Patent ID: 7983203

Claim:
A device comprising: a processing unit; and at least one memory including instructions, where the at least one memory and the instructions are configured, with the processing unit, to cause the device to at least: receive an aggregate frame that includes a frame field having one or more subfields corresponding to respective one or more devices that is allocated an offset period in the aggregate frame for an uplink and downlink data transfer, wherein the aggregate frame contains multi-rate data arranged in data sequences, and wherein each data sequence includes frames of one data rate of the multi-rate data; read control information in the frame field of the aggregate frame, determining that the frame field includes a subfield for a specific device; read a rate offset value and a station offset value for at least one of reception and transmission of data; determine an offset period value for the specific device comprising, calculating an offset length to an offset period allocated to the specific device in the aggregate frame, wherein the offset length is calculated using information stored in at least the subfield for the specific device; and invoke a sleep mode having a duration that is not greater than the determined offset period value.