The present document defines the common test environment required for testing Client and Server implementations for compliance to the Mission Critical Services over LTE protocol requirements defined by 3GPP. It contains definitions of reference conditions and test signals@ default messages and other parameters@ generic procedures@ and@ common requirements for test equipment with the goal for facilitating testing in general and test procedures specification in particular. Various parts of its content are referred to from other parts of the Mission Critical Services over LTE protocol conformance testing specification e.g. TS 36.579-2 [2] and TS 36.579-3 [3]. The present document does not define the common test environment required for testing the implementation of the underlining LTE protocols@ i.e. the LTE bearers used for transport of the Mission Critical Services signalling and media. This is defined in TS 36.508 [6] and referred to from the present document whenever needed. In regard to default messages or other information elements contents@ the present document refers to content defined in requirements specifications specified by 3GPP or other organisations. In the case of Session Initiation Protocol (SIP) and Session Description Protocol (SDP) information elements the present document refers to those specified in TS 34.229-1 [21] and explicitly specifies only those relevant for the purposes of the Mission Critical Services over LTE protocol conformance testing. In the present release of the specification only Mission Critical Push To Talk (MCPTT) Services are considered. Future releases may include other Mission Critical Services.