Optic fibre cable (OFC) offers a significant advantage over other communication mediums due to its unlimited capacity, high degree of security and long-term economic gains. Further, it finds extensive application across industries. While the use of OFC in the telecom industry is widespread, it can also be used for intelligent transportation systems, connecting the power transmission infrastructure and in the biomedical industry. Despite several uses of fibre, India has very low OFC penetration as compared to other emerging countries. Lower income levels leading to service affordability issues have limited penetration among customers.

Powergrid

Powergrid Corporation of India Limited (Powergrid) is responsible for managing the country’s power transmission network. It has leveraged the convergence of the power sector with the telecom sector by making low-cost and high quality telecom infrastructure available on its existing and planned transmission infrastructure. Currently, the utility has an overhead OFC network of 35,000 km and an additional 33,000 km is under implementation. Earlier, the power system was operated through power line carrier communication. Communication between the substations and generating stations was carried out through the same lines that carried power by modulating the frequency. The company diversified into telecom as the grid started becoming more complex and power systems started increasing in size, leading to a higher data requirement. The company found it worthwhile to replace its conventional earth wire with earth wire carrying optic fibre, called optical ground wire (OPGW), to manage communication on the grid.

Optic fibre can be incorporated with power lines using technology like OPGW, wrap, lash, metallic self-supporting, all dielectric self-supporting (ADSS), and optical phase conductor. While OPGW technology is the most dominant, followed by ADSS, the other  technologies are still not very common. In ADSS technology, fibre is deployed inside high density polyethylene tubes and it is suitable for transmission lines of up to 220 kV.  This technology is flexible, reliable and long lasting, and can be installed without shutting down power. In addition, it is easy to commission and maintain, and is ideal for reinforcing the existing networks. ADSS technology also has the advantage of being weather-proof and free from electromagnetic interference. OPGW, on the other hand, is appropriate  at sites where ground wire is available and is best suited for high voltage lines. In fact, it acts as an earth wire as well as OFC. The integration of telecom networks with the transmission system ensures high availability of communications networks.

By incorporating optic fibre in its network, Powergrid has not only been able to better manage communication on its power transmission network, but has also been able to sell its surplus capacity and optimise asset returns.

RailTel

RailTel Corporation of India is a public sector enterprise with Mini-Ratna status. It is one of the largest neutral telecom infrastructure providers in the country owning a pan-Indian optic fibre network with exclusive right of way along railway tracks covering about 7,000 stations. The company offers a wide range of telecom services for telecom companies, government departments, enterprises, banks and educational institutions. RailTel currently has an OFC network along 44,300 route km of railway tracks. It provides OFC connectivity at more than 4,400 railway stations (including more than 600 long-haul and 3,800 short-haul stations). It has a high capacity bandwidth of up to 800G at 60 locations and an IP network for triple- play services of voice, video and data.

RailTel is also one of the three partners in the National Optical Fibre Network project. Its scope of work is spread across 36,000 panchayats in 11 states. Further, the company is laying fibre network in six north-eastern states under the Universal Service Obligation Fund. It  is also the lead organisation involved in the deployment of the National Knowledge Network, which connects various institutions of higher learning in the country. The company is currently focusing on delivering services to the enterprise and retail sectors. It has already launched services such as data centres, Wi-Fi, cloud and telepresence on its OFC network. It is also in talks with Indian Railways for launching an information and communications technology-based signalling system through its fibre network.

Conclusion

OFC has tremendous potential in terms of offering telecom and broadband connectivity. However, huge costs are involved in laying this infrastructure. There is a need to develop an appropriate environment for sharing passive and active infrastructure among service providers in order to ensure faster OFC deployment and service roll-out.

Based on presentations by Manoj Pandey, DGM, Telecom, Powergrid; and Ravi Vishwakarma, DGM, Projects, RailTel Corporation