Empowering utilities with better communication networks

Ulrich Kohn
Power pylons

Communications networks have always been critical to energy companies, but the emergence of distributed power generation and active sensors has made them even more important. It’s now essential that the communication network delivers secure and resilient connectivity, synchronization, and central control. It’s the underlying convergence layer enabling secure, real-time access for people and processes to any information at any time. 

Historically energy companies have installed discrete solutions for supervisory control and data acquisition (SCADA), tele-protection, site monitoring, and internal communication using different communication protocols and frequently also different media. Now they need to evolve to an open, multi-service architecture. SCADA and monitoring systems, protection relays as well as voice services or CCTV security solutions will become integrated into a common IT and OT solution.

The evolution and migration of the communication network within a power utility is not an easy task. Requirements from existing networks need to be considered and future capabilities must be met while security and availability must not be compromised. 

Continue to support legacy interfaces

Power utilities operate large, geographically dispersed networks. Any innovation needs to happen in a phased approach with continuing support for legacy systems. Established asynchronous and synchronous interfaces such as RS232 or STM1 or application-specific interfaces such as C37.94 for tele-protection have to be supported, while Ethernet over DWDM becomes the common physical interface with IP as the service integration layer on top.

Service separation and security

Having one communication network for many services creates the need for secure traffic isolation. Virtual LAN technologies such as Ethernet VLAN as well as MPLS and MPLS-TP are widely applied technologies. In energy networks, MPLS-TP gained momentum and might be complemented by segment routing, which is compatible to MPLS and IPv6 and minimizes operational complexity. Encryption can be used in addition for services with high security requirements. MACsec at Ethernet or IPsec at the IP layer are the preferred choices, while MACsec with lower overheads is best for latency-sensitive applications. 

Re-designing synchronization networks

Many power utilities apply a high number of GNSS receivers at their substations for access to precise time. Increasingly though, there are concerns about unavailability caused by jamming and spoofing as well as issues around operational complexity with thousands of receivers needing to be monitored and maintained. Delivering accurate synchronization with the packet network is a sensible approach to initially backup GNSS-delivered timing and eventually become the main timing source. This requires timing-aware switches and routers supporting SyncE and PTP in combination with highly stable core grandmasters that meet stringent ePRTC (enhanced primary reference time clock) specifications. Again, there’s a requirement to support legacy interfaces such as IRIG-B at substations or NTP, while NTP is introduced.

Availability and service assurance

Failures of network components or fiber breaks cannot be avoided, but the impact can be minimized with resilient and well monitored networks. Protection mechanism such as optical path protection, Ethernet ring protection or redundant MPLS paths can instantly repair network failures in an automated way. There is, however, also a need to identify the failed component and initiate immediate repair. This is done through sophisticated OAM capabilities at the optical, Ethernet and IP/MPLS layer. A failure in the passive fiber network can be detected and localized within milliseconds with the help of OTDR-based fiber monitoring solutions. What’s more, with the help of fiber sensors for security and environment applications, any threat to the physical infrastructure can be detected immediately.

Ease of network integration

Communication networks must combine DWDM transport with IP routing and Ethernet as well as MPLS switching. This means integrating technology from several suppliers utilizing standardized interfaces and open protocols. Domain management systems need to be interfaced into a single umbrella system for managing end-to-end services and to provide a clear display of the network status. Standards-compliant information models and modelling languages are key to controlling costs. 

Technology experts are joining forces

Communication networks for power utilities are covering applications in very different competence domains. There are IT applications that need standard IP connectivity over fixed and wireless networks but also utility OT applications such as SCADA and tele-protections with domain-specific protocols and interfaces. Suppliers with OT experience and products will work with suppliers addressing the IT and service provider market in order to combine their solutions and meet both current and future communication requirements.

Power utilities and timing diagram

This is why OTN Systems and ADVA have joined forces to pre-integrate and test a network solution for power utilities. Both companies own a leading portfolio in their home markets, and their combined solution perfectly meets the most demanding communication requirements of critical infrastructures.

OTN Systems is providing a market-leading network solution for specific industrial segments including metros, light rails, oil and gas, power utilities and mining. With its new product line, XTran, the company is well positioned to offer market-leading solutions to those enterprises. 

ADVA is a supplier of optical transport and packet switching technology, predominantly addressing the service provider market as well as data center interconnect solutions for enterprises. Its carrier-grade network products are a perfect solution for communication networks with power utilities, combining operational simplicity with highly available and resilient design. In addition, ADVA offers infrastructure assurance solutions for passive monitoring of fiber and infrastructure. Oscilloquartz, a fully owned ADVA company, is a market-leading supplier of synchronization solutions. Its portfolio was recently extended with PTP power profile, NTP server and IRIG-B interfaces for seamless migration of legacy synchronization solutions towards highly accurate PTP technology.

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