4G & 5G Networks

What they are (quick):

• 4G (LTE) — packet-switched mobile broadband system optimized for mobile internet, voice via VoLTE, mature ecosystem.

• 5G (NR — New Radio) — next-gen radio + core for much higher peak throughput, lower latency, massive device density and network slicing.

Core architecture difference:

• 4G uses EPC (Evolved Packet Core) — relatively centralized.

• 5G uses 5G-Core (5GC) — cloud-native, service-based, supports edge computing, flexible control/user plane split.

Radio / spectrum & performance:

• 4G: typically licensed sub-1GHz and mid bands (e.g., 700–2600 MHz). Good coverage & building penetration; typical LTE downlink tens of Mbps → 100+ Mbps in good cells.

• 5G: uses low-band (coverage), mid-band (balance of speed/coverage), and mmWave (extremely high throughput, short range). 5G delivers peak Gbps (mmWave) and much lower latency (as low as ~1–10 ms in optimized deployments).

Key 5G capabilities (why migrate):

• eMBB — enhanced mobile broadband (high throughput).

• URLLC — ultra-reliable low-latency (industrial control, remote surgery).

• mMTC — massive machine-type communication (IoT at scale).

• Network slicing — virtual networks tailored per use-case (e.g., public safety slice).

Deployment patterns & evolution:

• Many operators deploy NSA (Non-Standalone) first — 5G NR radio using existing 4G core — then move to SA (Standalone) with full 5GC benefits.

• Densification: 5G (especially mid/mmWave) requires more small cells, edge sites, and fiber backhaul.

• Edge computing: 5G commonly integrates MEC (Multi-Access Edge Computing) to cut latency and keep data local.

Security & operational notes:

• Both require strong encryption, SIM/USIM provisioning and mutual authentication. 5G adds more network-level security features but also new attack surfaces (software stacks, APIs). Harden cores, use secure API gateways, and keep software/hardware patched.

• Regulatory compliance (lawful intercept, privacy) must be planned with local authorities.

Typical use-cases by tier:

• 4G best: wide coverage mobile broadband, voice fallback, legacy IoT.

• 5G best: dense urban hotspots, fixed wireless access (FWA) for gigabit home internet, industrial automation, low-latency remote operations, massive IoT.

Cost & migration considerations:

• 5G rollout costs include spectrum purchase, new radios + small cells, fiber backhaul and core cloudization. Operators often do phased rollout focused on urban and high-ARPU areas first. ROI depends on FWA, enterprise services, and new revenue from slicing/IoT.