Abstract: A multi-SIM wireless device checks whether each of the (e.g., two) SIMs has received sub-frames in successive intervals prior to a current interval. If such a condition is satisfied by all the SIMs, the wireless device allocates several successive (transmit) intervals to a first SIM before allocating next successive (transmit) intervals to another SIM. If such a condition is not satisfied, the sub-intervals may be allocated according to any other approach (i.e., not constrained by the requirement of successive sets of transmit intervals to the two SIMs) as suited for the specific situation. The allocated sub-frame intervals are used to send the acknowledgements of the previously received sub-frames.