To provide this almost limitless flexibility, 5G is an extremely complex technology. Evidence of this complexity can be seen by looking at the 3GPP’s timeline for standardization. Release 15 started with an “early drop” in December 2017, necessary for the first deployments to go ahead, while more time has been needed to complete the planned “late drop” -- now scheduled for June 2019 – that finalises further specifications. The task of defining work items for the next Release 16 has already started and is currently discussing new features and services such as C-V2X, 5G NR in unlicensed bands, and URLLC support.
In addition to the complexity, the great diversity of services 5G is expected to support -- and their differing requirements in terms of bandwidth, data volume, response time – means ensuring adequate Quality of Service (QoS) for each is critical for network resources to be managed efficiently.
From the user perspective, an acceptable Quality of Experience (QoE) is sought. With large numbers of devices and a wide variety of services, leveraging networks’ mMTC and URLCC capabilities, defining and testing QoE, and determining suitable thresholds for each metric is set to become a much more complex and challenging task than in previous technology generations.