The user requirements contained in this URS 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@ described in TR 102 021-1 [i.1]@ clauses 4.2 and 4.3 and the Future of TETRA workshop held during the TETRA World Congress 2007@ TR 102 621 [i.2]. The present document provides the user requirements for TETRA interworking and roaming. The present document is applicable to the specification of TETRA Release 2.1 equipment.