LTE vs 5G SA Architecture Comparison

Both LTE and 5G (Fifth Generation) represent major advancements in wireless communications, but they differ significantly in their architectural design, performance, and deployment strategies. The transition from LTE to 5G is not just about faster speeds but also involves structural changes in network design, enhanced security, and a shift toward cloud-native implementations.

LTE Architecture

5G Architecture

Core Network Architecture: EPC vs. 5GC

• 5G Core (5GC) follows a service-based architecture (SBA), meaning functions communicate via APIs, whereas LTE’s EPC follows a monolithic approach.
• Network slicing allows 5G to create virtual networks customized for different applications.

Feature	LTE (Evolved Packet Core – EPC)	5G (5G Core – 5GC)
Architecture Type	Centralized	Service-Based (Cloud-native)
Mobility Management	Handled by MME	Handled by AMF
Data Forwarding	S-GW & P-GW	UPF (Distributed and Scalable)
Control & User Plane Separation (CUPS)	Not fully implemented	Fully Implemented
Network Slicing	Not Supported	Supported
QoS Model	Fixed Bearer-Based	Flexible Flow-Based
Edge Computing	Not Natively Supported	Fully Integrated
Interworking with Legacy Networks	Supports 2G/3G	Primarily Interworks with LTE

Radio Access Network (RAN): eNB vs. gNB

• 5G gNB is split into CU (Centralized Unit) and DU (Distributed Unit), allowing for scalable deployments and centralized control.
• LTE’s eNB does not support flexible architecture or multi-RAT integration as efficiently as 5G.

Feature	LTE (eNB)	5G (gNB)
Access Technology	OFDMA, SC-FDMA	OFDMA, Flexible Numerology
Base Station Types	Macro eNB	Macro gNB, Small Cells
Beamforming	Limited Support	Massive MIMO and Beamforming
Latency in RAN	~10ms	~1ms
Frequency Range	Up to 6 GHz	Sub-6 GHz + mmWave (24GHz+)
Connectivity	Single RAN Option	Multi-RAT with LTE, Wi-Fi, NR
DU-CU Split	Not Implemented	Fully Supported

Network Slicing and Virtualization

• 5G introduces network slicing, allowing operators to allocate resources dynamically for IoT, URLLC, and eMBB applications.
• LTE lacks such flexibility, making it inefficient for diverse use cases.

Feature	LTE	5G
Network Slicing	Not Supported	Fully Supported
Function Virtualization	Partial NFV Support	Full NFV & SDN Integration
Cloud Deployment	Limited	Fully Cloud-Native
Edge Computing	Minimal	Supported via MEC
Dynamic Resource Allocation	Static	AI-based Dynamic Allocation

Latency and Throughput

• 5G reduces latency 10x compared to LTE, enabling applications like autonomous driving, VR, and remote surgery.

Feature	LTE	5G
Latency	~10ms	<1ms (URLLC)
Maximum Throughput	~1 Gbps	Up to 20 Gbps
Data Scheduling	Fixed Frame Structure	Flexible Numerology
Peak Spectral Efficiency	~15 bps/Hz	~30 bps/Hz
HARQ Retransmission Time	~8ms	~2ms

Mobility Management: LTE vs. 5G

• 5G uses AMF for mobility management, reducing handover latency significantly.

Feature	LTE	5G
Mobility Control Function	MME	AMF
Handover Delay	~50ms	<10ms
X2 Handover	Supported	Xn Handover for Lower Delay
Seamless Roaming	Limited	Enhanced Support

Spectrum and Frequency Bands

• 5G supports mmWave, which enables high-speed data transmission but requires denser deployments.

Feature	LTE	5G
Frequency Bands	Sub-6 GHz	Sub-6 GHz + mmWave
Carrier Aggregation	Limited to 5 carriers	Supports up to 16 carriers
Massive MIMO	Basic	Advanced Beamforming

Security Enhancements

5G introduces encryption for subscriber IDs (SUPI) to prevent attacks.

Feature	LTE	5G
Authentication	Static Keys	Dynamic SUPI Encryption
Signalling Security	Vulnerable to DoS	Secure SBA Signalling
IoT Security	Weak	Stronger Authentication for mMTC

Application Use Cases

5G enables new applications (AR, autonomous driving, industrial automation) that LTE cannot support.

Use Case	LTE	5G
Smartphones & Mobile Broadband	✓	✓ (Higher Speed)
IoT & Smart Cities	Limited	✓ (mMTC Support)
Autonomous Vehicles	✗	✓ (URLLC)
AR/VR & Gaming	✗	✓ (Low Latency)

The transition from LTE to 5G represents a major evolution in network architecture, performance, and capabilities. LTE uses a centralized Evolved Packet Core (EPC) with limited virtualization and fixed network functions, while 5G introduces a cloud-native, service-based architecture (5GC) with network slicing, edge computing, and AI-driven automation. The Radio Access Network (RAN) in LTE is based on eNodeB (eNB), whereas 5G uses gNodeB (gNB) with Massive MIMO, beamforming, and flexible numerology, enhancing coverage and efficiency. 5G offers ultra-low latency (<1ms), higher speeds (up to 20 Gbps), and expanded frequency bands (mmWave support), making it ideal for IoT, autonomous vehicles, AR/VR, and smart cities.