By Paul Fadlovich, Laird Connectivity
The utility industry has been one of the fastest adopters of Internet of Things (IoT) technology, with billions of wireless devices already playing vital operational roles for electrical utilities, natural gas utilities and municipal water entities. In the electrical industry, specifically, these IoT devices are being used across every aspect of operations, including in power generation plants, on long-haul transmission lines, in local distribution networks, and in homes and businesses where power is consumed. These IoT networks are forming a new layer of digital infrastructure that allows utilities to better maintain equipment, increase worker safety, increase operational efficiency, deploy renewable technologies, meet sustainability goals, predict rather than respond to faults, and more.
All of those IoT devices rely on their antennas to successfully provide the connectivity, often in challenging environments that are unique to the utility industry. That is particularly true for electrical Transmission and Distribution (T&D). I should note here that I could have a similar discussion of the importance of antenna selection and implementation for other aspects of electrical utility operations. For example, IoT antennas face many challenges in power generation plants that require smart antenna strategies. And the same is true for antennas used in residential devices like smart meters, smart thermostats, etc. But for this article, I will focus on transmission and distribution because IoT has such a big role to play in this aspect of operations and because T&D applications present some significant challenges for antenna performance.
Below is a discussion of those challenges as well as a checklist of practical advice about how your organization should navigate critical decisions regarding your antenna strategy for those devices:
Metal Is Often the Enemy of Antennas – Metal structures can cause chaos for the Radio Frequency (RF) dynamics of an IoT deployment, negatively impacting the performance of antennas in ways that undermine their ability to do the job you need them to do. Transmission towers and other distribution equipment typically have a high concentration of metal surfaces that create significant RF challenges – with each tower or pole having unique RF fingerprints that even make one T&D site dramatically different from another that is nearby. For these reasons, IoT devices that will be on or near T&D equipment should be designed with antennas that are selected to overcome these RF difficulties, with RF modeling and testing as key steps to ensure that a device deployed in the field will perform as needed.
Antennas Need to Be Truly Rugged – In addition to the RF challenges above, T&D deployments also face unique environmental conditions that other kinds of IoT deployments do not face. Antennas located in an industrial building, for example, will not face intense daytime heat, sub-freezing overnight temperatures, rain, sleet, wind vibration and curious birds pecking at them – but in T&D locations they can experience these types of challenges on a daily basis. For those reasons, outdoor IoT devices need antennas that are rugged to a degree that far exceeds other kinds of smart utilities projects. The word “rugged” is thrown around a lot in the antenna industry, so close scrutiny and testing of an antenna’s toughness and performance in varying environmental conditions is critical. I should also note that some manufacturers market their antenna solutions as rugged, but they only offer a 30-, 60- or 90-day warranty. That clearly communicates their lack of faith in the products’ ability to perform in challenging environments. Make your vendor offer honest warranties that reflect how long a truly rugged product should last.
Be Skeptical of Data Sheets – Data sheets are one of the primary ways that engineering teams evaluate and select antennas for IoT projects, but there is a problem. Too often, data sheets don’t tell the full story about how an antenna will truly perform. The specifications may not necessarily be falsehoods, but they can be selectively chosen. They also don’t reflect real-world conditions because they are based on testing conducted in an idealized setting that is very different from the real world – especially the real world of T&D environments. This is particularly true of gain figures for example that can be deceptively high on a datasheet but that gain may be in a direction that it entirely irrelevant to the real world use of the antenna. An antenna that looks perfect on paper can prove to be underwhelming once it is deployed by a utility, which is why skepticism and testing is so important. It is important to have an antenna partner that will ask questions about the T&D sites, the specific location where devices will be attached, their RF dynamics and other specifics – all of which will help select antennas that will successfully overcome RF challenges for those variables.
Plan for Multiple Co-Existing Wireless Technologies – One of the biggest antenna-related challenges for T&D is the number of wireless technologies that must co-exist. We see IoT applications for the utility industry integrating Wi-Fi, GPS/GNSS, Cellular, LoRaWAN and even VHF radios all as part of the same network solution. Placing multiple antennas on a device to support these technologies is complex from a design perspective, so the best practice is often to select antennas that include multiple wireless protocols in a single solution – co-located in a way that minimizes interference and optimizes performance.
Vehicular IoT Should Have Its Own Antenna Strategy – I am mentioning fleet vehicles here because utilities often have a dedicated set of vehicles for T&D maintenance and repair. Since these vehicles often serve as communications hubs for T&D work being done in the field, your organization may want to think about antenna strategy for these vehicles as an adjunct to antenna strategy for IoT deployments on transmission and distribution networks. Vehicular IoT has a specific set of challenges that are distinct from static IoT implementations, not only because of the mobility of a vehicle but also because of the variety of wireless technologies operating inside and outside a car or truck. Also, there are varying RF dynamics of vehicles that have materials such as metal or fiberglass that make antenna placement on different materials require different types of antennas to operate effectively. Working with a specialist in RF dynamics will allow you to have a custom strategy for vehicles that may be very different from antenna strategy for other aspects of your T&D operations.
Sometimes Custom is the Best Solution – There are thousands of off-the-shelf antennas for IoT projects, but sometimes none of them are well suited for the project at hand because of too many tradeoffs. In that situation, a custom antenna may be the best option. Working with an antenna manufacturer to design and install custom antennas can eliminate those tradeoffs with an antenna that is optimized for the exact device, use case and deployment environment.
Paul Fadlovich is the Director of Product Management, Antennas at Laird Connectivity, which provides a full range of antenna solutions and wireless modules that simplify the process of using wireless technology. In this role at the company, Fadlovich leads development of the breadth of Laird’s antenna solutions. He has over 20 years of experience in solving antenna customer challenges for a wide variety of wireless technologies including Wi-Fi, cellular, GPS/GNSS, LMR/FirstNet and many IoT applications utilizing Cat M1, NB IoT, Sigfox/LoRa and other technologies. Paul earned his Engineering degree from the University of Minnesota, and he earned his MBA from San Diego State University.