The Wi-SUN Alliance says India is entering a major growth phase, with large deployments already underway. CEO Phil Beecher discusses mesh networking, AI, post-quantum security, and opportunities for Indian product developers in an interview with Nidhi Agarwal from Electronics For You.
Q. What technical problems was Wi-SUN Field Area Network (FAN) designed to solve that existing wireless technologies could not?
A: Wi-SUN was designed to provide interoperable, large-scale wireless mesh networking for critical infrastructure, particularly utility smart metering. When the Wi-SUN Alliance was formed, most available solutions were proprietary and offered by individual meter manufacturers, meaning devices from different vendors could not work together. Wi-SUN standardised the communication technology to enable interoperability across vendors while also delivering enterprise-grade security, creating a reliable and secure networking platform for large utility deployments.
Q. How does a Wi-SUN FAN work in a typical utility deployment?
A: Wi-SUN FAN is based on the IEEE 802.15.4 standard and supports multiple radio modulation techniques, allowing utilities to choose the right balance of range, data rate, and power consumption for different deployment scenarios. It uses Internet Protocol (IP), enabling integration with proven internet-based security architectures. The network is self-forming and self-healing, with devices communicating through a multi-hop mesh, so if a smart meter cannot directly reach the utility gateway because of buildings, thick walls, or other obstacles common in dense urban environments, it automatically routes data through neighbouring devices. Wi-SUN FAN also uses frequency hopping, allowing devices to switch channels if one becomes congested, experiences poor propagation, or is affected by interference or a denial-of-service attack, thereby improving network reliability, resilience, and security.
Q. How does Wi-SUN maintain reliable communication in large and dense mesh networks with hundreds or thousands of nodes?
A: Wi-SUN is designed to perform better as mesh networks become denser. Its use of frequency hopping enables devices to make maximum use of the available radio bandwidth while reducing interference. If a point-to-point connection experiences a problem, devices can automatically reroute traffic through neighbouring nodes. Likewise, if there is a point of failure anywhere in the network, communication is automatically redirected around that failure, ensuring uninterrupted operation. Wi-SUN also supports multiple border routers, which are equivalent to data concentrators. For example, in a smart meter network with around 1000 devices, traffic may normally pass through a single border router. If additional border routers are deployed and one of them fails, the network automatically routes communications through another border router, allowing data to continue reaching the utility without interruption.
Q. Is there a practical limit on Wi-SUN network size, hop count, and latency in real-world deployments?
A: Yes, there are practical limits. The Wi-SUN specification allows up to 32 hops between a device and the edge of the network, but in reality that would introduce too much latency, so most deployments typically use four to five hops, and sometimes up to six. The number of devices connected to each border router depends on the application. For typical smart metering applications, a border router generally serves around 500 to 1000 devices. If the application requires higher data rates and lower latency, utilities may reduce that number to around 100 to 200 devices per border router. Another advantage of Wi-SUN is that border routers are generally not expensive. While environmentally protected versions cost more, deployments with around 100 to 200 devices can use relatively low-cost border routers, helping keep the overall network cost down.
Q. How does Wi-SUN optimise power consumption for battery-powered field devices?
A: Wi-SUN uses different radio modulation techniques depending on the application. Higher data-rate applications use orthogonal frequency-division multiplexing (OFDM), which has higher power consumption, while battery-powered devices use a simpler modulation technique called frequency shift keying (FSK) that enables very low energy consumption during transmission. Power usage is further reduced through duty cycling, where the radio remains off most of the time and turns on only when communication is required. One of the design goals for battery-powered Wi-SUN devices was to achieve up to a 20-year battery life for applications such as water and gas meters. These battery-powered devices communicate with another part of the mesh network that remains continuously active. Since Wi-SUN networks can deploy more router nodes than cellular systems, the transmission distance for battery-powered devices can be shorter, allowing them to transmit at lower power and further reduce energy consumption.
