1xBTS 1xBTS

Channel Planning

The BTS selects its RF carrier via a single (band_class, band_subclass, cdma_channel) triple in config/bts.json (see Configuration Reference → channel). From that triple, the runtime derives TX (downlink) and RX (uplink) center frequencies and the broadcast CDMA_FREQ / BAND_CLASS overhead fields, per 3GPP2 C.S0057-F.

Open the CDMA Channel Calculator → Compute TX/RX frequencies and validity for any (band, subclass, N).

Supported band classes

BandDescriptionTX formula (MHz)RX formula (MHz)DuplexSubclasses
BC0800 MHz Cellularpiecewise (3 segments around 870/825)piecewise−45 MHz0–3
BC11900 MHz PCS1930.000 + 0.050·N1850.000 + 0.050·N−80 MHz0
BC2TACSpiecewise (3 segments)piecewise−45 MHz (sub 0–2) or +45 MHz (sub 3 ATG)0–3
BC3JTACSpiecewise (4 segments around 860)piecewise around 915+55 MHz (mobile higher)0
BC4Korean PCS1840.000 + 0.050·N1750.000 + 0.050·N−90 MHz0
BC5450 MHz NMTpiecewise (5 segments + 2 singletons)piecewise−10 MHz0–13 (blocks A–N)
BC62 GHz IMT-20002110.000 + 0.050·N1920.000 + 0.050·N−190 MHz0
BC7Upper 700 MHz746.000 + 0.050·N776.000 + 0.050·N+30 MHz (mobile higher)0
BC81800 MHz1805.000 + 0.050·N1710.000 + 0.050·N−95 MHz0
BC9900 MHz925.000 + 0.050·N880.000 + 0.050·N−45 MHz0
BC10Secondary 800 MHzpiecewise (2 segments)piecewise−45 MHz (sub 0–3) or −39 MHz (sub 4)0–4
BC11European PAMR 400 MHzsame formula as BC5same−10 MHz0–11 (subset of A–N; F/G/H not specified)
BC12800 MHz PAMR915.0125 + 0.025·N870.0125 + 0.025·N−45 MHz0–2
BC132.5 GHz IMT-2000 Extension2620.000 + 0.050·N2500.000 + 0.050·N−120 MHz0
BC14US PCS Extension1930.000 + 0.050·N1850.000 + 0.050·N−80 MHz0
BC15AWS2110.000 + 0.050·N1710.000 + 0.050·N−400 MHz0
BC16US 2.5 GHz2617.000 + 0.050·N2495.000 + 0.050·N−122 MHz0
BC17US 2.5 GHz FL-onlyNot specified in spec——rejected
BC18700 MHz Public Safety757.000 + 0.050·N787.000 + 0.050·N+30 MHz (mobile higher)0
BC19Lower 700 MHz728.000 + 0.050·N698.000 + 0.050·N−30 MHz0
BC20L-Band1525.000 + 0.050·N1626.500 + 0.050·N+101.5 MHz (mobile higher)0
BC21S-Band MSSpiecewise (2 blocks)piecewise−190 MHz (block A) / −170 MHz (block B)0
BC22Mobile Satellite SystemNot specified in spec——rejected

Default: BC0 / sub 0 / N=384 → 881.520 MHz TX, 836.520 MHz RX.

Valid channel ranges

Valid channels load silently; Cond (Conditionally Valid) channels emit a WARN at startup and proceed; anything else is rejected.

BandSubValid (N)Cond (N)
BC001–311, 356–644, 689–694, 739–777, 1013–1023—
BC011–311, 356–644, 689–779, 1013–1023—
BC021–142, 991–1023—
BC031–142, 991–1023, 1048–1323—
BC1025–275, 325–375, 425–675, 725–775, 825–875, 925–1175276–324, 376–424, 676–724, 776–824, 876–924
BC200–600—
BC210–1000—
BC220–600, 1329–2047—
BC232048–2108 (ATG, reverse duplex)—
BC301–799, 801–1039, 1041–1199, 1201–1600 (even N only)—
BC400–599—
BC50–13per block A–N (see C.S0057-F Table 2.1.6-3)—
BC6025–1175—
BC7023–198—
BC8025–1475—
BC9025–675—
BC10050–150151–199
BC101250–350200–249, 351–399
BC102450–550400–449, 551–599
BC103650–670600–649
BC104770–870—
BC110–11per block A–L (F/G/H not specified)—
BC12065–214—
BC12194–144—
BC122105–20625–104, 207–214
BC13025–1375—
BC14025–275, 325–375, 425–675, 725–775, 825–875, 925–1175, 1225–1275276–324, 376–424, 676–724, 776–824, 876–924, 1176–1224, 1276–1299
BC15025–875—
BC160165–1435—
BC17—rejected (not specified)—
BC18045–95, 145–19596–144
BC19023–98, 143–218, 263–33899–142, 219–262
BC20013–667—
BC21025–175, 225–375—
BC22—rejected (not specified)—

