White paper Are Networks in Emerging Markets Ready for Terabit/s Scale Optics? Author Sudipta Bhaumik*, Puneet Agarwal*, Prasanna Pardeshi*, Deepak Sanghi**, Praveen Kumar**, *Sterlite Technologies Ltd, India ; **Bharti-Airtel India Ltd; ***Ciena India Pvt Ltd. Abstract High speed transmission in emerging economies may suffer Optical Signal to Noise Ratio (OSNR) shortfall below today’s design norms. We quantify the sources of this shortcoming on 100Gb/s to 200Gb/s transmission in one of the largest global markets for optical networks. Key Words Optical Fiber properties, Fiber characterization, Macro-bend loss, OSNR, Fiber optics link loss 1. Macro bends losses and its impact on fber network With the adoption of capital intensive 10-100 Gb/s transmission systems in many emerging markets such as India, the requirement of a predictable delivered OSNR in the outside plant is of paramount importance. In such economies, intense construction activity and poor installation practices lead to severe restrictions on predictable signal quality. Optical attenuation levels rise considerably beyond the beginning-of-life (BOL)/time of installation values. As a consequence of increased attenuation and the change in received OSNR (ROSNR), premature link failures especially at 100Gb/s – 200Gb/s and increased costs due to cable replacement are an operational reality. Service providers in these markets are challenged in the optimal allocation and utilization of network routes. In this paper, we identify and measure one prevalent cause of such shortfalls – macrobend losses. While well understood historically, we show here that these prevalent values of increased attenuation impact the deployment of high bit-rate communications. For the frst time, quantitative span loss results that are surprisingly beyond expected design values are presented for in- service optical networks. Multiple spans covering a total length of 197 km on live fber were measured. It was found that the existence of multiple macro-bends at joint closures or fber termination systems signifcantly increased the link loss in addition to other sources (splice, connector, fber-attenuation, et cetera). Specifcations with high bend tolerance relative to the ITU-T G.652.D category fber cable are proposed to mitigate the problem [3]. The enhanced specifcation ensures improved life of optical fber cable towards the deployment of 200Gb/s transmission and beyond [4].