II-New: X60: A Cross-Layer Reconfigurable Multi-Gigabit WLAN Testbed at 60 GHz

我们今天正在经历无线网络流量的爆炸式增长，这是由快速增长的移动设备和需要带宽的应用程序驱动的。行业研究预测，到2020年，总带宽需求将增长1000倍。尽管人们对提高WiFi和蜂窝网络的频谱效率进行了数十年的研究，但现有技术只能提供短期解决方案。毫米波（mmWave）技术，例如，在IEEE 802.11ad标准支持的未经许可的60 GHz频段，最近作为传统WiFi的替代方案出现，承诺每秒有数千兆比特的吞吐量。尽管直到最近，由于毫米波信号的高衰减和易受阻塞，60 GHz硬件的商业用途一直局限于短距离视距场景，例如无线对接，但该项目设想将毫米波技术用于建筑通用用途。用于家庭和企业环境的多千兆无线局域网将提供永远在线的连接，但吞吐量比今天的2.4/5 GHz WiFi网络高一个数量级。阻碍实现这一愿景的研究工作的一个主要因素是缺乏测试平台，因为无法同时提供高性能和高水平的可重构性和控制的60 GHz硬件。该项目将构建X60，这是一个基于软件定义的60 GHz测试平台，将在PHY， MAC和网络层提供高水平的可重构性，同时支持与IEEE 802.11ad标准相当的信道宽度和速度。每个测试平台节点由美国国家仪器公司的基于fpga的毫米波收发器和SiBeam公司的12元相控天线阵列组成。由于在无线网络社区中没有其他类似功能的测试平台，使用fpga提供了充分的灵活性，并使人们能够实现更广泛的通信和网络解决方案，从当前的标准本身到全新的通信和网络解决方案。从通道的宽带特性开始，将开发最大限度提高频谱效率的创新调制和新的物理层（PHY）同步机制，作为该项目的一部分。在介质访问控制（MAC）层，将研究新的波束形成/波束导向和速率自适应算法以及损耗微分算法。在网络层，该项目将研究无线中继和智能反射器阵列的使用，以改善连通性、覆盖范围和网络容量，并探索基于软码分复用/多址原则的全新集成PHY/MAC跨层架构——一种与IEEE 802.11标准根本不同的方法。该项目将为X60测试平台开发软件，并将该基础设施支持的研究项目产生的测量数据提供给无线网络社区。

We are experiencing today an explosion in wireless network traffic driven by the rapidly growing number of mobile devices and bandwidth hungry applications. Industry research predicts a 1000-fold increase in aggregate bandwidth demands by 2020. In spite of decades of research on improving spectrum efficiency in WiFi and cellular networks, existing techniques can only offer short-term solutions. The millimeter-wave (mmWave) technology, e.g., in the unlicensed 60 GHz band supported by the IEEE 802.11ad standard, has recently emerged as an alternative to legacy WiFi, promising multi-Gigabits per second throughput. Although the commercial use of 60 GHz hardware has been limited until recently to short-range line-of-sight scenarios, e.g., wireless docking, due to the high attenuation and vulnerability to blockage of mmWave signals, this project envisions the use of mmWave technology for building general purpose, multi-Gigabit wireless Local Area Networks for home and enterprise environments that will offer always-on connectivity but an order of magnitude higher throughput than today's 2.4/5 GHz WiFi networks. One major factor that has hindered research efforts towards this vision is the lack of testbeds due to the unavailability of 60 GHz hardware that can simultaneously offer both high performance and high levels of reconfigurability and control. This project will build X60, a software defined based 60 GHz testbed that will offer high level of reconfigurability at the PHY, MAC, and network layer, and, at the same time, support channel widths and speeds commensurate to those of the IEEE 802.11ad standard. Each testbed node consists of an FPGA-based mmWave Transceiver from National Instruments integrated with a 12-element phased antenna array from SiBeam Inc. With no other testbeds of similar capabilities available in the wireless networking community, the use of FPGAs lends full flexibility and enables one to implement a broader range of communication and networking solutions, ranging from the current standard itself to radically new communication and networking solutions. Starting from the broadband characterization of the channel, innovative modulations that maximize the spectral efficiency and new physical layer (PHY) synchronization mechanisms will be developed as part of this project. At the Medium Access Control (MAC) layer, novel beam forming/beam steering and rate adaptation algorithms as well as loss differentiation algorithms will be studied. At the network layer, the project will investigate the use of wireless relays and smart reflector arrays to improve connectivity, coverage, and network capacity, as well as explore a radically new integrated PHY/MAC cross-layer architecture founded on soft code-division multiplexing/multiple access principles - an approach fundamentally different from that of the IEEE 802.11 standards. The project will make the the developed software for the X60 testbed and the measurement data generated from research projects enabled by this infrastructure available to the wireless networking community.