Patent Application
20070106913
This invention relates to techniques for providing power over a network data communication line for systems that have multiple power sources, and more particularly for systems that receive power through power over Ethernet (POE) connections.
Various approaches have been proposed for providing network data communications and power over the same infrastructure. One well known wired network data communication standard is the Ethernet standard. Providing power over Ethernet cabling in while still allowing Ethernet data communication is known as power over Ethernet (POE). One standard for providing power over Ethernet cabling is the IEEE 802.3af standard. Some of the first applications utilized for POE include Ethernet connected IP telephones, wireless local area network access points and security cameras. Such equipment often has relatively low power requirements that are suited for the generally low power available under the POE standard.
Providing power through network data communication cabling is typically accomplished through the use power sourcing equipment (PSE) such as switches, routers, hubs, etc and powered devices (PD) such as IP phones, wireless access points, client-end devices, etc. In POE applications, the PSE may provide power to the PD through the use of the data wire pairs. The PSE may alternatively also provide power to the PD through the use of “spare” wire pairs in the Ethernet cabling (for applications in which spare wire pairs exist). So that power is not undesirably sent from a PSE to a non-PD device, a multi-stage handshake transpires between the PSE and PD devices. The handshaking process includes signature/detection, classification, power start-up and power disconnect stages. The signature/detection stage involves the PSE probing the PD to see if the PD is POE compliant. The classification stage involves the PD identifying the level of power that the PD requires. The start-up stage involves ramping the supplied voltage to the full voltage level and the disconnect stage disables the provision of power when the PD is determined to have been disconnected.
In POE applications, the PSE may provide a 44-57 V DC voltage level (nominally 48 V DC) to the PD. However, current POE standards generally limit the supplied power to a maximum of 12.95 W at the PD. Many devices that could advantageously receive power over a data communication line, however, require more power than may be available over the data communication line according to current standards. Consideration is being given to new or modified standards that would supply more power to powered devices; however, even such increased power levels may still be unsatisfactory for many applications.
One device for which the power supplied across a data communication line is generally insufficient for standard operation is a personal computer. Even low power computers such as notebook or laptop computers typically require more power than may be available from a data communication line. For example as described above current IEEE POE standards provide a maximum of 12.95 W to a PD. Many notebooks or laptop computers, however, have power requirements in the 65 to 150 W range. It would be desirable to provide a technique to advantageously utilize power supplied across a data communication line even when the PD has higher power requirements than is available from the data communication line.
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. The devices that may utilize power provided across a data communication line are wide ranging and include information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
One exemplary prior art information handling system 100 is shown in
A method and system are disclosed for utilizing power provided from a data communication line for operation of an information handling system. The power from the data communication line may be utilized even when the information handling system being powered requires more power than is available from the data communication line. More particularly, power management techniques are provided that couples the power from a data communication line to the power systems of the information handling system. The information handling system may include a plurality of power sources of which the data communication line power is just one such source. Power management circuitry identifies and characterizes the power available from the data communication line and integrates the power with the power available from other power sources. Thus, the information handling system may operate from power available from the data communication line in conjunction with power from one or more other power sources. The multiple power sources may be utilized together to operate the information handling system. The data communication line power may also be utilized to charge a battery when the information handling system is turned off or if the system is operating from one of the other power sources. The information handling system may also operate with power solely supplied from the data communication line, for example when the system is in a suspend or hibernate mode. In one embodiment, the data communication line may be an Ethernet connection through which POE techniques are implemented.
In another embodiment, a method of managing the power resources of an information handling system is provided. The method may include providing a low power data network power connection within the information handling system for obtaining power from a network connection through which data is also provided. The method may further include identifying and qualifying the power that is available from the data network and providing information regarding the power that is available from the data network to the information handling system so as to manage the power resources of the information handling system.
In another embodiment, a method of controlling the power management system within an information handling system is provided. The method may include providing power management control circuitry and coupling the power management control circuitry to network power control circuitry, the network power control circuitry configured to receive power from a data network for operating at least in part at least a portion of the information handling system. The method may further include providing feedback and control amongst the power management control circuitry, the data network power control circuitry, and the at least one of power source.
In still another embodiment, an information handling system is disclosed. The information handling system may include at least one battery coupled to the information handling system for providing power to the information handling system and a data network power circuit configured to be coupled to at least one data network line to receive power from a data network. The information handling system may further include system power management resources coupled to both the battery and the data network power circuit; the system power management resources configured to enable power to be utilized by the information handling system from both the at least one battery and the data network together.
It is noted that the appended drawings illustrate only exemplary embodiments of the invention and are, therefore, not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
As described in more detail below, a technique is disclosed herein for utilizing power provided from a data communication line for operation of an information handling system. The power from the data communication line may be utilized even when the information handling system being powered requires more power than is available from the data communication line.
For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components.
Thus, as shown in
In addition to communication with the AC-DC adapter, the batteries and the charger/selector, the power management circuitry 206 may communicate with network power control circuitry 240. The network power control circuitry 240 may indicate the availability of power on the data communication line 220. The availability of such power may then be communicated such to the power management circuitry 206. In addition, the network power control circuitry 240 may characterize the power available from the network according to voltage, current, maximum wattage, stability, etc. and feed such information to the power management circuitry 206. Power management circuitry 206 may then incorporate the power provided by the network in a manner to efficiently operate the information handling system and/or charge the batteries. The power management circuitry 206 may also communicate with the power control circuitry 240 to indicate a current system status in which power from the data network is not needed by the information handling system 100. In circumstances in which the additional power from the data network is not needed by the system, the power control circuitry 240 (and/or PD circuitry within the power control circuitry 240) may communicate with the PSE to indicate that the information handling system 100 will not accept power from the PSE. Thus, power at the network 230 level may be directed towards other systems requiring power or simply conserved.
