Energy-efficient positioning for the Internet of Things

Location data is required for a plethora of Internet of Things (IoT) applications running on billions of mobile devices worldwide. A few example applications include asset tracking, search-and-rescue operations and the scientific monitoring of air or water quality. Global Navigation Satellite Systems (GNSSs), such as Global Positioning System (GPS) or Galileo, have been established as the standard for worldwide localization. However, the rapidly increasing need to locate IoT devices in recent years has exposed several shortcomings of traditional GNSS approaches. These limitations include the weak signal propagation in indoor and dense environments, a high energy consumption and the inability to communicate a location to a remote end user. Therefore, several industries have shown an increasing demand for alternative, innovative, and energy-efficient positioning solutions that are more suited in an IoT context. In contrast to GNSS, Low Power Wide Area Networks (LPWANs) were designed for energy-efficient communication of small sensor readings in a metropolitan area. In this type of terrestrial networks, thousands of IoT devices can send a message to nearby gateways, which in turn deliver the message to a central server. Interestingly, the uplink communication signals can be exploited to locate the mobile transmitter. Such a localization approach benefits from the low-power and low-cost LPWAN communication, as well as from the coverage in indoor environments. Another very promising alternative to GNSS is the use of satellites in Low Earth Orbit (LEO) for Positioning, Navigation and Timing (PNT). Driven by the recent ‘New Space’ movement, the commercialization of the space market has opened the door to a myriad of opportunities. The thousands of LEO satellite launches of Iridium, SpaceX, Amazon, OneWeb and many others enable applications such as high-quality satellite telephony, worldwide Internet access and smart agriculture through Earth Observation. Providing PNT services through LEO satellites in an ...