Cybersecurity in Private Cellular Networks

As factories continue to grow using project-to-project initiatives up to wholescale smart factory implementations, connectivity becomes more critical to enabling the technology and tools that accelerate change. A new generation of manufacturing applications require a new type of high-performance networking solution. Some of the applications include sensors for machine and process monitoring; video analytics for quality control; robotics and autonomous machines for operational efficiency; and redesigned production facilities that can be easily reconfigured to accommodate multiple product lines or modifications to production processes. 

For this new generation of applications, manufacturers should consider Private Cellular Networks (PCNs). PCNs are highly secure, flexible, and very reliable with the ability to define Quality of Service (QoS) based on application-specific requirements. PCNs give CIOs a more secure, flexible, and cost-effective networking alternative than other currently available options. Securing PCNs requires a shift from securing Information Technology (IT) assets, such as servers, storage, and applications, that have characteristics of short lifecycles, to securing Operational Technology (OT) assets, such as IoT devices, sensors, manufacturing assets, where the lifecycle is typically 10-25 years.

Security is of paramount importance in the implementation of a PCN for all manufacturers – from aerospace defense contractors to semiconductor fabricators to automobile companies. As the number of connected devices and applications inside the manufacturing facility increases, so does the potential security threat.

Factors for a Secure PCN 

Here are some factors to consider when implementing PCNs:

• Zero-trust architecture for OT environments: The zero-trust security model is based on a set of system design principles, which acknowledges that threats exist both inside and outside of traditional network boundaries. This model ensures that the concept of least privilege is applied for every access decision. 

• Threat modelling: Threat modelling that is normally integrated into the organization’s security practices can be used to assess the introduction of the PCN. Examples include the STRIDE (Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, and Elevation of Privilege) and PASTA (Process of Attack Simulation and Threat Analysis) threat models.

• Vulnerability management: PCN assets must be integrated into an organization’s vulnerability and incident management programs.

• Supply chain: Great emphasis needs to be placed on having trusted suppliers, securing the use of open-source software, hosted infrastructure platforms, and ensuring secure software development.

Identifying Potential Threats

The first step in securing a PCN is to identify potential attack threats. The main components of a PCN are described below and shown in Figure 1:

• Mobile Core: The Evolved Packet Core (EPC) in LTE or the 5G Core (5GC) in 5G provides the intelligence and management of the cellular network. The network functions can be on premise, cloud-hosted or hybrid with the control plane in the cloud and the user plane on premise.

• Radio Access Network (RAN): In a PCN, the radios are known as Citizens Band Services Devices (CBSDs). The CBSDs are managed by a Radio Management System (RMS) that is typically cloud-hosted. The RAN layer connects the User Equipment to the Mobile Core and OT platforms.

• User Equipment (UE): UEs are the end-user devices in the network that need connectivity to the OT platforms. They can include mobile phones; tablets; machine connectivity for robots and autonomous vehicles; unmanaged devices such as sensors; and other IoT devices. Each UE must have a Subscriber Identity Module (SIM) or software-based electronic SIM (eSIM) to attach to the PCN.

• Network Management System (NMS): The NMS provides remote management and monitoring. Located on premise or in the cloud, it is integrated to a ticketing system supporting Day 2 Services.

• Spectrum Access Services (SAS): The SAS is a third-party application that manages the wireless spectrum used in the PCN.

Potential attacks to a PCN can impact every network component:

• Mobile Core Networks: Bad actors will attack the control plane signaling network, destabilize the mobile core with authentication requests (Authentication Flooding), or exploit software vulnerabilities either in the application or the operating system.

• RAN: Bad actors can masquerade as a trusted RAN, tricking the UEs to connect to the untrusted device rather than to the real RAN. Bad actors can intercept data/voice traffic at the RAN level and route valid traffic to networks/systems they control, thereby facilitating further attacks.

• Transport Network: Data traffic can be intercepted through the backhaul network. Bad actors will steer or mirror data traffic to collect useful information or destabilize the data network.

• UE: UE attacks are executed through SIM compromise, where a bad actor uses a valid SIM card in another device to gain access to the network. Malware can be deposited on the UE which will be used to take over the device. Bad actors can instigate a Distributed Denial of Service (DDoS) attack by using botnets throughout the network. 

