nterface (e.g., embedded sensors), long life spans during which an IoT device may change ownership several times (e.g., consumer goods), and non-provi- sioned IoT devices (e.g., consumer goods). These applications necessitate secure mechanisms to dynamically establish or refresh credentials and subscriptions. New access technologies, including licensed and unlicensed, 3GPP and non-3GPP, are driv- ing new efforts for creating access independent security mechanisms that are seamlessly available while the IoT device is active. A high level of 5G security is essential for mission-critical communications, for example, in industrial automation, V2X services, industrial IoT, and the smart grid. Expansion into enterprise, vehicular, and public safety markets will drive the efforts toward increased end-user privacy protection. 5G security is attempting to address all of these new requirements while continuing to pro- vide connection/session security consistent with 3GPP legacy systems. 4 ITU-R IMT-2020 Standardization Activities ITU has a long and reputable history in developing radio interface standards for mobile communications in the form of recommendations and reports. The development of standards for IMT systems, which started in late 1990's, encompassing IMT-2000 and IMT-Advanced [3], helped globalized the 3G and 4G networks and this trend will continue to evolve in to 5G with publication of IMT-2020 recommendations (see Fig. 15). In early 2012, ITU-R22 initiated a path finding program to develop vision for IMT systems in 2020 and beyond, set- ting the stage for widespread 5G research activities that subsequently ensued around the world. ITU toward IMT for 2020 and beyond at http://www.itu.int/. Introduction and Background lxxv Vision Development Deployment of IMT- of IMT-2020 Development of Vision Deployment of IMT-Advanced IMT-Advanced Development of Deployment of IMT- IMT-2000 IMT-2012 vision IMT-2010 vision Rec. ITU-R M.1645 Rec. ITU-R M.2083 Study question on the future public land mobile IMT-2000 IMT-Advanced 