Development of a new MAC protocol for Indirect Diffused Free Space Optical Communications

In this thesis, a set of three media access control (MAC) schemes for an indirect diffused light free-space optical communications (ID-FSOCs) are proposed. ID-FSOC has been recently proposed to establish wireless high-speed (i.e., greater or equal to 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. Obviously if we want to use a technology that relies on optical communication and laser light we need to investigate new protocols, never standardized before, to deal with this physical characteristics. The performance and scalability of proposed schemes are analyzed; and also the impact of the zoom-in time of a receiver is considered in the evaluation. Results show that the proposed MAC schemes achieve high channel utilization and higher throughput than carrier-sense multiple access schemes.