A Survey on Ultraviolet C-Band (UV-C) Communications

Recent advances in semiconductor laser and light emitting diode devices, able to efficiently operate in the solar blind regime, have brought the oblivious ultraviolet C-Band (UV-C) communications to the fore again. The non-light-of-sight transmission ability as well as the negligible background noise effect are a few of the intriguing benefits offered by this alternative broadband wireless solution. Motivated by such inherent characteristics, the current survey presents a quick and clear entry point to the topic, useful to the researchers who first get confronted with UV-C communications. To better understand the UV-C systems, a brief classification in the introductory section and a trace back to the historical evolution of this technology from its very beginnings to the current trends are provided. Then, several aspects related to the transceiver device characteristics are addressed, whereas particular emphasis is given on channel modeling including the major degrading effects, such as absorption and scattering. Modulation and multiple access schemes as well as other ways for performance enhancement as diversity and encoding techniques are also summarized. Since networking is necessary to overcome the short UV-C range, interference, connectivity, and coverage issues are thoroughly investigated. Finally, the study is concluded with a discussion regarding the challenges needed to make UV-C systems able to meet the high demands of the next generation wireless networks.