Patent ID: 8923217

Claim:
A method, comprising: transmitting, in a frequency band, information to wireless communication devices, including a first device and a second device, that participate in a space division multiple access based communication, wherein the transmitting comprises (i) transmitting spatially steered first signals that form the space division multiple access based communication and concurrently provide data to the wireless communication devices, and (ii) transmitting one or more second signals to the wireless communication devices to control transmission of acknowledgements from the wireless communication devices in the frequency band, wherein the acknowledgements indicate a successful reception of a respective portion of the data; monitoring for the acknowledgements in the frequency band, wherein monitoring for the acknowledgements in the frequency band comprises detecting a lack of reception of an expected acknowledgement from the first device based on an end of a point coordination function (PCF) interframe space (PIFS) duration after an end of the spatially steered first signals; and selectively transmitting, based on the lack of reception of the expected acknowledgement and the end of the PIFS duration, a third signal in the frequency band to prevent a transmission from a wireless communication device that is not participating in the space division multiple access based communication, wherein selectively transmitting the third signal comprises transmitting information to control a transmission of a response from at least one of the wireless communication devices.