The present document provides Stage 1 interception requirements within a 3GPP network. The specification describes the service requirements from a Law Enforcement point of view only. The aim of this document is to define an interception system for 3GPP networks that supports a number of regional interception regulations@ but these regulations are not repeated here as they vary. Regional interception requirements shall rely on this specification to derive such information as they require. Lawful interception services may include both passive collection of information related to PLMN services provided to a user targeted for interception and active PLMN service invocation in support of lawfully authorized surveillance activities relating to a particular target. This specification considers requirements for both forms of lawful interception. Which PLMN services are subject to lawful interception is defined in national regulations. The presence of a requirement in this specification does not in itself infer or mandate that a 3GPP operator has an obligation to implement any network service capability@ which is not otherwise required to meet LI obligation compliance in relation to specific regulated services@ offered by that 3GPP operator. Only those specific requirements and sub-sections of this specification which are applicable to specific network and/or service capabilities implemented in a 3GPP operator??s network shall be considered in scope for that operator. In all cases@ national regulations define which requirements are applicable to 3GPP operators in each country relative to the services offered by each 3GPP operator. As such not all requirements in 33.106 will apply in all national jurisdictions or to all 3GPP operator deployments (e.g if an operator does not offer voice services@ then voice LI requirement in this specification do not apply unless otherwise mandated in national regulations). Editor??s Note: Scope needs to be enhanced more clearly differentiate between traditional 3GPP service usage reporting and wider LI requirements covered national lawful interception obligations. These interception requirements shall be used to derive specific network requirements. For details see: Stage 2: 3GPP TS 33.107 [9]; Stage 3: 3GPP TS 33.108 [10].