Q. What are the biggest factors affecting network performance in urban versus rural deployments?
A: In urban deployments, one of the biggest challenges for traditional wireless technologies is the presence of radio shadows—areas where signals cannot easily reach because of obstacles. Modern cities contain large amounts of reinforced concrete and glass, while older cities often have thick stone buildings and narrow streets that create equally difficult radio environments. For example, historic areas such as the City of London, with its centuries-old stone structures, or dense parts of Old Delhi present significant propagation challenges. Wi-SUN performs well in these environments because of its mesh networking architecture. Even when a device cannot establish a direct connection to the border router, it can communicate through neighbouring nodes, allowing the network to maintain reliable coverage despite physical obstacles.
Q. How does adaptive frequency hopping improve reliability in congested RF environments?
A: The available spectrum in any radio frequency (RF) environment is limited, and when multiple wireless technologies share the same band, congestion can occur. Wi-SUN technology optimises the use of the available bandwidth not only within the Wi-SUN network but also while sharing the spectrum with other devices. Although heavy traffic naturally limits the number of devices that can communicate and the bandwidth available, Wi-SUN improves network efficiency through its wireless mesh architecture. Another important advantage is that mesh nodes can adjust their transmit power. This allows geographically separated groups of devices to communicate with their nearby neighbours without interfering with each other. While adaptive power control is not part of the official Wi-SUN specification, it is commonly implemented by member companies in their products to further improve network reliability.
Q. How does Wi-SUN avoid interference from other wireless technologies such as LoRaWAN, Bluetooth, and other sub-GHz technologies?
A: Wi-SUN operates in the sub-GHz frequency band, which is shared with several other wireless technologies depending on the region. To minimise interference, Wi-SUN uses frequency hopping, allowing devices to continuously switch between channels instead of remaining on a single one. It also supports channel avoidance, meaning that if a particular channel experiences excessive interference, the network identifies it as unsuitable and stops using it. Additionally, Wi-SUN benefits from OFDM, whose coding techniques improve interference mitigation and help maintain reliable communication even in challenging RF environments.
Q. Can Wi-SUN coexist with private LTE or private 5G networks in the same utility deployments?
A: Yes. In fact, Wi-SUN and private long-term evolution (LTE) or private 5G are often complementary technologies rather than competing ones. Wi-SUN FAN operates in a different frequency band from LTE, which uses licenced spectrum. In many utility deployments, particularly in the United States, Wi-SUN FAN is used to create the wireless mesh network connecting field devices, while the border router sends the aggregated data back to the utility office over LTE. Depending on the deployment, the border router may also use fibre or Wi-Fi for this higher-bandwidth connection.
This combination makes efficient use of the available spectrum. Cellular technologies are well suited for transmitting large blocks of data over long distances, whereas they are less efficient for the small packets generated by applications such as smart meter readings. Wi-SUN FAN efficiently collects data from smart meters, switch reclosers, and other distribution equipment, aggregates data from hundreds of meters, and then forwards it over a cellular connection to the utility office in a highly efficient manner.
Q. Were any technical changes required to achieve ISO, IEC, and IEEE standardisation?
A: No technical changes were required. The process began when the Wi-SUN Alliance submitted its specification to Institute of Electrical and Electronics Engineers (IEEE), where it became IEEE 2857. A liaison between IEEE and IEC/ISO then resulted in the same specification being adopted as ISO/IEC/IEEE 32857. In addition, IEEE has a liaison agreement with the Bureau of Indian Standards (BIS), and the specification has also been adopted by BIS, meaning the same technical specification has been recognised by international as well as Indian standards bodies without requiring any changes to the technology.
Q. Beyond protocol compliance, what does the Wi-SUN certification process test?
A: The Wi-SUN certification program goes beyond simply verifying protocol compliance. It also includes testing of the certificate-based authentication mechanism used in Wi-SUN FAN. During certification, specific test certificates are installed on devices to validate the complete authentication, security exchange, and verification process. In addition, manufacturers are encouraged to participate in interoperability (plugfest) testing, where devices from different vendors are tested together. Although this interoperability testing is not currently a mandatory part of certification, it helps manufacturers identify and resolve interoperability issues before deployment.
