In-vehicle network management using virtual networks

A network management approach for use in a vehicle to control activation of electronic control units (ECUs) networked together throughout the vehicle. The ECUs are grouped together by function into virtual networks, with each virtual network including those ECUs used in carrying out a particular control task, such as controlling power windows or automatic headlights. The virtual networks are activated using a messaging protocol that specifies which virtual network is being activated. Periodic messages specifying the virtual network are also used to maintain it active. This permits the ECUs to be maintained in a low power quiescent state when the control functions are not needed, while allowing only those needed for a particular control task to be awakened and maintained in an activated state to carry out their associated control task. An ECU can activate one of the virtual networks by transmitting a wake-up signal followed by a message identifying the virtual network. Each of the ECUs receive this message and, if it is a member of the virtual network being initialized, maintains itself in an active state to carry out the control task associated with the virtual network. The other ECUs return to the quiescent state. Using this approach, an ECU is able to activate only the necessary ECUs for a particular control task without having to know which or how many ECUs are involved in performing the task.