Wireless & Cellular

LTE is the dominant global mobile network. VoLTE, QoS bearers, and EPC architecture are directly relevant when building mobile-connected applications, IoT modules, or carrier infrastructure.

5G is the foundation for edge compute, private networks, URLLC industrial automation, and mmWave backhaul. Understanding network slicing, SA vs NSA deployment modes, and QoS flows is critical for 5G-connected application design.

Every server, switch, and cloud datacenter runs on Ethernet. Understanding frames, MTU, VLANs, and flow control prevents subtle performance and networking bugs.

VLANs are how you segment networks in every datacenter and enterprise. You'll hit 802.1Q any time you configure a switch, provision cloud VPCs, or troubleshoot inter-tenant isolation.

802.1X is how enterprises authenticate devices before allowing network access. Required knowledge for corporate Wi-Fi, VPN alternatives, and zero-trust network access designs.

Wi-Fi 6/6E is the current enterprise and consumer wireless standard. OFDMA and TWT are especially relevant for dense IoT deployments and high-density venues like offices and stadiums.

GSM underpins SMS delivery, international roaming, and network fallback. Understanding A-interface, MSC, and MSISDN is essential for any telecom or SMS gateway integration.

LTE-M is the go-to for IoT devices needing voice, mobility, and moderate data rates on cellular. PSM and eDRX power modes directly affect battery life design in firmware and device management.

NB-IoT is the cellular choice for deep coverage (underground, rural) and ultra-low-power IoT: smart meters, agricultural sensors, and asset trackers. NIDD and CoAP integration are key design decisions.

eSIM is now standard in smartphones (iPhone XR+, Android flagships), laptops, and cellular IoT modules. Understanding SGP.22 RSP is essential for telecom apps that provision cellular connectivity programmatically.

Wi-Fi 7 is arriving in enterprise and consumer hardware now. MLO's simultaneous multi-band operation fundamentally changes how wireless latency and throughput scale.

UMTS/HSPA was the bridge from 2G voice to mobile internet. IMS architecture from UMTS carries forward into LTE VoLTE. Understanding HSPA variants helps debug mobile data fallback scenarios.