At the start of this year, telecommunication giants Nokia and AT&T announced they were teaming up to offer North American utilities a solution for consistent and secure connectivity for distribution applications.
The pair now offer a private mobile broadband spectrum - Long Term Evolution (LTE) - with the purpose of helping utilities to build out and operationalise field area networks (FAN).
The offering comes as distribution companies look for solutions to address three key challenges - monitoring the grid, integrating renewables and deploying automation.
The dedicated spectrum is spearheaded at applications such as advanced metering infrastructure, SCADA, vehicle to grid, voltage and VAR optimisation and fault detection.
At the time of the launch, Kamal Ballout, Global Energy Segment Leader at Nokia, and Michael Troiano, VP, Internet of Things at AT&T, described a private LTE network as being the fabric of a utility’s strategy to monitor, control and automate distribution grids.
While still a relatively new technology to utilities, LTE has been widely deployed by mobile service providers worldwide. And in Europe, the European Utilities Telecom Council is actively seeking a dedicated spectrum.
Why LTE for field area networks?
A Nokia whitepaper points to LTE being well suited for a FAN buildout due to its high spectral efficiency. It can also operate in numerous frequency bands and accommodate different channel size, catering to different spectrum availability situations and applications.
And by providing a private spectrum, the solution aims to help prevent utilities installing multiple FANS to cover different grid applications and having insufficient bandwidth to support distribution automation “becoming a choke point of the smart grid”, according to a Nokia video on Converged FAN.
The partnership between Nokia and AT&T is seeking to remove Internet of Things bandwidth restriction by allowing utilities to lease the 2.3GHz WCS block C and D private spectrum as well as have the fallback of AT&T’s commercial network.
This latter benefit aims to appeal to distribution companies that have either not extended their network to keep pace with edge device deployment or want to start with a commercial network and later move over to a private one.
But how essential is it to use a private spectrum compared to other communication solutions?
Nokia believes the demands of a FAN - to cost-effectively cover thousands (if not more) of square kilometers of their service territory and have high availability under all circumstances - point to the need to utilise a licensed spectrum to reduce the risk of interference.
The robustness of the connection is equally important to its flexibility. Centralised applications such as SCADA and DMS require connectivity between the device and the operations centre, while newer distribution automation applications are likely to adopt a decentralised approach, states the Nokia whitepaper.
For example, a local control computer needs to acquire line data from voltage/current sensors and operate grid devices such as switches accordingly. Therefore the FAN needs to provide local connectivity between the computer, sensors and switches to facilitate short response time.
Since these applications are crucial to the operation of the grid, data transport needs to be secure. Nokia says it has responded to this need by building the solution from the bottom up with security as the bedrock.
Nokia’s white paper notes that Infrastructure operators in other mission-critical segments such as public safety and mining are already planning and deploying private LTE networks.
Role of IP/MPLS
A good solution to meeting these demands is IP/MPLS, a field-proven networking technology that can support point-to-point (P2P) and multipoint TDM, Ethernet and IP virtual private networks (VPNs), to provide needed communications to connect remote field device (via the FAN), substation and operations centre without constraints.
The value for utilities is that every MPLS service uses its own virtual forwarding instance, ensuring network resource segregation to form a dedicated VPN for each smart grid application and preventing applications from accidentally interfering with each other as a result of a device misconfiguration or malfunction.
By driving the power of IP/MPLS deep into the distribution environment, said Nokia’s Ballout, the utility is well positioned to build and operationalise a FAN to meet all future smart grid requirements.
Private LTE spectrums - hear from the experts
Is this spectrum right for your utility? Hear more about the technology and its utility use cases in an Engerati-Nokia webinar - IoT bandwidth: Benefits of a privately owned LTE network