A method, comprising: transitioning a network interface of a first wireless communication device from a low power state to an active state, wherein when the network interface is in the low power state, the network interface is unable to at least one of (i) transmit signals via a wireless communication medium and (ii) receive signals via the wireless communication medium, and when the network interface is in the active state, the network interface is capable of both (i) transmitting signals via the wireless communication medium and (ii) receiving signals via the wireless communication medium; after transitioning the network interface to the active state, determining whether a communication channel is available; generating a data unit that includes a request for a second wireless communication device to transmit to the first wireless communication device data for the first wireless communication device that is buffered at the second wireless communication device; in response to determining that the communication channel is available, transmitting to the second wireless communication device, via the communication channel, the data unit that includes the request; receiving from the second wireless communication device, via the communication channel, an indication of whether there is data for the first wireless communication device buffered at second wireless communication device; and receiving, from the second wireless communication device and when there is data for the first wireless communication device buffered at second wireless communication device, data for the first wireless communication device that was buffered at the second wireless communication device. transitioning a network interface of a first wireless communication device from a low power state to an active state, wherein when the network interface is in the low power state, the network interface is unable to at least one of (i) transmit signals via a wireless communication medium and (ii) receive signals via the wireless communication medium, and when the network interface is in the active state, the network interface is capable of both (i) transmitting signals via the wireless communication medium and (ii) receiving signals via the wireless communication medium; after transitioning the network interface to the active state, determining whether a communication channel is available; generating a data unit that includes a request for a second wireless communication device to transmit to the first wireless communication device data for the first wireless communication device that is buffered at the second wireless communication device; in response to determining that the communication channel is available, transmitting to the second wireless communication device, via the communication channel, the data unit that includes the request; receiving from the second wireless communication device, via the communication channel, an indication of whether there is data for the first wireless communication device buffered at second wireless communication device; and receiving, from the second wireless communication device and when there is data for the first wireless communication device buffered at second wireless communication device, data for the first wireless communication device that was buffered at the second wireless communication device.