For the past two years, utility provider Ameren has been testing a private LTE network with equipment from Nokia and CommScope and spectrum from AT&T and Anterix. Now company officials are increasingly hinting that Ameren is preparing to shift from the testing phase to the deployment phase.

"Ameren envisions a future where broadband plays a key role in the control and management of our network, providing enhanced communication with co-workers, resulting in a better experience for our customers," said Bhavani Amirthalingam, Ameren's chief digital information officer, in announcing the company's intention to lease Anterix's 900MHz spectrum for its network. "Ameren intends to use a private LTE network for a wide range of applications slated to expand over time."

Ameren is a publicly traded utility providing energy services to roughly 2.4 million customers across 64,000 square miles in Illinois and Missouri. The company currently operates an aging Harris P25 LMR system for wireless communications and, as part of its long-term strategy, plans to migrate to an LTE network. The effort dovetails with the company's new $7.6 billion "smart energy plan" announced last year, which focuses on innovating and upgrading Ameren's current energy grid.

Ameren's private LTE ambitions began taking shape in 2018, when the company asked the FCC for permission to begin testing a private network using spectrum from Anterix. "Ameren intends to use a private LTE network for AMI [advanced metering infrastructure] or AMI backhaul, distribution and gas system sensors and controls, substation backhaul, and monitoring and control of customer-owned distributed energy inverters. The applications at these sites include SCADA [supervisory control and data acquisition], remote engineering access, Wi-Fi, telephony, push-to-talk, and general workforce mobility applications," the company said in its 2018 testing application to the FCC.

Earlier this year, the company outlined the results of those tests in a report with the Utilities Technology Council, a trade group that represents US energy and utility companies.

"In support of the integrated grid, Ameren's network strategy is to minimize the dependency on carriers and third-party service providers for communications supporting grid management by moving to a private network," the company wrote. "The objective is to implement a robust wide-area network backbone utilizing fiber-optic communications in the grid, provide private wireless backhaul communications for distribution automation, SCADA, corporate local-area network, physical security and metering, and provide a standardized and highly secured packet-based, end-to-end network solution. While building a fiber communications network isn't new in our industry, the building of a wireless field-area network using private LTE is relatively new."

The company said its live trials were held in Illinois across several different cell towers up to 260 feet tall, covering several miles of territory, and two electricity substations.

The company said that it tested a variety of applications, including the collection of metering data through its own mesh network, then transmitting that data over an unnamed public cellular network to Ameren's operations. The company also said it tested remote wireless access to its distribution substations and voice calling, including Wi-Fi calling, on its private LTE network.

Importantly, Ameren said it tested operations in both Anterix's 900MHz spectrum and AT&T's 2.3GHz WCS spectrum. That's noteworthy because AT&T and Nokia announced an effort in 2016 to develop a private, secure LTE network for utilities using AT&T's WCS spectrum. The two companies have been silent on the topic since that announcement.

It's unclear whether Ameren plans to use spectrum from AT&T for its planned private LTE network in addition to spectrum from Anterix.

"Ameren is committed to investments that ensure the electric grid delivers clean and reliable energy. The letter of intent signed with Anterix is one step in that direction," the company said in response to questions from Light Reading on the topic. "While we have investigated several spectrum options, we feel most utilities will need multiple spectrums to meet their network needs. We believe 900MHz will be a solid anchor spectrum for our network to meet the needs of our business and our customers."

The Wall Street analysts at B. Riley FBR estimated that Ameren could end up paying Anterix anywhere from $4 million to $20 million per year for the use of Anterix's 900MHz spectrum.

To be clear, Ameren is not alone in its interest in private LTE networks. For example, Duke Energy and the New York Power Authority (NYPA) are among the other utilities that have signaled their interest in building their own private LTE networks. However, Ameren will need to wait for the FCC to authorize LTE operations in Anterix's spectrum before it can begin constructing its network.

Nonetheless, the growing trend toward private wireless LTE networks, especially among utilities, is becoming clear.

— Mike Dano, Editorial Director, 5G & Mobile Strategies, Light Reading | @mikeddano