WIRELESS COMMUNICATIONS SYSTEMS AND METHODS UTILIZING GROUP FRAME ACKNOWLEDGMENT

摘要

A first entity transmits a group of frames addressed to a second entity over a wireless communications medium, concluding with a last frame indicating an end to the group of frames. A frame from the transmitted group is received at the second entity. A frame is then transmitted from the second entity which indicates reception of a frame from the transmitted group of frames, in response to reception of the last frame at the second entity or expiration of a predetermined time interval, preferably in response to the earlier of reception of the last frame at the second entity and expiration of a predetermined time interval after first receiving a frame from the transmitted group of frames at the second entity. The first entity preferably refrains from transmitting frames addressed to the second entity from the first entity until the frame which indicates reception of a frame from the transmitted group of frames is received at the first entity. Preferably, a single frame is transmitted to indicate reception of all frames from the transmitted group of frames which are received by the second entity. Preferably, the second entity has an active mode in which the second entity is continuously operable to receive frames transmitted by the station and a standby mode in which the second entity is intermittently operable to receive frames transmitted by the station to thereby consume less power than in the active mode, and the frame which indicates reception of a frame requests the standby mode. In response to reception of the request, a frame may be communicated from the first entity to the second entity commanding the second entity to the active mode or the standby mode.