Mobile unit tracking system
March 4, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesRoad navigation system Apparatus for and a method of determining compass headings GPS/self-contained combination type navigation system Mobile transmitter/receiver Satellite radio signal tracking method for GPS receivers Tracking system Universal dynamic navigation, surveillance, emergency location, and collision avoidance system and method Geodetic surveying system using multiple GPS base stations Vehicle locating and communicating method and apparatus Position identification system Patent #: 5221925 InventorsAssigneeApplicationNo. 205753 filed on 03/04/1994US Classes:701/213, Using Global Positioning System (GPS)342/357.1, Combined with telecommunication342/385, Beacon or receiver342/451, By computer342/457, Land vehicle location (e.g., bus, police car701/200NAVIGATIONExaminersPrimary: Black, Thomas G.Assistant: Day, Julie D. Attorney, Agent or FirmInternational ClassH04B 001/00AbstractA communication network keeps track of the locations of mobile units which utilize the network. On powering up, the mobile units determine their current locations using signals broadcast, for example, by overhead satellites. They then send data communication messages to the network describing their locations. The network saves the locations and returns data messages that describe borders which surround the mobile units' locations. The mobile units repetitively determine their current locations on a regular schedule. When their current locations are outside of their prescribed borders, they send other location data messages to the network to update the location data being maintained by the network and to receive a definition of a new border. | |
