Beams of the Future? [AP-S Turnstile]

Which technology offers all of the following advantages? (1) full-duplex gigabit Ethernet throughput (2) no RF-spectrum licensing (3) immunity to EMI (4) low-cost installation in less than a day. The answer is free-space optics (FSO), a line-of-sight optical link. Like all technologies, free-space optics is not without its problems. Fog can absorb and scatter light, seriously degrading the optical link. Atmospheric turbulence can result in scintillation, a temporal and spatial variation in light intensity that leads to high bit-error rates in data transmission. Seismic activity and wind currents (eddies) can cause the optical beam to wander, resulting in potential signal loss. Notwithstanding the above challenges, recent activity in both academic (such as Oxford and Harvard) and corporate sectors (for example, Lightpointe and Cablefree Solutions) suggests that free-space optics may, indeed, become the "beams of the future."