Review Article
Free Space Optics: Current Applications and Future Challenges
Table 2
Comparison table of various techniques based on system parameters on wavelength of 1550 nm [
4,
5,
11,
21].
| Technique | Weather condition | Attenuation level (dB/km) | Power level (dBm) | Data rate | Link distance (km) |
| SAC OCDMA-FSO | SDD | Heavy rain | 8.68 | 0 | 2.5 Gbps | 1.1 | Clear sky | 3 | 0 | 2.5 Gbps | 1.3 |
| OFDM-FSO | OFDM-OSTB-FSO | Clear | 0.155 | 0 | 2 Gbps | 10 | 5 Gbps | 6 | Mild clear | 0.441 | 0 | 2 Gbps | 9 | 5 Gbps | 5 | Low haze | 1.537 | 0 | 2 Gbps | 5.4 | 5 Gbps | 3.4 | Mild haze | 4.285 | 0 | 2 Gbps | 3.2 | 5 Gbps | 2.2 | Heavy haze | 10.115 | 0 | 2 Gbps | 1.8 | 5 Gbps | 1.15 | Low fog | 15.55 | 0 | 2 Gbps | 1.35 | 5 Gbps | 1 | Mild fog | 33.961 | 0 | 2 Gbps | 0.720 | 5 Gbps | 0.540 | Heavy fog | 84.904 | 0 | 2 Gbps | 0.360 | 5 Gbps | 0.300 | OFDM-OSSB-FSO | Clear | 0.155 | 0 | 2 Gbps | 10.2 | 5 Gbps | 6.2 | Mild clear | 0.441 | 0 | 2 Gbps | 8 | 5 Gbps | 5.2 | Low haze | 1.537 | 0 | 2 Gbps | 5 | 5 Gbps | 3.6 | Mild haze | 4.285 | 0 | 2 Gbps | 2.8 | 5 Gbps | 2.5 | Heavy haze | 10.115 | 0 | 2 Gbps | 1.7 | 5 Gbps | 1.4 | Low fog | 15.55 | 0 | 2 Gbps | 1.26 | 5 Gbps | 1.2 | Mild fog | 33.961 | 0 | 2 Gbps | 0.740 | 5 Gbps | 0.590 | Heavy fog | 84.904 | 0 | 2 Gbps | 0.360 | 5 Gbps | 0.310 |
| | Very clear | 0.065 | −10 | 2.5 Gbps | 150 | | Clear | 0.233 | 10 | 2.5 Gbps | 150 | | Light haze | 0.55 | 20 | 2.5 Gbps | 150 | | Heavy haze | 2.37 | 40 | 155 Mbps | 150 | | Heavy haze | 2.37 | 30 | 155 Mbps | 55 | WDM-FSO | 622 Mbps | 51.52 | | Light rain | 6.27 | 30 | 155 Mbps | 22 | | 622 Mbps | 20.8 | | Medium rain | 9.64 | 30 | 155 Mbps | 14.7 | | 622 Mbps | 13.9 | | Heavy rain | 19.28 | 30 | 155 Mbps | 7.6 | | 622 Mbps | 7.2 |
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