LTE / 4G
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.
What It Defines
Long Term Evolution is the 4G cellular standard: OFDMA/SC-FDMA air interface, Evolved Packet Core (EPC), eNodeB architecture, EPS bearers, S1/X2 interfaces, VoLTE (IMS-based voice), and LTE-A carrier aggregation. Releases 8–14 define the core standard. Still the dominant global mobile network.
Canonical (Normative)
Convenient (Practical)
The global collaboration of telecommunications standards bodies that produces the mobile network specifications: GSM/EDGE, UMTS/HSPA, LTE/4G, 5G NR, and IMS. Technical specifications (TS) and reports (TR) are freely available at 3gpp.org. Releases (Rel-8, Rel-15, Rel-17…) provide versioned capability sets.
Related Specs
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.
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.
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SIP is the PSTN of the internet. Every VoIP platform (Twilio, Vonage, AWS Chime, Asterisk, FreeSWITCH) speaks SIP. Building any communications product requires understanding INVITE flows, registration, and codec negotiation via SDP.