Media Access Schemes for Indirect Diffused Free-Space Optical Networks

In this paper, we propose a set of three media access control (MAC) schemes for an indirect diffused light free-space optical communications (ID-FSOCs). ID-FSOC has been recently proposed to establish wireless high-speed (i.e., 1 Gbps) network access using FSO from stations that have no line-of-sight (LOS) with the access point. ID-FSOC employs a diffuse reflector (DR) to uniformly reflect diffused light from an incident laser to all directions, except towards the DR. To establish a link, ID-FSOC requires LOS between the transmitter and the DR and between DR and the receiver. In this way, ID-FSOC relaxes the location of stations as long as they keep LOS to the DR. We analyze the performance and scalability of proposed schemes. We also consider the impact of the zoom-in time of a receiver in our evaluations. Our results show that our proposed MAC schemes achieve high channel utilization and higher throughput than carrier-sense multiple access schemes.