The present document contains the user requirements which are described in non-technical terms and are based on an analysis of the results for air interface enhancements from the TETRA Release 2 Market Questionnaire (see Bibliography)@ described in TR 102 021-1 [i]@ clauses 4.2 and 4.3. The present document defines the user requirements for the Subscriber Identity Module (SIM). The present document is applicable to the specification of TETRA Release 2 equipment.