for me, a class D or E starport has a single satellite in a geostationary orbit above the starport, set to broadcast "welcome to Example! you are required to proceed to the starport at 12 degrees north of the equator at this longitude for arrival and customs" (or some similar message that tells them where to go). ...
Kinda depends on the local circumstances. I can't see some little world whose total population wouldn't fill a high school auditorium spending money on a satellite to direct the occasional passer-by to the only town on the planet. Likewise, some low tech world might not want to spend money importing off-world satellite tech when the occasional visitor is quite competent to home in on a simple ground-based beacon. On the other hand, some restrictive government who'd as soon arrest you as look at you might put up a satellite to make sure you land where they can keep an eye on you - and might be inclined to call out their air force if you don't.
Maybe Hangar 18 is a secret Class-E starport where the gub'mint can make sure the occasional visitor to Sol system doesn't have contact with us locals. :smirk:
What kind of traffic control you need depends on what kind of traffic you have. We were debating the question of traffic volume elsewhere. There was, not surprisingly, some disagreement over numbers, but the estimates ranged from 50 or so a day for the very most active ports to no more than a couple a year - in a good year - for the more isolated places. Coordinating 50 or so ships a day is not a particularly difficult feat, but Earth has had mid-air collisions since 1922, under circumstances and in volumes of air in which you'd have thought a collision was pretty unlikely. (Which, in the final analysis, is why many of them occurred.) And, you want to make sure the inbound or outbound traffic does not run afoul of your satellites or, if landing, your aircraft. There are also some governments who are downright finicky about where strangers set down their ships.
For ports that might see no more than one ship or so a day, traffic control may consist of little more than an open frequency where the inbound ship can call in and say, "I'm here," so the local port official can take time from his other job and get to the port in time to meet the inbound captain. For worlds with significant local tech and population but little space traffic, it might also include instructions that keep him clear of local satellites and, if landing, aircraft; the pilot may actually spend more time talking to air traffic controllers handling the various air space regions he flies through on the way to the downport. It's only likely to get more complicated than that at a handful of worlds that have to deal with more than one ship in space at any given time, places like Mora, Glisten and Rhylanor.