MARK IV INDUSTRIES CORP. Patent applications |
Patent application number | Title | Published |
20110304434 | MULTI-PROTOCOL ELECTRONIC TOLL COLLECTION SYSTEM - A system and method for dynamically selecting a communication protocol in an electronic toll collection system. A first reader communicating under a primary communication protocol is connected to a roadway antenna. If a transponder of the primary protocol is detected within a predetermined duration, then the first reader maintains its access to the roadway antenna so that it may perform an electronic toll transaction with the detected transponder. If a transponder of the primary protocol is not detected within a predetermined duration, then the first reader will switch over access of the antenna to a second reader operating under a secondary protocol so that the second reader may perform an electronic toll transaction with a detected secondary protocol transponder. | 12-15-2011 |
20090201169 | Real-Time Location Systems and Methods - A real-time location system for identifying and locating tagged items. The system may include an identification protocol that tracks in-network transponders and assigns dynamic in-network identification numbers to in-network transponders. The system includes a locator function that employs time-of-arrival analysis. Rather than attempt to synchronize the time base at each reader, the system and process eliminate the need to sync the readers and also eliminate the impact of differential receive delays in the respective readers. Both the transponder and a master reader transmit locate signals, which are measured at slave readers. The system relies on differences in time-of-arrival of the two signals at the respective slave readers to determine the likely location of the transponder. | 08-13-2009 |