Q. How does Wi-SUN protect utility networks from spoofing, replay attacks, and unauthorised devices?
A: Wi-SUN uses multiple layers of security to protect utility infrastructure. First, all device communications are encrypted, ensuring message confidentiality. Every message also includes an integrity check through a digital signature, allowing receivers to verify that the message has not been altered. Devices are authenticated before joining the network using certificate-based authentication. Each device is provisioned at manufacturing with a digital certificate, similar to a passport, along with authorisation credentials that specify which network it is allowed to join. When the device powers up, it performs a secure exchange with an authentication server to verify both its identity and its permission to join the intended network. To prevent replay attacks, every transmitted frame includes frame security with a frame counter. If an attacker captures and retransmits a previous message, it will be rejected because the frame counter will no longer be valid.
Q. How does Wi-SUN support secure firmware-over-the-air (FOTA) updates?
A: Wi-SUN’s combination of flexible data rates, long communication range, and bidirectional communication makes it well suited for firmware-over-the-air (FOTA) updates. The available bandwidth allows large firmware images to be transferred reliably, while two-way communication enables acknowledgements and handshaking during the update process. Security is ensured through firmware signing. The same certificate infrastructure used for device authentication also supports digital signatures for firmware images. Before installing an update, the receiving device verifies the firmware’s digital signature to confirm that it originated from a trusted source and has not been tampered with. This prevents attackers from installing unauthorised or malicious firmware on devices.
Q. With quantum-safe cryptography becoming increasingly important, how is Wi-SUN preparing for the post-quantum era?
A: Wi-SUN continues to evolve its specifications to address emerging security requirements. The next generation of the specification is already being developed, and utilities have identified post-quantum security as an important requirement. The Advanced Encryption Standard (AES) encryption currently used for securing Wi-SUN communications is already considered post-quantum safe by the U.S. National Institute of Standards and Technology (NIST) for message encryption. The alliance is now focusing on strengthening the authentication process by incorporating post-quantum cryptographic algorithms. The current direction is to use the module-lattice-based key-encapsulation mechanism (ML-KEM) as a post-quantum key exchange mechanism, providing stronger protection against future quantum computing threats.
Q. How does Wi-SUN support distribution automation, fault detection, and self-healing power grids?
A. Wi-SUN FAN 1.1 introduces higher data rates of up to 2.4Mbps, reducing latency and enabling faster communication between devices. Its mesh networking architecture also allows smart meters, which monitor not only electricity consumption but also power quality, power factor, and perform basic fault monitoring, to route information locally instead of sending it all the way back to the utility’s back office before action can be taken. Border routers and similar edge devices can process this information locally using built-in intelligence, and if configured by the utility, the processed data can be sent directly to distribution management systems. This local data collection and processing enable faster fault detection, quicker response, and more effective distribution automation.
Q. How does Wi-SUN prioritise critical utility traffic during emergencies?
A. Critical traffic prioritisation is handled at the network layer. Although Wi-SUN does not currently include a formal quality of service (QoS) capability as part of its specification, Wi-SUN member companies consistently implement basic QoS mechanisms based on the specific operational requirements of individual utilities, allowing critical traffic to be prioritised during emergency situations.
Q. What tools are available for network monitoring and predictive maintenance in Wi-SUN networks?
A. Wi-SUN itself does not define a specific network monitoring or predictive maintenance framework. Because the underlying technology is based on IPv6 and supports the Constrained Application Protocol (CoAP), different network management protocols can run over a Wi-SUN FAN network. Two widely used open standards are Lightweight M2M (LwM2M) and the CoAP Simple Management Protocol (CSMP). LwM2M has also been specified by the Bureau of Indian Standards for applications such as network management, while CSMP is another open standard with several implementations. The choice of protocol is left to the utility or municipality, depending on its requirements, and a Wi-SUN device can even support both protocols simultaneously.
