An apparatus for an Evolved Node-B, eNB (104, 300), the apparatus comprising transceiver circuitry and hardware processing circuitry, the hardware processing circuitry being arranged to configure the transceiver circuitry to: transmit (505, 510), during an uplink control portion of a downlink subframe, a first beam refinement training signal and an uplink scheduling block to a first User Equipment, UE (102, 400), according to a downlink transmission direction from the eNB (104, 300) to the first UE (102, 400); and transmit (515, 520), during a downlink control portion of the downlink sub-frame, a second beam refinement training signal and a downlink scheduling block to a second UE (102, 400) according to a downlink transmission direction from the eNB (104, 300) to the second UE (102, 400), wherein the uplink scheduling block indicates scheduled uplink resources for a scheduled uplink transmission by the first UE (102, 400) and the downlink scheduling block indicates scheduled downlink resources for a scheduled downlink transmission to the second UE (102, 400), characterised in that: when a first downlink sub-frame format is used, the first beam refinement training signal transmitted during the uplink control portion is transmitted before the uplink scheduling block and the second beam refinement training signal transmitted during the downlink control portion is transmitted before the downlink scheduling block; when a second downlink sub-frame format is used, the first beam refinement training signal transmitted during the uplink control portion is transmitted after the uplink scheduling block and the second beam refinement training signal transmitted during the downlink control portion is transmitted after the downlink scheduling block; and wherein the first downlink sub-frame format is used when a number of active UEs is below a predetermined threshold and the second downlink sub-frame format is used when the number of active UEs is not below the predetermined threshold. transmit (505, 510), during an uplink control portion of a downlink subframe, a first beam refinement training signal and an uplink scheduling block to a first User Equipment, UE (102, 400), according to a downlink transmission direction from the eNB (104, 300) to the first UE (102, 400); and transmit (515, 520), during a downlink control portion of the downlink sub-frame, a second beam refinement training signal and a downlink scheduling block to a second UE (102, 400) according to a downlink transmission direction from the eNB (104, 300) to the second UE (102, 400), wherein the uplink scheduling block indicates scheduled uplink resources for a scheduled uplink transmission by the first UE (102, 400) and the downlink scheduling block indicates scheduled downlink resources for a scheduled downlink transmission to the second UE (102, 400), characterised in that: when a first downlink sub-frame format is used, the first beam refinement training signal transmitted during the uplink control portion is transmitted before the uplink scheduling block and the second beam refinement training signal transmitted during the downlink control portion is transmitted before the downlink scheduling block; when a second downlink sub-frame format is used, the first beam refinement training signal transmitted during the uplink control portion is transmitted after the uplink scheduling block and the second beam refinement training signal transmitted during the downlink control portion is transmitted after the downlink scheduling block; and wherein the first downlink sub-frame format is used when a number of active UEs is below a predetermined threshold and the second downlink sub-frame format is used when the number of active UEs is not below the predetermined threshold. when a first downlink sub-frame format is used, the first beam refinement training signal transmitted during the uplink control portion is transmitted before the uplink scheduling block and the second beam refinement training signal transmitted during the downlink control portion is transmitted before the downlink scheduling block; when a second downlink sub-frame format is used, the first beam refinement training signal transmitted during the uplink control portion is transmitted after the uplink scheduling block and the second beam refinement training signal transmitted during the downlink control portion is transmitted after the downlink scheduling block; and wherein the first downlink sub-frame format is used when a number of active UEs is below a predetermined threshold and the second downlink sub-frame format is used when the number of active UEs is not below the predetermined threshold.