As 2G and 3G networks are retired worldwide, the traditional circuit-switched automotive emergency call system (CS-eCall) is rapidly giving way to next-generation eCall (NG-eCall) built on 4G and 5G IMS architecture. Regulators in several regions have set mandatory deadlines for the technology transition. For vehicle makers and suppliers, understanding those deadlines and completing test and certification planning is essential to market access for new models.

CS-eCall versus NG-eCall: the core differences

The mission of an eCall system is to trigger an emergency call automatically or manually after an accident, transmit the minimum set of data (MSD) such as vehicle location and incident information to a public safety answering point (PSAP) and establish a voice channel. The underlying architecture of the two generations differs fundamentally:

Technology: CS-eCall is circuit-switched; NG-eCall is next-generation packet-switched.

Network: CS-eCall runs on 2G GSM or 3G UMTS circuit-switched domains; NG-eCall runs on 4G LTE or 5G NR packet-switched domains over IMS.

Voice: CS-eCall uses end-to-end circuit voice in the CS domain; NG-eCall uses VoLTE or VoNR high-definition voice with AMR-WB wideband coding.

MSD transmission: CS-eCall uses an in-band modem embedded in the voice channel; NG-eCall sends MSD out-of-band over SIP signalling in milliseconds, falling back to in-band mode when working with legacy PSAPs.

MSD version: CS-eCall uses MSD V2 at about 140 bytes; NG-eCall uses MSD V3 with greatly expanded capacity and more vehicle status fields.

Voice channel: CS-eCall is exclusive — voice and data are time-shared, the voice channel is muted while MSD is transmitted and call setup takes 4 to 10 seconds; NG-eCall is concurrent — voice and data are sent at the same time over VoLTE or VoNR and call setup is much faster.

Signalling: SS7 ISUP for CS-eCall; SIP/IMS for NG-eCall.

Handover: GSM/UMTS handover in both directions for CS-eCall; 4G/5G handover both ways with one-way fallback to 2G/3G CS for NG-eCall.

In short, CS-eCall carries data inside the voice channel, while NG-eCall is an all-IP architecture running data and voice in parallel. The latter offers generational gains in speed, capacity, voice quality and future extensibility, and is the inevitable choice as networks are retired.

Latest regulatory deadlines worldwide

1. China: mandatory AECS national standard

GB 45672-2025, the Automotive Emergency Call System (AECS) standard, was published in April 2025 and is China's first mandatory national standard for automotive emergency calling:

· The system must support at least 4G networks.

· 1 July 2027: mandatory for M1 passenger cars applying for new type approval.

· 1 July 2028: mandatory for M1 passenger cars already type-approved.

· 1 January 2028: mandatory for N1 light trucks applying for new type approval.

· 1 January 2029: mandatory for N1 light trucks already type-approved.

2. EU: NG-eCall fully mandatory

Regulation (EU) 2024/1180 sets the EU transition timetable:

· 1 January 2026: all vehicles applying for new type approval must be equipped with NG-eCall; applications supporting only 2G/3G CS-eCall are no longer accepted.

· 1 January 2027: all newly registered vehicles must be equipped with NG-eCall and existing CS-eCall certificates become invalid.

· Supporting standards: EN 17184:2024 (NG-eCall system requirements) and EN 17240:2024 (end-to-end conformance test methods).

Note: CEN/TS 17240:2018 may still be used during the transition, but certificates are only valid until 1 January 2028, so new projects should adopt EN 17240:2024 directly.

3. UN Regulation No. 144

UN R144 is a global regulation under the UNECE 1958 Agreement. Revision 1 incorporates the NG-eCall framework, referencing CEN/TS 17184 and CEN/TS 17240 and supporting 4G/5G IMS architecture.

4. Middle East developments

· UAE: UAE.S 5019:2024 replaces the 2018 edition and moves towards NG-eCall. Certificates are issued by TDRA and are a precondition for vehicle access.

· Saudi Arabia: under SASO 2944:2023, from 1 January 2028 all M1 passenger cars and N1 light commercial vehicles applying for new type approval must meet eCall requirements.

· GCC: member states are progressively adding eCall to the mandatory annual vehicle certification list, with test requirements largely harmonised in GSO 2698:2022.

NTEK eCall test solution

Our laboratory is equipped with a complete Rohde & Schwarz eCall test system built around the CMX500 5G radio communication tester, together with the CMW500 wideband radio communication tester and the SMBV100B GNSS simulator, providing one-stop testing across mainstream eCall standards.

R&S CMX500: supports LTE and 5G NR signals with integrated IMS core network emulation and PSAP simulation — the main platform for NG-eCall testing.

R&S CMW500: the platform for traditional CS-eCall testing, emulating GSM, WCDMA and LTE signals and remaining compatible with legacy projects.

R&S SMBV100B: multi-constellation GNSS simulator covering GPS, BDS, GLONASS, Galileo and SBAS signals to verify positioning performance.

Standards covered

(EU) 2017/79; (EU) 2025/1871; EN 16454:2023; EN 17240:2024; UN R144 Rev.1; GB/T 45086.1-2024; GB/T 43187-2023; GB 45672-2025; UAE.S 5019:2024; SASO 2944:2023.

Capability highlights

· Full technology coverage: CS-eCall and NG-eCall tested on the same platform, supporting all networks from 2G to 5G.

· Complete testing: emergency call functionality, protocol conformance and navigation performance relevant to eCall certification.

· High automation: standardised test cases run automatically and reports are generated automatically, with efficient testing and traceable data.

· Pre-testing: diagnostic pre-tests before formal certification identify design issues early and substantially raise the first-time pass rate.

NTEK advice

2026 and 2027 are the critical window for the global switch from CS to NG eCall, and mandatory deadlines in the EU, the Middle East and other major markets are already set. Companies should plan their technology route early and work with a laboratory that offers complete capability and multi-standard coverage, so products reach the market on time and in compliance.

NTEK Group has an experienced eCall test team, complete test facilities and multi-standard coverage. For eCall testing and certification planning or to book pre-tests, please contact our technical team for one-to-one project support.