# PSON: A Serialization Format for IoT Sensor Networks
## 1 Introduction  
The next generation of telecommunications networks (fifth generation or 5G) aims to redefine the rules of the game in connectivity in many respects. The capabilities of the new generation are overwhelming: data rates of up to 10 Gbps (10-100 times better than the current 4 and 4.5G networks), latencies of 1 millisecond, network availability of 99.999%, 100% coverage, 90% reduction in network power consumption, and increased capacity of simultaneously connected users are expected [1]. Beyond improved speed, or latency, 5G is expected to unleash a massive IoT (Internet of Things) ecosystem [2] in which networks can meet the communication needs of billions of connected devices with the right capabilities [3]. The 5G specifications and use cases go far beyond mobile communication, the service experienced by the end user. Specifically, the new 5G standard defines different operational scopes or categories, which are eMBB (enhanced Mobile Broadband), URLLC (Ultra-Reliable Low-Latency Communications), and mMTC (massive Machine Type Communications) [4]. The aim of eMBB is to substantially improve the bandwidth of mobile communications with moderate latency and thus provide a solution for emerging applications related to virtual reality, augmented reality, UltraHD quality applications, 360\({}^{\circ}\) video streaming, etc., which will be further enhanced in the future; for example, it will be boosted in 2021. On the other hand, URLLC [5] refers to ultra-reliable communications with very low communication latency. URLLC will support a range of advanced services for latency-sensitive connected devices to enable applications across a wide spectrum, such as factory automation, autonomous driving, industrial internet, remote surgery, and smart grids, among others. In addition, within the proposed 5G specification, mMTC services [4], which are massive machine-to-machine communications, are also defined. These are specifications focused on providing a cost-effective and robust connection to billions of devices without overloading the network. It will serve devices whose typical use case is to send small amounts of information on a regular basis, enabling optimal use of the power of IoT devices, as the vast majority of IoT devices are battery-powered. Within the Internet of Things, 5G's mMTC technology is being postulated as an unprecedented connectivity solution for the development of connected products and services [6; 7]. The specification sets requirements around networking devices with up to 10 years of battery life, coverage penetration of 164 dB with a capacity of 160 bits per second, coverage density to support up to one million connected devices per square kilometer, communication latencies of less than 10 s for 20 bytes of data, and a crucial element for massive scaling: very inexpensive hardware [4]. In addition, this specification states that 5G networks and mMTC should support more features and applications over time, such as positioning, mobility, or multicast communication capability, among others. The mMTC will rely on two network standards, NB-IoT (Narrowband-IoT) and LTE-M, which are 3 GPP specifications particular to IoT [8]. NB-IoT and LTE-M are part of LPWANs (Low-Power Wide-Area Networks), such as Sigfox, ZigBee, and LoRa [9], which are technologies that offer ranges of several kilometers and low power consumption. They mitigate the shortcomings of WPANs (Wireless Personal Area Networks), such as WiFi and Bluetooth, which, although still widespread [10], have limitations with respect to their range (only a few tens of meters) and their power consumption [11], which is why they cannot be extensively used in IoT contexts. The main advantage of the LPWAN approach in 5G compared to other technologies is that they are within the licensed spectrum (so they are immune to interference) and use the infrastructure of telephony networks, so there is no need to deploy their own infrastructure.