It's Scenario 1
Basically everything is a network made up of devices now ... it's either a PAN which is a network made up of mobile devices or it's a Host which is just a "mega" device that is not mobile and can support near infinite devices
Thanks!
EDIT: This is very useful, and I personally think this represents a much needed simplification of architecture for the purpose of bringing the hackers into the game alongside the team.
1st through 3rd Edition required a LOT of knowledge of the rules and the ability to engage in non-linear/highly theoretical thinking. Hackers in these editions were basically playing a different game from the rest of the team, in my experience.
4th improved upon this by simplifying the architecture dramatically, putting it more in line with real-world networks and required a much more practical and logical approach. However, hackers often ended up being better off not accompanying the team on a run, instead hacking from another location.
I never played 5th Edition, but from reading the books it took a step in the highly theoretical direction, back towards 3rd. Hosts, and especially the Foundation, was something with very few real world parallels, and it seemed hard to wrap ones head around just how certain things worked. I'm not sure how hackers operated in 5th, to be honest, as it seemed like they had options for both remote and in-person hacking.
From my limited exposure to 6th, it seems like this edition has once again taken a more rational, logical approach to network architecture, and this seems to indicate that the Matrix will be more practical than it has been in the past. I hope this is true, because few things would make me happier than being able to merge the hacking aspects of the game with the social, combat, and magic aspects. Cheers!