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Radar and infrared technologies can detect impending rear-end and lane-change collisions. However, these technologies cannot detect impending intersection collisions because they require line-of-sight communications. Wireless communication technology will be a viable technology for detecting intersection collisions. In this paper, we assumed that every vehicle is equipped with a wireless communication unit and every intersection has a wireless unit called the Intersection Traffic Controller (ITC). All vehicles near an intersection communicate with the corresponding ITC to send their dynamic information such as speed, acceleration, lane number, road number, and distance from the intersection. Though the wireless technology will be a viable technology for developing intersection collision warning systems, it is subject to various types of security attacks unless the system is properly designed.

Continuous demand for fuel efficiency mandate “Drive-by-Wire” systems. The goal of Drive-by-Wire is to replace nearly every automotive hydraulic/mechanical system with electronics. Drive-by-Wire and active collision avoidance systems need fault tolerant networks with time triggered protocols, to guarantee deterministic latencies. CAN is an event triggered protocol which has features like high bandwidth, error detection, fault confinement and collision avoidance based on message priority. However, CAN do not ensure message latency, which is critical for real time application. TTCAN (Time Triggered CAN) removes this fallacy of CAN by providing exclusive time windows for those messages that need deterministic latencies. In addition to the exclusive windows, there are arbitration windows too, which make way for event triggered communications. In TTCAN, if an error occurs within an exclusive or arbitration window, retransmission of the message is not allowed.

The continuous demand for fuel efficiency requires the use of drive-by-wire technology. Steer-by-wire and brake-by-wire are examples of drive-by-wire technology. CAN is a good protocol for various vehicle modules to communicate over a single bus. With CAN, safety critical messages might not be received and transmitted within certain specified latencies. The need to receive and deliver safety critical messages on time pushed the researchers to come up with a better communication protocol. The time-triggered CAN (TTCAN) system can guarantee deterministic latencies provided there are no faults in the system. TTCAN protocol does not allow retransmission of a message if the message failed to go due to the presence of errors. Thus, if a fault occurs during the transmission of a safety critical message, the message will not be able to go to its destination node. As a result, the safety of the vehicle and the occupants will be compromised.

The demand for drive-by-wire, telematics, entertainment, multimedia, pre-crash warning, remote diagnostic and software update, etc. will significantly increase the complexity of the future in-vehicle communication networks. New types of communication networks will also be necessary to satisfy the requirements of safety and fuel efficiency, and meet the demand for new features. Different sets of vehicle electronic modules will require different types of networks. For example, drive-by-wire and active collision avoidance systems need fault tolerant networks with time-triggered protocols, to guarantee deterministic latencies; multimedia systems need networks with high bandwidth to transfer video files; and body control electronics need low-bandwidth networks to keep the cost down. As the size and complexity of these networks increase, ease of integration has become a major challenge for design engineers.

The demand for drive-by-wire, pre-crash warnings, telematics and many new features will require very high bandwidth from future in-vehicle networks. One straightforward solution to satisfy the bandwidth requirements of future vehicle networks would be to use a higher bandwidth bus or to use multiple busses. However, the use of a higher bandwidth bus would increase the cost of the network. Similarly, the use of multiple busses would increase the cost and the complexity of the wiring. Another option would be the development of a higher layer protocol to reduce the amount of data to be transferred. This paper presents an adaptive data-reduction algorithm based on the CAN (Controller Area Network) protocol.

From time to time vehicles need to have their software modules updated for various reasons, such as the introduction of new features in vehicles, the need for changing the navigation map, the need for fine tuning various features of the vehicles, and many others. The software in a vehicle's electronic control unit (ECU) can be updated either at a service station or remotely via wireless links. Remote software update has many advantages: it can save consumers valuable time by not requiring them to bring their vehicles to service stations; software in multiple vehicles can be updated in parallel to save auto companies time and money; software in all recall vehicles can be updated in a timely manner, and so on. There are two main issues related to the remote software update operation. One issue is the bandwidth required for the update operation, and the other issue is the security of the communication links. In another paper we addressed the security issue of the communication links.

Future vehicles will have many features that include, but are not limited to, drive-by-wire, telematics, pre-crash warning, highway guidance and traffic alert systems. From time to time the vehicles will need to have their software modules updated for various reasons, such as to introduce new features in vehicles, the need to change the navigation map, the need to fine tune various features of the vehicles, etc. A remote software update has a number of advantages, such as it does not require consumers to take their vehicles to the dealers, and the dealers do not need to spend time on vehicles on an individual basis. Thus, remote software updates can save consumers' valuable time, as well as cost savings for the vehicle manufacturers. Since wireless links have limited bandwidth, uploading software in thousands of vehicles in a cost-effective and timely manner is a challenge. Another major issue related to the remote software update is the security of the update process.