The physical plant of recycling, mining, and "garbage gun" functions were always located in the center of any Interplanetary Space Station's disk. There, also usually obverse was the entrance/exit module.
Towns were on the outside perimeter of the outlying rings themselves; where the rotation velocity created a centrifugal 1 Earth-Gravity. The inhabitants were Earthlings.
Transportation between the nonspinning hub and the spinning disk was a tedious affair by 25th-century standards. An Earth-based consortium, a foundation of commercial interests, had offered a billion shekels to anyone who could produce a working alternative to the standard mode of intercommunity travel.
The worst part the least popular was the physical experience of being brought "up to spin" in that central tube so as to be able to enter one of the ports to the radial disk. Not a bother in the larger wheels, the "spin-up" of a smaller community's portal chamber could be nauseating.