An apparatus for a user equipment, UE, for use in an Long Term Evolution, LTE, wireless communication network comprising processing circuitry to provide a Frequency Division Duplex - Time Division Duplex, FDD-TDD, hybrid automatic repeat request acknowledgement, HARQ-ACK, feedback procedure for a primary serving cell, PCell, by being configured to: establish a connection to the primary serving cell, PCell, and a secondary serving cell, SCell, of an enhanced-Node B, eNB, of the LTE wireless communication network, the PCell having a TDD uplink-downlink configuration and the SCell having a FDD configuration; receive downlink data through the PCell and SCell; categorize a type of downlink data subframe in use by the SCell as a Type-1 downlink, DL, subframe or a Type-2 DL subframe; select a hybrid automatic repeat request, HARQ, timing sequence configuration for use with downlink data received from the SCell based on the type of downlink data subframe received from the Scell and the UL/DL configuration on the PCell; and transmit acknowledgement information associated with the downlink data subframe received from the SCell according to the selected hybrid automatic repeat request, HARQ, timing sequence configuration in an uplink, UL, subframe over the connection to the PCell; wherein a timing sequence configuration with which to transmit an acknowledgement/negative acknowledgement, ACK/NACK, comprises the table: UL/DL Configuration on PCell Subframe n 0 1 2 3 4 5 6 7 8 9 0 - - 6, 5 5 4, 5 - - 6, 5 5 4, 5 1 - - 7, 6, 5, 4 4 - - - 7, 6, 5, 4 4 - 2 - - 8, 7, 6, 5, 4 - - - - 8, 7, 6, 5, 4 - - 3 - - 11, 10, 9, 8, 7, 6 6, 5 5, 4 - - - - - 4 - - 12, 11, 10, 9, 8, 7 7, 6, 5, 4 - - - - - - 5 - - 13, 12, 11, 10, 9, 8, 7, 6, 5, 4 - - - - - - - 6 - - 7, 5, 4 7 5 - - 7, 5, 4 7,4 - or the table: UL/DL Configuration on PCell Subframe n 0 1 2 3 4 5 6 7 8 9 0 - - 6,5 5 4,5 - - 6,5 5 4,5 1 - - 7,6,5 4,5 - - - 7,6,5 4,5 - 2 - - 8, 7, 4, 6, 5 - - - - 8, 7, 4, 6, 5 - - 3 - - 7,6,11,10 6,5,10 5,4,10 - - - - - 4 - - 12,8,7,11,10 6,5,4,7,10 - - - - - - 5 - - 13, 12, 9, 8, 7, 5, 4, 11, 6,10 - - - - - - - 6 Option 1 - - 7,5 7,5 5 - - 7,5,4 7,4 - Option 2 - - 7,8 7,6 5,6 - - 7,5 7,5 wherein the tables show the HARQ timing k, with k>=4, for the DL subframe n-k on the SCell whose ACK/NACK is to be transmitted in the UL subframe n on the PCell; wherein a Type 1 downlink data subframe comprises a subframe that is a downlink data subframe on both the PCell and the SCell, or that is a downlink data subframe on both a scheduling cell and a scheduled cell in a case of a cross-carrier scheduling configuration, and wherein more than one TDD serving cell is configured and the configured scheduling cell is not the PCell; and/or wherein the Type 2 downlink data subframe comprises a subframe that is downlink only on the SCell. establish a connection to the primary serving cell, PCell, and a secondary serving cell, SCell, of an enhanced-Node B, eNB, of the LTE wireless communication network, the PCell having a TDD uplink-downlink configuration and the SCell having a FDD configuration; receive downlink data through the PCell and SCell; categorize a type of downlink data subframe in use by the SCell as a Type-1 downlink, DL, subframe or a Type-2 DL subframe; select a hybrid automatic repeat request, HARQ, timing sequence configuration for use with downlink data received from the SCell based on the type of downlink data subframe received from the Scell and the UL/DL configuration on the PCell; and transmit acknowledgement information associated with the downlink data subframe received from the SCell according to the selected hybrid automatic repeat request, HARQ, timing sequence configuration in an uplink, UL, subframe over the connection to the PCell; wherein a timing sequence configuration with which to transmit an acknowledgement/negative acknowledgement, ACK/NACK, comprises the table: UL/DL Configuration on PCell Subframe n 0 1 2 3 4 5 6 7 8 9 0 - - 6, 5 5 4, 5 - - 6, 5 5 4, 5 1 - - 7, 6, 5, 4 4 - - - 7, 6, 5, 4 4 - 2 - - 8, 7, 6, 5, 4 - - - - 8, 7, 6, 5, 4 - - 3 - - 11, 10, 9, 8, 7, 6 6, 5 5, 4 - - - - - 4 - - 12, 11, 10, 9, 8, 7 7, 6, 5, 4 - - - - - - 5 - - 13, 12, 11, 10, 9, 8, 7, 6, 5, 4 - - - - - - - 6 - - 7, 5, 4 7 5 - - 7, 5, 4 7,4 - or the table: UL/DL Configuration on PCell Subframe n 0 1 2 3 4 5 6 7 8 9 0 - - 6,5 5 4,5 - - 6,5 5 4,5 1 - - 7,6,5 4,5 - - - 7,6,5 4,5 - 2 - - 8, 7, 4, 6, 5 - - - - 8, 7, 4, 6, 5 - - 3 - - 7,6,11,10 6,5,10 5,4,10 - - - - - 4 - - 12,8,7,11,10 6,5,4,7,10 - - - - - - 5 - - 13, 12, 9, 8, 7, 5, 4, 11, 6,10 - - - - - - - 6 Option 1 - - 7,5 7,5 5 - - 7,5,4 7,4 - Option 2 - - 7,8 7,6 5,6 - - 7,5 7,5 wherein the tables show the HARQ timing k, with k>=4, for the DL subframe n-k on the SCell whose ACK/NACK is to be transmitted in the UL subframe n on the PCell; wherein a Type 1 downlink data subframe comprises a subframe that is a downlink data subframe on both the PCell and the SCell, or that is a downlink data subframe on both a scheduling cell and a scheduled cell in a case of a cross-carrier scheduling configuration, and wherein more than one TDD serving cell is configured and the configured scheduling cell is not the PCell; and/or wherein the Type 2 downlink data subframe comprises a subframe that is downlink only on the SCell.