Future Wi-Fi: enhanced indoor modelling and waveform design & analysis

Wi-Fi技术是我们联网生活不可或缺的一部分。世界上超过70%的无线数据通过全球Wi-Fi标准之一传输。20多年来，布里斯托尔大学的通信系统和网络（CSN）集团一直致力于这些技术的发展，以及符合这些技术的产品。WiFi为移动办公和节省成本提供了机会，这对许多组织都很有吸引力。然而，安全要求在未经授权的拦截、利用或拒绝服务方面提出了许多挑战，需要在任何安装中考虑。加密和身份验证提供了一些答案，但也需要从信息保障（IA）的角度确定无线信号可能在多大程度上“泄漏”到预期覆盖区域之外。为此，人们有兴趣以更高的保真度了解室内传播环境，以确定可能导致总体传播损失低于在相同距离的自由空间中球形传播所期望的条件。第一年将用于开发室内光线追踪模型（这将扩展移动通信实验室使用的工具的功能）。该模型将考虑不同的属性类型、壁厚和材料类型，并将支持任意建筑结构（包括大型多用户住宅）。主要重点将放在已建立的2.4 GHz和5.8 GHz频段上，但为了证明该模型的未来，毫米波频率（未经许可的60GHz频段）也将被考虑，以确保支持未来的建筑内无线电标准，如IEEE 802.11ad。射线追踪模型将结合全3D天线测量，以及最新Wi-Fi标准的复杂系统级模拟器（代码已经存在）。为了提高模型的准确性，将对一系列情况进行测量，例如沿走廊、假天花板、电缆管道和楼梯井传播，目的是确定比通常预期范围更大的情况。同样，毫米波测量将在几个属性中进行，以调整，校准和验证光线追踪操作（即与墙壁，地板和天花板的潜在衍射和漫射散射相互作用）。该项目将利用CSN集团价值数百万英镑的设备和设施，如我们的消声室、宽带信道测深器和信道模拟器。

Wi-Fi technologies are integral to our internet-connected lives. In excess of 70% of the world's wireless data passes over one of the global Wi-Fi standards. For more than 20 years the University of Bristol's Communication Systems and Networks (CSN) Group has contributed towards the development of these technologies, and to products that conform to them.WiFi presents opportunities for mobile working and cost savings which are attractive to many organisations. How-ever, security requirements pose a number of challenges with regard to unauthorised interception, exploitation or service denial and need to be considered in any installation. Encryption and authentication provide some of the answer, but there is also a need to determine from an Information Assurance (IA) perspective how far wireless sig-nals may 'leak' outside the intended coverage area. To this end there is an interest in understanding the indoor propagation environment with greater fidelity, to determine conditions which may cause an overall propagation loss lower than would be expected from spherical spreading in free space over the same distance.The first year will be spent developing an indoor ray-tracing model (this will extend the capabilities of the tool used in the Mobile Communications Lab). The model will consider different property types, wall thicknesses and material types, and will support arbitrary building structures (including large multi-user dwellings). The primary focus will be on the established 2.4 and 5.8 GHz bands however to future proof the model, mmWave frequencies (unlicensed 60GHz band) will be considered also to ensure support for future in-building radio standards such as IEEE 802.11ad.The ray-tracing model will be combined with full 3D antenna measurements, with sophisticated system-level simula-tors of the latest Wi-Fi standards (code already exists). In order to improve the accuracy of the model measurements will be made for a range of scenarios, for example propagation along corridors, false ceilings, cable ducts and stair-wells, with the goal of identifying cases which give a larger range than would normally be expected. Similarly MmWave measurements will be taken in several properties to tune, calibrate and verify the ray-tracing operation (i.e. the underlying diffraction and diffuse scatter interactions with walls, floors and ceilings. The project will make use of the CSN Group's multi-million pound equipment and facilities, such as our anechoic chamber and our wideband channel sounder and channel emulators.