A method for communication includes allocating time intervals for a first communication session over a first connection between a wireless terminal and a base station of a long-range wireless data network, which operates in accordance with a first protocol defining time frames having downlink and uplink sub-frames. Time slots are allocated for a second communication session over a second connection between the terminal and a peripheral wireless device, which operates in accordance with a second, short-range time-slotted protocol, which is different from the first protocol and has a retransmission mechanism. The time slots are synchronized with the downlink and uplink sub-frames defined by the BS. Operation of the second connection is inhibited during some of the time slots that overlap the downlink sub-frames, so as to invoke the retransmission mechanism and cause the terminal to transmit only during the time slots that do not overlap the downlink sub-frames.