5G Principles Virtual Laboratory

Laboratory Objectives

5G NR PHY

Understand 5G New Radio physical layer principles including numerology, frame structure, and modulation schemes.

Massive MIMO

Explore spatial multiplexing and beamforming techniques using large antenna arrays at the gNB.

Network Architecture

Study the 5G Core (5GC) and gNB architecture including CU/DU/RU splits and service-based architecture.

Network Slicing

Understand how 5G enables multiple virtual networks (eMBB, URLLC, mMTC) on shared infrastructure.

Theoretical Background

1. 5G New Radio (NR) Physical Layer

5G NR is the global standard for 5G wireless air interface, designed to support diverse use cases from enhanced mobile broadband (eMBB) to ultra-reliable low-latency communications (URLLC) and massive machine-type communications (mMTC).

•Frequency range: Sub-6 GHz (FR1) and mmWave 24-100 GHz (FR2)
•Flexible numerology with subcarrier spacing (SCS) of 15, 30, 60, 120, 240 kHz
•CP-OFDM for downlink and uplink (DFT-s-OFDM optional for UL)

5G NR Numerology

μ	SCS (kHz)	Slots/ms
0	15	1
1	30	2
2	60	4
3	120	8
4	240	16

2. Massive MIMO and Beamforming

Massive MIMO employs large antenna arrays (64-256 elements) at the base station to serve multiple users simultaneously through spatial multiplexing. This technology significantly improves spectral efficiency and energy efficiency.

Spatial Multiplexing Layers Up to 8 layers

Beamforming Gain 10log₁₀(N)

Array Configuration 8×8, 16×16

Beamforming Techniques

Analog Phase shifters control RF signal phase; cost-effective but limited to single beam per RF chain.
Digital Full baseband control enables multiple simultaneous beams; requires dedicated RF chain per antenna.
Hybrid Combines analog beamforming with digital precoding; balances performance and complexity.

3. 5G Network Architecture

🏗️

gNB (Base Station)

Next-Generation Node B connecting UE to 5G Core. Split into CU, DU, and RU.

🧠

5G Core (5GC)

Service-based architecture with AMF, SMF, UPF, AUSF, UDM, PCF functions.

📡

NG Interface

Connects gNB to 5GC; Xn interface connects gNBs for mobility.

gNB Function Splits

Central Unit (CU) PDCP, SDAP, RRC. Non-real-time processing in cloud/edge data centers.

Distributed Unit (DU) RLC, MAC, HARQ. Real-time processing at edge locations.

Radio Unit (RU) PHY lower layer, RF. Located at cell tower with antennas.

4. Network Slicing

Network slicing enables multiple virtual networks with different characteristics to run on shared physical infrastructure. Each slice is an isolated end-to-end network tailored for specific service requirements.

eMBB Slice

• High bandwidth: 1 Gbps+
• Moderate latency: 10ms
• Use case: 4K/8K video, VR

URLLC Slice

• Ultra-low latency: 1ms
• High reliability: 99.999%
• Use case: Autonomous driving, industrial control

mMTC Slice

• Massive connections: 1M/km²
• Low power consumption
• Use case: IoT sensors, smart meters

Interactive Simulations

5G NR Waveform Generator

Explore 5G NR CP-OFDM waveform structure with flexible numerology.

Subcarrier Spacing (μ)

Modulation

FFT Size

1024

Cyclic Prefix Ratio

0.07 (Normal)

Symbol Duration:33.33 μs

CP Duration:2.34 μs

Slots/Subframe:2

Time Domain Signal (1 Slot = 14 Symbols)

Frequency Domain (Subcarriers)

5G NR Frame Structure (10 ms Frame)

Massive MIMO Beamforming

Visualize beam patterns from antenna arrays and spatial multiplexing.

Antenna Array

Carrier Frequency (GHz)

28 GHz (mmWave)

Beam Steering Angle (°)

30°

Number of Users

4 UEs

Beamwidth:12.8°

Array Gain:18.1 dB

Grating Lobes:None

Antenna Array Configuration

Beam Pattern (Polar Plot)

Spatial Multiplexing: User Separation

5G Network Architecture

Explore the 5G RAN and Core architecture with CU/DU/RU splits.

