DEDICATED SHORT RANGE COMMUNICATION (DSRC) SENDER VALIDATION USING GPS PRECISE POSITIONING TECHNIQUES
A system and method for authenticating a message transmitted in a vehicle-to-vehicle communications system. The sending vehicle will attach raw GPS data to a transmitted message it receives from GPS satellites that the sending vehicle uses to determine its own position. The transmitted message will also include the position of the sending vehicle that the sending vehicle has determined using the GPS data. The receiving vehicle will use the raw GPS data in the message and an RTK process to determine the position of the sending vehicle. The receiving vehicle will compare the position of the sending vehicle in the message with the position of the sending vehicle determined from the GPS data, and if they match, will authenticate the received message.
1 . A communications system comprising:
a sending sub-system receiving GPS signals, said sending sub-system generating a message to be sent that includes a data portion and a raw GPS measurement portion, said raw GPS measurement portion including at least part of the data received in the GPS signals and said data portion including a calculation of the sending sub-system's position using the GPS signals, said sending sub-system transmitting the message; and
a receiving sub-system that receives the message from the sending sub-system, said receiving sub-system using the raw GPS measurements in the message to determine the position of the sending sub-system and comparing the determined position of the sending sub-system with the calculated position in the data portion of the message to determine whether a match exists to determine the validity of the message.
2 . The system according to claim 1 wherein the system is a vehicle-to-vehicle communications system where the sending sub-system is on a sending vehicle and the receiving sub-system is on a receiving vehicle.
3 . The system according to claim 2 wherein the data portion of the message includes information about the sending sub-system including vehicle speed, vehicle acceleration, vehicle deceleration and vehicle stability control.
4 . The system according to claim 1 wherein the receiving sub-system includes a GPS real-time kinematic (RTK) engine that uses a real-time kinematics process to determine the position of the sending sub-system using the raw GPS measurements in the message.
5 . The system according to claim 4 wherein the receiving sub-system includes an RTK-based security manager that compares the calculated position of the sending sub-system in the data portion of the message with the determined position of the sending sub-system to determine the validity of the message.
6 . The system according to claim 1 wherein the raw GPS measurement portion of the message includes time-marked ranging codes and a carrier wave.
7 . The system according to claim 1 wherein the sending sub-system and the receiving sub-system also determine the velocity, acceleration and heading of the sending sub-system to validate the message.
8 . A communications system for transmitting messages between vehicles, said system comprising:
a sending sub-system on a sending vehicle receiving GPS signals, said sending sub-system generating a message to be sent that includes a data portion and a raw GPS measurement portion, said raw GPS measurement portion including at least part of the data received in the GPS signals and said data portion including a calculation of the sending sub-system's position using the GPS signals, said sending sub-system transmitting the message; and
a receiving sub-system on a receiving vehicle that receives the message from the sending sub-system, said receiving sub-system including a GPS real-time kinematics engine that uses a real-time kinematic (RTK) process to determine the position of the sending sub-system using the raw GPS measurements in the message, said receiving sub-system including an RTK-based security manager that compares the calculated position of the sending sub-system in the data portion of the message with the determined position of the sending sub-system to determine the validity of the message.
9 . The system according to claim 8 wherein the data portion of the message includes information about the sending sub-system including vehicle speed, vehicle acceleration, vehicle deceleration and vehicle stability control.
10 . The system according to claim 8 wherein the raw GPS measurement portion of the message includes time-marked ranging codes and a carrier wave.
11 . The system according to claim 8 wherein the sending sub-system and the receiving sub-system also determine the velocity, acceleration and heading of the sending sub-system to validate the message.
12 . A communications system for transmitting messages between vehicles, said system comprising a sending sub-system on a sending vehicle receiving GPS signals, said sending sub-system generating a message to be sent that includes a data portion and a raw GPS measurement portion, said raw GPS measurement portion including at least part of the data received in the GPS signals.
13 . The system according to claim 12 further comprising a receiving sub-system that receives the message from the sending sub-system, said receiving sub-system using the raw GPS measurement portion in the message to validate the message.
14 . The system according to claim 13 wherein the receiving sub-system uses a real-time kinematic (RTK) process to determine the position of the sending sub-system using the raw GPS measurements in the message, said receiving sub-system comparing a calculated position of the sending sub-system in the data portion of the message with the determined position of the sending sub-system to determine the validity of the message.
15 . The system according to claim 14 wherein the sending sub-system and the receiving sub-system also determine the velocity, acceleration and heading of the sending sub-system using the raw GPS measurements to validate the message.
16 . The system according to claim 12 wherein the raw GPS measurement portion of the message includes time-marked ranging codes and a carrier wave.