RailTel Corporation Of India Ltd.

DWDM

RailTel is in the advance stage of deployment of DWDM based optic fibre network across major cities in India. As envisaged to provide DWDM network across India, over 10000 RKM in phase-I has already been provided in Southern India. While the work for covering whole of India is expected to be completed this year. Ultimately RailTel will have a Pan-India network covering all major cities of India as shown in the map below.

DWDM provides opportunity of offering various services on single platform and hence it is being planned for capacity enhancement on important sections in the first phase. Dense Wave Division Multiplexing (DWDM) combines multiple optical signals so that they can be amplified as a group and transported over a single fibre to increase capacity. DWDM provides the flexibility to expand capacity in any portion of the network, an advantage that no other technology can offer. With the DWDM deployment, RailTel will be able to offer dedicated wavelengths to the high use business customers instead of dark fibres, thus saving the entire fibre as is case at the present.

DWDM network can carry different type of traffic (IP, ATM, SDH/SONET and Ethernet) at different speeds (1Gbps to 10 Gbps) over an optical channel. DWDM works by combining and transmitting multiple signals simultaneously at different wavelengths on the same fiber. This way one fiber is transformed into multiple virtual fibers. RailTel’s DWDM network has capacity of 400G expandable upto 800 Gbps. With the DWDM deployment, RailTel is offering dedicated wavelengths to the high use business customers instead of fibre.