The objective of this technical specification is to specify interworking between MC systems and LMR systems that satisfy the MCPTT requirements in 3GPP TS 22.179 [3]@ MCCoRe requirements in 3GPP TS 22.280 [2] and the MCData requirements (SDS only) in 3GPP TS 22.282 [4]. The present document refers to an InterWorking Function (IWF). The structure and functionality of the IWF is out of scope of the present document. The definition of reference points between the IWF and MC systems and the interactions between the IWF and MC systems are in scope of the present document.