Abstract: A system for performing diagnostic checks on a data message transmitted from a sensor and received by a receiver includes a receiver clock tick counter, a prescaler counter, a calibration pulse detector, a nibble counter, and a calculator. The system receives first and second data messages transmitted from the sensor. Pulse widths of first and second calibration pulses of the first and second data messages, respectively, and lengths of the first and second data messages are measured using the receiver clock tick, prescaler, and nibble counters based on a compensated receiver clock signal. Thereafter, the pulse widths of the first and second calibration pulses and the lengths of the first and second data messages are compared using the calculator to perform the diagnostic checks.

Abstract: A parking policy management system helps identify and enforce parking violations in real-time. By monitoring sensors distributed in a parking area, the system will determine whether one or more parking policies have been violated. The types of parking policies the system can monitor include duration, time of day, unauthorized vehicle, special permit parking, and paid parking. When a violation of a policy is detected, a notification may be delivered to enforcement personnel through the Internet, personal digital assistants (PDAs), cell phones, in-vehicle dashboards, and other means.

Abstract: A parking guidance system tracks available parking spaces and leads users to vacant spots through display boards placed at strategic locations in the parking lot. Sensor nodes are deployed at parking spaces or within traffic lanes to monitor parking space occupancy and wirelessly transmit this information. The sensor nodes form a wireless network that routes the knowledge of available spaces to the corresponding display boards and updates them in real time. Parking availability information may also be shared with users in a variety of other ways such as through the Internet, personal digital assistants, computers, mobile telephones, in-vehicle dashboards, and others.