By Stewart Kantor, Full Spectrum Inc.
No reasonable person would question the fact that we are entering a phase of explosive growth in consumer, commercial and industrial automation. Many of these applications have been rebranded under the new catch-phrase “Internet of Things” (IoT). For electric utilities and other mission critical entities, however, the wide-scale implementation of the IoT isn’t completely straightforward.
Electric utilities have been using data communications for remote monitoring and control since the late 1960s, long before the most advanced corporate enterprises adopted distributed data communications. The ready availability of public broadband wireless and wired IP networks, commonly used for today’s corporate and consumer data communications, introduces substantial risks to the operation of mission critical industrial networks and grids. Some of these risks are so substantial, from distributed denial-of-service (DDoS) to the introduction of many points of failure, that they may not warrant adoption of the technology, especially if the public networks lack sufficient security and quality of service. In recent years, however, new radio technologies have emerged that enable utilities to deploy cost effective, scalable, secure, private wireless Internet across their service territories.
Furthermore, these new radio technologies are capable of leveraging a utility’s existing wireless communications infrastructure to create a completely Private IoT.
SCADA: The data communications protocol that started it all
In the late 1960s, utilities introduced a new data communications protocol known as Supervisory Control and Data Acquisition (SCADA) and Automatic Generation Control. SCADA was originally designed to help utilities remotely monitor and control key elements of the electric grid, and today it continues to be the primary data communications protocol for the management of industrial networks worldwide. SCADA systems were initially implemented over highly reliable, circuit switch leased phone lines supplied by the incumbent local exchange carrier (ILEC). ILECs were closely regulated entities until the Telecommunications Act of 1996, which negatively impacted the mission critical design of the legacy landline telecommunications network. Today, SCADA systems continue to be the lifeblood of most industrial networks around the world but still depend on secure and reliable physical connections to be truly effective.
Legacy landline networks are deteriorating with no viable substitute of similar quality and security. As a result, utilities are left with a difficult choice of using either less secure, less reliable alternatives or no reasonable replacement at all. This has led utilities to search for new private wireless alternatives to address the gap.
Utility Owned and Operated Private Communications Networks
Prior to deploying SCADA networks, most U.S. utilities had already deployed mobile wireless voice systems known as private land mobile radio (PLMR). These networks are most commonly seen in use by first responders, as either radios installed in vehicles or handhelds. All utilities in the U.S. own, operate and maintain similar PLMR systems for their day-to-day operations such as troubleshooting and maintaining all aspects of the electric grid including coordinating their remote workforce during the restoration of power outages. These systems use small slices of VHF and UHF frequencies and are capable of transmitting voice communications over very long ranges.
In addition, PMLR systems are designed and operated in a similar fashion to commercial cellular networks except these networks are exclusively used by the utility. Even with the introduction and evolution of commercial cellular voice and data communications in the 1980s, utilities continue to operate, maintain and upgrade their PLMR systems at great expense.
Challenges With Commercial Cellular Networks
Utilities continue to use their own PLMR networks for a number of reasons including major concerns about the reliability and availability of commercial cellular networks during manmade and natural disasters. Commercial cellular base stations and tower sites are powered by the same electric grid that is maintained by the utility companies. Commercial wireless operators have chosen to provide only a minimal amount of backup power at their tower sites.
In 2008, after a series of natural disasters and prolonged network failures including outages during Hurricane Katrina, the FCC proposed an eight-hour minimum of backup power at all cellular tower sites, which was contested in court and eventually won by the cellular industry. The negative consequences of these limitations continue to be felt during natural disasters including simply with backup power of the cell sites. It also involves a host of security and service quality issues related to the fundamental design of commercial systems. For example, commercial wireless systems are designed and deployed with the assumption that only a small portion of subscribers are using the network at any one time for voice and data communications. This concept is referred to as oversubscription and it is a fundamental design flaw for mission-critical voice and data networks which need to be available with the same quality at all times.
Utility PLMR infrastructure is now emerging, however, as a perfect jump-off point for the implementation of a Private IoT, eliminating the gap created by the decay of the landline network and the security and quality of service issues posed by broadband commercial wired and wireless networks.
