Field Guide · protocol

Also known as: 5G NR, New Radio, 5G

5G NR (New Radio) is the 3GPP fifth-generation radio-access technology, built on a flexible OFDM framework with scalable numerologies, LDPC coding for data and polar coding for control, and heavy reliance on massive MIMO and beamforming.1 It spans two frequency ranges — sub-6 GHz (FR1) and millimetre-wave (FR2) — to serve high-throughput, low-latency, and massive-device use cases from a single framework.

scalable numerology (µ) 15 kHz · 1 ms slot 30 kHz 60 wider spacing → shorter slot → lower latency LDPC massive MIMO beam
5G NR scales OFDM subcarrier spacing (15/30/60 kHz and higher) to trade bandwidth for latency, pairs LDPC-coded data with beamformed massive-MIMO arrays.

Overview

5G NR keeps OFDM but makes its parameters configurable: subcarrier spacing can be 15, 30, 60, 120, or 240 kHz, letting an operator pick short slots for low latency at high frequencies or narrow spacing for coverage at low ones. It runs in non-standalone mode anchored to an LTE core, or standalone with a native 5G core. FR2 mmWave carriers offer huge bandwidth but short range, so they lean hard on beamforming to steer energy toward each user.

Technical characteristics

Property Value
Waveform CP-OFDM (downlink and uplink; optional DFT-s-OFDM uplink)
Numerology Subcarrier spacing 15–240 kHz (µ = 0–4)
Frequency ranges FR1: 410 MHz–7.125 GHz; FR2: 24.25–52.6 GHz
Channel bandwidth Up to 100 MHz (FR1), 400 MHz (FR2)
Data coding LDPC
Control coding Polar code
Modulation QPSK to 256-QAM
Multi-antenna Massive MIMO, analog/digital beamforming

Choosing LDPC for high-throughput data (efficient at long block lengths) and polar codes for short, reliable control messages was a defining decision of NR’s Release 15 design.

History

3GPP finalised the first NR specification in Release 15 (2018), with commercial launches beginning in 2019.2 Later releases added reduced-capability (RedCap) devices, non-terrestrial (satellite) access, and sidelink, broadening NR beyond handset broadband.

Deployment

5G NR rolled out worldwide from 2019 onward, most commonly as non-standalone sub-6 GHz service overlaid on existing LTE, with mmWave used for dense hotspots and fixed wireless access. It coexists with and aggregates alongside LTE at most operators.

Decoding it with GopherTrunk

GopherTrunk does not decode 5G NR. NR is a licensed, wideband, beamformed cellular air interface whose bandwidth, adaptive numerology, and encryption place it entirely outside the scope of a narrowband land-mobile trunking scanner. It appears in this guide to show where OFDM, LDPC, and polar coding meet in a real modern system, and why those algorithms matter to the broader RF world even though GopherTrunk’s decode chain targets single-carrier C4FM/QPSK trunking instead.

Sources

  1. 5G NR — Wikipedia, for the scalable OFDM numerology, LDPC/polar coding split, and FR1/FR2 band structure. ↩

  2. 5G system overview — 3GPP, for the Release 15 timeline and standalone/non-standalone architecture. ↩

See also