A method of transmitting a request for video data, comprising: - for each spatial element of a video in a user's field of view for which a client device does not possess a current high-resolution spatial-element frame, said client device transmitting one or more requests for high-resolution spatial-element frames of said spatial element of said video to a distribution node, said video comprising a plurality of spatial elements and a plurality of spatial-element frames for each of said plurality of spatial elements, said plurality of spatial-element frames comprising both intra-coded spatial-element frames and inter-coded spatial-element frames, only said inter-coded spatial-element frames being encoded with reference to one or more other spatial-element frames of said plurality of spatial-element frames, said one or more requests identifying said spatial element; and - for each of said spatial elements for which said one or more requests is transmitted, said client device receiving data relating to said spatial element of said video from said distribution node in response to said one or more requests, said data comprising a temporal segment of high-resolution spatial-element frames, said high-resolution spatial-element frames of said temporal segment each comprising a plurality of video pixels, characterized in that said one or more requests specify a starting point corresponding to a current time, said one or more requests are for data comprising a temporal segment of high-resolution spatial-element frames starting at said starting point, the first high-resolution spatial-element frame of said requested temporal segment of high-resolution spatial-element frames being intra coded, and said temporal segment of high-resolution spatial-element frames received by said client device starts at said starting point, the first one or more high-resolution spatial-element frames of said temporal segment of high-resolution spatial-element frames being intra coded. - for each spatial element of a video in a user's field of view for which a client device does not possess a current high-resolution spatial-element frame, said client device transmitting one or more requests for high-resolution spatial-element frames of said spatial element of said video to a distribution node, said video comprising a plurality of spatial elements and a plurality of spatial-element frames for each of said plurality of spatial elements, said plurality of spatial-element frames comprising both intra-coded spatial-element frames and inter-coded spatial-element frames, only said inter-coded spatial-element frames being encoded with reference to one or more other spatial-element frames of said plurality of spatial-element frames, said one or more requests identifying said spatial element; and - for each of said spatial elements for which said one or more requests is transmitted, said client device receiving data relating to said spatial element of said video from said distribution node in response to said one or more requests, said data comprising a temporal segment of high-resolution spatial-element frames, said high-resolution spatial-element frames of said temporal segment each comprising a plurality of video pixels,