Heterogeneous Backhaul for Cloud-Based Mobile Networks

To meet the increasing capacity demands of future mobile networks, dense deployment of radio access nodes in combination with partly centralized processing by means of a cloud-based architecture is a promising option. In such an architecture, the design and optimization of the backhaul plays a crucial role. In this paper, we review different backhaul technologies available and discuss their characteristics for use in cloud-based networks. We point out how a heterogeneous backhaul network and a flexible centralization enables the proposed architecture and give an outlook on how a joint design of access and backhaul can help in meeting the increased demands.

I. Introduction

Future mobile networks will have to provide an exceptionally high traffic volume with diverse data rates from machine-to-machine (low data rates) to 3D applications (high data rates). To cope with the exponentially growing traffic demand, small cells appear to be a relevant option for mobile network evolution. As the radio access point is placed closer to the user, the same spectrum could be reused to increase the overall capacity of the network tremendously. Furthermore, as the users are usually in the range of several small cells, the transmit and receive signals should be processed jointly. However, the successful dense deployment of small cells requires smart access and interference management techniques.