For those who wondering, this partnership is slightly different from what Facebook has with YTL. As you might be able to recall, that partnership is more skewed towards public infrastructure since it revolves around Terragraph.
As for the new partnership with Time, the network infrastructure will instead be utilized exclusively by Facebook and its extensive list of applications as well as services. From what we could gather from the announcement, it seems that the project is likely to involve undersea cables. Prior to this, both companies have worked together as part of the consortium that was responsible for the deployment of the Asia Pacific Gateway cable system back in 2012. Hence, this is not the first that Time and Facebook have collaborated in a network infrastructure project but as mentioned earlier, the full nature of their new project are not yet fully clear at the moment.
