What are the protocol stacks used in 5G?

In 5G, there are two primary protocol stacks: the control plane and the user plane. The control plane manages signaling and control functions, including NR for radio communication, NGAP for core network-RAN communication, NAS for mobility and security, RRC for radio resource control, and SMF for session management.

On the user plane, PDCP handles data packet optimization, RLC ensures reliability, MAC manages radio channel access, and PHY oversees physical transmission. Together, these protocol stacks facilitate efficient and reliable communication in 5G networks, supporting high data rates and low latency for various applications.

Let’s dive into the details of each:

Control Plane Protocol Stack:

The control plane handles signaling and control functions for setting up and managing connections in 5G networks. It is responsible for tasks like authentication, authorization, mobility management, and session establishment.

The control plane protocol stack consists of several key protocols:

NR (New Radio): NR is the air interface protocol in 5G, responsible for radio communication between user devices (UEs) and base stations (gNBs). It uses OFDM (Orthogonal Frequency Division Multiplexing) and advanced MIMO (Multiple-Input, Multiple-Output) techniques for efficient data transmission.
NGAP (Next-Generation Application Protocol): NGAP is used for communication between the 5G core network and the radio access network (RAN). It handles functions like handovers, mobility management, and control of user plane resources.
NAS (Non-Access Stratum): NAS is responsible for managing mobility, security, and session establishment for UEs. It deals with functions like attach and detach procedures, authentication, and key management.
RRC (Radio Resource Control): RRC is responsible for controlling the radio resources in the RAN. It manages the establishment, configuration, and release of radio connections, ensuring efficient resource utilization.
SMF (Session Management Function): SMF manages user sessions and is responsible for policy enforcement, session establishment, and Quality of Service (QoS) control.

User Plane Protocol Stack:

The user plane handles the actual data transfer between user devices and the network. It focuses on efficiently transmitting data packets without significant processing delays.

The user plane protocol stack includes:

PDCP (Packet Data Convergence Protocol): PDCP provides header compression, encryption, and integrity protection for user data packets. It helps optimize data transmission efficiency.
RLC (Radio Link Control): RLC is responsible for segmentation, reordering, and error correction of data packets to ensure reliable transmission over the radio interface.
MAC (Medium Access Control): MAC handles the scheduling and multiplexing of data packets on the radio channel. It manages resources and ensures efficient access to the radio spectrum.
PHY (Physical Layer): The PHY layer is responsible for the physical transmission of data over the airwaves. It includes modulation and coding schemes, as well as MIMO techniques to enhance data rates and coverage.

These protocol stacks work together to enable seamless communication in 5G networks, delivering high data rates, low latency, and support for a wide range of applications, including IoT and ultra-reliable communications. The use of these protocols ensures that there is always a clear structure with specific functions associated with each layer of the 5G network.