gy in the mid-1990s. Again these personal communications devices were designed to use the ISM band. Both 802.11 and Bluetooth standards were designed to form ad-hoc peer-to-peer networks, without the need to connect to a central node such as a base station. A need for telemetry, especially remote reading of utility usage meters gave rise to the ZigBee standard. Again, this standard uses an ISM band to facilitate remote electricity, gas or water meter readings, as well as enabling smart meters and devices. The above technologies, as well as a number of others such as near field communications (NFC) and visible light communications (VLC) devices mostly augment the broadband services discussed in previous chapters. Wireless Personal Communications Personal communications, also known as consumer communications, devices and standards generally complement (although at times compete) with public wireless standards such as 3G and 4G. These systems generally operate within the ISM unlicensed spectrum bands and are an important component in the delivery of broadband telecommunications services. Similar to other telecommunications systems, their success in the market place has depended on address- ing technological, business and policy issues. A number of technological challenges exist for systems operating in non-licensed bands. Historically these frequency bands are utilised by a large number of devices using a number of different standards. By definition, these devices operate in an uncoordinated fashion, and therefore mechanisms have been developed to ensure they can work under multi-user, multi- standard interference. Another challenge is network establishment in the absence of a central node. This has resulted in the design of special protocols for peer-to-peer and ad-hoc networking. A major technological challenge is associated with the fading characteristics of the indoor channels where most personal systems operate. Solid walls, desks and chairs, and movement of workers lead to significant signal power loss as well