• Mobile Infrastructure Systems: Bad actors can change network and equipment configurations to allow unauthorized access to infrastructure platforms such as the mobile core, RMS, or NMS.

• Third-Party Applications: Bad actors can infiltrate third-party applications and use the external IP network as an entry point into the PCN. 

Applying Zero-Trust Principles to PCNs 

PCNs benefit from 3GPP security practices, generally considered the most stringent, including zero-trust principles such as strong authentication and least privilege. These principles should be embedded by design. 

Guarding Against UE Threats: Traditional IT techniques, including subscriber authentication and device access control, should be extended to the PCN to guard against unauthorized access to the device. Device to network connectivity is protected through adoption of SIM technology within the device, either a physical hardware SIM or an eSIM. Further device-level protection can be added through practices such as SIM locking and multifactor authentication.

Minimizing Device and RAN Attacks: The risk of UE or RAN attacks is minimized by the implementation of both network to device authentication and air interface encryption mechanisms. The Authentication and Key Agreement (AKA) protocol is used for authentication between the UE and the mobile core in a PCN. In addition, the LTE/5G air interface in a PCN is protected by 3GPP standards that have defined multiple encryption algorithms to safeguard data transmission.

Protecting Infrastructure Systems: On-premise mobile core, RMS, and NMS platforms should be secured through an extension of existing enterprise IT security practices, enabling management using existing network management tools. 

Securing Backhaul Connections: Hardware security appliances can be used to protect the traffic over the S1 interface (backhaul) using Internet Protocol Security (IPsec) tunnels between the radios and the mobile core. Having IPsec on the backhaul helps maintain a zero-trust security in which nothing is trusted, and everything must be verified.

Summary

A company’s approach to securing their PCN should be no less rigorous than that of securing new IT architectures. There may be additional factors that require consideration when implementing the PCN, comprised of 3GPP architecture (UE, RAN, mobile core), non-3GPP defined architecture (switches, routers etc.), and OT (IoT devices). Some key practices are threat modelling, penetration testing, vulnerability assessments, border protection, and updating of security controls into the organization.

Figure 1: CTS Private Cellular Network

CTS provides custom, carrier-grade in-building and campus connectivity solutions for enterprises and mobile network operators, solving and managing the most complex networking challenges. CTS only provides one solution: the one that’s right for your business.

Opinions expressed by contributing authors are their own.

Author

David Mayers

Technical Program Manager, Communication Technology Services (CTS)

Private Cellular Networks – The Foundation for Your Digital Transformation

Modern manufacturing is increasingly reliant on interconnected devices communicating with each other to optimize operations and achieve automation of key production processes. In fact, a recent study shows that 84% of manufacturers surveyed had already adopted smart manufacturing or are actively evaluating solutions to invest in the coming year, which means connectivity will be more important than ever.

Connected devices provide critical data required to automate production, but connections to the digital realm for simulating processes and outcomes further enhance the ability of manufacturers to transform their businesses to compete on the global theater. Once a luxury, manufacturers have now become reliant on mission-critical connectivity. Current networking technologies used in many manufacturing facilities are often outdated, unreliable, fixed in terms of location, or all three — resulting in frequent downtime and production delays.

The Evolution of Wireless Technology

Wireless technologies have been prevalent in industrial applications for decades using proprietary radios to communicate with sensors for data collection and controllers for managing moving devices. While proprietary networks benefit from the ability to customize the specific implementation to the application, closed ecosystems are often expensive to implement and maintain while also limiting device availability.

The emergence of Wi-Fi offered a low-cost, standardized technology that was embedded in a wide variety of enterprise and industrial devices. While Wi-Fi has been deployed in industrial environments requiring flexibility, the technology has struggled to meet the increasingly complex connectivity requirements for digital transformation. Best-effort Wi-Fi networks suffer from interference that results in poor Quality of Service (QoS) and Quality of Experience (QoE) as the number of connected devices and throughput increase.

The Emergence of Private Cellular Networks

Cellular technology was developed for mission-critical military communications before being adopted by enterprises to increase workforce productivity outside of traditional, fixed office environments. Demand exploded among consumers as the technology became more affordable, evolving to the point where smartphones have become an indispensable part of modern life. Cellular networks are highly secure, mobile, and very reliable with the ability to define QoS based on application-specific requirements.