Q. How is AI being used in Wi-SUN networks today?
A: Artificial intelligence (AI) is being used across Wi-SUN networks for both edge intelligence and cybersecurity. Many smart meters now incorporate AI chips that perform edge processing, including energy usage disaggregation to identify the power consumption of individual appliances. For example, if a refrigerator’s compressor begins to fail, the smart meter can detect the change in its energy signature and alert the consumer before a breakdown occurs. Utilities also use AI to monitor power quality and detect faults in overhead power lines. Wi-SUN’s wireless mesh architecture supports these applications by enabling processing close to where the data is generated.
AI also strengthens cybersecurity. Because Wi-SUN is based on IPv6, every connected device has a unique IP address, allowing AI-based intrusion detection systems to monitor each device individually rather than only the gateway. If a cyberattack occurs, utilities can identify the exact device that has been compromised, providing greater visibility than technologies where monitoring is limited to the gateway.
Q. What security enhancements are planned for Wi-SUN, and what does the technology roadmap include?
A: Security remains a key focus for the Wi-SUN Alliance. The roadmap includes standardising the next versions of extensible authentication protocol transport layer security (EAP-TLS), the internet protocol used for secure device authentication, and developing support for post-quantum security. The alliance also continuously tracks developments in cybersecurity and follows evolving best practices, including the minimum security requirements being defined by the U.S. National Institute of Standards and Technology (NIST) for critical infrastructure. If new security measures become necessary and are not already part of the Wi-SUN FAN specification, they will be incorporated to ensure the technology remains as secure as practically possible.
Q. With Wi-SUN now becoming an ISO/IEC standard, what are the alliance’s top technology priorities for the coming years?
A. Our priorities include strengthening security by advancing post-quantum capabilities, expanding device authentication options, and modernising security algorithms. We are also improving device repudiation capabilities, making it easier to detect and remove devices from the network when necessary. Another focus is optimising routing algorithms to provide greater flexibility for distribution automation, particularly as utilities deploy more distributed energy resources (DERs) that require efficient peer-to-peer communication. Beyond utilities and smart metering, we are also exploring several new application areas with different communication and networking requirements, and we are actively working to address those evolving needs.
Q. How is the Wi-SUN Alliance preparing for the growing number of connected devices expected over the next decade?
A: As an industry alliance, Wi-SUN works closely with its member companies, which develop and supply products. The alliance supports them by providing testing and evaluation tools that enable faster and more efficient validation of products against the Wi-SUN specification before they undergo certification. It is also expanding the number of certification test laboratories so that more companies can test and certify their products, helping meet the growing demand for connected devices.
Q. How important is India to the Wi-SUN Alliance’s global strategy?
A: India is a strategically important market for the Wi-SUN Alliance because of its large-scale smart electricity meter rollout. Several alliance member companies are actively serving the Indian market, the alliance has a certification test laboratory in India, and it has established a regional marketing subcommittee focused on the country. More broadly, the alliance considers India an important part of its global strategy, as countries working to optimise energy usage through smart infrastructure are key to its long-term vision.
Q. Beyond advanced metering infrastructure (AMI), what opportunities do you see for Wi-SUN in India across smart cities, water utilities, and renewable energy projects?
A. Our initial focus has been on electric metering, but Wi-SUN is applicable to many other sectors as well. The latest versions of Wi-SUN also support water and gas metering, and I believe the water metering market in India is going to become very important. The technology is also well suited for smart city applications. For example, Hyderabad University has a Smart City Living Lab where Wi-SUN is being evaluated. Overall, Wi-SUN goes far beyond the utility market.
It is particularly effective for large-scale urban deployments. Smart street lighting can act as a canopy network or backbone to connect a wide range of city infrastructure, including smart signage, traffic management, and, in some regions, smart parking. While smart parking may not be a high priority in India today, traffic management certainly is. We are already seeing applications where Wi-SUN can be used to monitor traffic flow and dynamically adjust traffic signals based on real-time traffic conditions. So, there is a wide range of opportunities for Wi-SUN in India.
