Wireless systems at millimetre wave frequencies
User throughputs provided by existing 2.4GHz wireless local area network (WLAN) and new 5GHz orthogonal frequency-division multiplexing (OFDM) solutions are already foreseen as insufficient for dense urban deployment. Their extension by means of new modes in the unlicensed 59-65GHz band has been proposed to guarantee nomadic terminal mobility in combination with enhanced capacity and privacy. The hybrid dual frequency WLAN designed within the BROADWAY project provides for the smooth ad hoc extension of 5GHz OFDM HIPERLAN/2 technology at the 60GHz radio frequency band. Offloading infrastructure-based WLANs from data traffic and interferences, mobile terminals operating at 60GHz can form a separate ad hoc network. Its scalable system architecture was based on HIPERLAN/2 technology to ensure easy reconfigurability for backward compatibility. Furthermore, HIPERSPOT was equipped with a novel modified multi-carrier transmission scheme enhancing the robustness of transmissions at 60GHz. With HIPERSPOT, demanding emerging applications in highly dense areas can be accommodated and data exchange rates exceeding 100Mbps can be achieved. While the high path loss at the 60GHz initially seemed to be a disadvantage, it however confined HIPERSPOT operation in an indoor environment and within the limits of a room. In addition, higher frequency reuse could also be achieved, allowing a very high throughput network particularly suited for peer-to-peer communications. Importantly, 60GHz regulation allows much higher transmit power compared to other existing wireless local area networks (WLANs) and wireless personal area networks (WPANs). The BROADWAY project partner had therefore a key role to play in the extension of the IEEE802.15 standard, which addresses consumer needs for low-cost and high data-rate ad hoc wireless connections. Some of these applications include wireless keyboards and printers, personal video and digital cameras, digital audio players and headphone, home theatre systems and stereo system components among others. Project partner Motorola's contribution to the meetings of the study group formed to develop a millimetre-wave-based alternative physical layer for the existing WPAN standard IEEE802.15.3-2003 has been significant. The millimetre-wave WPAN will allow very high data rates for applications such as high-speed internet access, real time streaming and wireless data bus for cable replacement.
