After the considerable success of LTE, why do we need a new system with a new radio and a new core? First, 5G will boost some of the LTE key performance indicators to a new horizon: capacity, latency, energy efficiency, spectral efficiency, and reliability. We will describe the relevant radio and core features to enable optimizations (5G to be 10, 100, or 1000 times better than LTE) in these areas in respective chapters of the book. But this is only half of the 5G story. With the service‐based architecture 5G Core supports natively a cloud‐based architecture, the higher layer split of the radio protocol as specified by 3GPP paves the path for a cloud‐based implementation of the radio network or parts of it and network slicing will open totally new revenue streams for operators by offering their network as a service to vertical industries. Slicing will enable operators implementing logical networks for diverse use cases (e.g. industrial applications) in an optimal way on their physical hardware. The 5G System also supports compute and storage separation natively, and introduces enablers to support the ability to perform dynamic run time load (re‐)balancing with no impact to user's services. In addition, open interfaces and the possibility to expose data from network functions to third parties via open APIs enables operators to monetize these contextual real‐time and non‐real‐time data or simply use the data to optimize network deployment and configuration. Operators can broker information to different industries like providers of augmented reality services, traffic steering systems, factories, logistical systems, and utilities. Real‐time big data analytics will play a crucial role for this brokering model.

In a nutshell, the main intention of this book is to explain what 5G is from a technical point of view (considering 3GPP Release 15 content), how it can be used to enable new services, and how it differs from LTE. The book covers potential 5G use cases, radio and core aspects, and deals also with spectrum considerations and new services seen as drivers for 5G. Although 5G will not support IoT and massive machine‐type‐communication from the very beginning in 3GPP Rel‐15, we felt that this topic is extremely important and thus we provided a detailed description about IoT, M2M, and technical enablers like LTE‐M, NB‐IoT, GSM, 5G in this book.

Some familiarity of the reader with the basics of 3GPP networks, especially with LTE/EPC, would be helpful, but this is not a pre‐requisite to understand the main parts of this book. The reader can find a more detailed description of the book's content in the introduction section.

This book is intended for a variety of readers such as telecommunication professionals, standardization experts, network operators, analysts, and students. It is also intended for infrastructure and device vendors planning to implement 5G in their products, and regulators who want to learn more about 5G and its future applicability for a large variety of use cases. We hope everyone interested in the subject of this book benefits from the content provided.

The race towards 5G has already begun in major markets round the world like North America, China, Japan, and South Korea. To be first on the market with 5G is a key differentiator between operators and vertical industries. The year 2018 will be the first where 5G commercial networks are deployed in some key markets, even on a medium or large scale. People will start benefitting from the huge and broad step forward 5G is bringing to them individually with faster traffic downloads, faster setup times, lower latency, higher connection reliability and to the whole society with smarter cities, factories and traffic control coping with the challenges of the future. This brings us close to the vision of a truly connected world where everyone and everything are potentially connected with each other.

The Editors

December 2018