ETSI TS 103 462 V1.3.1 (2026-03)

Lawful Interception (LI); Inter LEMF Handover Interface

RTS/LI-00312

General Information

• Status: Not Published
• Technical Committee: LI - Lawful Interception
• Current Stage: 12 - Citation in the OJ (auto-insert)
• Due Date: 15-Mar-2026
• Completion Date: 04-Mar-2026

Standards Content (Sample)

TECHNICAL SPECIFICATION
Lawful Interception (LI);
Inter LEMF Handover Interface

2 ETSI TS 103 462 V1.3.1 (2026-03)

Reference
RTS/LI-00312
Keywords
handover, IP, lawful disclosure, lawful interception,
retained data, security
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3 ETSI TS 103 462 V1.3.1 (2026-03)
Contents
Intellectual Property Rights . 4
Foreword . 4
Modal verbs terminology . 4
Introduction . 4
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 7
3 Definition of terms, symbols and abbreviations . 7
3.1 Terms . 7
3.2 Symbols . 8
3.3 Abbreviations . 8
4 General aspects . 9
5 Architecture overview and functional description . 9
6 Delivery Handling . 10
6.1 General . 10
6.2 Description and purpose of the header fields . 10
6.2.1 Inter LEMF LIID . 10
6.2.2 Communication Identifier . 11
6.2.3 Sequence Number . 11
6.2.4 Timestamp . 11
6.3 Integrity . 11
6.4 Payload encryption . 11
6.5 Reliability . 11
6.6 Error Handling . 11
6.7 Keep alive . 12
7 Responding Interworking Function (resIWF) . 12
7.1 General . 12
7.2 Encapsulation function . 12
7.3 Mapping function . 12
7.3.1 General . 12
7.3.2 Timestamp . 12
7.3.3 Location information . 13
7.4 Interoperability function . 13
8 Encapsulation Handling . 13
8.1 General . 13
9 Transport layer . 14
Annex A (informative): Operational roles. 15
A.1 Introduction . 15
A.2 Requesting party (reqLEA/reqAA) . 16
A.3 Responding party (resLEA/resAA) . . 16
A.4 Executing Communication Service Provider . 16
Annex B (normative): Inter LEMF Handover (ILHI) ASN.1 . 17
Annex C (informative): Change history . 18
History . 19

