DSRC Dedicated Short Range Communications is a short- to medium-range wireless protocol specifically designed for use in automobiles, providing communication between vehicles and roadside equipment such as payment gantries. A sub-set of RFID technology and similar to that used in Hong Kong's Octopus cards, it is deployed in electronic road-pricing systems along the highways in Japan as well as in the Autotoll systems in Hong Kong tunnels. The technology is used primarily for tolling specific roads, but based on its technical maturity and ease of deployment it is also used on entrances to charging zones. Disadvantages include limited flexibility in charging according to vehicle usage within zones and the amount of necessary roadside equipment. VPS Vehicle Positioning Systems are more sophisticated location-based systems based on the United States' GPS system, but look set to become a cornerstone application on Europe's Galileo satellite system. Requiring a minimum of roadside equipment, European countries such as Germany are the earliest adopters, enabling truck monitoring across the length and breadth of the country's Autobahn network. Britain is looking to introduce a nationwide location-based charging system from 2010. Key advantages include more sophisticated charging models based on a vehicle's route and location, as well as the potential to sell on location-based services like vehicle tracking and fleet management to help offset the relatively high cost of installation.