EARS: Spectrum and Infrastructure Sharing in Millimeter Wave Cellular Networks

随着传统蜂窝频段频谱的严重短缺，30-300 GHz的毫米波频率作为下一代微蜂窝和微蜂窝无线网络的候选频段越来越受到人们的关注。毫米波频段提供了比当前蜂窝分配更大数量级的频谱，并通过波束形成和空间多路复用实现了超高维天线阵列的进一步增益。然而，由于在这些频率上传播的独特性质，蜂窝系统将需要进行重大重新设计，以充分利用这些频率的潜力。该项目研究了毫米波网络设计中的一个关键维度：资源共享，涉及多个运营商共享频谱和网络基础设施资源。人们认为，这种形式的共享对于充分利用这些频段提供的巨大带宽和天线自由度以及提供统计多路传输以适应业务的高度可变性质是至关重要的。这个跨学科的项目探索了毫米波资源共享的工程和经济方面。在工程方面，关键的挑战是频谱不仅必须在时间和频率上共享，而且必须在空间上共享。此外，还需要新的分散机制，以便在多方之间快速重新分配回程和核心网元。该项目开发信号处理方法、协议和网络优化算法，以促进频谱的定向共享以及动态重新路由和负载平衡。在经济和政策方面，研究了运营商、监管机构和第三方频谱和资源经纪人之间不同形式许可协议下的几种共享所有权模式。根据从工程方面获得的能力估计数，制定了经济模型，以评估诸如业务和资本成本以及联盟组建和市场集中度等关键指标。

With the severe spectrum shortage in conventional cellular bands, millimeter wave (mmWave) frequencies between 30 and 300 GHz have been attracting growing attention as a possible candidate for next-generation micro- and pico-cellular wireless networks. The mmWave bands offer orders of magnitude greater spectrum than current cellular allocations and enable very high-dimensional antenna arrays for further gains via beam-forming and spatial multiplexing. However, due to unique nature of propagation in these frequencies, cellular systems will need to be significantly redesigned to fully exploit the potential of these frequencies. This project investigates one key dimension in mmWave network design: resource sharing, involving the sharing of spectrum and network infrastructure resources by multiple operators. It is argued that sharing of this form will be essential to fully exploit the tremendous bandwidth and antenna degrees of freedom offered by these bands and also provide statistical multiplexing to accommodate the highly variable nature of traffic.This inter-disciplinary project explores both the engineering and economic aspects of mmWave resource sharing. On the engineering side, the key challenge is that the spectrum must be shared not only in time and frequency, but also space. In addition, new decentralized mechanisms are required to rapidly reallocate backhaul and core network elements across multiple parties. The project develops signal processing methods, protocols and network optimization algorithms to facilitate directional sharing of spectrum along with dynamic re-routing and load balancing. On the economic and policy side, several shared ownership models under varying forms of licensing agreements between the operators, regulatory agencies and third-party spectrum and resource brokers are investigated. Based on the capacity estimates obtained from the engineering side, economic models are developed to assess key indicators such as operating and capital costs and coalition formation and market concentration.