Network processing ensures high accuracy throughout the whole coverage area. CenterPoint VRS ensures repeatable accuracy year-over-year for precision guidance applications. A cellular communication modem, such as the DCM-300 or Ag3000, is used instead of a radio to receive this type of sub-inch correction. The cellular networks used in CenterPoint VRS are referred to as Continuously Operating Reference Stations (CORS). CORS uses a network of GPS/GNSS reference stations situated within the coverage area to transmit RTK corrections to the cellular modem on a tractor. Because this is a "networked" solution, the distance between the reference stations and the vehicle does not affect accuracy, making it a popular option in areas with spotty RTK radio tower coverage.