Units on the roof and in the building in one case, turret over the door on one side, a pod patrolling on the other side in a pattern that makes it impossible to stealth by them with even a single person in another, I forget the rest.
I have literally never been in a network tower mission where a ghostwalker/covert shinobi couldn't get to the console room concealed. And I have probably by now played about 50 of the things on a wide variety of difficulties, with a wide variety of advent strength (I just did a level 9 strength with no issues whatsoever).
A turret over the door does not prevent you from going in while maintaining concealment. If you activate ghostwalker, you can walk right up to the door with the turret right above your head and open it without the turret seeing you. I do this ALL the time. Maybe this is the one issue that makes you think it's impossible.
Units patrolling around shouldn't present an issue, just wait for ghostwalker, be patient, watch their patrols. Ghostwalker + covert makes them only be able to detect you if you are literally within melee distance (assuming no dark event, and 200% infiltration, maybe you don't even have to be that high on infiltration but I always do to make the mission safer in terms of number of enemies anyways).
It's completely unnecessary, but having a grappling armor can speed things up or make things a little bit easier (like you can grapple over the first room if it's one of those stupid glass wall obstacles, but again, it's
completely unnecessary as there's always another way around)
I don't think your problem is bad luck. The only issues I can think of are:
- you don't have ghostwalker/covert. I tried this both with and without many times because I wanted my shibobi to be a blade spec to help kill things. I eventually ran into one network tower mission where, with a blade shinobi, it was impossible to progress without ghostwalker/covert because the mob was just sitting there on one side, and there was a turret on the other. With ghostwalker/covert I could easily have gone through the tower door, but I found out the hard way it's required if you want 100% certainty of concealment success.
-you are trying during a dark event vigilance (increased enemy detection radius)
-you are trying less than 200% infiltration (probably doesn't make a big difference, but enemies have 1/6 less sight than usual at 200% compared to 100% and you might knock off one or two patrolling groups at max infiltration compared to 100%)