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, and transmitting the one or more second signals comprises transmitting first response scheduling information to cause the first device to transmit an acknowledgement during a first portion of an acknowledgement period and transmitting second response scheduling information to cause the second device to transmit an acknowledgement during a second, subsequent portion of the acknowledgement period; 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; and selectively transmitting, based on the lack of reception of the expected acknowledgement, a third signal in the frequency band during a remaining part of the acknowledgement period, wherein selectively transmitting the third signal comprises transmitting information to the second device to reschedule a transmission of a response from the second device; and characterized in that the first response scheduling information and the second response scheduling information are based on an acknowledgement response schedule (1255, 1260, 1270, 1275) generated based on reachability information received from the wireless communication devices after having performed reachability testing, wherein the reachability testing comprises determining whether a signal emanating from the first device is at least received by the second device. 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, and transmitting the one or more second signals comprises transmitting first response scheduling information to cause the first device to transmit an acknowledgement during a first portion of an acknowledgement period and transmitting second response scheduling information to cause the second device to transmit an acknowledgement during a second, subsequent portion of the acknowledgement period; 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; and selectively transmitting, based on the lack of reception of the expected acknowledgement, a third signal in the frequency band during a remaining part of the acknowledgement period, wherein selectively transmitting the third signal comprises transmitting information to the second device to reschedule a transmission of a response from the second device; and characterized in that the first response scheduling information and the second response scheduling information are based on an acknowledgement response schedule (1255, 1260, 1270, 1275) generated based on reachability information received from the wireless communication devices after having performed reachability testing, wherein the reachability testing comprises determining whether a signal emanating from the first device is at least received by the second device.