Multidimensional Convergence in Future 5G Networks

Abstract

Future 5G services are characterised by unprecedented need for high rate, ubiquitous availability, ultra-low latency and high reliability. The fragmented network view that is widespread in current networks will not stand the challenge posed by next generations of users. A new vision is required, and this paper provides an insight on how network convergence and application-centric approaches will play a leading role towards enabling the 5G vision. The paper, after expressing the view on the need for an end-to-end approach to network design, brings the reader into a journey on the expected 5G network requirements and outlines some of the work currently carried out by main standardisation bodies. It then proposes the use of the concept of network convergence for providing the overall architectural framework to bring together all the different technologies within a unifying and coherent network ecosystem. The novel interpretation of multi-dimensional convergence we introduce leads us to the exploration of aspects of node consolidation and converged network architectures, delving into details of opticalwireless integration and future convergence of optical data centre and access-metro networks. We then discuss how ownership models enabling network sharing will be instrumental in realising the 5G vision. The paper concludes with final remarks on the role SDN will play in 5G and on the need for new business models that reflect the application-centric view of the network. Finally, we provide some insight on growing research areas in 5G networking.

A Variable Rate Fronthaul Scheme for Cloud Radio Access Networks

“…A Fronthaul Aggregator (FHA) aggregates several such links from a cluster of RRUs and creates a Fronthaul Aggregated Link (FAL) which then connects to a centralized BBU pool, forming a tree-like network topology [14]. This abstract configuration could be implemented in practice with a Passive Optical Network (PON), by using a power splitter and Optical Line Terminal (OLT) as the fronthaul aggregator, with each RRU having an Optical Networking Unit (ONU) for communicating to the OLT [15]. It should be noticed that in general, a shared backhaul can provide substantial cost savings in dense cell deployments, as it allows to take advantage of statistical multiplexing across base stations.…”

“…, k M ) = 1 Therefore, the steady state probabilities of the aggregator can be obtained from (18). In this expression, the transition rates between different CPRI configurations λ i and µ i can be obtained from (12) - (15).…”

Access and Metro Network Convergence for Flexible End-to-End Network Design [Invited]

“…How these additional costs are apportioned across the services requiring the front hauling technology is a question that was beyond the scope of the DISCUS project and is a question for future projects [4]. Similarly the important question of whether the stringent front-hauling requirements on the fixed network could be relaxed further to increase reach and enable the lower cost and lower power consumption fixed network as described by the DISCUS architecture should also be properly addressed in future projects on 5G and beyond.…”

End-to-end network design and experimentation in the DISCUS project

“…To facilitate the use of current front-hauling protocols, some electronic processing would therefore need to be provided at a large number of LE sites to terminate the limited reach front hauling systems [7]. Depending on the size and power consumption of this equipment it may not be possible to close all the LEs that the proposed DISCUS architecture could enable.…”