Experimental Demonstration of a Radio on Free Space Optics System for Ubiquitous Wireless

One of the ultimate goals in next generation network design is to achieve an ubiquitous environment enabling connectivity between any wireless access system with optical fiber core network. Radio on Fiber (RoF) technology has been applied to realize a universal platform for transparently carrying various types of wireless services. By applying free-space optics (FSO) communication techniques combined with RoF, this concept can be extended to free space channels. This paper presents a new DWDM Radio on Free-Space Optics (RoFSO) system, which can be used to realize a universal platform to quickly and effectively provide ubiquitous wireless services to underserved areas avoided due to prohibitive costs associated with deploying optical fiber. To realize this RoFSO system, a next generation FSO system which provides seamless connection between free-space and optical fiber links by directly coupling the free-space propagated beam to a single mode fiber (SMF) is used. We have evaluated this new DWDM RoFSO system by conducting field experiments in simultaneous transmission of various kinds of wireless services; for example, 3GPP cellular, WLAN, terrestrial digital broadcasting TV (ISDB-T) signals; over extended durations. The preliminary results demonstrate the potential to utilize the RoFSO system for stable and reliable transmission of optical and radio frequency (RF) signals.