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DE-102023115599-B4 - ADJUSTING POWER PRIORITY IN A POWER-OVER-ETHERNET SYSTEM BASED ON THE AVAILABILITY OF AN ALTERNATIVE POWER SOURCE

DE102023115599B4DE 102023115599 B4DE102023115599 B4DE 102023115599B4DE-102023115599-B4

Abstract

Power-over-Ethernet (PoE) power supply device (PSE) (110) comprising the following: Ports (140) that can be connected via respective communication links to PoE-powered devices (PDs) (200) to power the PDs and exchange communications with them; and a control circuit (150) configured to operate in a state where a plurality of PDs (200) are connected to the terminals: from the multitude of PDs, link-layer protocol communications (160) are received, each comprising an alternative power field (161) indicating whether the PD that sent the respective communication has an alternative power source; and sets power priorities for the multitude of PDs at least partially based on the respective alternative power fields of the communications, in order to reduce a power priority of a first PD of the multitude of PDs relative to a standard value for the first PD if the first PD has an alternative power source (202).

Inventors

  • Murari Bhattacharyya
  • Nitin Duggal

Assignees

  • HEWLETT PACKARD ENTERPRISE DEVELOPMENT LP

Dates

Publication Date
20260513
Application Date
20230615
Priority Date
20221007

Claims (20)