New software defined radio technology using 4th generation wireless standards similar to LTE systems and operating in exclusive licensed VHF and UHF frequencies are enabling utilities to leverage their existing PLMR tower and backhaul infrastructure to implement a completely secure and scalable Private IoT. These new Private IoTs are designed in a similar fashion to operate over the utility’s service territory like PLMR networks but are completely independent of the public Internet, eliminating external security threats including the potential devastating impact of a DDoS.
These innovations in radio technology are occurring at an ideal time for utilities as they contemplate a major expansion in their SCADA networks to support automation of all aspects of the electric grid.
Leveraging PLMR Infrastructure for Private IoT
PLMR systems are economical to deploy because they require only a few base station tower sites to cover large geographic expanses. A typical PLMR radio tower is capable of covering 1,200-plus square miles. These systems achieve wide area coverage by using high power radio amplifiers in narrow bandwidth channels in low band radio frequencies. Early commercial cellular systems were an outgrowth of these very same PLMR systems and had a similar design and coverage capability. In the early days of cellular, this was the only economical way to offer service given how few customers used these networks. Today, it is hard to believe, but in 1985, there were only 350,000 cellular subscribers nationwide and the growth potential for commercial wireless was still very much in question. As the number of cellular users increased and the new-found demand drove costs down for phones and service rates, carriers shifted their concerns from coverage to capacity and from analog to digital in order to support thousands of simultaneous users off of a single tower site.
In the PLMR world, however, coverage has remained paramount in order to minimize the infrastructure costs to support a private network. So while PLMR systems continue to support 1,200-plus square miles of coverage per tower site, LTE systems today are designed to cover approximately 30 square miles per tower. This translates to 40 times the number of tower sites to achieve the same coverage as a modern PLMR system.
Enter SDR Technology and “Fog” vs. “Cloud”
Building off of a similar coverage structure to PLMR systems spectrum, new software-defined radio (SDR) technology additionally provides advanced data capabilities and quality of service features that exceed 4th generation LTE commercial wireless networks.
Utilities today are capable of installing new private wireless broadband base station technologies at their existing PLMR tower sites without the added requirement of additional tower installations. In doing so, they obtain coverage that parallels the PLMR system but with the support for high speed data.
These newer innovations, like Full Spectrum’s FullMAX network technology, have been designed from the ground up to meet the specific needs of utilities. Bandwidth allocation is just one fundamental design difference in private wireless utility networks vs. commercial 4G LTE systems. Commercial LTE systems are designed with dedicated downlink and uplink frequencies, with most of the bandwidth allocated to downlink in order to support high capacity downloads, and minimal bandwidth allotted to upstream.
Utility networks require the inverse with most of the critical data residing along the grid. This includes the capability to communicate with a host of devices and applications including monitoring and control of voltage regulators, capacitor banks, circuit breakers, switches and new high volume applications like distributed energy resources (e.g. remote solar storage). In current data network vernacular, utility data resides at the edge of the network in the “fog” vs. commercial systems that host data in “the cloud.”
Another critical difference between commercial and private utility networks is the need to prioritize data based on location, application and device. Commercial LTE networks are designed as best-effort systems with shared throughput and unpredictable and variable latency. Utility networks have varying degrees of data priority ranging from low priority, higher bandwidth smart meter traffic to high priority, latency sensitive, low bandwidth, switching traffic.
With software defined radio technology, these variables are under the utilities’ control and can be adjusted in real time. Unlike LTE communications networks that are designed for general consumer use, the Private IoT has been custom developed to meet data communication needs for utilities, providing a better solution for grid automation. Software-defined radio technology offers utilities control over data monitoring and communications throughout the grid with the added benefits of high reliability and rock-solid security.
This Private IoT never even touches the public Internet. Utilities are now in a position where automation is not only possible but it can be accomplished at a relative low cost by leveraging their existing infrastructure, ultimately warranting the adoption of this Private IoT.
Stewart Kantor is co-founder and CEO of Full Spectrum Inc., a California-based firm that designs, manufactures and sells its FullMAX brand of radio networks. He has 20 years of experience in the wireless industry including senior level positions at AT&T Wireless, BellSouth International and Nokia Siemens Networks.