Combining Wireless Optical and UWB for low data rate applications

Recent developments in the field of Ultra Wide Band (UWB) radio and networks led to the definition of a new Impulse Radio (IR) UWB-based IEEE standard for low data rate communications, named IEEE 802.15.4a. A typical feature of UWB radio is a large bandwidth together with limited available emission power, as set by regulatory bodies. UWB communications may, therefore, be severely affected by external interference. IR-UWB and Diffuse Wireless Optical (DWO) signals share a major feature of being impulsive in nature; we suggest that the combination of these two technologies may bring benefits, and overcome limitations. To this aim, we propose a strategy for combining these two physical layers by adopting a common Medium Access Control (MAC) protocol, based on selecting the most suitable physical layer as a function of external interference. Results obtained by simulation for different patterns of external interference indicate that system performance may be strongly improved by the proposed IR-DWO combination strategy.