Design a 5G NR time-frequency resource grid, see every resource element mapped,
and have the configuration checked against the 3GPP specifications as you work.

Built for RF and physical-layer engineers, students learning the NR air
interface, and anyone who has ever tried to reason about a resource grid from a
table of numbers.

WHAT IT DOES

Draws the grid. Frequency up the vertical axis with Point A at resource block 0,
OFDM symbols along the horizontal. Pinch to zoom, drag to pan, tap any element
to see which channel owns it and what else is mapped there.

Checks the configuration. Around 120 conformance checks run on every edit, each
citing the clause it comes from. Most findings carry a one-tap correction that
says what it will change before it changes it, and Fix all applies them in
dependency order.

Computes the numbers. Transport block size by the full TS 38.214 procedure,
effective code rate, throughput with the TDD duty cycle, CORESET capacity per
aggregation level, CSI-RS and SS/PBCH overhead, per-slot element accounting and
carrier timing.

Configures everything. About a hundred parameters, each named by its 3GPP
information element rather than a programmer's variable name, each carrying its
unit and the clause it comes from. Option lists are computed from the rest of
the configuration, so illegal combinations are largely unreachable rather than
merely reported afterwards.

CHANNELS AND SIGNALS COVERED

Synchronisation: PSS, SSS, PBCH and its DM-RS, SSB guard elements, cases A to E.
Control: CORESET including CORESET#0 from the MIB, PDCCH candidates with real
CCE-to-REG interleaving and candidate hashing, PDCCH DM-RS.
Downlink data: PDSCH, PDSCH DM-RS types 1 and 2, PT-RS.
Reference signals: NZP CSI-RS, ZP CSI-RS and TRS, all 18 rows of Table
7.4.1.5.3-1.
Uplink: PUSCH with DM-RS and PT-RS, PUCCH formats 0 to 4, PRACH, SRS.
Structure: bandwidth parts, TDD with two-pattern support, flexible symbols.

Five presets to start from, including n78 100 MHz TDD, n41 with SSB, n1 20 MHz
FDD and an FR2 400 MHz carrier.

PRIVACY

Everything runs on your device. No account, no network, no analytics, no
telemetry, no advertising, no permissions beyond the default. The only file the
app writes is your working configuration, in its own private storage.

ACCURACY

This is a design and teaching aid, not a conformance tool. The specification
tables are transcribed by hand and checked against structural rules, but verify
any figure against the published specifications before relying on it for
conformance work, a regulatory filing, or a configuration going to a live
network. Known limits are listed in the app.

References throughout are to 3GPP TS 38.211, 38.212, 38.213, 38.214, 38.331 and
38.101-1/-2. Not endorsed by or affiliated with 3GPP or ETSI.