  1. Power-over-Ethernet (PoE) power supply device (PSE) (110) comprising: ports (140) that can be connected to PoE-powered devices (PDs) (200) via respective communication links to power the PDs and exchange communications with them; and a control circuit (150) configured to: receive from the plurality of PDs (200) link-layer protocol communications (160), each comprising an alternative power field (161) indicating whether the PD that sent the respective communication has an alternative power source; and sets power priorities for the multitude of PDs at least partially based on the respective alternative power fields of the communications in order to reduce a power priority of a first PD of the multitude of PDs relative to a default value for the first PD when the first PD has an alternative power source (202).
  2. PSE according to Claim 1 , wherein setting the power priorities for the multitude of PDs includes, at least in part, setting them based on the respective alternative power fields of the communications, and the control circuitry: determining default values for the power priorities of the multitude of PDs; and The power priority of the first PD of the multitude of PDs is set to an adapted value that is lower than the default value for the first PD, in response to the alternative power field of the communication received by the first PD, which indicates that the first PD has an alternative power source.
  3. PSE according to Claim 1 , wherein setting the power priorities for the multitude of PDs, at least partially based on the respective alternative power fields of the communications, includes the control circuit: determining default values for the power priorities for the multitude of PDs; setting the power priorities of all PDs that do not have an alternative power source, as specified by the alternative power fields, to their respective default values; and setting the power priorities of all PDs that have an alternative power source, as specified by the alternative power fields, to respective adjusted values that are lower than the respective default values for the respective PDs.
  4. PSE according to Claim 1 , wherein setting the power priorities for the multitude of PDs includes, at least partially based on the respective alternative power fields of the communications, the control circuit reducing the power priorities of all PDs that have an alternative power source, as specified by the alternative power fields, relative to their respective standard values.
  5. PSE according to Claim 1 , wherein setting the power priorities for the multitude of PDs, at least partially based on the respective alternative power fields of the communications, includes the control circuitry for each of the PDs that has an alternative power source, as specified by the alternative power fields: determining whether the alternative power source of the respective PD is appropriate; and in response to a determination that the alternative power source of the respective PD is appropriate, decreasing the power priority of the respective PD relative to a default power priority value for the respective PD.
  6. PSE according to Claim 1 , where each alternative power field that indicates the presence of an alternative power source also indicates a type of alternative power source.
  7. PSE according to Claim 6 , wherein the control circuit is configured to negotiate with a given PD to terminate the power supply to the given PD in response to the alternative power field of a communication received by the given PD indicating that a certain type of AC power source is present.
  8. PSE according to Claim 6 , where the types of alternative power sources that can be specified by the alternative power fields include: a battery, a local power supply and/or a connection to a second PSE.
  9. PSE according to Claim 8 , where each alternative power field indicating that the transmitting PD has a battery also specifies an estimated operating time and/or battery charge level.
  10. PSE according to Claim 9 , wherein the control circuit is configured to compare, for each PD that has a battery as specified by the alternative power fields, the estimated runtime and/or state of charge of the battery against a threshold and: to set a power priority of the respective PD to a default value if the estimated runtime and/or state of charge of the battery is below the threshold; and to set a power priority of the respective PD to a customized value lower than the default value in response to the estimated runtime and/or state of charge of the battery being greater than the threshold.
  11. PSE according to Claim 1 , wherein the control circuit is configured to detect a change in the system state and, in response to the detection of the change in state, to reset the power priority of one or more PDs from a previously assigned customized value to a default value.
  12. PSE according to Claim 1 , where the alternative performance field comprises a time-length-value (TLV) data structure of a data unit of the link layer protocol.
  13. Power-over-Ethernet (PoE) powered device (PD) (200) comprising: a port (271) that can be connected via a communication link to a PoE power supply device (PSE) (110) to receive power from the PSE and exchange communications with it; and a control circuit (270) configured to: determine whether a power source other than the PSE is available to the PD; send a link-layer protocol communication (160) to the PSE via the port, which includes an age native power field (161) includes, which indicates whether the PD has the alternative power source to reduce a power priority of the PD relative to a standard value for the PD when the PD has an alternative power source (202).
  14. PD after Claim 13 , wherein the control circuit is configured to, in response to the determination that an alternative power source is available for the PD, determine a type of alternative power source and specify the type of alternative power source in the alternative power field of communication.
  15. PD after Claim 14 , where the types of alternative power sources detected by the control circuit include a battery, a local power supply and a connection to a second PSE.
  16. PD after Claim 15 , wherein the control circuit is configured to provide an estimated runtime and/or battery charge level in the communication alternative power field in response to the determination that an alternative power source is available for the PD and that the alternative power source is a battery.
  17. PD after Claim 13 , where the link layer protocol is one of the following: Link Layer Discovery Protocol (LLDP), Cisco Discovery Protocol (CDP), Foundry Discovery Protocol (FDP), Nortel Discovery Protocol (NDP), or Link Layer Topology Discovery (LLTD).
  18. PD after Claim 13 , where the alternative performance field comprises a time-length-value (TLV) data structure of a data unit of the link layer protocol.
  19. System comprising: one or more Power-over-Ethernet (PoE) powered devices (PDs) (200), each PD comprising: a PD PoE port (271); and PD control circuits (270); and a PoE Power Supply Equipment (PSE) (110) comprising: PSE PoE ports (140) that can be connected via respective communication links to the respective PD PoE ports of the PDs to power the PDs and exchange communications with them; and a PSE control circuit (150), whereby the PD control circuit of each PD is configured to send a Link Layer Protocol communication (160) to the PSE when the respective PD is connected to one of the PSE PoE ports, which includes an alternate power field (161) indicating whether the respective PD has an alternate power source (202); whereby the PSE control circuit is configured to receive the Link Layer Protocol communications from the PDs when the PDs are connected to the PSE PoE ports; and sets the respective power priorities for the PDs at least partially based on whether the PDs have the respective alternative power sources as specified in the respective communication alternative power fields, in order to reduce a power priority of one PD of the PDs relative to a standard value for the PD if the PD has an alternative power source.
  20. System according to Claim 19 , wherein the link layer protocol is one of the following: Link Layer Discovery Protocol (LLDP), Cisco Discovery Protocol (CDP), Foundry Discovery Protocol (FDP), Nortel Discovery Protocol (NDP), or Link Layer Topology Discovery (LLTD); and wherein the alternative performance field comprises a time-length-value (TLV) data structure of a data unit of the link layer protocol.

