A communications system for generating a connectivity map for use in a moving platform , said communications system comprising at least one platform application and being configured to effect wireless data communication between said moving platform and another node by means of one of a plurality of supported communications links in accordance with a communications plan, wherein said communication system is configured to: identify a message or set of messages required to be transmitted from or received by said moving platform; and generate a connectivity map by, for each of a plurality of different specified attitudes or orientations derived from one or more predicted trajectories of said moving platform: identifying available transmitters for wireless transmission of said message or set of messages and/or identify available receivers for wireless reception of said message or set of messages; for each identified transmitter, determining a transmitter metric and/or for each identified receiver, determining a receiver metric; and defining a connectivity metric, based on said transmitter metrics and/or receiver metrics for said respective specified attitude or orientation, said connectivity metric being representative of a quality of a respective associated communications link for effecting transmission or reception by said moving platform of said message or set of messages in respect of said respective specified attitude or orientation of said moving platform. identify a message or set of messages required to be transmitted from or received by said moving platform; and generate a connectivity map by, for each of a plurality of different specified attitudes or orientations derived from one or more predicted trajectories of said moving platform: identifying available transmitters for wireless transmission of said message or set of messages and/or identify available receivers for wireless reception of said message or set of messages; for each identified transmitter, determining a transmitter metric and/or for each identified receiver, determining a receiver metric; and defining a connectivity metric, based on said transmitter metrics and/or receiver metrics for said respective specified attitude or orientation, said connectivity metric being representative of a quality of a respective associated communications link for effecting transmission or reception by said moving platform of said message or set of messages in respect of said respective specified attitude or orientation of said moving platform. identifying available transmitters for wireless transmission of said message or set of messages and/or identify available receivers for wireless reception of said message or set of messages; for each identified transmitter, determining a transmitter metric and/or for each identified receiver, determining a receiver metric; and defining a connectivity metric, based on said transmitter metrics and/or receiver metrics for said respective specified attitude or orientation, said connectivity metric being representative of a quality of a respective associated communications link for effecting transmission or reception by said moving platform of said message or set of messages in respect of said respective specified attitude or orientation of said moving platform. <EOS>