Transition to Packet Networks

Hierarchy) and SONET (Synchronous Optical Networking) infrastructures, which provided the necessary deterministic performance, extensive Operations, Administration, and Maintenance

(OAM) capabilities, and high reliability. The communication networks of the electric grid are at a critical juncture due to the growing demand for data services and the widespread adoption of IP and Ethernet technologies. Legacy systems such as TDM (Time Division Multiplexing),

SONET, and SDH, once considered reliable, have become outdated, costly, and incapable of meeting modern operational requirements.

Goals:

Transition to Packet Transport Networks (PTNs) using IP/MPLS (Internet Protocol/ MultiProtocol Label Switching) with MPLS-TP (Multi-Protocol Label Switching-Transport Profile) emerging as the preferred solution for delivering reliable, scalable, and cost-effective communication. Utility has adopted a phased approach to migrate from legacy system to packet network by leveraging MPLS-TP technology, ensuring minimal disruption and maintaining system reliability.

Results:

The Utility has deployed IP/MPLS including MPLS-TP in approximately 250 substations.

The Utility has upgraded its communication infrastructure with minimum disruption and achieved below milestones:

i) Backbone network availability of more than 99.9% [1], ii) Improved network performance with enhanced bandwidth, iii) 24x7 proper network monitoring support to ensure real time control, iv) Reliability and resilience of power systems have been enhanced. This paper presents practical experience gained during the migration from legacy system network to packet-based IP/MPLS networks used for transmission utility in India. The paper concludes that packet networks can meet protection requirements with properly engineered

QoS and states that carefully designed and secured packet networks have proven in practice to be able to reliably support mission-critical power system communication providing scalability, interoperability, and future readiness.