Network solutions for the line-of-sight problem of new multi-user indoor free-space optical system

Abstract

Recent developments in solid-state light-emitting diode (LED) materials and devices are driving a resurgence in the use of free-space optics (FSO) for wireless broadband communication. This technology uses the visible spectrum provided by ‘white’ LEDs, which are becoming ubiquitous in lighting and has some desirable properties competitive with existing radio-frequency communications. By leveraging the low-cost nature of LEDs and lighting units there are many opportunities to exploit this medium for widespread optical communication deployment. The optical medium, however, has distinct characteristics that must be managed, such as directionality and susceptibility to noise sources in the visible spectrum. In this study, the authors present a new indoor FSO communication system, also known as a visible-light communication system that achieves satisfactory data rates while supporting multiple access under line-of-sight constraints. A hexagonal device design is proposed and investigated in the context to two communication protocols designed to manage point-to-point and point-to-host cases. Theoretical analysis and simulation of the two protocols using this hexagonal transceiver design indicate suitability for addressing high data-rate communications between peer devices; or between multiple devices using the peer-to-host model. A new medium access control scheme will also discussed.