ETSI
4 ETSI TS 103 462 V1.3.1 (2026-03)
Intellectual Property Rights
Essential patents
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pertaining to these essential IPRs, if any, are publicly available for ETSI members and non-members, and can be
found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to
ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the
ETSI IPR online database.
Pursuant to the ETSI Directives including the ETSI IPR Policy, no investigation regarding the essentiality of IPRs,
including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not
referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become,
essential to the present document.
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3GPP Organizational Partners. oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and of ®
the oneM2M Partners. GSM and the GSM logo are trademarks registered and owned by the GSM Association.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Lawful Interception (LI).
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
Introduction
The objective of the present document is to form the basis for a standardized handover interface, that will deliver the LI
and/or RD information via IP-based networks between Law Enforcement Authorities under various European treaties
and local regulations in case of:
• legal assistance;
• legal assistance regarding the European Investigation Order in criminal matters [i.1];
• (bilateral) administrative assistance.
The present document is intended to cover the following:
• transmission of intercepted Content of Communication (CC) and Intercept Related Information (IRI);
NOTE: This includes data that is already processed or stored on the LI system.
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5 ETSI TS 103 462 V1.3.1 (2026-03)
• transmission of traffic and location data (RD), administrative data according to ETSI TS 102 657 [i.4] and
error codes according to ETSI TS 102 232-1 [6] are for further study.
Besides the EIO Directive, there is also a need in some countries to exchange stored or LI data in real time between
different LEMFs or between a primary LEMF and a secondary analysis framework (this forms another use case for the
interface).
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6 ETSI TS 103 462 V1.3.1 (2026-03)
1 Scope
The present document specifies the LEMF to LEMF interface to support (as a minimum) European Investigation Orders
(EIOs) related to LI and/or RD. The present document aims to be capable of securely handling real-time and stored data
transfer between LEMFs in accordance with ETSI TS 102 232 parts 1 [6] to 7 [12] and the related 3GPP TS 33.108 [5]
for LI.
In the present document RD is for further study.
Local LI handover interfaces frequently use dedicated networks for delivery with local specific security features. With
the EIO Directive in place, there is a need to have a common Handover Interface to allow real-time exchange between
LEMFs that can be located in different countries, under different jurisdictions.
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found in the
ETSI docbox.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long-term validity.
The following referenced documents are necessary for the application of the present document.
[1] Void.
[2] ETSI TS 103 280: "Lawful Interception (LI); Dictionary for common parameters".
[3] Void.
[4] ETSI TS 103 307: "CYBER; Security aspects for LI and RD Interfaces".
[5] ETSI TS 133 108: "Digital cellular telecommunications system (Phase 2+) (GSM); Universal
Mobile Telecommunications System (UMTS); LTE; 3G security; Handover interface for Lawful
Interception (LI) (3GPP TS 33.108)".
[6] ETSI TS 102 232-1: "Lawful Interception (LI); Handover Interface and Service-Specific Details
(SSD) for IP delivery; Part 1: Handover specification for IP delivery".
[7] ETSI TS 102 232-2: "Lawful Interception (LI); Handover Interface and Service-Specific Details
(SSD) for IP delivery; Part 2: Service-specific details for messaging services".
[8] ETSI TS 102 232-3: "Lawful Interception (LI); Handover Interface and Service-Specific Details
(SSD) for IP delivery; Part 3: Service-specific details for internet access services".
[9] ETSI TS 102 232-4: "Lawful Interception (LI); Handover Interface and Service-Specific Details
(SSD) for IP delivery; Part 4: Service-specific details for Layer 2 services".
[10] ETSI TS 102 232-5: "Lawful Interception (LI); Handover Interface and Service-Specific Details
(SSD) for IP delivery; Part 5: Service-specific details for IP Multimedia Services".
[11] ETSI TS 102 232-6: "Lawful Interception (LI); Handover Interface and Service-Specific Details
(SSD) for IP delivery; Part 6: Service-specific details for PSTN/ISDN services".
[12] ETSI TS 102 232-7: "Lawful Interception (LI); Handover Interface and Service-Specific Details
(SSD) for IP delivery; Part 7: Service-specific details for Mobile Services".
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7 ETSI TS 103 462 V1.3.1 (2026-03)
[13] ISO 3166-1: "Codes for the representation of names of countries and their subdivisions — Part 1:
Country codes".
[14] Recommendation ITU-T X.680: "Information technology - Abstract Syntax Notation One
(ASN.1): Specification of basic notation".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long-term validity.
The following referenced documents may be useful in implementing an ETSI deliverable or add to the reader's
understanding, but are not required for conformance to the present document.
[i.1] Directive 2014/41/EU of the European Parliament and of the Council of 3 April 2014 regarding
the European Investigation Order in criminal matters.
[i.2] ETSI TR 102 503: "Lawful Interception (LI); ASN.1 Object Identifiers in Lawful Interception and
Retained data handling Specifications".
[i.3] ETSI TS 101 671: "Lawful Interception (LI); Handover interface for the lawful interception of
telecommunications traffic".
NOTE: ETSI TS 101 671 is in status "historical" and is not maintained.
[i.4] ETSI TS 102 657: "Lawful Interception (LI); Retained data handling; Handover interface for the
request and delivery of retained data".
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the terms given in ETSI TS 101 671 [i.3], ETSI TS 102 232-1 [6] and the
following apply:
NOTE: This may contain additional information.
mapping: function that maps every element of a given set to a distinct element of another set
mappingInfo: output of the mapping function
originalPayload: optional output part of the interoperability function containing the unmodified received data
real time: information and communication technologies that are able to generate and deliver information in a
time-frame similar to the real-life process that it is assisting
requesting AA (reqAA): Authorized Authority from the country that takes the initiative for the LI request
requesting IWF (reqIWF): function to format data from ILHI format into local format
requesting LEA (reqLEA): Law Enforcement Agency from the country that takes the initiative for the LI request
requesting LEMF (reqLEMF): Law Enforcement Monitoring Facility from the country that takes the initiative for the
LI request
resPayload: mandatory output part of the interoperability function
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