A method of operating an Orthogonal Frequency Division Multiplex, OFDM, data communication system comprising a trusted OFDM subsystem and an access OFDM subsystem, the method comprising: the trusted OFDM subsystem receiving trust challenge data and responsively encoding the trust challenge data with a physically-embedded read-only trust key to generate encoded trust data and transferring the encoded trust data; the access OFDM subsystem receiving first user data from an access communication network into an access network receive buffer system; the trusted OFDM subsystem receiving second user data from a trusted communication network into a trusted network receive buffer system and responsively transferring a resource request to the access OFDM subsystem; the access OFDM subsystem receiving the resource request and responsively retaining first OFDM resource blocks and allocating and indicating second OFDM resource blocks to the trusted OFDM subsystem, wherein the first and second OFDM resource blocks are mutually exclusive; the access OFDM subsystem scheduling the first user data using the first OFDM resource blocks and responsively transferring the first user data from the access network receive buffer system to an access Common Public Radio Interface, CPRI, transmit buffer system; the trusted OFDM subsystem scheduling the second user data using the second OFDM resource blocks and responsively transferring the second user data from the trusted network receive buffer system to a trusted CPRI transmit buffer system; and the trusted OFDM subsystem determining a CPRI transmit sequence based on the allocated and indicated second OFDM resource blocks, transferring the first user data from the access CPRI transmit buffer system to a CPRI communication system using the CPRI transmit sequence, and transferring the second user data from the trusted CPRI transmit buffer system to the CPRI communication system using the CPRI transmit sequence. the trusted OFDM subsystem receiving trust challenge data and responsively encoding the trust challenge data with a physically-embedded read-only trust key to generate encoded trust data and transferring the encoded trust data; the access OFDM subsystem receiving first user data from an access communication network into an access network receive buffer system; the trusted OFDM subsystem receiving second user data from a trusted communication network into a trusted network receive buffer system and responsively transferring a resource request to the access OFDM subsystem; the access OFDM subsystem receiving the resource request and responsively retaining first OFDM resource blocks and allocating and indicating second OFDM resource blocks to the trusted OFDM subsystem, wherein the first and second OFDM resource blocks are mutually exclusive; the access OFDM subsystem scheduling the first user data using the first OFDM resource blocks and responsively transferring the first user data from the access network receive buffer system to an access Common Public Radio Interface, CPRI, transmit buffer system; the trusted OFDM subsystem scheduling the second user data using the second OFDM resource blocks and responsively transferring the second user data from the trusted network receive buffer system to a trusted CPRI transmit buffer system; and the trusted OFDM subsystem determining a CPRI transmit sequence based on the allocated and indicated second OFDM resource blocks, transferring the first user data from the access CPRI transmit buffer system to a CPRI communication system using the CPRI transmit sequence, and transferring the second user data from the trusted CPRI transmit buffer system to the CPRI communication system using the CPRI transmit sequence.