Private 4G and 5G networks are rapidly becoming a cornerstone of utility modernization. Unlike legacy radio or fixed-line networks, private 4G and 5G deliver the coverage, reliability, and resilience required to connect critical assets across vast service territories, from substations and renewable generation sites to millions of smart meters and IoT sensors at the edge.

With built-in identity access control through SIM technology, stronger security and the ability to scale seamlessly, cellular networks enable utilities to support mission-critical applications, enhance operational resilience and unlock new use cases such as predictive maintenance, digital twins and real-time grid control.

Whether a utility builds its own private mobile network or relies on a public mobile network, the security requirements remain the same. Visibility into all assets, a Zero Trust security posture, and resilience from the grid core to the edge are essential. This is increasingly pressing as legacy network architectures and standards such as NERC CIP raise expectations for monitoring and control.

As utilities adopt private 4G and 5G networks, these environments must meet the same rigorous standards of security and resilience that apply across the energy sector. This means systematically identifying and protecting critical assets, enforcing strong access controls, continuously monitoring traffic for anomalies, and maintaining tested recovery plans. In practice, private mobile networks should follow a security-by-design approach, embedding visibility, Zero Trust principles, and resilience throughout the network, from the grid core to the farthest edge device.

Utilities already manage one of the most complex systems in the world, the grid. Securing private mobile networks is more manageable when guided by three pillars:

• Secure the Core
• Secure the Edge
• Secure AI

Secure the Core

Securing the mobile core requires visibility into every device, session, and application. Any gap creates implicit trust and exposes the organization in ways Zero Trust is designed to prevent. Research from Palo Alto Networks’ State of OT Security Report shows that more than 70% of operational technology (OT) breaches originate in the IT environment, underscoring the need for stronger  governance of IT, cloud, and other internal access  alongside unified strategies for defending critical infrastructure.

To strengthen defenses, utilities need advanced visibility and prevention services that work across IT and OT. These services include capabilities such as inline deep learning to block malware and exploits, DNS protection to disrupt malicious domains and tunneling attempts, and machine learning–powered URL filtering to stop phishing in real time. In addition, OT-aware inspection extends visibility to industrial protocols and assets, helping reduce the attack surface by eliminating blind spots in the mobile core and connected devices.

Together, these protections fortify the network, prevent unauthorized movement between IT and OT, and align with global standards such as IEC 62443 and NIST SP 800-207, which emphasize continuous monitoring and access control.

Secure the Edge

Many legacy devices cannot natively connect to cellular networks with a SIM card. Utilities often deploy routers that appear as a single device but actually connect multiple endpoints with varying levels of security. Without segmentation and inspection, these routers create blind spots and significantly expand the attack surface.

To close this gap, utilities need visibility and prevention services at the edge, not just connectivity. Next-generation firewalls (NGFWs) such as the PA-400-5G provide both. They bring visibility through Zero Trust enforcement and microsegmentation, ensuring that traffic between devices and applications is monitored and controlled. They add resilience with SIM redundancy for automatic failover, secure communication, and centralized management that unifies core and edge operations.

By deploying advanced NGFW cellular devices at the edge, utilities extend Zero Trust, microsegmentation, and application-aware protection all the way to endpoints. This reduces the exposed attack surface of legacy devices and mitigates many of the risks introduced by non-cellular equipment.

Secure AI

Utilities are increasingly adopting AI for emerging use cases such as predictive maintenance, grid automation, and customer operations. But the same capabilities that fuel AI also expand the threat landscape. Always-on connectivity, edge apps, MEC workloads, and third-party GenAI tools used by field teams create new attack vectors—from poisoned sensor data and prompt injection to model tampering and supply-chain risks in the AI toolchain.

Point products can’t keep up with this complexity. What’s needed is a security-by-design approach that spans the grid core, the mobile edge, and the AI pipeline—one platform that gives unified visibility, consistent policy, and scalable defenses across multiple domains. That’s the ethos behind Palo Alto Networks’ Secure AI by Design approach. Utilities must protect not just how AI is used, but also how it is built.

Field technicians and employees increasingly rely on GenAI from phones, tablets, and laptops—often on unmanaged devices over public or private mobile networks. Prisma Browser extends the power of Precision AI to provide real-time visibility, control, and data protection for third-party GenAI use across any device, so sensitive prompts, outputs, and session data stay governed even at the edge.

Launched this year, Prisma AIRS™ discovers, assesses, and protects AI applications, agents, models, and datasets across their lifecycle. Risks such as poisoned training data, prompt injection, and model tampering can directly impact service continuity. A compromised AI model or dataset does not just represent a data breach — it could trigger incorrect grid automation decisions, disrupt operations, or even jeopardize public safety. Prisma AIRS™ addresses these risks with capabilities such as model scanning, runtime protection, red teaming, agent safeguards, and posture management together with advanced AI-driven threat intelligence. Prisma AIRS™ helps detect novel attacks and stop zero-days before they impact operations.

Building Resilience Across the Grid

Private 4G and 5G networks are reshaping the way utilities operate, bringing scale, reliability, and new possibilities. To realize these benefits securely, utilities must embed visibility, Zero Trust, and resilience across the entire network, from core to edge to AI. By shrinking the attack surface at every layer of the grid, utilities can ensure not only the continuity of critical services but also the safety and trust of the communities they serve.

To explore how private 4G and 5G security can be designed for your grid, request a consultation with our private 5G and OT experts.