The Most Fitting NoSQL DB for a Decentralized Hub-and-Spoke System

We are building a distributed system that has an Hub-and-Spoke topology: central office and remote sites which are connected to the central office, in low-bandwidth (~10Mbps) WAN connection.

The system is managing data which could be updated at any site, and should also be replicated across the whole system.

The system should support working when disconnected from the network. When the network re-connects, data should be synchronized again.

We are considering using a NoSQL DB for managing our data. However we are a bit overwhelmed by the many different alternatives.

We'd love to hear suggestions about fitting solutions.

What kind of data are you talking about? Is it already modeled in some way?

I haven't heard of people using NoSQL systems as a replacement for site-decentralized RDBMS scenarios which you would normally look at something like replication for. Some are probably better suited to this than others - e.g. MongoDB. Of course, the major RDBMS vendors all have their flavors of replication. In many cases, site replication is handled with master-slave, with the site being master and central office being slave, so that remote operation can run without connection.