Every hybrid-radio receiver resolves a station through DNS before it shows a logo, a schedule, or now-playing art. UndertowIQ is the neutral custodian of that identity layer for the United States, one deterministic, coded name for every licensed station across every band, derived straight from the call sign and the FCC license. No registration required to exist; claim yours to light it up.
RadioDNS is an open standard, but the US has no neutral operator issuing identities across the whole band, and the official spec never defined an analog-AM bearer at all. UndertowIQ fills both gaps: a single authority that mints a stable, coded identity for every US station, honors existing registrations, and resolves each one to its RadioEPG, RadioVIS, and RadioSPI services. The identity is computed, not assigned, so it is reproducible by anyone and owned by no one.
Every band shares the same shape: a coded, lowercase-hex bearer FQDN. The colored segments below are keyed to what each one means.
Managed twin under fm.zerotrustradio.org. Exactly the RadioDNS RDNS01 rule, the US just derives the PI from the call sign (NRSC-4-B) instead of reading it off an RDS encoder.
Official RadioDNS defines no analog-AM bearer, so UndertowIQ defines one structured
exactly like FM. Every station is published under both the coded form and the
human-readable callsign form; a facility-{id}.am.zerotrustradio.org alias points at the same
identity. Neither form is an alias of the other, both are first-class, permanently.
The uniquely-American digital band. Managed twin under hd.zerotrustradio.org;
hybrid AM-HD lives under hd.am.zerotrustradio.org.
Where the official standard already defines a bearer (DAB SId/EId, DRM SId, AMSS), UndertowIQ uses it verbatim rather than inventing a parallel one.
Deterministic and reproducible, the same call sign and license always yield the same name, computed by anyone, assigned by no one.
a0.10620, in 10 kHz units, zero-padded to five digits.00780, the carrier in kHz, zero-padded to five digits.Each identity CNAMEs into the managed zone, which carries the standard RadioDNS service records a receiver looks up next.
| Service | Record | Purpose |
|---|---|---|
| RadioEPG | _radioepg._tcp · SRV → :443 | schedules & station metadata (SI/PI) |
| RadioVIS | _radiovis._tcp · SRV → :61613 | now-playing slideshow & text (STOMP) |
| RadioSPI | _radiospi._tcp · SRV → :443 | rich service & programme information |
The SRV records point at the UndertowIQ edge CDN. Service Information is published
as one master RadioSPI 3.1 document listing every service; per-station content, RadioEPG logos, RadioVIS slideshows, RadioTAG, is keyed by FCC facility ID, stable
across call-sign changes and matching the facility-{id} zone alias.
| Content | Canonical path |
|---|---|
| RadioSPI · master SI | radiodns/spi/3.1/SI.xml |
| RadioEPG logos | radiodns/logos/{facility_id}/ |
| RadioVIS slideshow | radiodns/vis/{facility_id}/ |
| RadioTAG | radiodns/tag/{facility_id}/ |
Resolve any bearer to its live identity, its published SI
service (names, logos, streams), and these content URLs via the public resolver:
GET /rdns/resolve?bearer=<fqdn>.
Provider-grade where it counts, the receiver-facing resolution path is pure, redundant, cryptographically-signed DNS. No single point of failure in what a radio actually queries.
Every identity, down to each dormant station, is individually
signed and validates end-to-end (AD: true) at any DNSSEC-aware resolver. Bearers are served
from four redundant nameservers on independent hosts; service content is delivered from a dedicated edge
CDN. Identities are computed from public FCC data, so the namespace is reproducible by
anyone and captured by no one.
The identity space is pre-built for the entire United States. Every licensed AM and FM facility already has a dormant, unclaimed identity waiting, see the live occupancy census and browse the signed zones on the records page.
If you operate a US station, your coded identity already exists, dormant and unclaimed. Light it up, point it at your EPG/VIS/SPI services, and every hybrid receiver resolves you correctly.