/pcq/media/agency_attachments/L8pkS8gpnodJThOdAfv1.jpg)
Follow UsBMRC used existing unused dark fibre infrastructure which resulted not only in monetary gains but also avoided digging of roads thereby avoiding public ordeal
In a developing economy like India, infrastructure forms the backbone for future growth. We all feel proud of projects like the rapid transit rail system that is operational in Kolkata, Delhi, and recently in Bangalore. But one major inconvenience that we often face while such infrastructure projects are being implemented is the digging of roads and all the re-routing that results from it. On a lighter note, it seems as if roads are built in the country to be dug up! So when the authorities take steps to minimize public suffering because of such things, they are always welcomed. One of the highlights of this particular implementation is that it avoided digging of roads for its LAN/WAN interconnectivity. There are of course, other highlights about this implementation, which we'll also talk about.
Bangalore Metro Rail Corporation, a joint venture of the Govts of India and Karnataka, has an East-West corridor that's 18.10 kms long. It starts from Baiyappanahalli in the East and terminates at the Mysore Road terminal in the West. Plus, there's a 24.20 kms long North-South corridor commencing at Nagasandra in the North and terminating at Puttenahalli in the South. This is the first metro rail project in India commissioned with 750V DC Third Rail on Standard Guage. The Bangalore Metro has been designed for a capacity of 40000 PHPDT (Peak Hour Peak Direction Trips). The number of passengers expected to travel on the metro everyday is estimated at 12 lakhs in 2013 and 19 lakhs in 2021.
In other metro rail systems (Delhi and Kolkata), there are two separate networks used at every metro station--One for operating the signaling and transmissions systems (S & T) & SCADA-TP, Tetra Radio, & Telephone; and the other for transmitting application data (ERP). Due to this, every single LAN at the stations and the depots involves using of leased line modems (line drivers), signal converters (G 703 to V.35 ) and one router. This obviously resulted in a huge capital cost. Plus, the connectivity that can be achieved per pair of fiber used is 2048 kbps, which for current applications and operational software like ERP is very less. It also puts a constraint on adding more online applications in the future, due to bandwidth limitations.
About the Implementation
BMRC decided to learn from the limitations of the other two metro rail implementations, and integrated these two networks by utilizing the existing unused raw fiber pair (usually referred to as dark fiber) that's running along the metro line. The entire connectivity was achieved by directly connecting the fiber ports of Advanced Layer 3 switches, which form the LAN backbone, to the via duct fiber pairs by using long haul fiber transceivers known as SFP's. These SFP's can drive Gigabit Ethernet signals to 40 kilometers.
How is the networking implementation that has been done in Bangalore different from the ones done in Kolkata and Delhi Metro projects?
span In Kolkata and Delhi, they could not conceptualize using existing laid out fibers for other uses besides signaling. There is lots of unutilized fiber that has been laid out for redundancy, which in Bangalore is being used to connect local networks at stations to the WAN.
Besides using it internally you have are also going to lease out existing infrastructure to generate funds, can you tell us about it?
Out of the 96 core fiber cables laid out under viaducts running along metro line only, 40-50 are being used by BMRS, rest of them can be leased out to telecom service providers. Suppose there is connectivity requirement between two stations A and B, then already laid out fiber line can be used to connect one point to another. The money generated due to this would increase the return on investment made in infrastructure. The free dark fibers will be put to tender in short course of time.
What is USP of this project?
The unique feature about this project is that the existing BMRCL fiber infrastructure was used which saved time & money for the service provider.
Impact of the Deployment
With the above implementation in place of 2048 kbps channel interconnecting the stations and depots serially, the entire network is a Gigabit network and is 100% switched without the use of any WAN devices. With this integrated network in place, LAN interconnectivity at each point has resulted in a saving of `6 to 7 Lakhs for each station and `10 to 14 lakhs for each depot. Maintenance costs saved are phenomenal. Additionally this implementation reduced the man power and skill sets required for operations. With the current implementation, all operations including the ticket issue counters and ticket readers are currently online with the ERP systems. The infrastructure can further be used to add more applications for data, voice or video. One more benefit of this project is that as the fiber is laid below the viaduct, the chances of disturbing the fiber is absolutely zero. This means there will be long lasting connectivity for both BMRC and the clients who would lease dark fibers for private usage.