The present document provides the User Requirement Specifications (URS) for the TETRA air interface enhancements translated into terms of: ? network performance aspects; ? terminal performance aspects; ? location information aspects. The present document is applicable to the specification of TETRA Release 2.1 equipment. The user requirements contained in the present document are described in non-technical terms and are based on discussions in TC TETRA WG1 and on an analysis of the results for air interface enhancements from the 2001 TETRA Release 2 Market Questionnaire and the 2007 Future of TETRA workshop [i.1].