Over the last few decades, commercial mobile communication has evolved from voice-only to mobile broadband (MBB), enabling a multitude of services including ubiquitous use of the internet and, as a consequence, providing an important contribution to global economic and social development. In 2014, there were close to 7 billion subscriptions globally and this number is expected to increase further to 9.5 billion by 2020, including machineto-machine (M2M) connections. Furthermore, forecasts from industry and academia as well as general consumer trends point towards continuing growth beyond 2020 in the demand for MBB.
The percentage of data subscriptions is now increasing very rapidly as a result of the rising number of smartphones, tablets, etc. As a result, the volume of data traffic in mobile networks has exploded. The set of available services is expected to expand considerably, for instance with e-health, education and intelligent transport systems and will facilitate development of other industry sectors. In a more general perspective, 5G mobile systems should support the development of a fully networked society, the internet of things/ M2M communication and cloud-based services. Requirements on these services will be instantaneous access/low latency, very high bitrates and Quality-of-Service (QoS), low energy consumption and long battery life. It is however worth noting that not all these requirements necessarily will be relevant all the time. Mobile services should enable access to any type of content anytime and anywhere.