Nessum: Bridging the IoT Communication Gap—Visualizing Future Social Infrastructure with Technology That Connects Even Underwater

What if ordinary power outlets could serve as network entry points, linking a wide range of devices to the internet with no new infrastructure? Power line communication (PLC) began from that vision and is now becoming a reality, with the Technology Sector of Panasonic Holdings Corporation serving B2B customers under the Nessum brand. Nessum’s primary use case is to realize IoT networks where Wi-Fi and 4G/5G can’t, such as in factories and other infrastructure environments.

We spoke with Michimasa Aramaki of the Technology Sector of Panasonic Holdings Corporation (Panasonic HD), who leads the international standardization and deployment of Nessum, about its development and outlook.

High Definition Power Line Communication (HD-PLC) was developed in 2002. At the time, Michimasa Aramaki was working at Panasonic’s R&D division in Silicon Valley, where he was overseeing Next-Gen communication technology development.

HD-PLC arrived just as the concept of a “third internet” was emerging around power line communication technology. Such technology would allow the expansion of internet access to remote areas that xDSL* and CATV lines were difficult to reach. Panasonic also saw HD-PLC as a critical strategic technology. Aramaki notes, “I found the concept of delivering power and communications through a single infrastructure to be very compelling.”

* Digital Subscriber Line: general term for using telephone lines (copper cables) for high-speed digital communications.

Many others shared Aramaki’s view of HD-PLC’s potential for connecting home appliances to networks, and work to commercialize this “dream technology” accelerated. But Japan’s legal framework lagged behind, and even hampered the conduct of experiments. Aramaki didn’t wait. He rented apartments in California and Texas, and with help from local employees who opened their own homes, he rotated more than a hundred engineers through these temporary research facilities to conduct development and field testing. With can-do spirit and hands-on work, the technology was progressively refined.

But the rapid spread of smartphones and Wi-Fi standards like IEEE 802.11n changed things dramatically. At the same time, work to standardize HD-PLC (IEEE 1901) lagged far behind Wi-Fi and was not achieved until 2010. The result: HD-PLC’s potential to play a role in home networks actually diminished.

This led to the decisive strategic pivot that spawned Nessum. The development team decided to reorient their efforts from in-home (B2C) use to buildings and social infrastructure (B2B), where the operating environments are challenging and reliability requirements are tougher.

But the pivot to B2B infrastructure came with its own unique challenges. A residence might require up to about 30 nodes,* but buildings, factories and other large-scale infrastructure require thousands of nodes, with transmission distances up to several kilometers. Multi-hop technology** meets this challenge with proprietary Panasonic HD algorithms.

* Nodes: any devices or endpoint (computers, servers, routers) participating in the network.
** Multi-hop technology: enables long-distance communications using terminals themselves as repeaters.

Aramaki: “This technology lets us cover a transmission range of several kilometers with 1,024 nodes. This became the next step toward B2B and Nessum’s deployment to infrastructure.”

By leveraging in-place wiring and using “multi-hop” data-relay techniques, Nessum has evolved into a robust network platform capable of supporting social infrastructure. To meet the challenges presented by existing infrastructure, Nessum is proceeding as a technology “Bridging the IoT Communication Gap,” with building automation and other infrastructure as their main target.

Aramaki: “We decided to leave areas where Wi-Fi works reliably to Wi-Fi, and promote Nessum for locations that radio waves have trouble reaching.”

Aramaki noted that Wi-Fi signals fail to reach many locations, including elevators where radio signals are blocked by metal walls, underground facilities where manual inspection is impractical, and mine and tunnel worksites.

Aramaki: “Even if an accident or other emergency were to occur in a location like a mine, there will always be some electrical wiring present, such as for lighting or excavation equipment. By connecting PLC modems* to both ends of that wiring, you can monitor the situation with remote cameras and communicate with an accident site. In the same way, when disaster response requires urgent network restoration, communication is possible wherever power lines are present.”

