Detection and Tracking using Wireless Networks

无障碍通信正在成为大多数人日常生活的重要组成部分。商业用户和私人用户都越来越希望能够在任何地点与人联系并获取信息，而不仅仅是在办公室或工作场所。手机令人难以置信的成功进一步提高了用户在这方面的期望。为了满足这种需求，基于无线局域网（LAN）的新一代连接可能性正在建立，称为Wi-Fi。Wi-Fi或无线保真度允许你在家里的椅子上、酒店房间的床上或工作的会议室里连接到互联网，而不需要电线。Wi-Fi是一种像手机一样的无线技术。支持Wi-Fi的电脑在室内和室外发送和接收数据；基站范围内的任何地方。它比最快的有线调制解调器连接速度快几倍，并迅速被安装在许多地方，如公司设施、机场、酒店、咖啡店和其他配备Wi-Fi接入的公共场所。无线网络也通过WiMax扩展到更远距离的户外系统。Wi-Fi和WiMax基于被称为IEEE 802的行业标准技术。这是相对容易和廉价的实施，并被广泛部署在许多公共领域和商业环境。据估计，2004年Wi-Fi卡的出货量将超过3000万张，这说明了这项技术令人印象深刻的增长速度。因此，无线局域网传输可以看作是未来广泛可用的局部区域信号。除了通信方面，这些信号还有可能用于其他目的。特别令人感兴趣的是利用雷达原理探测物体和人的可能性。在传统的雷达中，脉冲是由同一设备发送和接收的。在其最简单的形式，这允许用户检测目标是否存在，以及在脉冲返回之前的时间延迟距离雷达有多远。如果发射器和接收器是分开的，那么处理会稍微复杂一些，但基本原理仍然适用。为此目的使用无线局域网传输可能导致从无处不在和可访问的来源发展监视能力。所有的传输信号都已经具备，可以设计一个相对简单的接收系统来执行这项任务。当然，在将这些相对简单的原则应用于实际情况时，有许多问题需要克服。拟议的全面研究方案将在这些初步结果的背景下审查问题，并旨在证明基于无线网络的监视系统是现有系统的可行替代方案和补充。还将审查将这种技术与一个现有系统（摄像机）结合起来的情况。这样的组合可以提供一个强大的工具来检测例如异常或可疑行为。伦敦大学学院已经开始了这项技术的初步可行性研究，结果很有希望，并且已经建立了基本的目标检测能力。这个项目涉及一个全新的领域。这项技术的成功发展将导致局部区域探测的重大进步。这种系统将补充正在进行的对其他局部区域检测技术的研究，例如使用移动电话系统和射频识别标签的技术。这项技术可用于许多目的，包括改善私人和公共领域的内部和外部安全，以及识别和跟踪货物和人员。具体的应用可以是减少犯罪、减轻恐怖主义威胁以及探测和跟踪赃物。

Accessible communications are becoming an important part of most people's everyday life. Both business and private users increasingly expect to be able to contact people and get information from any location, not just while at the office or workplace. The incredible success of the mobile phone has further increased the expectations of users in this area. To cater for this demand, a new generation of connectivity possibilities based on wireless local area networks (LAN's) named Wi-Fi is being established.Wi-Fi, or Wireless Fidelity allows you to connect to the Internet from your chair at home, a bed in a hotel room or a conference room at work without wires. Wi-Fi is a wireless technology like a cell phone. Wi-Fi enabled computers send and receive data indoors and out; anywhere within the range of a base station. It's several times faster than the fastest cable modem connection and is rapidly being installed in many locations, such as corporate facilities, in airports, hotels, coffee shops and other public areas equipped with Wi-Fi access. Wireless networking is expanding to longer range outdoor systems as well via WiMax. Wi-Fi and WiMax are based upon an Industry standard technology known as IEEE 802. This is relatively easy and inexpensive to implement and is being widely deployed in many public areas and commercial settings. It has been estimated that over 30 million Wi-Fi cards would ship in 2004 illustrating the impressive rate of growth of this technology. Wireless LAN transmissions can thus be viewed as a future, widely available local area signal. Apart from the communications aspect, these signals have the potential to be used for other purposes. Particularly of interest is the possibility of detecting objects and people using the principles of Radar. In conventional Radar pulses are transmitted and received by the same equipment. In its simplest form this allows the user to detect whether a target is present and how far away from the radar it is by the time delay before the pulse is returned. IF the transmitter and receiver are separated then the processing is slightly more complex but the basic principles still apply. Using wireless LAN transmissions for this purpose could lead to the development of a surveillance capability from a ubiquitous and accessible source. All the transmissions would already be available and a relatively simple receiver system could be designed to carry out this task. There are, of course, many problems to be overcome in applying these relatively simple principles in a real world situation. The proposed full research programme will examine the problems in the context of these initial results and aim to demonstrate that a surveillance system based on wireless networks is a viable alternative and addition to existing systems. The integration of this technique with one existing system (video camera) will also be examined. Such a combination could provide a powerful tool to detect for example anomalous or suspicious behaviour. UCl have already started an initial feasibility study of the technique with promising results and basic target detection capability has already been established. This project addresses a completely new area. Successful development of this technology would result in a major advance in local area detection. Such a system would complement ongoing research into other local area detection techniques such as those using mobile phone systems and RFID tagging. This technique could be used for many purposes including improving internal and external security in private and public areas and identification and tracking of goods and people. Particular applications could be in crime reduction, terrorist threat mitigation and stolen goods detection and tracking.