For example, if AC power is not connected, the power from the network and one or more batteries may be combined to supply power to the power planes 126. Alternatively, the power planes 126 may be operated from one battery while the data network supplied power is utilized to charge the other battery. Further, the network supplied power may be utilized to charge all batteries when the system is turned off. In still yet another embodiment, the power from the data network may be the sole power source utilized to power the information handling system, particularly when the system is placed in a low power consumption mode of operation such as a suspend or hibernate modes. In yet another embodiment, the power from the data network may be utilized to support advanced system management features. For example, the power from the data network may be utilized to support the low power consumption needs of a system that is shut down in a Wake On LAN mode (a mode where a network adapter has a very-low-power mode to monitor the network for special packet data that will wake up the rest of the system). Thus, it will be recognized that the power from the data network may be utilized in a wide variety of manners when AC power is not connected to the system and the embodiments described herein are merely exemplary.
Though the data network power may be most advantageously utilized if the AC power is unavailable, the data network power may still be utilized even if AC power is available. For example, even though AC power is available, the amount of power available may not be sufficient to for simultaneously utilizing all features of the information handling system. In one example, AC power may be available however the available power may not be sufficient to both operate the information handling system and charge the batteries of the system. In such a circumstance, the additional availability of the data network power may be sufficient such that the system may be operated and the batteries charged.
The data network power may be efficiently utilized even if the available data network power is less than the total power required to operate the information handling system in a normal mode of operation. In this regard, the data network power may be characterized as a low power DC power source. The power management circuitry 206 may integrate the usage of this low power source in combination with some, all, or none of the other higher power sources (for example AC-DC adapter 102, battery 108 and battery 110). By identifying the availability of a secondary low power source and characterizing the power availability from the secondary power source, the power management circuitry may apply the power from the secondary power source in the most efficient manner depending upon the number and type of other power sources, the current power demands of the information handling system, the available charge remaining on the batteries, etc. In this manner although the low power level network power supply may not be self-sufficient for full operations of the information handling system, the network power supply may still significantly enhance power system operations when the information handling system is connected to a network which has power delivery services available.
The power control circuitry 240 may include any of wide variety of circuits that receive, identify and/or characterize the data network power. One embodiment related to the POE applications is shown in
Control circuitry 340 may optionally provide a range of functions. In a simplest form, control circuitry 340 may merely communicate with the powered device circuitry 310 to identify the availability of data network provided powered. This may be indicated on control line(s) 350 that is coupled to the power management circuitry 206 of the information handling system 200. The control line(s) 350 may be configured in accordance with a communication interface standard such as for example, an 12C interface, SMBus interface, SST interface, OneWire interface or other interface standard. The control circuitry 340 may also be configured to provide multiple status signals. For example, the control circuitry may indicate that power is available and an indicator of the characteristics of the power. The indicator may be that the power is within an acceptable range or that there is a fault with the power levels being provided. Furthermore, power detection and characterization circuits may be provided in the powered device circuitry 310 and/or the control circuitry 340 so that more advanced characterization information (voltage, maximum wattage, current, etc.) may be provided on the control line(s) 350. In addition, the control line(s) 350 may provide on, off, reset, control etc. signals to/from the power management circuitry 206 so as to turn on, turn off, or reset the power control circuitry 240, to indicate whether power is available, indicate a high/low power status, or to set the power control circuitry 240 to refuse power from the PSE or sense the current voltage.
Thus, described herein is a method of not only providing power to an information handling system from a data network but also identifying the existence and characteristics of the provided power so that the information handling system may integrate the power available from the data network with one or more other power sources. The techniques described herein provide for a qualification and quantification of the power source available from the data network. This information may then be feed into the power management resources to optimize the overall system power performance. In addition to identifying the power source capabilities to the system, feedback control may be provided to the power control circuitry 240 to further enhance performance.
As shown in
It will be recognized that the data communication line that provides power as described herein may be any of a wide variety of network hardwired communication lines. For example, a wide variety of hardwire communication standards are known that may advantageously also provide power including USB, IEEE 1394a, Ethernet, extensions to the IEEE 802.3af, other future Ethernet related standards, etc. In general, the techniques described herein may be useful for providing an additional power source from any data communication line through which power may be delivered to system in addition to the data being communicated. Though exemplary embodiments are described herein with regard to Ethernet cabling and POE, it will be recognized with the benefits of this disclosure that the power management techniques are applicable to non-Ethernet data communication.
The techniques described herein may function with prior art power systems by the addition of the power control circuitry 240 and a BIOS update that integrates the management of the data network power source with the other power sources.
Further modifications and alternative embodiments of this invention will be apparent to those skilled in the art in view of this description. It will be recognized, therefore, that the present invention is not limited by these example arrangements. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is to be understood that the forms of the invention herein shown and described are to be taken as the presently preferred embodiments. Various changes may be made in the implementations and architectures. For example, equivalent elements may be substituted for those illustrated and described herein, and certain features of the invention may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. For example, the various communication protocols described herein (such as 802.11a/b/g/n, UWB, cellular, etc.) are merely exemplary and it will be recognized that other current and future standards may equally utilized the techniques described herein. Furthermore, the prioritization classes described herein are merely exemplary and other classes of traffic and/or other levels of priority may be utilized while still providing the benefits of the concepts disclosed herein.
