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nr sa 5g

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The 5G system architecture includes two main components: 5G Core (5GC) and 5G New Radio (NR). The 5G Standalone (SA) mode refers to a deployment scenario where 5G NR is used as the only radio access technology without relying on any legacy networks. Here's a technical overview of the 5G NR SA architecture:

1. 5G Core (5GC):

  • AMF (Access and Mobility Management Function): Manages the mobility of the user equipment (UE) by handling registration, location updating, and handovers.
  • SMF (Session Management Function): Responsible for session setup, modification, and termination. It also manages data traffic and interacts with the user plane function (UPF) for data forwarding.
  • UPF (User Plane Function): Handles the user plane traffic, including packet routing, forwarding, and encapsulation/decapsulation.
  • UDM (Unified Data Management): Manages subscription data, authentication, and authorization information for the user.
  • PCF (Policy Control Function): Enforces policies related to quality of service (QoS), access control, and flow control.
  • NEF (Network Exposure Function): Provides a mechanism for exposing network capabilities to authorized third-party applications.
  • AUSF (Authentication Server Function): Performs authentication and key generation functions for the UE.
  • NRF (NF Repository Function): Maintains information about the network functions available in the network.
  • NSSF (Network Slice Selection Function): Selects and communicates with the AMF and SMF for the establishment of slices based on the UE's capabilities and requirements.
  • AF (Application Function): Supports network functions by providing application-specific functions.

2. 5G New Radio (NR):

  • gNB (Next-Generation NodeB): The gNB provides the radio interface to the user equipment. It handles functions such as radio resource management, connection establishment, and mobility management.
  • NG-RAN (Next-Generation Radio Access Network): Comprises gNBs and the NG-RAN nodes, collectively providing the radio access for 5G.
  • NR PDCP (Packet Data Convergence Protocol): Handles protocol data units (PDUs) for the user plane, providing functions such as header compression and ciphering.
  • NR RLC (Radio Link Control): Manages the logical link control for the user plane, including segmentation, reordering, and error correction.
  • NR MAC (Medium Access Control): Controls access to the radio resources, scheduling transmissions, and managing HARQ (Hybrid Automatic Repeat Request) processes.
  • NR PHY (Physical Layer): Handles the transmission and reception of physical signals over the air interface.

3. Interfaces:

  • N1 Interface: Interface between gNBs for Xn signaling.
  • N2 Interface: Interface between gNBs for Xn user plane data.
  • N3 Interface: Interface between gNB and 5GC for control plane signaling.
  • N4 Interface: Interface between gNB and 5GC for user plane data.

4. User Equipment (UE):

  • The UE connects to the 5G network through the gNB, and it communicates with the 5GC for various services.

Key Features:

  • Network Slicing: The ability to create multiple virtual networks (slices) tailored to different use cases.
  • Ultra-Reliable Low Latency Communication (URLLC): Ensures low-latency and high-reliability communication, suitable for applications like autonomous vehicles and industrial automation.
  • Massive Machine Type Communication (mMTC): Supports a large number of devices with diverse communication requirements.