Towards 5G

17Point to Multi-point, In-band mmWave Backhaul for 5G Networks

Rakesh Taori and Arun Sridharan

Samsung Research America, Mountain View, CA, USA

17.1 Introduction

The next generation of cellular systems (5G) is expected to meet the rapidly growing demands for data through densification of networks using high-capacity small cells [1]. As networks become dense (through small cell deployments):

• the cost of bringing fiber to every small cell becomes prohibitively expensive [2]
• inter-cell interference increases and becomes a limiting factor in achieving higher cell capacities [3]
• handover is more frequent, causing the associated handover signaling overhead to increase [4].

Using wireless technologies to lower the cost of wiring (digging/trenching to lay wire/fiber in the ground) a cell, for instance by deploying point-to-point microwave links, is already a well-accepted approach [5]. However, even to meet the 4G cellular data rate requirements, the number of point-to-point microwave links is already very high [6, 7] and 5G networks are likely to be even more dense. The first identifiable issue therefore is a cost-effective method for connecting 5G base stations (BSs) to the network (BS–to-network communication).

Inter-cell interference management necessarily involves inter-BS communication. Extensive studies in 3GPP working groups has revealed that latency is a particularly sensitive issue for the achievable performance of cell-edge throughput and/or interference mitigation schemes ...