Mobile communication system
US5581249A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 15, 1996 |
| Grant date | Dec 3, 1996 |
| Priority date | — |
| Expiry date | Feb 15, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08G1/017
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A mobile communication system for highway toll charging and the like includes road-side units which periodically poll vehicle-mounted units. When traffic near a road-side unit is slow, repeated polling of a given vehicle-mounted unit that has not moved out of the road-side unit's communicable area may result in erroneous double charging of a toll. It is possible to set a fixed delay in the vehicle-mounted unit to avoid this; in this case, however, a toll may erroneously not be charged if the vehicle passes through the same or another road-side unit within the delay period. To solve this problem, the road-side unit calculates a response delay having a length appropriate to avoid the above-described effects based on the speed of vehicles passing it and transmits the response delay to the vehicle-mounted units.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.