Q. Are there any ongoing or planned Wi-SUN deployments or pilot projects in India?
A. Yes, there are several fairly large Wi-SUN deployments underway in India. However, our member companies tend to be quite cautious about publicly sharing details of these projects. We can provide information through publicly available press releases if needed, but I can confirm that multiple significant deployments are currently taking place.
Q. What are the biggest barriers to wider Wi-SUN adoption in India? Is it spectrum availability, awareness, or policy?
A. I think awareness is currently one of the biggest challenges. As you know, there are competing technologies in the market, and they do not always present Wi-SUN in the most positive way. As wider deployments take place and people see the reliability and resilience of Wi-SUN networks, that should encourage greater adoption. India is still at the beginning of its Wi-SUN journey. In other parts of the world where we have large deployments, we have seen a snowball effect, with utilities watching the success of early adopters before becoming confident enough to implement the technology themselves. That is the current situation in India. There are already some large Wi-SUN rollouts taking place, and once their success is proven, I expect adoption to increase significantly.
Q. As India’s electronics manufacturing ecosystem grows, do you expect to see more Wi-SUN certified products designed and manufactured in the country?
A. I certainly hope so. India already has a number of meter manufacturers, and I believe there is a strong opportunity not only for the domestic market but also for exports. We have been discussing this with Wi-SUN member companies in India that are looking to manufacture Wi-SUN products for larger international markets, including the Middle East. So, besides serving India’s own needs, Wi-SUN products designed and manufactured in the country could also contribute to India’s growing electronics export market.
Q. Is the Wi-SUN Alliance planning to expand its presence in India through certification labs, technical workshops, training programs, or partnerships?
A. Yes. We already have one certification lab in India, and if it reaches a point where it has more business than it can handle, we will consider expanding the certification infrastructure. We are also looking at conducting technical workshops and training programs in India to support the local ecosystem and encourage wider adoption of Wi-SUN technology.
Q. What opportunities will the Wi-SUN ecosystem create for Indian embedded engineers and product developers?
A. One of Wi-SUN’s biggest strengths is that its specifications are open. Unlike some competing alliances or organisations that keep their specifications protected, Wi-SUN has contributed its specifications to IEEE and IEC, allowing any manufacturer to obtain a copy and develop products that comply with international standards. Wi-SUN’s role is to provide a testing and certification program, and we are committed to offering that at a reasonable cost so companies of all sizes, including those based in India as well as other parts of the world, can certify their products and participate in the ecosystem.
Q. What gaps still exist in the Wi-SUN ecosystem, and how is the Alliance addressing them?
A. There is still some scepticism among certain smart meter vendors about whether they want to implement Wi-SUN, but we believe training and education will help address those concerns. We are also continuously expanding and refining the Wi-SUN specifications while working closely with complementary industry organisations through liaison agreements. For example, the Device Language Message Specification (DLMS) User Association’s DLMS/COSEM (companion specification for energy metering) protocol has been specified by the Bureau of Indian Standards as a smart meter application protocol, and the Wi-SUN Alliance has a liaison with that organisation. Similarly, Lightweight M2M has been specified, and Wi-SUN works with the Open Mobile Alliance (OMA) to ensure compatibility. These collaborations help us deliver a complete protocol specification that integrates complementary technologies.
Q. Looking ahead, what will define the next phase of wireless networking for utilities beyond smart metering?
A. The next phase will be driven by the growing adoption of distributed energy resources, where integrating renewable energy into the grid requires a flexible communications architecture. Security and network resilience will continue to be essential, while there are also significant opportunities to optimise power distribution and improve the efficiency of the overall electricity network. In many parts of the world, including some regions in India as well as Africa and Southeast Asia, communities still lack reliable grid connectivity, creating opportunities to deploy localised solar or wind generation along with local power distribution systems that depend on communication networks. Energy storage will also become increasingly important, as renewable power must be stored and made available when needed, and these storage systems also require reliable communications. Overall, there is substantial opportunity for wireless networking technologies to improve the efficiency, reliability, and flexibility of future power grids.
