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

由于移动的设备和带宽需求巨大的应用程序数量迅速增长，我们目前正在经历无线网络流量的爆炸式增长。行业研究预测，到2020年，总带宽需求将增长1000倍。尽管在提高WiFi和蜂窝网络中的频谱效率方面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频带中，最近已经出现作为传统WiFi的替代方案，承诺每秒多个比特的吞吐量。尽管60 GHz硬件的商业使用直到最近还限于短距离视线场景，例如，无线对接，由于毫米波信号的高衰减和易受阻塞，该项目设想使用毫米波技术为家庭和企业环境构建通用的多千兆位无线局域网，该网络将提供始终在线的连接，但吞吐量比当今的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，这是由于60 GHz硬件无法同时提供高性能和高水平的可重构性和控制。该项目将构建X60，这是一个基于60 GHz测试平台的软件定义，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。每个测试台节点都由National Instruments的基于FPGA的毫米波收发器和SiBeam Inc.的12单元相控阵天线阵列集成而成。由于无线网络社区中没有其他具有类似功能的测试平台，FPGA的使用提供了充分的灵活性，使人们能够实现更广泛的通信和网络解决方案，从当前标准本身到全新的通信和网络解决方案。从信道的宽带特性开始，最大限度地提高频谱效率的创新调制和新的物理层（PHY）同步机制将作为该项目的一部分开发。在媒体接入控制（MAC）层，将研究新的波束形成/波束控制和速率自适应算法以及损耗区分算法。在网络层，该项目将研究使用无线中继和智能反射器阵列来提高连接性、覆盖范围和网络容量，并探索一种基于软码分复用/多址原理的全新集成PHY/MAC跨层架构--这种方法与IEEE 802.11标准的方法有根本的不同。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.