System-level terms — bands, duplexing, aggregation, and the loops

5G Systems Notes · Reference · System Concept map · PDSCH · Hub

The remaining terms on the concept map are the ones that sit around the physical layer — which band it runs in, how the two directions share the air, how carriers combine, and the control loops that decide what happens next slot.

Concepts defined here. FR1 and FR2 · PAPR · TDD and FDD · Carrier aggregation · Scheduling · Link adaptation · DRX · eMBB, URLLC, mMTC · AI/ML in the RAN

EVM is in ref-modulation §5, where the constellation argument that needs it lives.


The concepts this note covers

Each concept now has a page of its own. This note is the narrative — the group read as one argument, with the connective tissue that a page-per-concept cannot carry. The pages are the definitions, and each one shows what to learn before it.

ConceptWhat it isNeedsPrimary clause
AI/ML in the RANLearning inside the radio, and at what timescale2TS 38.214 §5.2.1.4.2, TR 38.843
Carrier aggregationSeveral carriers, one device2TS 38.101-1 §5.5, TS 38.213 §10
DRXDiscontinuous reception — how a device sleeps2TS 38.321 §5.7
FR1 and FR2The two frequency ranges, and why they behave differently0TS 38.101-1 §5.1, TS 38.101-2 §5.1
Link adaptationChoosing a rate the link will actually carry2TS 38.214 §5.1.3, §5.2.2.1
PAPRPeak-to-average power ratio1TS 38.211 §6.3.1.4
SchedulingWho gets the grid, this slot2TS 38.213 §10, TS 38.321 §5.4
TDD and FDDSharing a frequency in time, or using two2TS 38.213 §11.1
URLLC and eMBBThe service classes, as configurations3TR 38.913 §7.5, §7.9

Which to read. Come here to see how these ideas hang together; go to a term page when you want one definition, its prerequisites, and everything that depends on it. The concept map indexes all 118, and its hierarchy puts them in learning order.


Sources

DocumentClauseWhat it gives
TS 38.101-15.1, 5.5, 6.4.2Table 5.1-1, the frequency range definitions; band combinations and MSD; EVM
TS 38.2114.5Carrier aggregation — the one-sentence design
6.3.1.4DFT-spread OFDM, the low-PAPR uplink waveform
TS 38.21311.1TDD slot configuration and the slot format
10.1, 10.2PDCCH monitoring; validation of SPS activation
TS 38.2145.1.3, 5.2.2.1The MCS and CQI tables link adaptation moves between
5.2.1.4.2, 5.2.2.2.10–.11csi-InferencePrediction-r19 and the predicted-PMI codebooks
TS 38.3215.4Logical channel prioritisation — the device's own scheduling
5.7DRX and its timers
TR 38.9137.1, 7.5, 7.6, 7.9–7.11The targets of Table 1
Table 1: The clauses this reference note stands on. All are in the archive folder Courses (RAW)/5G Topics except TS 38.101-2, which covers FR2 and is not held here - the FR2 rows of the frequency-range table are quoted from TS 38.101-1 Table 5.1-1, which defines all three ranges even though it specifies only FR1 bands.
5G Systems Notes · Reference · System Top · Concept map · Hub