NR Cell Identity (NCI) Calculator
Decode a 36 bit NR Cell Identity into its gNB ID and cell ID components. Per 3GPP TS 38.413 §9.3.1.7. Supports any operator configured gNB ID length from 22 to 32 bits.
Last verified 2026-04-15 against 3GPP TS 38.413 v18.3.0 §9.3.1.7 · Release 18
NCI structure
NCI (36 bits) upper bits = gNB ID (22 to 32 bits) lower bits = Cell ID (4 to 14 bits = 36 - gNB_ID_length) Decoding: cell_ID_mask = (1 shiftLeft cell_ID_length) - 1 cell_ID = NCI AND cell_ID_mask gNB_ID = NCI shiftRight cell_ID_length
Common splits
| gNB ID length | Cell ID length | Max gNB per PLMN | Max cells per gNB |
|---|---|---|---|
| 22 | 14 | 4 194 304 | 16 384 |
| 24 | 12 | 16 777 216 | 4 096 |
| 26 | 10 | 67 108 864 | 1 024 |
| 28 | 8 | 268 435 456 | 256 |
| 32 | 4 | 4 294 967 296 | 16 |
Worked example (24 bit split)
Given: NCI in hex = 0x0A1B2C3D4 gNB_ID_length = 24 bits cell_ID_length = 36 - 24 = 12 bits Decode: cell_ID_mask = (1 shiftLeft 12) - 1 = 0xFFF cell_ID = 0x0A1B2C3D4 AND 0xFFF = 0x3D4 = 980 gNB_ID = 0x0A1B2C3D4 shiftRight 12 = 0x0A1B2C3 = 10 598 595 Result: cell 980 of gNB 10598595 in the operator network
Worked example (22 bit split)
Given: NCI in hex = 0x000FA002A gNB_ID_length = 22 bits cell_ID_length = 36 - 22 = 14 bits Decode: cell_ID_mask = (1 shiftLeft 14) - 1 = 0x3FFF cell_ID = 0x000FA002A AND 0x3FFF = 0x002A = 42 gNB_ID = 0x000FA002A shiftRight 14 = 0x3E8 = 1000 Result: cell 42 of gNB 1000 in the operator network
A 22-bit gNB ID supports up to 4 194 304 gNBs with 16 384 cells each — common in dense 5G NR macro deployments.
Read NCI live on Android
HiCellTek RF Monitor reads the full NCI and derived gNB ID from the Android Telephony API. Shown alongside PCI, NR-ARFCN, SSB index and serving cell metrics.
Frequently asked questions
What is NR Cell Identity (NCI)?
A 36 bit value that uniquely identifies a cell within a PLMN. Defined in 3GPP TS 38.413 §9.3.1.7 as part of the Global gNB ID structure.
What is the difference between NCI and PCI?
PCI is a 10 bit physical layer identifier (0 to 1007), reused many times across the network. NCI is a 36 bit logical identifier, globally unique inside the PLMN.
How does NCI split into gNB ID and cell ID?
Upper bits are gNB ID (22 to 32 bits, operator configurable). Lower bits are cell ID (36 - gNB ID length, so 4 to 14 bits).
What is the most common gNB ID split?
24 bits for gNB ID, 12 bits for cell ID. This supports up to 16 million gNBs and 4096 cells per gNB, a good match for European macro deployments.
Is NCI broadcast over the air?
Yes, the full Cell Global Identity (PLMN + NCI) is broadcast in SIB1 per TS 38.331 §6.2.2.
How does NCI relate to LTE ECI?
ECI is 28 bits (TS 36.413). NCI is 36 bits (TS 38.413). The extra 8 bits accommodate denser 5G networks with more gNBs and more cells per gNB.