SigFox Transmission technology. UNB Principles and performances

Why UNB technology?

The Internet of Things (IoT) is a recent development in communications systems. The aim is to connect physical devices, vehicles, buildings and even animals to the Internet without direct human intervention to control them. This means extending the connectivity already present in computers and telephones to virtually any object, by equipping it with a chip and a radio interface.

Originally, the services offered by the IoT were limited to home automation, connecting devices such as thermostats, energy meters, lighting control systems, music distribution and control systems, remote video broadcast boxes...

Gradually, the target applications have been extended to all objects and even living beings, such as health monitoring, smart grids, smart cities, logistics, wildlife monitoring and tracking, home automation and security. All these applications require dedicated base stations to establish a gateway between the communicating objects in the cell, and the Internet bubble that handles the collection and processing of the data collected. It's important to note that IoT is characterized by the small size of the data to be transmitted (often reduced to a few bytes), compared with "human" communications.

To limit operators' operating costs (and keep their tariffs reasonable in relation to the amount of data transmitted), their infrastructure needs to be as small as possible. To achieve this, they need BSs (base stations) covering as large an area as possible. This requirement is met, for the most shared vision, by a star topology with a very long range (devices communicate directly with the BS). There are several strategies for extending the range of a wireless transmission:

• increase transmission power. This solution is difficult to accept because of the power consumption involved. The nodes (which are generally battery-powered) need to be kept at a low level of energy consumption in order to preserve their lifespan. In addition, the potential health impact of increased exposure to radio waves must also be taken into account. ;

• design highly sensitive receivers. However, the cost of these receivers would be higher. They could be deployed on the few base stations, but not en masse on all nodes, which would not allow downlink ;

• design new transmission technologies. This latter possibility has been adopted by...