 loT applications [10]. 750 Chapter 6 IoT (URLLC), in order to underline their distinct requirements. Massive IoT comprises applications involving exchange of small and infrequent data packets to/from numerous standalone devices. Hence, for economic viability, such devices must be implemented with low-cost and low-power consumption without stringent latency requirement. Consequently, the network technology providing connectivity to such devices must satisfy these require- ments and support high capacity. On the other hand, mission-critical IoT category consists of time-sensitive applications, with latency requirements in the order of fraction of a milli- second, such as remote surgery and vehicle-to-vehicle communications. These applications demand high reliability, availability, and very low latency. Server/cloud-based big data analytics and machine learning are central to the majority of IoT business models. IoT uses MTC to harvest data and route control messages between widely distributed things (e.g., sensors or actuators) and cloud-based intelligence. Many topologies include gateway nodes as aggregation points between IoT devices and the cloud. NB-IoT uses a narrow channel bandwidth which can be deployed either in-band with LTE, in the LTE guard-bands, or in reused GSM spectrum. The enhancements to LTE baseline have been selected such that NB-IoT can be deployed via software upgrades to the existing LTE or GSM infrastructure. The NB-IoT requirements include 10-year battery life, very low device implementation cost and complexity, and a network capacity of more than 50,000 devices per cell. The NB-IoT is designed to allow less than 10 seconds latency and aims to support long battery life. For a device with 164 dB coupling loss (i.e., the measure of coverage of a wireless access technology), a 10-year battery life can be reached, if the UE data transmissions are limited to 200 bytes on average per day. The LPWA networks provide connectivity to mMTC applications and require radio access technologies that can de