# Trends in LPWAN Technologies for LEO Satellite Constellations in the NewSpace Context
## 1 Introduction  
NewSpace represents a modern approach to space missions, characterized by three main elements: space privatization, satellite miniaturization, and the development of innovative services utilizing space data [1]. This concept diverges from traditional government-led space programs, emphasizing the role of private companies, like SpaceX and Rocket Lab, in satellite manufacturing and launching. The adaptation and screening of Commercial of The Shelf (COTS) components boosted the miniaturization of satellites, including cube, micro-, and nanosatellites, enabling deployment in a single launcher and facilitating more accessible access to low Earth orbits (LEOs) [2]. Satellites in LEOs, orbiting between 160 and 2000 km above Earth's surface [1], offer various services. These include Earth observation, Internet connectivity, scientific research, satellite navigation, integration with 5G technology, and tracking for aeronautical and maritime purposes. These services result from the combined effects of space privatization and the trend toward smaller satellites [3]. NewSpace has catalyzed the emergence of the Satellite Internet of Things (IoT), enabling direct data collection from terrestrial sensors through compact, yet efficient, LEO satellites [4]. Previously, such data gathering would necessitate an extensive network of Earth stations. However, NewSpace advancements have facilitated cloud-based services that provide shared ground station networks and advanced computing capabilities for data processing. Furthermore, LEO constellations are transforming IoT connectivity, particularly in remote regions, with companies like FOSSA Systems, Sateliot, or Lacuna at the forefront of this development. The advent of satellite-based low-power wide area networks (LPWANs) marks a significant evolution in the IoT landscape, offering global connectivity to devices at costs competitive with terrestrial providers, thereby promising a substantial expansion of connected devices [5]. IoT is revolutionizing various industries by enabling connectivity across various devices, from sensors to autonomous vehicles, automating and enhancing operationalprocesses. The advent of LEO satellite networks has broadened the connectivity possibilities for IoT devices in remote or isolated regions. It is a supplementary connectivity option in areas with terrestrial IoT networks. However, satellite IoT communications have challenges, including managing many devices, interference issues, and security concerns. Addressing these challenges is essential for the efficient and secure functioning of IoT satellite networks [6; 7; 8; 9]. NewSpace's emergence has notably transformed the space industry, increasing accessibility for various players [10]. The space economy is on a consistent growth trajectory, with forecasts suggesting a value ranging from several hundred billion to multiple trillion dollars by 2040 [11]. Concurrently, the IoT satellite market is anticipated to grow substantially, with expectations of its value escalating from USD 1.1 billion in 2022 to USD 2.9 billion by 2027 [12]. This survey employs a methodical and technology-focused approach to comprehensively analyze satellite IoT communications in the rapidly evolving NewSpace era, characterized by significant advancements in satellite technologies and their terrestrial counterparts, such as LPWAN. This study offers an updated, technology-focused analysis that surpasses previous surveys in scope and depth. It involves a critical comparison with previous works. For example, reference [5] presents a general overview of machine-type communication from space, treating the LPWAN as a subset and not fully engaging with the NewSpace specifics emphasized in this survey. Survey [13], at present several years old, does not incorporate the latest developments in the nanosatellite context addressed here. While discussing the applications, reference [14] does not delve into the technological intricacies as thoroughly as this study.