Assertion: train's location | /r/CapableOf | keep track of trains
Facets:
value: to them
type: TRANSITIVE-OBJECT
value: via a wireless data network
type: MANNER
value: directly
type: MANNER
Source sentences:
text: While some PTC systems interface directly with the existing signal system, others may maintain a set of vital computer systems at a central location that can keep track of trains and issue movement authorities to them directly via a wireless data network.