TELECOM_CALCULATORS: ARFCN, EARFCN & NR-ARFCN Frequency Mapping Tools
Precision engineering calculators for RF channel mapping, identity decoding, and timing advance analysis.
Technical_Necessity
For security researchers utilizing Software Defined Radios (SDRs) and protocol analyzers, translating between raw spectrum data and network-specific parameters is a fundamental requirement.
Our calculators provide the mathematical bridge between Absolute Radio Frequency Channel Numbers (ARFCN) and their corresponding uplink/downlink frequencies. This is critical for correctly tuning hardware to sniff signaling traffic or perform vulnerability assessments on specific cellular bands.
Furthermore, decoding Mobile Country Codes (MCC), Mobile Network Codes (MNC), and Tracking Area Codes (TAC) allows for precise identification of carrier infrastructure, facilitating site surveying and the detection of unauthorized or rogue base stations.
Precision RF Mapping
Bidirectional conversion for 2G ARFCN, 3G UARFCN, 4G EARFCN, and 5G NR-ARFCN. Includes support for TDD/FDD duplex modes and channel bandwidth verification.
Identity Validation
Parse Cell Identity (CI), Physical Cell ID (PCI), and Global Cell Identity (GCI) across all generations. Essential for verifying network topology.
- ►ARFCN / EARFCN / NR-ARFCN
Translate channel numbers to MHz with precision offset handling for all 3GPP operating bands.
- ►MCC/MNC/TAC Decoding
Global lookup and validation for PLMN IDs and regional tracking areas.
All calculations performed by the TelcoSec toolkit are derived directly from the relevant 3GPP technical specifications. ARFCN-to-frequency conversions follow the formulas defined in TS 45.005 (GSM), TS 25.101 (UMTS), TS 36.101 (LTE), and TS 38.101 (5G NR). For each calculation, the output includes both the uplink (UL) and downlink (DL) centre frequencies, along with the corresponding channel bandwidth and duplex separation for the identified operating band.
The Timing Advance (TA) calculator uses the LTE and 5G NR propagation delay model as defined in TS 36.213 and TS 38.213. Each TA unit corresponds to a round-trip propagation delay of approximately 3.7 microseconds in LTE (with Tc = 1/30.72 MHz), translating to a cell-range estimate of approximately 550 metres per TA increment. This is especially valuable during field assessments for approximating the geographic distance between a device and a serving base station, which can be cross-referenced against cell site databases to detect anomalous IMSI-catcher deployments.
MCC/MNC decoding is cross-referenced against the ITU-T E.212 and GSMA PRD IR.21 databases, ensuring that carrier identification is accurate across all international roaming regions. Researchers can use these decoded identifiers to map signaling traffic to specific operators and national regulatory regimes, which is essential for verifying compliance with regional telecommunications security mandates.
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Advanced calculators for timing advance, duplex spacing, and band mapping are available in the TelcoSec Engineer Hub.
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