Wireless networks: What next for radiowave propagation research

This paper chronicles the progress in wireless information transmission and reception, and discusses future trends in radiowave propagation research. Since the conception of wireless transmission, a number of pioneers have successfully understood and characterised the behaviour of narrowband, wideband and ultra-wideband signal transmission in a variety of environments and spectral regions. The physics of signal propagation mechanisms is now well understood and represented by deterministic and stochastic models. Frequency, spatial and polarisation properties of signal propagation have also been exploited. So are there any fundamental research problems left? The aim of this paper is to provoke discussion and debate so that the state-of-the-art of radiowave propagation is understood and further challenges are amassed.