Radio resource management: approaches and implementations from 4G to 5G and beyond

Radio resource and its management is one of the key areas of research where technologies, infrastructure and challenges
are rapidly changing as 5G system architecture demands a paradigm shift. The previous generation communication
technologies require customizations and upgrades as 5G will remain inclusive for significantly long duration. Radio
resource management (RRM) schemes that are evolved during LTE/LTE-A network environment period will remain
relevant for 5G, however, these schemes must become more intelligent and adaptive for future as features and requirements
of network and users will be diverse and highly demanding. In this paper, a comprehensive view is provided upon various
aspects of RRM, its challenges and existing schemes. The existing RRM schemes are presented with their respective
architecture which has significant impact on the approaches. The problem of RRM is multi-dimensional and different
dimensions are presented with their respective solutions such as interference or energy management. In this paper study of
legacy and state of the art RRM schemes is presented with their features and inefficiencies in the modern telecommunication
era of heterogeneous, ultra-dense, very low latency and highly reliable mobile network. In addition to this various
comparison among approaches and schemes are presented for analyzing the solutions. The need of RRM solution is critical
and this paper aim is to outline the challenges, existing solutions and directions for research to find and develop smarter and
more adaptive schemes for future.