Home Participating Manufacturers in IOP The following manufacturers of TETRA core equipment have signed up to the Interoperability Rules of Engagement and may participate in any Interoperability (IOP) testing activity: ManufacturerCompanyAirbusAirbus Defence & SpaceDammDamm Cellular System A/SEastcomEastcomEtelmEtelm SASFunkwerkFunkwerk Security Communications GmbHHBFECHebei Far East Communication System Engineering Co LtdHyteraHytera Communication Co LTD (China)HMF Smart SolutionsHMF Smart Solutions GmbHKaitecKaitec GmbHLeonardoLeonardo CompanyMotorolaMotorola SolutionsRohillRohill Technologies B.V.SepuraSepura plcSmart RouteSmart RouteTeltronicTeltronic S.A.U.