FDD downlinkFDD uplinkTDDSDLSUL
Reading the map
Low, mid, high — three different games
Low band (< 1 GHz) propagates kilometres and punches through walls, but the slivers are narrow — 10–20 MHz FDD pairs. It carries coverage layers (n28, n71, n20).
Mid band (1–7 GHz) is where 5G capacity lives: n78/n77 C-band offers 100 MHz TDD blocks with workable propagation — the reason operators paid record sums for 3.5 GHz. NR-U (n46/n96/n102) adds unlicensed headroom.
mmWave FR2 (24–71 GHz) trades reach for raw bandwidth: 400 MHz carriers, beamforming mandatory, range measured in hundreds of metres. Hotspots, FWA and venues — not blanket coverage.
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Common questions
Which frequency bands does 5G use?
5G NR defines two ranges: FR1 from 410 MHz to 7.125 GHz (bands n1–n104, including the C-band workhorses n77/n78) and FR2 from 24.25 to 71 GHz (n257–n263). Each band in TS 38.104 Table 5.2-1 specifies exact UL/DL ranges and a duplex mode.
What is the difference between FDD, TDD, SDL and SUL bands?
FDD bands pair separate UL and DL ranges; TDD bands share one range in time; SDL (supplementary downlink) is DL-only spectrum aggregated for extra capacity; SUL (supplementary uplink) is UL-only low-band spectrum paired with a mid-band carrier to extend uplink coverage.
Why is n78 the most important 5G band?
n78 (3.3–3.8 GHz TDD) hits the balance point: enough spectrum for 100 MHz carriers, propagation that still covers urban macro grids, and near-global allocation — so device support is universal. Most commercial 5G capacity worldwide rides on it.
Do bands overlap?
Heavily. n77 fully contains n78; n41/n90 share 2496–2690 MHz; the 2100 MHz range appears in n1, n65 and n66. Overlaps exist because regional regulators carved the same spectrum differently — devices declare which band numbers they support.
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