ITU‑T does not issue certificates. It publishes Recommendations – it does not issue certificates. When the industry says "ITU‑T certification," it means conformance testing against Recommendations to obtain a report for market access. Get this straight, and you won't go wrong.

1. ITU‑T Certification – Identify the Correct Recommendation and Version

1.1 Which Recommendation series applies to your product?

·ITU‑T Recommendations are divided by series: H‑series covers multimedia audio/video; G‑series covers transmission systems. In automotive and consumer electronics, you will repeatedly encounter H.324 – audio/video terminal communication over circuit‑switched networks.

·Two things must be distinguished: H.324 (PSTN fixed network) and 3G‑324M (mobile 3G video telephony) are not the same. The vast majority of in‑vehicle terminals use 3G‑324M – writing only "H.324" is insufficient.

·An even more critical confusion: H.324 Annex C covers mobile‑environment multimedia communication – it applies to in‑vehicle video‑call terminals (head‑unit video calls). EU eCall voice compliance is based on ITU‑T P‑series (P.1100/P.1110/P.1140) plus EN 17184 – not H.324. Do not steer eCall projects towards H.324 testing – that wastes money.

1.2 Lock down the version number
Recommendations are revised – the same H.324 has multiple Annexes with very different test items. Lock the version number before testing – submitting an old version against a new market will be rejected. Also, Recommendations distinguish mandatory subsets from optional extended features – list all optional features before testing – missing extensions invalidate the report.

  2. ITU‑T Certification – Choosing a Lab

2.1 ITU‑T does not accredit labs
ITU‑T issues no certificates, does not manage labs, and does not review reports – it only publishes standards. Testing is performed by third parties against the Recommendations. The weight of your report depends on the lab's accreditation and whether the target market accepts it.

2.2 Accreditation requirements

·For EU exports: lab must be ISO 17025 accredited – scope covering the corresponding Recommendations.

·For Japan: the Radio Law / Telecommunications Business Law follows ARIB – not a direct copy of ITU‑T text. Your ITU‑T metrics must be mapped to ARIB clauses. ISO 17025 does not guarantee RCB acceptance – overseas report acceptance is independently assessed by the RCB. Some RCBs require test methods to match Japanese specifications – submitting raw ITU‑T schemes may not be accepted.

Before choosing a lab, confirm that the target market accepts reports from that lab. Finding out after the report is issued means wasted effort.

  3. ITU‑T Certification – Test Process Breakdown

3.1 Sample preparation
Audio/video terminal samples must be in production‑ready state – with codecs and protocol stack complete. Engineering samples with missing functions will fail tests.

Sample quantity: do not default to two. H.324 two‑way calling (originating + terminating) requires two units; one‑way audio only requires one. Writing "two" blindly makes single‑audio clients overpay.

3.2 Core test items
H.324 / 3G‑324M testing has two major blocks:

·Protocol layer: call establishment, capability negotiation, multiplexing protocol, control protocol.

·Media layer: audio codec conformance, video codec conformance.

Note: base H.324 only defines H.263 – H.264 is a later addition. Newer in‑vehicle terminals are adopting H.265 – but that is not part of the base H.324 mandatory subset.

POLQA voice quality testing is a major item for audio/video terminals. POLQA is based on ITU‑T P.863 – it is a test‑tool algorithm specification. H.324 protocol standards do not require POLQA – the two are independent standards systems – many confuse them. Results are presented as MOS scores – below threshold = fail.

3.3 How long?
Full H.324 testing: 4–6 weeks. This assumes no major non‑conformities in the first round. Protocol‑stack compatibility issues – one round won't be enough – timeline extends. Lab equipment scheduling also affects progress – confirm scheduling status when discussing timelines.

  4. ITU‑T Certification – How to Use the Report

4.1 The report is not a certificate
An ITU‑T test report is evidence of conformance to Recommendations – it has no official validity period. The "two years" often cited in the industry is a common practice – not a global rule. Different Notified Bodies have very different acceptance windows – some accept reports within three years; some new projects only accept fresh reports against the latest Recommendation. Do not treat it as a fixed expiry – check against the target market.

4.2 Multi‑market reuse
One report can be used across multiple markets – EU CE RED audio/video terminals and Japan MIC certification referencing 3G‑324M test items – both can reuse data. However: the test methods, limits, and standard versions must match the target market's regulatory requirements. Different countries may add supplementary test conditions – the report is not universally applicable as‑is.

  5. ITU‑T Certification – Change Determination

5.1 Software changes
Changes to codec versions, protocol‑stack implementation logic, or call‑control flows – these affect test results – require assessment of retest scope.

UI changes that do not touch the protocol or media layers – can be handled simply. However, if the UI affects audio gain, echo‑suppression parameters, or call auto‑control logic – even if the core protocol stack is untouched – media‑layer results can still be affected. Do not assume that "UI" automatically grants exemption.

5.2 Hardware changes
Changing the audio chip, video‑processing chip, or baseband chip – two scenarios must be distinguished:

·Same model, same firmware chip replacement – PCB unchanged – some labs accept difference assessment – not necessarily full retesting.

·Cross‑model replacement – requires full retesting.

Do not apply a blanket rule.

For ITU‑T certification steps, contact BlueAsia at 13534225140 (King) or king.guo@cblueasia.com.