Guest editorial deployment issues and performance challenges for 5G, Part I

There are rapid developments towards the deployment of 5G and hardly a day goes by without the release of a major announcement concerning 5G. Many of these developments are happening in parallel as there is a race against time for 5G deployment. Various test beds have been established, laboratory trials and proof of concept trials of individual building blocks of 5G are already underway or have been completed, large scale system trials are also happening or are planned and standardisation efforts in the ITU, 3GPP, IEEE, etc. are also in progress. In the case of ITU/3GPP, the standards are expected to be completed by 2019. Many candidate bands for 5G in the centimetric and mm wave range were identified by the World Radio Conference (WRC) 2015 and are expected to be finalized by WRC 2019, while coexistence studies of 5G and existing systems in the new candidate bands are underway.