IR.52 is common guidelines for MMS (Multimedia Messaging Service as specified by 3GPP & OMA) inter-operator connections in order to prevent non-interoperable and/or inefficient MMS networks. Areas covered are MMS specific issues in roaming and interworking, addressing schemes, message routing, inter-operator specific security issues and requirements for inter-PLMN backbone caused by MMS and it concentrates on the network level issues.