STANAG 4748 digital underwater signalling for network node discovery

What it is

STANAG 4748 is a NATO Standardization Agreement, Edition 1, dated 24 March 2017. It is not a technical specification. It is the agreement by which NATO nations commit to implement ANEP-87, Edition A, the Allied publication that sets the digital underwater signalling standard for network node discovery and interoperability. The document's own aim is to respond to an interoperability requirement, stated in two parts: to "enable underwater communications systems deployed on NATO and civilian platform to establish robust digital communications for node discovery and data exchange," and to ensure that digital underwater communications "do not interfere with analog underwater telephony compliant to STANAG 1074." Read on its own, STANAG 4748 requires nothing of a supplier or manufacturer beyond one thing: proving a device's interoperability once it exists. The digital underwater signalling requirements themselves sit in ANEP-87, not in this cover.

Who it binds, and how

Like every STANAG, this one is explicit that it binds nations rather than organisations. Its letter of promulgation describes the enclosed agreement as one "which has been ratified by member nations, as reflected in the NATO Standardization Document Database (NSDD), is promulgated herewith." Under "Agreement," participating nations agree to implement ANEP-87, Edition A - a national commitment made by ratification, not a duty a manufacturer signs up to by reading this document. Ratification and implementation stay separate steps: nations "are invited to examine their ratification of the STANAG and, if they have not already done so, advise the NSO of their intention regarding its implementation," and are separately "requested to provide to the NSO their actual STANAG implementation details." So "is STANAG 4748 mandatory" has no single answer: it depends on whether a given nation has ratified and implemented it, and on whether a contract or tender in front of a manufacturer invokes ANEP-87 by name.

Where a manufacturer actually meets it

The one place this cover names a supplier-facing role at all is interoperability testing. "Compliance to the standard will be ensured through interoperability testing with at least three other compliant devices, or with a standard implementation maintained by the Centre for Maritime Research and Experimentation (CMRE)/NATO Science and Technology Organization (STO)." That testing is not run by an assessor: "all such testing is to be performed and reported by the manufacturer and all costs are to be borne by the manufacturer." There is no accredited body, notified body or government inspector named anywhere in the document. Before that stage, the document also points industry toward an earlier route in: nations work with their national industries through the NATO Industrial Advisory Group on Digital Acoustic Communications and Networking, where "participating industry" can "identify requirements and procedures for implementing compliant digital communications and node discovery" onto their own underwater acoustic modems and telephony equipment.

A signalling standard, not a physical interface standard

The interoperability requirement this STANAG responds to has a second half that is easy to miss: new digital signalling must coexist with what is already deployed. The document requires that digital underwater communications "do not interfere with analog underwater telephony compliant to STANAG 1074" - a coexistence constraint on top of the node-discovery requirement, not just an aspiration. STANAG 1074 is named once, as that constraint, and sits outside our catalogue.

A cover agreement, not the signalling specification itself

A reader who only has STANAG 4748 in hand does not yet have the digital underwater signalling specification it points to. That sits in ANEP-87, Edition A. The document also names one other related NATO document, STANAG 1475, which covers ANEP-85's material interoperability requirements for submarine escape and rescue, and it names AAP-03 as the source of the reporting forms nations and partner nations use. This is Edition 1: the document states plainly that "this STANAG does not supersede any document."

Reporting and review

National decisions on ratification and implementation are recorded in the NATO Standardization Document Database. Nations report effective implementation "using the form at Annex H to AAP-03(J)," and partner nations separately report adoption "using the form at Annex G to AAP-03(J)." The STANAG itself "is to be reviewed at least once every three years," with the result "recorded within the NSDD" - a check on whether the agreement is still current, not an audit of any manufacturer's equipment. Nations and NATO bodies may propose changes at any time through a standardization proposal to the tasking authority, processed at the next review. It is a NATO non-classified document, free to obtain from the NATO Standardization Document Database; NATO does not charge for its standardization documents and we do not host or sell copies.

What it does not cover

STANAG 4748 sets out no digital underwater signalling requirement of its own - that detail sits entirely in ANEP-87. It also names no certification or accreditation scheme: the only check described is manufacturer-run interoperability testing against peer devices or a CMRE reference implementation, and a periodic review of the agreement's own currency, not a certificate issued to a nation, an organisation or a piece of equipment.

Standards it references

• STANAG 1475Background