Millimetre-Wave Backhaul for 5G Networks: Challenges and Solutions

Abstract

The trend for dense deployment in future 5G mobile communication networks makes current wired backhaul infeasible owing to the high cost. Millimetre-wave (mm-wave) communication, a promising technique with the capability of providing a multi-gigabit transmission rate, offers a flexible and cost-effective candidate for 5G backhauling. By exploiting highly directional antennas, it becomes practical to cope with explosive traffic demands and to deal with interference problems. Several advancements in physical layer technology, such as hybrid beamforming and full duplexing, bring new challenges and opportunities for mm-wave backhaul. This article introduces a design framework for 5G mm-wave backhaul, including routing, spatial reuse scheduling and physical layer techniques. The associated optimization model, open problems and potential solutions are discussed to fully exploit the throughput gain of the backhaul network. Extensive simulations are conducted to verify the potential benefits of the proposed method for the 5G mm-wave backhaul design.

Optimal Multicommodity Spectrum‐Efficient Routing in Multihop Wireless Networks

“…The large bandwidth of mm-wave is also accompanied by a high path loss, which necessities the use of multihop relaying across the small-cell base stations [2]. Intelligent routing methods will also be needed for the underlying applications of 5G, e.g., the Internet of Things (IoT) [3].…”

Beamspace multiplexing for wireless millimeter-wave backhaul link

“…Heterogeneous network (HetNet), which could provide efficient spatial reuse, together with the disruptive technologies, such as massive-MIMO and millimeter-wave (mm-wave) communication, are considered as a promising solution [2]. In current cellular networks, backhaul data traffics between cell base-stations (BSs) and the central macro-cell BS are normally fulfilled using high capacity fiber connections.…”

“…However, in future HetNets the cost of fiber infrastructures between macro-cell BS and small-cell BSs, which provide high capacity within a small spatial coverage, would be prohibitively high, simply due to the fact of a huge number of small-cells and their high flexibility, e.g., the site of a small-cell can be moved according to the change of user distributions. As a consequence, great efforts have been devoted to the wireless backhaul, especially in mm-wave band [2] [3] because the larger available frequency bandwidth is able to provide higher spectrum efficiency [4].…”

On the Capacity and the Optimal Sum-Rate of a Class of Dual-Band Interference Channels

“…Most studies on microwave and mm-wave dual-band transmission have focused on how to improve network layer performance metrics of cellular access or backhaul networks by using the high-bandwidth, highly directional mm-wave links [9,13]. For example, the authors in [7] posed the problem of optimal resource allocation in a cellular setting in the dual microwave and mm-wave band, and showed that certain network level performance parameters, e.g., the number of simultaneously supported users and the link connection probability, are vastly improved with their proposed solution.…”

“…In contrast, microwave links are much more reliable due to rich scattering and diffraction, but cannot support as high rates as the mm-wave links. Thus, in a dual-band setting, conventional traffic and control information can be reliably communicated over microwave links, and high data-rate traffic can be sent through mm-wave links [2,7,[9][10][11][12][13][14][15].…”