Description

INTRODUCTION Power over Ethernet (PoE) enables the transmission of data and power signals over a single Ethernet cable. This allows a PoE-enabled electronic device to communicate with a network and receive power over the same cable, potentially leading to greater flexibility in device placement (e.g., the device no longer needs to be located near a power outlet or have long power cables to reach one). In a PoE system, a device that supplies power to other devices via PoE is called Power Sourcing Equipment (PSE), and the devices that receive power from the PSE are called Powered Devices (PDs). The PSE generally also acts as a network element, such as a switch or router. PDs can also be network elements (e.g., a wireless access point, a PoE repeater/hub, etc.), network endpoints (e.g., a security camera, an Internet of Things (IoT) device, etc.), or any other electronic device with a PoE port. In a PoE system, the total power the PSE can deliver at any given time ("available power") may be less than the total power all connected PDs are consuming or intend to consume at that time ("power demand"). A power demand exceeding the available power of a PSE can be referred to as a "PSE power disturbance." A PSE power disturbance can occur for a variety of reasons. For example, the PSE may be designed such that the maximum total power it can deliver is less than the sum of the maximum output power per port. For instance, if a hypothetical PSE has a maximum total output power of 80 W and six ports, each capable of delivering a maximum output power of 20 W, then the sum of the maximum output power per port (6 × 20 W = 120 W) exceeds the available power (80 W). In such examples, if all ports of the PSE are connected to PDs consuming the full maximum power per port, then the power demand at that time exceeds the available power. Another example: Even if the PSE is designed so that the maximum total output power equals or exceeds the sum of the maximum output power per port, the actual available power at a given time may fall below the maximum available power, for example, due to a power outage of the PSE or other fault events. US 2007 / 0 135 086 A1 Describes a device (PD) configured to receive power via a communication link, such as an Ethernet connection, that has a power interface controller for implementing a power supply protocol. The power interface controller captures several pieces of PD information representing different properties of the PD in order to transmit the PD information to a power supply device. DE 11 2011 105 767 T5 Describes a test device for connection to a power supply unit, the test device comprising: a network connector for connection to the power supply unit, which can provide power and communications to the test device; an auxiliary power source that can provide power to the test device; a power selection module for setting a power level based on a user input, wherein several non-zero power levels are adjustable based on different user inputs by the power selection module, and wherein the test device is adjustable to emulate a consumer device associated with a particular class; a power negotiation module for negotiating the power from the power supply unit connected via the network connector, based on the power level set by the power selection module; and an error indicator to indicate that the negotiation has failed. SHORT DESCRIPTION A Power-over-Ethernet (PoE) power supply device (PSE) according to claims 1 to 12, a Power-over-Ethernet (PoE) powered device (PD) according to claims 13 to 18 and a system according to claims 19 and 20 is disclosed. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure can be understood from the following detailed description, either alone or together with the accompanying drawings. The drawings serve to further understand the present disclosure and are an integral part of the present description and are incorporated therein. The drawings illustrate one or more examples of the present teaching and, together with the description, explain certain principles and modes of operation. In the drawings: This is a block diagram showing an example of a PoE-PSE. This is a block diagram that illustrates an example of a PoE-PD. is a block diagram showing an example of a PoE system with a PSE and connected PDs. is a process flow diagram that represents a first example of a procedure that can be performed by a PoE PSE. is a process flow diagram that shows a second example procedure that can be performed by a PoE-PSE. is a process flow diagram showing a third example procedure that can be performed by a PoE-PSE. is a block diagram showing an example of a storage medium that stores instructions that can be executed by a processor of a PoE-PSE. is a block diagram showing an example of a storage medium that stores instructions that can be executed by a processor of a PoE PD. is a process flow diagram showing a fourth example procedure that can be performed by a PoE-PSE. DETAIL