Wireless is getting personal
While mobile communications networks will inevitably take time to reach their full potential, the attention of the PACWOMAN project consortium has already turned to the longer term. Future broadband mobile technology will not just be about higher data transfer rates or public networks. The evolution of the so-called third generation (3G) networks must put user needs centre stage. PACWOMAN's research on ultra-wideband (UWB) radio technology followed this user-centric approach and aimed to pave the way for advanced network design concepts. The UWB radio technology is considered as an emerging technology with a multitude of potential applications. The main applications are Personal area networks (PANs) to link one person's digital devices together, or Local area networks (LANs) to link devices in a room. This technology provides for data transfer rates as high as a gigabit per second, but is also suitable for the emerging Body area networks (BANs), requiring low data transfer rates. The UWB propagation channel is, however, highly dependent on the type of the transmitter and receiver antennas, and more importantly on the operating conditions. For example, the presence of a human body in the proximity of the UWB antennas can dramatically change the characteristics of the radio channel. Engineers at the Centre Suisse d'Électronique et de Microtechnique SA investigated the potential of imprinting information on the transmitted signal using various modulation techniques. Based on the UWB device specifications set by the Federal Communications Commission (FCC), a novel solution was proposed for low to medium data transfer rates (not exceeding 5\;Mbit/s). This was based on fast On-off keying (OOK), the simplest technique of binary modulation. The motivation for this approach was the availability of off-the-shelf hardware and software, making it relatively easy to implement. Furthermore, a new technology – referred to as Frequency domain UWB – was employed to eliminate the need for synchronisation between transmitter and receiver. A scaled-down prototype of UWB transmitter and receiver has been designed and is intended for medical tele-monitoring at home and live transmission of webcam video.
