Abstract
5G is coming with a promise to provide ubiquitous coverage with high data rate availability. To do so, densification of access points to enhance the system capacity is anticipated. For managing such densely populated network, 5G will be employing Centralized Radio Access Network (CRAN), where most of the Radio Access Network (RAN) functionalities are centralized in a central processing unit. This centralization reduces operational costs and eases implementation of advanced technologies, such as, Cooperative multipoint (CoMP) and enhanced inter-cell interference coordination (eICIC), in a cost efficient way. However, CRAN imposes stringent requirements on the fronthaul, i.e. the link connecting access points to the central unit, in terms of capacity and latency. Furthermore, future fronthaul networks are expected to rely on wireless technologies, since wired options are costly, not scalable and not always suitable for all scenarios. Therefore, meeting the expected requirements of fronthaul network utilizing capacity-limited wireless technologies may become an inescapable bottleneck. In this paper, we study different functional splits at the PHY layer in terms of data rate requirements and operational cost, and discuss the combination of different splits aimed at minimizing the overall cost and maximizing the centralization gains, while keeping the capacity requirements below the limit of the fronthaul.
Highlights
Popularity of mobile devices and data-rich applications are putting high capacity demand on the future wireless networks
To meet the expected performance, Centralized Radio Access Network (CRAN) is identified as a key enabler, where most of the Radio Access Network (RAN) functionalities are centralized in a Baseband Unit (BBU) and the Access Points (AP), known as Remote Radio Heads (RRH), perform basic Radio Frequency (RF) functionalities
Functional splits at the PHY layer are a key enabler of the Flexible RAN concept that allows the centralization of upper layers, i.e. MAC, Radio Link Control (RLC), etc, while relaxing the stringent throughput requirements in FH network
Summary
Popularity of mobile devices and data-rich applications are putting high capacity demand on the future wireless networks. 68% operators consider wireless technologies as a priority element for 5G [1] With this in mind, in [5], authors anticipated that wireless FH options operating in a higher carrier frequency will be more popular in future practical CRAN, compared to optical fibre based FH networks. In this article, we analyse the throughput and cost performance of different splits at the PHY layer utilizing wireless options in the FH network. We provide a solution to offer the best use of the splitting at the PHY layer in a capacity-limited FH network, i.e. not capable to meet full CRAN requirements in all the FH links managed by a common BBU. This paper is concluded identifying future potentials of this work
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call