Patent ID: 7920585

Claim:
A vehicular communication device comprising: means for performing data communications with other on-vehicle devices through a signal line wired in a vehicle and switching a communication method used for the data communications to any of a plurality of communication methods; means for storing control information indicating a relationship with a communication method suitable for data communications between parts of the vehicle and the performing means; and means for acquiring operating states of parts of the vehicle from a control unit controlling the parts of the vehicle, determining a communication method suitable for the performing means to perform data communications, based on the acquired operating states and the control information stored in the storing means, and switching a communication method used by the performing means for data communications to the determined communication method; wherein the performing means is capable of switching the communication method used for the data communication to a first communication method for high speed communications and a second communication method having a lower communication speed and higher noise resistance than the first communication method; the control information is set such that the first communication method is normally selected, and the second communication method is selected when the operating states of parts of the vehicle have changed into those in which a communication failure could occur due to noises occurring in the signal line with the first communication method; the first communication method is a orthogonal frequency division multiplexing method, and the second communication method is a spread spectrum method; the control information contains sub-carrier information defining sub-carriers causing communication failures for each of the operating states of parts of the vehicle, when the performing means performs the data communication method by the orthogonal frequency division multiplexing method; and the acquiring means, when the performing means selects the orthogonal frequency division multiplexing method as the communication method used for data communications, based on the sub-carrier information, eliminates sub-carriers causing the communication failures from sub-carriers used by the performing means to perform data communications by the orthogonal frequency division multiplexing method, or avoids the use of information transmitted using the sub-carriers.