Mobile communication devices, such as user equipment (UE) using 3GPP-LTE or LTE Advanced, may communicate directly with another UE through a system called Device-to-Device (D2D) communication. The establishment of a D2D communication session may involve having one of the UEs trigger the signaling procedures. In particular, a D2D resource re-allocation method may be used to optimize the D2D communication resource utilization efficiency in a dynamic manner, which is fully controlled by one of the D2D pair (termed the master UE or M-UE). The M-UE may be arranged to re-allocate resources based on the buffer status report (BSR) of the UEs in the D2D communication session. The M-UE may be further arranged to dynamically change the configuration of the transmission window based on characteristics of the D2D communication session.