Keynote Address 1

WLANs have adopted radio wave-based technology, for example Bluetooth, IEEE802.11 and the emerging ultra wideband (UWB) systems. The demand for network access is growing rapidly, yet radio bandwidth is limited. In the future, radio frequencies may be insufficient to accommodate a large number of users or devices. As a consequence, infrared indoor wireless communications has been proposed as an alternative to provide additional capacity. The most attractive feature of infrared WLANs is virtually unlimited and worldwide unregulated bandwidth because the infrared frequencies range from 300 GHz to approximately 300 THz. The optical transceiver can be made smaller and cheaper than an RF transceiver module. In addition, the optical circuitry consumes little power, therefore, battery life can be very long. A comparison of different communications standards, e.g., IEEE802.11, UWB, Bluetooth and an optical link in terms of power consumption and bit rate has shown that optical systems achieve the highest bit rate and the least energy consumption normalized by the bit rate.