mmWave-Based Mobile Access for 5G: Key Challenges and Projected Standards and Regulatory Roadmap

Wireless communication using millimetre-wave (mmWave) systems, i.e. systems operating at frequencies between 30 and 300GHz, has long been used for point-to-point radio links, wireless backhaul, and more recently fixed wireless access as well as LAN communication. This notwithstanding, the use of this vast and diverse band and the adjacent lower bands (more specifically, the 6-100GHz region which this paper focuses on and collectively refers to as mmWave) for mobile access has until recently been thought impossible due to technical as well as regulatory constraints. Recent successful super-fast demos which use the mmWave technology for mobile access have pushed the boundaries and made the use of 6-100GHz bands for mobile access perhaps the most talked-about development on the road to 5G. This paper assesses the relevant regulatory and standardisation challenges (in addition to providing a critical summary of the technical ones). By examining various proposed 3GPP timelines, the ITU work plan, ETSI ISG mWT, NGMN, and 5G-PPP activities (among others), we show that a picture is indeed emerging of regulatory and standardisation plans, and we draw up a projected industry roadmap - still with a lot of unknowns on the road to mmWave access, which we also identify. This roadmap and the complex interplay of different actors which we also capture will help various research activities across the world in aligning their work with the emerging standardisation and regulation framework. We additionally contribute some new insight into integration of mmWave communications into various proposed 5G architectures.