BC5/BC11 use per-block (A–N / A–L) ranges; see C.S0057-F Tables 2.1.6-3 and 2.1.12-3.

Typical channels per spec Preferred Set tables (SR1 only; for SR3 multi-carrier sets see the §2.1.x-6 tables in C.S0057-F).

BandSubclass / BlockPrimaryOther preferred
BC0sub 0 / A283691
BC0sub 0 / B384777
BC0sub 1 / A779738
BC0sub 1 / B486568
BC0sub 2 / A’401022
BC0sub 3 / A”127340
BC1A2550, 75, 100, 125, 150, 175, 200, 225, 250, 275
BC1D325350, 375
BC1B425450, 475, 500, 525, 550, 575, 600, 625, 650, 675
BC1E725750, 775
BC1F825850, 875
BC1C925950, 975, 1000, 1025, 1050, 1075, 1100, 1125, 1150, 1175
BC2A79679, 1365
BC2B379947, 1932
BC2ATG (sub 3)2078—
BC3A76872
BC4A2550, 75, 100, 125, 150, 175
BC4B225250, 275, 300, 325, 350, 375
BC4C425450, 475, 500, 525, 550, 575
BC5A210160, 260
BC5B220120, 170
BC5C14747, 97
BC5D673573, 623
BC5E731781, 831
BC5F18411903, 1965
BC5G12911353, 1415
BC5H12131089, 1151
BC5I19292, 142
BC5J255305, 355
BC5K15751625, 1675
BC5M21097, 110, 147, 160, 260, 2017, 2018
BC5N21047, 97, 110, 147, 160, 260, 2017, 2018
BC6025every 25 channels: 50, 75, …, 1150, 1175
BC7C2348, 73, 98, 123, 148, 173, 198
BC8025every 25 channels: 50, 75, …, 1450, 1475
BC9025every 25 channels: 50, 75, …, 650, 675
BC10sub 0 / A50100, 150
BC10sub 1 / B250300, 350
BC10sub 2 / C450500, 550
BC10sub 3 / D650670
BC10sub 4 / E770820, 870
BC11A210160, 260
BC11B220120, 170
BC11C14747, 97
BC11D673573, 623
BC11E731781, 831
BC11I19292, 142
BC11J255305, 355
BC11K15751625, 1675
BC12A89139, 189
BC12B94144
BC12C106156, 206
BC13A–S2550, 75 (per-block triples through 1875)
BC14A25(same A/D/B/E/F/C as BC1) plus G: 1225, 1250, 1275
BC15A2550, 75, 100, 125, 150, 175
BC15B225250, 275, 300, 325, 350, 375
BC15C425450, 475
BC15D525550, 575
BC15E625650, 675
BC15F725750, 775, 800, 825, 850, 875
BC16A165190, 215, 240, 265, 290, 315, 340, 365, 390, 415, 440
BC16B495520, 545, 570, 595, 620, 645, 670, 695, 720, 745, 770
BC16C825850, 875, 900, 925, 950, 975, 1000, 1025, 1050, 1075, 1100
BC18D4570, 95
BC18Public Safety Broadband145170, 195
BC19A2348, 73, 98
BC19B143168, 193, 218
BC19C263288, 313, 338
BC20025every 25 channels: 50, 75, …, 625, 650
BC21A2550, 75, 100, 125, 150, 175
BC21B225250, 275, 300, 325, 350, 375

“Primary” is the spec’s Primary CDMA Channel where defined, otherwise the first channel in the Preferred Set. BC17 and BC22 are Not Specified per spec.