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US 8,026,627 B2Granted
Powered device for power over Ethernet system with increased cable length
AssigneeBroadcom Corporation
InventorAsif Hussain
Life of this patent
Estimating the term…
Abstract
A Powered Device (PD) in a Power Over Ethernet system that supports increased cable lengths of more than 100 m is provided herein. The proposed PD design requires no modifications at the PSE side. Embodiments include example modifications of IEEE 802.3af PD system rules, including example modifications of PD classification and port voltage ranges to enable increased cable length PoE.
Claims22
A Powered Device (PD) for use in a Power over Ethernet (PoE) system, comprising:
- a PD chip that receives a DC port voltage from a Power Source Equipment (PSE), said PSE connected to the PD by a cable;
- a first circuit, coupled to said DC port voltage, operable when said DC port voltage is within a detection voltage range of said PD chip to provide a detection signature of said PD chip to said PSE;
- a second circuit, coupled to said DC port voltage, operable when said DC port voltage is within a classification voltage range of said PD chip to provide a classification signature of said PD chip to said PSE;
- and
- a third circuit, coupled to said DC port voltage and to said second circuit, that receives said classification signature from said second circuit and that dynamically determines a turn on voltage and a turn off voltage of said PD chip based on said classification signature and a maximum voltage drop across said cable;
- thereby allowing said PD chip to operate when said received DC port voltage during a post startup phase is lower than an IEEE compliant minimum voltage for said post startup phase.
3 more elements
A Power over Ethernet (PoE) system, comprising:
- a power source equipment (PSE);
- a powered device (PD);
- and
- a cable that connects said PSE and said PD;
- wherein said PD receives a DC port voltage from said PSE, said PD comprising:
- a first circuit, coupled to said DC port voltage, operable when said DC port voltage is within a detection voltage range of said PD to provide a detection signature of said PD to said PSE;
- a second circuit, coupled to said DC port voltage, operable when said DC port voltage is within a classification voltage range of said PD to provide a classification signature of said PD to said PSE;
- and
- a third circuit, coupled to said DC port voltage and to said second circuit, that receives said classification signature from said second circuit and that dynamically determines a turn on voltage and a turn off voltage of said PD based on said classification signature and a maximum voltage drop across said cable;
- thereby allowing said PD to operate when said received DC port voltage during a post startup phase is lower than an IEEE compliant minimum voltage for said post startup phase;
- and
- wherein said PSE is in compliance with at least one of the IEEE 802.3af standard, the IEEE 802.3 at standard, and a legacy PoE standard.
9 more elements
A method for enabling an increased reach Power over Ethernet (PoE) system, comprising:
- determining a resistance of a cable connecting a Power Source Equipment (PSE) and a Powered Device (PD) of a PoE system;
- detecting a power class of said PD;
- and
- determining a post start up DC port voltage range and a classification voltage range for said PD according to said power class of said PD and said cable resistance;
- configuring said PD according to said determined post start up DC port voltage range and classification voltage range;
- and
- receiving a voltage from said PSE at said PD;
- wherein said post start up DC port voltage range has a minimum voltage that is lower than an IEEE compliant minimum PD port voltage for a post start up phase.
5 more elements
Dependencies are inferred from the claim text.