the network. Interconnection is a specific type of access implemented between public network operators; “interconnection agreement” means the technical and commercial arrangements entered into between two providers in relation to the provision of interconnection; 3(a) of 51(I) of 2012. “interface” means a termination point of a network which is a physical connection point at which a user is provided with access to a public electronic communications network, and/or a radio interface specifying the radio communications route between radio equipment and its technical specifications; “item of correspondence” means a communication in written form on any kind of physical medium to be conveyed and delivered at the address indicated by the sender on the item itself or on its wrapping; books, catalogues, newspapers and periodicals are not regarded as items of correspondence; “ITU” means the International Telecommunication Union; “leased lines” means electronic communications facilities which provide for transparent transmission capacity between network termination points and which do not include on-demand switching (switching functions which the user can control as part of the leased line provision); “licence” means (i) authorisation, in the form of general authorisation or individual right of use, prescribing rights and obligations, to persons regarding the provision of electronic communications services and/or the establishment or operation of 36