Intelligent power and control policy for automotive applications

Abstract

In automotive networking applications, data about vehicle's environment can be used in conjunction with a control policy to manage the performance and power usage of a networked device. The control policy can dynamically adjust the balance between link power and performance of the device's communications interface by taking into account the vehicles current situation and user preferences, e.g. location, destination, speed, sensor status, or the like. Controlling the balance between link power and performance of networked devices can be important in maximizing power savings without unacceptably decreasing network performance.

What is claimed is: 
     
         1 . A controller for use in an automotive area network (AAN) employing an Ethernet protocol, the AAN including a plurality of subsystems, the controller comprising:
 at least one first PHY configured to establish physical communication pathways to second PHYs included in the plurality of subsystems;   a processor configured to:
 select a power control policy based on a current operating environment of the AAN; and 
 in accordance with the power control policy, selectively wake-up particular second PHYs. 
   
     
     
         2 . The controller of  claim 1 , further comprising:
 controlling, in accordance with the power control policy, a power level associated with an Ethernet data link established via at least one of the physical communication pathways.   
     
     
         3 . The controller of  claim 1 , wherein at least one of the second PHYs is included in a subsystem controller associated with a particular subsystem of the AAN, the subsystem controller comprises:
 a communications interface coupled to a plurality of subsystem devices included in the particular subsystem of the AAN; and   a processor configured to:
 establish subsystem data links between the subsystem controller and the plurality of subsystem devices; and 
 control power states of the subsystem data links. 
   
     
     
         4 . The controller of  claim 1 , wherein the power control policy selected applies exclusively to a particular type of subsystem. 
     
     
         5 . The controller of  claim 1 , wherein the processor is further configured to:
 control placement of the second PHYs into a standby state that limits a frequency of communication.   
     
     
         6 . The controller of  claim 1 , wherein the processor is further configured to:
 control placement of the second PHYs into a standby state that limits a type of communication.   
     
     
         7 . The controller of  claim 1 , wherein the processor is further configured to:
 control placement of the second PHYs into a low power state that allows power-up of the second PHY, but prevent power up of at least some higher level device circuitry.   
     
     
         8 . A device for use in an automotive area network (AAN), the device comprising:
 a first Ethernet PHY included in a controller and coupled via the AAN to a second Ethernet PHY included in an endpoint device; and   the first Ethernet PHY configured to transmit a power-state command to the second Ethernet PHY based on an AAN control policy and a current operating environment of the AAN.   
     
     
         9 . The device of  claim 8 , wherein the power-state command includes a command to alter a link state associated with a data link between the first Ethernet PHY and the second Ethernet PHY. 
     
     
         10 . The device of  claim 8 , wherein the AAN control policy specifies that a power state of the second Ethernet PHY is to be set based on a level of utilization of a data link associated with the second Ethernet PHY. 
     
     
         11 . The device of  claim 8 , wherein the power-state command includes a command to delay power-up. 
     
     
         12 . The device of  claim 8 , wherein the first Ethernet PHY controls placement of the second Ethernet PHY into a standby state that limits a frequency of communication. 
     
     
         13 . The device of  claim 8 , wherein the first Ethernet PHY controls placement of the second Ethernet PHY into a standby state that limits a type of communication. 
     
     
         14 . The device of  claim 8 , wherein the controller prevents the endpoint device from receiving power over Ethernet for a set period of time. 
     
     
         15 . An automotive area network (AAN) employing an Ethernet protocol, the AAN comprising:
 a plurality of devices, each of the plurality of devices including individual first PHY circuitry;   a control system including second PHY circuitry, the control system configured to establish Ethernet data links via a physical communication path between the individual first PHY circuitry and the second PHY circuitry; and   the control system further configured to control placement of the individual first PHY circuitry associated with particular devices of the plurality of device into various power states as specified by a control policy.   
     
     
         16 . The AAN of  claim 15 , further comprising:
 at least one subsystem controller including a third PHY circuitry configured to interface with the automotive Ethernet network; and   the control system is further configured to selectively control a power state of an Ethernet data link associated with the at least one subsystem.   
     
     
         17 . The AAN of  claim 15 , wherein the control system is further configured to:
 control placement of the individual first PHY circuitry into a power state that limits a frequency of communication over an Ethernet data link.   
     
     
         18 . The AAN of  claim 15 , wherein the control system is further configured to:
 control placement of the individual first PHY circuitry into a power state that limits a type of communication.   
     
     
         19 . The AAN of  claim 15 , wherein the control system is further configured to:
 partially wake at least one device of the plurality of devices by powering up the individual first PHY circuitry associated with the at least one device, but preventing power up of at least some higher level circuitry associated with the at least one device.   
     
     
         20 . The AAN of  15 , wherein the control system is further configured to:
 prevent the first device from receiving power over Ethernet until further notice from the control system, or until a set period of time has elapsed.