The present document is step 3 of a three-step approach to describe a generic Handover Interface (HI) for the provision of lawful interception from a Network Operator, an Access Provider or a Service Provider (NWO/AP/SvP) to the Law Enforcement Agencies (LEAs). The provision of lawful interception is a requirement of national law, which is usually mandatory for the operation of any telecommunication service.

Step 1 contains the requirements for lawful interception from a users (LEAs) point of view and is published in TS 101 331 [1].

Step 2 describes the derived network functions and the general architecture (or functional model) and is published in ES 201 158 [2].

The present document specifies:

• the generic flow of information as well as the procedures and information elements, which are applicable to any future telecommunication network or service;
• the network/service specific protocols relating to the provision of lawful interception at the Handover Interface (HI), for the following networks/services:
  • switched circuit; and
  • packet data.

The technologies covered in the present document are: GSM, TETRA, GPRS, ISDN, PSTN, fixed NGN (including PSTN/ISDN emulation) and fixed IMS PSTN simulation.

NOTE: As new networks and/or services are developed, the present document will be expanded as the relevant standards become available.