Apparatus comprising an interface for receiving a respective uplink data stream from each of three or more further apparatuses, and for transmitting a respective downlink data stream to each of the further apparatuses; and a logic system in communication with the interface. The logic system is configured: to receive first data in the uplink data stream received from a first one of the further apparatuses; and in a first mode, to include at least some of the first data in the respective downlink data streams transmitted to every other one of the further apparatuses, or, in a second mode, to include at least some of the first data in the downlink data stream transmitted to a second one of the further apparatuses and to omit or attenuate substantially all of the first data in the downlink data stream transmitted to at least a third one of the further apparatuses. Corresponding methods and computer readable media are disclosed.