Workshop on Next Generation Backhaul/Front haul Networks (BackNets'2015)

Industry consensus on the vision for 5G is slowly forming, it will pull together a wide range of applications from very low bit rate M2M to ultra-high speed internet access, and the key feature will be flexibility. The technology and standards will be developed by 2020. One of the challenges will be creating a technology that can use the wide contiguous bandwidths in the mmWave band to integrate the backhaul while using the same band for fronthaul. This keynote will consider the technology challenges, and investigate the possibility of using the 27 - 40 GHz band from theory, to channel measurements and will give an introduction to possible solutions. Finally it will provide challenges to the research community for areas we need more work in.

The rapid pace of demand for mobile data services and the limited supply of capacity by the current wireless access networks infrastructure are leading network operators to increase the density of base station deployments, particularly in urban areas, to improve the network performance. This densification, made possible by small-cell deployment, also brings in a novel set of challenges, specifically related to cost of ownership of which backhaul is of primary concern. In this context, we will first talk about the non-line-of-sight (NLOS) wireless radio-frequency (RF) backhaul solution, which has a low cost of ownership as compared to other backhaul candidates. We will then talk about the potential provided by the free-space optical (FSO) solution as well as the challenges that have to be surpassed before FSO backhaul can be massively deployed.

After a brief introduction to 5G small cells, the backhauling requirements for these small cells and different backhauling technologies (both wired and wireless) will be discussed. Then the challenges in wireless backhauling will be outlined. To this end, two different approaches for wireless backhauling of 5G small cells based on full-duplexing and massive MIMO techniques in a multi-tier RAN architecture will be presented. The performances of these approaches will be illustrated through numerical results. At the end, several open research challenges related to wireless backhauling of 5G small cells will be outlined.

Increasing the capacity of next-generation backhaul and access networks is becoming one of the most challenging tasks of the industry this decade. As traditional mechanisms to increase spectral efficiency approach their theoretical limits, new and disruptive techniques are needed to satisfy the growing demand of mobile data traffic. Consequently, the fifth generation (5G) cellular access system is expected to make extensive use of small cells to increase the density and capacity by several hundred times in comparison with 4G systems. Not only cellular access, wireless backhaul solutions require increased density and capacity. While considerable focus has been rightfully put into exploiting licensed frequency bands below 6 GHz, the vast amount of licensed frequency spectrum in millimetre wave (mmWave) bands has seen little use by cellular access systems despite holding far greater potential for enhancing capacity. This panel session will invite experts in mmWave technology from both Academia and Industry to present their view of mmWave systems for next generation cellular systems, Channel measurement and Modelling, MIMO and MU-MIMO technology in mmWave bands.