>either this was extremely early and advanced and in a very affluent, high density city that could justify and capitalise on its benefits...

People visiting Stockholm nowadays - or even people living there, for that matter - have little idea how poor and slum-ridden the city was just fifty years ago: the town center was full of small and cramped apartments housing whole families in single rooms, lacking bathrooms and toilets (everyone shared a row of earth toilets in the yard, and washed once a week in communal baths).

So, based on the high-tech and affluent Stockholm you see now, it’s easy to jump to the conclusion that this was an “early and advanced” technical solution, when actually it’s simply a product of the very small scale of the town. The area ‘inomtullarna’ (which comprises the entire city center, excluding the dormitory suburbs), could easily fit inside the single London borough of Camden, for instance.

Yes as a native I have heard if this, but Sweden was also a relatively rich and technologically advanced country at the time despite all the slums of Stockholm so I assume there must have been wealthy parts too.

That's the story of every city, it does not say how big of an area this tower serviced but I would guess that the area was dense and expensive enough. Also the company that built this went on to merge with Ericsson which managed quite well in the telephony area. A big part was that they managed to deliver telephony subscripions to so many people so fast, Stockholm was way a head of e.g. London (20x) counting telephones per capita. There are several reasons for this the comming population explosion that created the slums you talk about was one.

During the period this tower was needed the population of Stockholm more than doubled so how the slums where distributed will most probably have changed during this time.