How 5G Standalone (SA) Networks Differ from Non-Standalone (NSA)

1. Structural Architecture: How NSA vs. SA Work

                         5G ARCHITECTURE COMPARISON

    5G Non-Standalone (NSA)                     5G Standalone (SA)
    (Dual Connectivity Model)                  (Pure End-to-End 5G)

   ┌────────────────────────┐                ┌────────────────────────┐
   │    4G EPC Core Node    │                │     5G Core (5GC)      │
   │  (Evolved Packet Core) │                │  (Cloud-Native SBI)    │
   └───────────┬────────────┘                └───────────┬────────────┘
               │                                         │
        ┌──────┴──────┐                           ┌──────┴──────┐
        ▼             ▼                           ▼             ▼
   ┌─────────┐   ┌─────────┐                 ┌─────────┐   ┌─────────┐
   │ 4G eNB  │   │ 5G gNB  │                 │ 5G gNB  │   │ 5G gNB  │
   │ (Anchor)│   │ (Data)  │                 │ (Base)  │   │ (Base)  │
   └─────────┘   └─────────┘                 └─────────┘   └─────────┘

5G Non-Standalone (NSA) Architecture

• Core Network: Utilizes the legacy 4G Evolved Packet Core (EPC).
• Radio Network: Pairs a 4G base station (eNB) with a 5G New Radio base station (gNB).
• Operation: The 4G network acts as the anchor for control signaling, session setup, and mobility management. The 5G radio layer is attached strictly as a high-speed user-plane data pipe (Dual Connectivity).

5G Standalone (SA) Architecture

• Core Network: Driven entirely by a Cloud-Native 5G Core (5GC) built on a Service-Based Architecture (SBA).
• Radio Network: 5G gNB base stations connect directly to the 5G Core without needing 4G signaling anchors.
• Operation: All control plane signaling and user plane data flow purely through native 5G protocols end-to-end.

2. Technical Feature & Performance Comparison

3. Advanced Capabilities Unlocked Only by 5G SA

                   ADVANCED SERVICES ENABLED BY 5G SA CORE

┌────────────────────────┐    ┌────────────────────────┐    ┌────────────────────────┐
│    Network Slicing     │    │  Ultra-Low Latency     │    │ Multi-Access Edge      │
│     (Virtual 5GC)      │    │        (URLLC)         │    │     Computing (MEC)    │
├────────────────────────┤    ├────────────────────────┤    ├────────────────────────┤
│ Divides physical fiber │    │ Sub-5ms response for   │    │ Moves cloud servers directly│
│ and radio into customized│  │ autonomous driving,    │    │ to cell towers for zero-│
│ virtual networks.      │    │ robotics, and surgery. │    │ delay compute processing.│
└────────────────────────┘    └────────────────────────┘    └────────────────────────┘

1. End-to-End Network Slicing: Telecom operators can split a single physical 5G SA network into multiple isolated virtual networks tailored to specific SLAs (e.g., one slice for emergency services, another for high-speed video streaming, and a third for industrial sensors).
2. URLLC (Ultra-Reliable Low-Latency Communication): 5G SA removes the 4G core routing delays, reducing latencies to single-digit milliseconds. This is essential for time-critical applications like automated guided vehicles (AGVs) and remote surgical equipment.
3. Native Edge Integration (MEC): Multi-Access Edge Computing connects directly with the 5G User Plane Function (UPF) at local cell sites, processing local data without sending it to distant centralized data centers.

4. Strategic Deployment & Trade-offs

• Why Carriers Deployed NSA First: Upgrading cell towers with 5G radio antennas while retaining the existing 4G packet core allowed telecom operators to launch 5G marketing and offer high download speeds quickly without completely rebuilding their core data center infrastructure.
• The Migration to SA: As enterprise demands shift toward industrial automation, smart cities, and private enterprise networks, mobile networks are migrating to full 5G SA to unlock structural efficiencies, lower operating costs, and new monetization models.