Substation modernization has become a critical priority for utilities as they navigate the transition to a new energy future. Utilities must maintain support for existing substation applications, such as teleprotection and SCADA, while adopting advanced new technologies such as IEC 61850-based grid automation. This transition also requires the integration of IT-driven solutions, including CCTV systems and IoT sensors, to enhance monitoring and operational safety.

Rethinking substation communications

A comprehensive rethinking of substation communication infrastructure is essential for succeeding with this modernization endeavor. The goal is to create a resilient, agile network that can seamlessly support legacy systems and meet the demands of modern, intelligent operational technology (OT) and IT applications.

This future substation network could be divided into three zones:

1. A legacy OT zone for supporting critical TDM-based applications such as differential protection and SCADA
2. An IEC 61850 zone for supporting intelligent electronic devices (IEDs) and automation applications at the station, bay and process levels
3. An IT zone for supporting systems such as CCTV cameras and sensors

Building an IP/MPLS network for tomorrow’s substations

The Nokia Substation of the Future network blueprint is purpose-designed to support this new architecture (Fig. 1). Composed of substation routers, substation switches and a network automation platform, this comprehensive IP/MPLS solution enables utilities to address the networking needs of technologies in all zones.

Fig. 1 Nokia Substation of the Future network blueprint

In the legacy OT zone, the solution provides seamless connectivity for critical applications that rely on TDM-based communications. It offers a rich portfolio of TDM interfaces, including C37.94, RS-232, G.703 and E&M, and can transport the TDM traffic onto the IP/MPLS wide area network (WAN) with the same quality of service (QoS) and reliability as SONET transport.

For the IEC 61850 zone, the solution delivers high-performance Ethernet networking for the station bus and process bus. It enables efficient connectivity for IEDs and applications across the station, bay and process levels, supporting protocols such as Sampled Values, GOOSE, synchrophasor, interlocking and busbar protection.

In the IT zone, the solution offers high fanout and high Power over Ethernet (PoE) networking capabilities. It supports IT devices such as CCTV cameras, VoIP phones, IoT sensors, Wi-Fi access points and security access systems. These capabilities enable utilities to integrate modern monitoring and communication technologies into their substation infrastructure.

Five key network capabilities for substation modernization

Utilities face increasing pressure to modernize substation network architecture as they refresh and expand their grids. To do this, they need to extend reliable and scalable connectivity across their grids for new applications while integrating the existing systems. Our Substation of the Future network blueprint directly addresses these challenges with innovative capabilities that drive measurable benefits and a profound industry impact.

Here are five must-have capabilities provided by our blueprint:

1. Graceful TDM migration 

The blueprint connects with deployed critical TDM-based applications, including differential protection and SCADA. Network innovations such as Asymmetric Delay Control (ADC) for mitigating network asymmetry and Active Multipoint Pseudowire (AMP) for hitless redundancy protection ensure that communications reliability and QoS meet the requirements of demanding applications such as L87 differential protection.

2. Resilient and precise time synchronization

Time synchronization is foundational to grid automation. In addition to using GNSS/GPS as the timing source, the blueprint can use the IEEE 1588 Power Utility Profile to distribute time data from the Primary Time Reference Clock (PTRC) through the WAN to all devices in the substation. The use of the Best TimeTransmitter Clock Algorithm (BTCA), formerly called the Best Master Clock Algorithm, and boundary clock provides robust resiliency for the distribution of synchronized timing.

3. Quantum-safe network security

IEC 62351-9, the international standard for power system data and communication security, acknowledges the substantial threat posed by quantum computing to the security of utility communication. The standard highlights particular concern for the public key algorithms widely used to encrypt grid communications. 

It will take years for developers and vendors to incorporate post-quantum cryptography (PQC) in their applications, so utilities need to upgrade their encryption protection to quantum-safe levels immediately. Our substation routers address this need with quantum-safe MACsec encryption that can thwart the emerging quantum threat today.

4. Readiness for future communication bandwidth growth

Our blueprint can support 10 GE and 100 GE connections to substation routers. This provides abundant bandwidth for emerging and future grid applications as utilities embrace more data-driven and application-centric operations. Additionally, our substation routers are equipped with coherent optics that offer cost-effective transport and seamless compatibility with any underlying optical transport infrastructure. They provide utilities with maximum flexibility and scalability.

5. High network node programmability

Utilities expect their communication networks to have a long service life, yet the demands on these networks continue to evolve. The Substation of the Future blueprint addresses these demands by emphasizing highly programmable network nodes that offer the flexibility to adapt and scale over time. This programmability ensures that as new applications, protocols, and operational requirements emerge, the network can be updated and optimized without costly hardware replacements. With these capabilities, utilities can future-proof their network investment and support continuous innovation.

Discover our expanded IP portfolio at the 2025 UTC T&T Conference

For more 30 years, we have partnered with utilities to address their mission-critical communication needs. As the energy landscape evolves, so do the requirements of communications infrastructure. In response, we are expanding our mission-critical IP networking portfolio to help utilities advance and future-proof their networks. 

We invite you to join us at the 2025 UTC Telecom & Technology Conference in Long Beach, California, from June 16-19 to explore our latest innovations and offerings. You can also download our new Mission-critical Networking for Utilities brochure and visit the 7705 SAR web page to learn about the expanded portfolio. 

We look forward to continuing to support utilities as they navigate the exciting energy journey ahead.