Fronthauling for 5G LTE-U Ultra Dense Cloud Small Cell Networks

TL;DR

This paper reviews the challenges and options for fronthaul technology in ultra dense 5G LTE-U small cell networks, highlighting the advantages and hurdles of various candidate solutions.

Contribution

It provides a comprehensive overview of fronthaul challenges and surveys multiple candidate technologies for 5G LTE-U UDCSNet fronthauling.

Findings

Optical fiber offers high capacity but high deployment cost.

Millimeter-wave and Wi-Fi unlicensed spectrum provide flexible options with challenges.

Sub 6GHz licensed spectrum and free-space optical are viable alternatives with specific trade-offs.

Abstract

Ultra dense cloud small cell network (UDCSNet), which combines cloud computing and massive deployment of small cells, is a promising technology for the fifth-generation (5G) LTE-U mobile communications because it can accommodate the anticipated explosive growth of mobile users' data traffic. As a result, fronthauling becomes a challenging problem in 5G LTE-U UDCSNet. In this article, we present an overview of the challenges and requirements of the fronthaul technology in 5G \mbox{LTE-U} UDCSNets. We survey the advantages and challenges for various candidate fronthaul technologies such as optical fiber, millimeter-wave based unlicensed spectrum, Wi-Fi based unlicensed spectrum, sub 6GHz based licensed spectrum, and free-space optical based unlicensed spectrum.