Optical power allocation for adaptive WDM transmissions in free space optical networks

Attracting increasing attention in recent years, the Free Space Optics (FSO) technology has been recognized as a cost-effective wireless access technology for multi-Gigabit rate wireless networks. Radio over Free Space Optics (RoFSO) provides a promising enhancement to optical fiber systems. In an RoFSO system using wavelength-division multiplexing (WDM), it is possible to concurrently transmit multiple data streams consisting of various wireless services at very high rate. In this paper, we develop power allocation schemes for adaptive WDM transmissions to combat the effect of weather turbulence in FSO networks. The problem of optical power allocation under power budget and eye safety constraints is investigated for adaptive WDM transmission in RoFSO networks. Simulation results show that WDM RoFSO can support high data rates even over long distance or under bad weather conditions with an adequate system design.