Our Case Studies

Empowering the nation's leading power carrier

Strengthening a Central Transmission Utility to scale up operations across 136 sites in 5 states, by commissioning a solution with 10,000 km of optical fibre cables.


The Eastern region of the nation's foremost power carrier comprised of 5 states, with a land area of 425,432 sq km. This was essential to empower the industrial activities occuring in the region.

In order to enable business continuity and failsafe distribution, we commissioned 10,023 km of a complex meshed OFC-based high capacity network.

The Task

Given our experience and impeccable capability in delivering turnkey solutions since 1998, we were entrusted by a Central Transmission Utility in India with their Communications Equipment Package for the establishment of a Fibre Optic Communication System in the Eastern Region of its operations.

This region sees major demands from core industrial centres of strategic national importance on account of being rich in natural resources such as coal and minerals. The region is served by a mix of 765kV, 400kV and 220kV lines with several thermal and hydroelectric power plants feeding the grid, which supplies over 125 billion units annually.

The Communication System implemented plays a key role in the day-to-day grid operations monitoring, supervision and control over the inter-state transmission system, scheduling of despatch of electricity within the region and exchange of operational surpluses amongst interconnected regions.

The whole gamut of system design, engineering, procurement, integration, Factory Acceptance Testing, installation, commissioning, Site Acceptance testing and handover of the system was successfully accomplished by us.

The Challenge

The project encompassed 136 sites, spanning 10,031 km of linear OFC distance. Delivering a project for a customer that transmits about 50% of the total power generated in India, via its transmission network, was a challenge that needed the utmost care and precision.

Ultra long repeater-less hops, stringent physical conditions of working in high electromagnetic fields, and non-air-conditioned rooms that called for tailored cabinet design and layout were all challenges that stood as a test to our overall competence.

The Solution

We designed a meshed network architecture with 151 SDH links. Further strengthening our dependable relationship with Coriant, we offered the hiT 7025 as STM 4 and hiT 7080 as STM 16 equipment with redundant hardware, 1+1 MSP for all SDH links and RSTP for Ethernet ring protection.

Various user data types were segregated using VLANs. Configurations with up to 5 MSP directions of SDH traffic were provided. A total of 156 numbers of Drop-insert multiplexers from Loop Telecom (AM3440) were provided for synchronous and asynchronous data interfaces, analogue voice, and VF E&M trunks.

14 low-level cross-connect switches were provided at key points for interconnections of the lower order voice and data services. The 151 SDH links with redundant configuration were centrally managed through a TNMS at National and Regional centres. In order to assure the availability of the system, telecom power supply systems with 8 hours of battery backup were provided.

Long-haul spans exceeding 200 km are a key accomplishment of this project. This was made possible through a combination of advanced optical transceivers, optical booster amplifiers and preamplifiers to push the limits of repeaterless fibre optic transmission to unprecedented levels using established, off-the-shelf devices.

Substantial cost-savings in capex and opex were achieved by eliminating unnecessary repeaters at locations with no actual communication requirements.

The Highlights

  • Meticulous planning and bespoke designing capabilities within Commtel allowed it to complete the project within the stipulated contractual period.
  • We were tasked with migrating the existing microwave network to the newly deployed state-of-the-art optical transmission system with minimal disruption in service.
  • Intensive testing of equipment at the local facility before dispatch to the site allowed for seamless deployment, a standing testament to our robust internal practices.
  • We provided a mix of services to cater to current and future needs including mission-critical Ethernet services, synchronous and asynchronous data, video conferencing, VOIP, and analog voice.
  • 5 SDH links with a distance of over 200 km between them were deployed without any repeater stations.
  • All-optical amplification solutions with COTS devices.
  • Superlative design with battery backup for uninterrupted services even during power outages.

The Benefits

Our 3C delivery model of Conceptualize, Construct and Care stood true to its core as it delivered on the promises made through different stages of the project.

Our detailed design, strong relations with partners, and customer-centric project management made sure that that the customer’s expectations were well surpassed. It has been Commtel’s endeavour to make the customer the centre of their universe and to always think on their behalf.

Uninterrupted access to Commtel’s expert personnel along with timely updates regarding the progress made in the project brought to the fore an amicable environment further enhancing the working camaraderie from both sides.

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