI regulation allows devices on this frequency to send messages for 1% of the time per hour. Devices can only send a defined number of message per day to be compliant with the rule, and our commercial contracts were designed to match this limitation.
It is a direct application of the European ETSI regulation :
- There are 3600 secs in one hour
- 1% of 3600 is 36 secs, so a device can emit 36 seconds per hour
- A Sigfox messages takes 6 seconds to be sent (for zone 1 devices)
- So you can send 36/6 = 6 message / hour , so 24x6 = 144 messages a day. ( we keep 4 messages for protocol use)
NB : This rule is just an example of what is done in EMEA region (Europe, Middle east, Africa), depending on location, limitation can be very different.
To get more details on the Sigfox technology, you can download the Technical overview available below.