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The control plane (PUSH+ATOM/RSS) should not present a problem for a mobile device but certain mobile devices have access to native notification services that could work even better (eg iPhone notifications). The size of each notification message is very small (a torrent info-hash) which should not present a problem for any notification technology.
The limited storage available to most mobile devices means that the user needs to have control over which datasets to download. The reference storage-node implementation will download all subscribed datasets. On a mobile device it may be desirable to apply a size-based policy to determine which to download.