* Modems: devices that enable internet communication by modulating/demodulating analog signals like ADSL (telephone) and CATV with the digital signals used by PCs and smartphones.

Nessum’s strengths are evident in its partnership with the global HVAC manufacturer Daikin Industries, Ltd. Daikin had been looking to break free from outdated, low-speed communication methods to advance its building management systems.

Aramaki: “Daikin presented us with a once-in-decades opportunity to overhaul its HVAC communication methods. The timing was ideal, and Nessum’s capabilities were a perfect match for their needs. What they valued above all was Nessum’s ability to make effective use of existing wiring. Today, as a member of the Nessum Alliance, Daikin is a powerful partner in helping us bring this technology to the world.”

Nessum is gaining momentum in Europe and the United States. Germany and Spain in particular were promoting the adoption of smart meters using wireless communication (LTE). But they faced a serious problem: meters installed underground were inaccessible to LTE.

Power Plus Communications in Germany and Teldat in Spain have been promoting deployment. In the United States, GE Vernova has adopted Nessum for communication equipment in smart grids. At Enlit Europe 2025, a leading global energy-sector event held in Spain in November 2025, a test called PlugFest was conducted by six companies from as many countries to verify interoperability among devices from different manufacturers. After the test, the results were made publicly available.

A technology that Japan has championed for many years and established as an international standard has finally begun to gain mainstream traction in Europe.

Nessum is evolving beyond wired communications, and Nessum AIR communicates using very low-power radio waves via antennas with a range of around one meter. Such “self-limiting communications” has advantages in terms of security as well as convenience.

Aramaki: “Nessum AIR is a short-range wireless technology that is similar to NFC used in smartphones. It allows broadband, high-speed communication, and at distances of around one meter, radio transmission is possible without complex antennas. Precisely because the range is so limited, this technology can be used for precise position control and security. It also offers new potential in areas where conventional wiring or wireless communication is difficult, such as the rotating robot-arm components or surveillance cameras that are mounted behind glass.”

Practical underwater communication using magnetic fields is also in sight. The aim is communication with divers and submersible drones, where radio-wave communication is extremely difficult. Particularly for Japan as a maritime nation, expectations for next-gen underwater communications technology are extremely high. Exploitation of resources such as rare earths, and infrastructure maintenance for offshore wind power, are at the top of the list.

Aramaki: “Nessum can communicate at several megabits per second over a distance of about ten meters, even under water. This has already allowed us to test scenarios such as a submerged diver sending video to a surface ship via smartphone.”

Aramaki also has a vision of the future that Nessum can open up through “digital twin” integration. By leveraging Nessum’s capabilities and installing sensors in all kinds of locations, seamless sensing becomes a reality.

Aramaki: “The digital-twin approach will allow real objects to be projected into the virtual world, enabling real-time remote monitoring of equipment and facilities. It will also make it possible to monitor and manage familiar infrastructure environments, such as buildings.”

In a society facing population decline and aging, Nessum’s importance will only grow, thanks to its ability to easily integrate existing infrastructure into communications networks for automated and remote collection of all kinds of data.

Rather than manufacture semiconductors for Nessum in-house, Panasonic HD has adopted an IP licensing model. Thus, instead of treating Nessum as a proprietary technology limited to Panasonic, the strategy is to propagate it as an open standard, adaptable by manufacturers globally.

Nessum is a dream that was born with PLC, survived the disruptive rise of Wi-Fi, pivoted to meet the unique challenges of B2B, and is now transforming into an indispensable technology for bridging communications gaps in infrastructure. Aramaki’s goal is to make it the global standard.

Aramaki: “When companies evaluate different communication technologies, we hope Nessum will be seen as an affordable, easy-to-implement option—the one people turn to first.”

From “The Future of Technologies Connecting People” (Nikkei Business Online Edition for Monday, February 2, 2026)