They're looking for more open technology that they can use as parts of their system. As opposed to, say, the present cellular systems where it's:
1. Hard to create your own cell network (in contrast to a wifi or ethernet network).
2. Limited choice on vendors (again, in contrast to wifi and ethernet).
5G's potential ubiquity and utility, but limited vendors, is an issue for the DoD. They want to use it, but if they can't build out their own 5G infrastructure reliably with a decent variety of vendors it's a no-go.
1. Hard to create your own cell network (in contrast to a wifi or ethernet network).
2. Limited choice on vendors (again, in contrast to wifi and ethernet).
5G's potential ubiquity and utility, but limited vendors, is an issue for the DoD. They want to use it, but if they can't build out their own 5G infrastructure reliably with a decent variety of vendors it's a no-go.