the existing and forthcoming cellular access and core networks. In March 2018, 3GPP decided that no NR-based solution will be studied or specified for the LPWA use cases and those use cases would be exclusively addressed by the evolving 3GPP Maximum coupling loss is a measure of the attenuation of the radio signal between the transmitter and receiver. Maximum coupling loss is the largest attenuation that the system can support with a defined level of service. This can also be used to define the coverage of the service. Internet of Things 749 LTE-M and NB-IoT standards. This important decision was motivated by operators' and major vendors' implementation and deployment plans for LTE-M and NB-IoT in 2018 + . In essence, the operators and vendors did not want an NR-based solution for mMTC use cases to distract the market and jeopardize their ongoing developments plans around the world. It was further decided that the enhancements (if any) to coexistence between NR and LTE-M/NB-IOT beyond what is supported in 3GPP Rel-15 can be studied as part of 3GPP Rel-16 [9]. Considering the 3GPP decision, LTE-based NB-IoT solution will be the 3GPP technology to address LPWA applications, and thus we will study the theoretical and practi- cal aspects of this technology in this chapter. 6.1 General Aspects and Use Cases The IoT market is expected to cover several industry segments and a wide range of applica- tions with different quality of service (QoS) requirements. Fig. 6.2 shows the partitioning of IoT applications into two broad segments namely massive IoT (mMTC) and mission-critical Massive loT Mission-critical loT Traffic safety and control Logistics, tracking and fleet management Smart building V2X services Smart Remote metering manufacturing /industrial applications Smart Capillary networks Remote healthcare Smart agriculture Low-cost, low-energy, small data packets, Ultra-reliable, very low latency, very high and massive number of connections availability Figure 6.2 Differing requirements for massive and mission-critical