Architecture Mode

Function Split Option

Number of gNBs

3 gNBs

Active Flow

Latency (CU-DU):2-3 ms

Latency (DU-RU):100 μs

Fronthaul BW:25 Gbps

5G Architecture Topology

Select a flow and click Animate to see signaling procedures

Network Slicing

Visualize how 5G creates isolated virtual networks for different services.

eMBB Slice

Enhanced Mobile Broadband

URLLC Slice

Ultra-Reliable Low Latency

mMTC Slice

Massive Machine Type

Traffic Load (%)

50%

eMBB Bandwidth:

URLLC Priority:

mMTC Connections:

Slice Isolation & Resource Allocation

End-to-End Slice Architecture

Laboratory Procedure

1

5G NR Waveform Analysis

Steps:

Select different subcarrier spacing values (15, 30, 60, 120 kHz)
Observe how symbol duration changes inversely with SCS
Change modulation scheme and observe constellation density
Analyze cyclic prefix overhead vs. SCS
Record slot duration for each numerology

Expected Observations:

Higher SCS → Shorter symbol duration → Lower latency
Higher SCS → Wider subcarrier spacing → Better for high mobility
CP-OFDM maintains orthogonality with cyclic prefix
Frame structure: 10ms frame, 1ms subframe, variable slots

2

Massive MIMO Beamforming

Steps:

Configure antenna array (4×4, 8×8, or 16×16)
Set carrier frequency (sub-6 GHz vs. mmWave)
Adjust beam steering angle from -60° to +60°
Observe beamwidth narrowing with larger arrays
Enable multiple users and observe spatial separation

Expected Observations:

Beamwidth ≈ 102°/(N×d/λ) for linear array
Array gain increases with number of elements (10log₁₀N)
mmWave requires beamforming for coverage
Spatial multiplexing enables multiple data streams
Beam steering follows sin(θ) phase progression

3

5G Architecture Function Splits

Steps:

Select architecture mode (D-RAN, C-RAN, Cloud)
Choose function split option (Option 2, 7, or 8)
Animate UE registration flow (UE→gNB→AMF→AUSF→UDM)
Observe PDU session establishment
Compare latency requirements for each split

Expected Observations:

Option 2: PDCP/RLC split, F1 interface, ~3ms latency
Option 7: High-PHY split, requires very low latency
Option 8: RF/Baseband split, CPRI/eCPRI interface
C-RAN enables centralized processing and coordination
5G Core uses service-based architecture (SBA)

4

Network Slicing

Steps:

Enable/disable different slice types (eMBB, URLLC, mMTC)
Adjust traffic load percentage
Observe resource allocation per slice
Analyze isolation between slices
Compare QoS parameters for each slice type

Expected Observations:

eMBB: High bandwidth, moderate latency, best effort
URLLC: Guaranteed latency <1ms, 99.999% reliability
mMTC: Massive connections, low power, infrequent transmission
Slices share physical resources but maintain logical isolation
NSSF selects appropriate slice based on UE subscription

Laboratory Report Guidelines

Report Structure

1
Title Page: Course name, experiment title, student name, date, ID
2
Objectives: State clearly what the experiment aims to demonstrate
3
Theory: Brief explanation of 5G principles relevant to the experiment
4
Procedure: Step-by-step description of simulations performed
5
Results: Screenshots, graphs, measurements with proper labels
6
Discussion: Analysis of results, comparison with theory, error analysis
7
Conclusion: Summary of key findings and learning outcomes
8
References: 3GPP specifications, textbooks, technical papers

Assessment Criteria

Understanding of Concepts 30%

Experimental Execution 25%

Data Analysis & Results 25%

Report Presentation 20%

Key Questions to Address:

• How does flexible numerology enable diverse 5G use cases?
• What is the trade-off between beamwidth and array gain?
• Why is the CU/DU split important for 5G deployment?
• How does network slicing achieve isolation between tenants?