s or sensors are autonomous, deployed at difficult-to-reach loca- tions and required to support a very long battery life. The applications that can be supported by mMTC are being dreamed up and deployed all the time, SO the possible uses for this technology are limitless. Examples include smart metering, environmental (air and water quality) monitoring, fleet management, weather station reporting and forecasting, farming, smart cities (waste, traffic, and parking management), and just about everything else you can imagine. Any reason to support the collection of the measurements from a massive number of sensors will use mMTC services and technologies. uRLLC (ultra-reliable and low-latency communication): Sometimes also referred as critical machine-type communication (cMTC), these human- and machine-centric communication cases demand stringent low latency as well as high reliability and availability. The use cases for such requirements apply to industries such as aviation, healthcare, factory automation, smart grids, oil and gas, transportation, and many others. LTE and its evolutionary developments are very mature and capable technologies; however, there are many emerging requirements that were not possible to address with LTE. Hence, 3GPP initiated a development of new radio access technology known as New Radio (NR). NR for 5G is equivalent to LTE for 4G or UMTS to describe 3G technology. 3GPP Release 15 defines the first phase of the 5G NR standard, which reuses many of the underly- ing structures and features of LTE, focusing on the tight integration of 4G LTE and 5G radio access technology (see Figure 10-21). However, being a totally new radio technology, NR is not required to maintain full backward compatibility but to address a different set of technical solutions. Common higher layers Interworking 4G LTE evolution 5G NR Backward compatible Release 15 and beyond 4G spectrum 5G spectrum 10-GHz 30 GHz 1GHz 3 GHz 10-GHz 30 GHz 10-0 GHz Above 6 GHz Below 6 GHz including below 6 GHz Figure 10-21 Evolution of 4G 