Abstract: According to an example aspect of the present invention, there is provided a method, including receiving, by a wireless device of a first wireless network, a control request frame from a second access node of a second wireless network, the control request frame including at least a number of nulls for the wireless device. The wireless device selects a subset of antenna elements, wherein the number of antenna elements is in accordance with the number of nulls for the wireless device, and the antenna elements are selected based on reception powers of antenna elements of at least a frame from a first access node of the first wireless network and/or the second access node of the second wireless network. The wireless device transmits a control response frame with the selected antenna elements, and a data frame to the first access node with the selected antenna elements.

Abstract: A method for training an environmental analysis system, the method comprising: receiving a data model of an environment; forming, in dependence on the data model, a first training input comprising a visual stream representing the environment as viewed from a plurality of locations; forming, in dependence on the data model, a second training input comprising a depth stream representing depths of objects in the environment relative to the plurality of locations; forming a third training input, the third training input being sparser than the second training input; and estimating, using the analysis system, in dependence on the first and third training inputs, a series of depths at less sparsity than the third training input; and adapting the analysis system in dependence on a comparison between the estimated series of depths and the second training input.