During the SESAR definition phase we had to spend a lot of time explaining to the various authors that talking about System Wide Information Management (SWIM) using the old terminology is counter productive and will only make the documents more difficult to understand (and easier to misunderstand). Let me explain.
For some reason, most people thought that down-linking data from an aircraft was the thing to do and they used this term also in the SWIM context not realizing that down-linking is an action you undertake to achieve something and in concept level descriptions you need to specify first what you want to achieve and then talk about the “how” later. An aircraft in the air will publish its information so that those interested will learn about it and those looking for it can find it. Users who need the information will subscribe to it and hence will also get it. By using the term down-linking instead of publishing, writers did manage to create the impression that aircraft will be sending down loads of data to every imaginable destination… This is not the SWIM way of working and shows clearly why proper terminology is important if we want to see the correct picture.
I used the example of down-linking since it was one of the most consequently returning errors but similar examples could be drawn from the descriptions of how ATC units will communicate in the SWIM environment. There the favorite, and equally wrong, terms were “sending information to other units” and “defining the proper interfaces”. Obviously, information sharing means that the cumbersome point to point connections and expensive interfaces are eliminated and replaced by the “virtual information pool” into which everyone publishes their data and from which subscribers get what they are interested in and in which users interested in certain information can find it… Not using the proper terminology creates confusion and once more the impression that wires will be burning red with all the stuff that everyone will be sending to everyone else.
Although the above probably sounds perfectly logical, even documents being created these days tend to fall back to the old terms, regardless of the fact that their meaning has been overtaken by the SWIM concept.
Having fought this battle for a long time with varying degrees of success, I was really pleased to spot in the March 8 issue of Aviation Week and Space Technology, in an article about the US ADS-B network going live, a description of how the ADS-B control stations, each handling data from several service volumes, will deliver its data to the en-route, terminal and tower control units via the network. Each control unit will subscribe to the data of its service volume… John Kefaliotis, ITT’s ADS-B program manager actually described what they were doing as a mini-SWIM!
You will of course note that this solution also implements one of the basic tenets of the SWIM concept, namely that it is the end users, and NOT the data originators, who decide what they want to get.
One can only hope that the proper use of the SWIM terminology will now become a matter of course also in Europe. We should stop down-linking any more confusion.