Unlike legacy industrial wireless solutions and Wi-Fi, cellular networks utilize FCC-licensed wireless frequencies to ensure interference-free operations. Historically, the FCC auctioned wireless frequencies in large geographic areas and at great cost, making it difficult for enterprises to justify competing with the mobile network operators to acquire them. With the recent introduction of Citizens Band Radio Services (CBRS) spectrum by the FCC, enterprises can now acquire low-cost, wireless licenses as the basis for enterprise-focused Private Cellular Networks (PCNs). PCNs leverage small cell infrastructure and a virtualized network architecture that can be easily integrated with existing enterprise IT infrastructure.

Delivering on the Promise of Digital Transformation

A CBRS PCN is an excellent choice when a manufacturing facility requires high throughput, has massive numbers of devices, and needs enhanced security and reliability. PCNs provide more control over data transmission and provide dedicated and secure connectivity with edge computing platforms, keeping data local for analytics and low latency processing. They can also connect a larger number of devices than Wi-Fi without sacrificing performance. PCNs can be customized to meet application-specific requirements such as guaranteed throughput for video used in finished goods inspection or low latency communications required for real-time command and control of manufacturing processes. While current PCNs are largely based on 4G or LTE technology, 5G expands PCN capabilities with higher throughput, lower latency, and massive device connectivity — all crucial enablers for long-term industrial digital transformation.

PCNs have the potential to revolutionize manufacturing processes and help companies achieve key production goals by providing:

• Secure, reliable, low-latency operations for real-time machine-to-machine communication to thousands of devices

• Critical data infrastructure to support automation

• Mission-critical performance for real-time monitoring and control of safety and security systems

• Application-optimized data connectivity that enables more efficient and productive operational technologies to be implemented operations.

Creating a Strong, Future-Proof Network Foundation

Wireless connectivity solutions have become increasingly essential in Industry 4.0 factories, where automation, digitalization, and data-driven processes are the norm. Selecting the correct type of network for a manufacturing plant is critical to ensure smooth and efficient facility operation. The network is the backbone of the plant’s communication system, connecting various devices and systems and facilitating the transfer of data and information. Choosing the wrong network can lead to slow data transfer speeds, dropped connections, and other network-related issues, resulting in lost productivity, increased downtime, and even safety risks.

A PCN can enable faster communication, real-time monitoring, and improved manufacturing processes. While off the shelf “PCN in a box” solutions exist, a one-size-fits-all approach should be avoided when trying to ensure maximum ROI for your next-generation networking investment. Each facility has unique communication needs based on factors like size, layout, construction materials, equipment, and operations. In addition, deployment challenges can include integration into existing Operational Technology and Information Technology platforms, application performance optimization, data security, and interweaving solutions across multiple networks. A customized PCN solution that meets the specific needs of your facility can lead to better performance, cost-effectiveness, and employee productivity. A trusted solution partner can help ensure that you select and implement the PCN architecture and infrastructure that best meets your needs, enabling you to reach your transformation goals.

Author

Robert Cerbone, VP Product Management and Marketing, CTS

The New Utility

Communication Technology Services helps property owners integrate wireless communications

In the United States today, it is estimated that more than 85 percent of adults between the ages of 18 and 49 own a smart phone. This percentage will continue to grow each year until traditional landlines and cell phones are obsolete. We expect and depend on wireless voice and data to be available everywhere all the time in both our personal and professional lives.

Wireless Communication

It is estimated that 80% of all wireless voice calls originate inside a building. As a result, most commercial properties need to make sure that they are providing exceptional wireless communications infrastructure to their tenants and/or customers. This is no longer a luxury, but a necessity, much like electricity or running water.

“This is no longer a luxury, but a necessity, much like electricity or running water. ”

The best way for a building owner to provide the necessity of wireless communication service is through the installation of a distributed antenna system, commonly referred to in the industry as a DAS. Simply put, a DAS is a collection of antennas placed in strategic locations throughout a building or outdoor space, designed to provide enhanced coverage and reliability than that offered by the wireless service providers’ cell towers.

An Industry Leader

Communication Technology Services, known in the industry as CTS, is the industry leader and a trusted integrator for all of the major wireless service providers, having successfully deployed over 6,000 distributed antenna systems nationwide. With almost three decades of history, CTS is designing, building, managing, servicing and consulting on DAS projects, large and small, across all vertical markets nationwide.