National Security and Emergency Preparedness

Description

National Security and Emergency Preparedness (NS/EP) in the 3GPP context defines a framework of requirements, capabilities, and features within mobile networks to support communications for authorized government users and emergency responders during times of crisis, disaster, or national emergency. It is not a single technology but a comprehensive set of service enablers standardized to ensure that critical communications can be maintained even when public networks are experiencing extreme congestion, partial failure, or intentional attack. The 3GPP specifications, such as TS 22.854 (Service requirements for NS/EP), TS 22.862 (Priority service), and TS 22.953 (Mission Critical Services), lay the foundation for these capabilities.

Architecturally, NS/EP functionalities are integrated across multiple network domains. Key components include the User Equipment (UE), which must support identity modules and client functions for priority access; the Radio Access Network (RAN), which implements priority-based radio resource scheduling and admission control; and the Core Network, which handles service authorization, session management, and policy enforcement. A central element is the Home Subscriber Server (HSS) or Unified Data Management (UDM), which stores subscriber profiles indicating NS/EP authorization levels (e.g., priority levels). The Policy Control Function (PCF) uses these profiles to formulate policies that are enforced by the Session Management Function (SMF) and the Access and Mobility Management Function (AMF) in 5G, or analogous nodes in earlier generations.

How it works involves a multi-layered approach. First, **Priority Service** ensures that calls or sessions from authorized NS/EP users are given higher priority in network procedures. This includes priority access (getting a signaling channel during random access), priority scheduling (getting radio resources during congestion), and priority queuing in core network elements. Second, **Pre-emption** may be invoked in extreme scarcity. This allows a high-priority NS/EP session to disconnect or degrade an existing lower-priority session to free up necessary resources. The network uses standardized Quality of Service (QoS) identifiers (QCI/5QI values dedicated for priority services) to differentiate traffic. Third, **Resilience and Robustness** features ensure service continuity. This includes mechanisms for fallback to other radio access technologies (e.g., from 5G to 4G), routing session through geographically diverse network paths, and supporting service in isolated operation mode for limited local communication when backhaul is lost. The end-to-end service invocation is typically triggered by the UE indicating its priority credentials during registration and session establishment, which the network validates against policy rules.

Purpose & Motivation

The standardization of NS/EP capabilities in 3GPP was motivated by the critical need to ensure that mobile networks, which have become the primary communication infrastructure, can serve as a reliable tool for national security agencies, emergency services (police, fire, medical), and government leadership during catastrophic events. Historical events like natural disasters (e.g., earthquakes, hurricanes) and terrorist attacks have demonstrated that public networks quickly become congested, making it impossible for first responders to coordinate effectively. Prior to standardized NS/EP features, solutions were often proprietary, nation-specific, or relied on separate dedicated networks (like TETRA or FirstNet), which are costly and lack the ubiquity and advanced features of commercial cellular networks.

3GPP's work integrates these critical capabilities directly into commercial standards, allowing network operators to offer them as a service layer. This addresses the limitations of previous approaches by leveraging the scale, continuous innovation, and widespread coverage of public networks while overlaying guaranteed access for authorized users. It solves the problem of "network busy" scenarios by introducing controlled prioritization within the shared resource pool. Furthermore, it provides a globally harmonized framework, which is essential for interoperability during international incidents or for roaming emergency personnel. The creation of these standards represents a collaborative effort between the telecommunications industry and government entities to enhance public safety and national security through improved communication resilience.

Key Features

• Priority access, scheduling, and queuing for authorized users during network congestion.
• Pre-emption mechanisms to free resources for highest-priority communications.
• Use of standardized QoS identifiers (e.g., specific 5QI values) for NS/EP traffic.
• Network-based authorization and policy control for NS/EP service invocation.
• Support for service continuity and resilience, including fallback and isolated operation.
• Framework applicable across 4G (EPS) and 5G (5GS) system architectures.

Evolution Across Releases

Defining Specifications