Nowadays, free space optics (FSO) is becoming popular and is very competitive to the fiber optic technology for providing broadband services at very high data rates without the requirement of any spectrum licensing. FSO links can be installed within a few hours and at a very low cost. As compared to the optical fiber, FSO links do not have any problem of faults during digging and maintenance of roads. However, during obstructive climatic conditions such rain, the FSO link losses become high and are not suitable for long-distance transmission. While the single-mode fiber (SMF) link is suitable for such conditions as the link losses are almost independent on the climatic conditions. To leverage the benefits of both FSO and SMF, this paper proposes a Hybrid FSO/Fiber Optic based dual-link architecture that is capable of transmitting data at 20GBPS for a distance up to 5 km. The FSO link is useful for clear weather conditions and fiber optic link is useful for adverse environmental conditions especially for rainy days where link losses are high and require high transmitter powers. By imposing the fiber optic link for rainy days, a significant amount of energy consumption is reduced since losses inside the optical fiber are very low. The architecture provides the reliability against the failure of any one of the links by switching the operational link to the ideal link and vice versa. The architecture supports the dedicated point to point, overlay broadcasting to transmit dedicated and common data respectively. The architecture further adds the reliability against the failure of any link between a remote node (RN) arrayed waveguide grating (AWG) to the optical networking unit (ONU), as the services may be continued on the broadcasted wavelength until the recovery of the original link.

如今，自由空间光学（FSO）变得越来越流行，并且在无需任何频谱许可的情况下，以非常高的数据速率提供宽带服务的光纤技术具有非常强的竞争力。FSO链接可以在几个小时内以非常低的成本安装。与光纤相比，FSO链路在挖掘和维护道路时没有任何故障问题。但是，在诸如雨水等阻塞性气候条件下，FSO链路损耗变高，不适合长距离传输。尽管单模光纤（SMF）链路适用于这样的条件，因为链路损耗几乎与气候条件无关。为了充分利用FSO和SMF的优势，本文提出了一种基于混合FSO /光纤的双链路体系结构，该体系结构能够以20GBPS的速度传输长达5 km的数据。FSO链路可用于晴朗的天气条件，而光纤链路可用于不利的环境条件，特别是在链路损耗高且需要高发射功率的雨天。通过在雨天使用光纤链路，由于光纤内部的损耗非常低，因此可减少大量能源消耗。通过将操作链路切换到理想链路，反之亦然，该体系结构可提供针对任一链路故障的可靠性。该体系结构支持专用的点对点，覆盖广播以分别传输专用和公共数据。