Cable Imbalance Diagnostics Between Channels That Include Wire Pairs for Power Over Ethernet Transmission
Cable imbalance diagnostics between channels that include wire pairs for power over Ethernet transmission. In one embodiment, measurements of one or more characteristics of a first channel that includes a first of four twisted wire pairs in a network cable are performed along with measurements of one or more characteristics of a second channel that includes a second of the four twisted wire pairs in the network cable. A determination is then made as to whether the measured one or more characteristics of the first channel and the measured one or more characteristics of the second channel indicate an imbalance between the first channel and the second channel. Adjustments such as isolation, reporting or compensation can then be made in response to the determination
1 . A method, comprising:
measuring one or more characteristics of a first channel that includes a first of four twisted wire pairs in a network cable, and one or more characteristics of a second channel that includes a second of the four twisted wire pairs, wherein the four twisted wire pairs are used to deliver power from a power sourcing equipment to a powered device;
determining, by the power sourcing equipment, whether the measured one or more characteristics of the first channel and the measured one or more characteristics of the second channel indicate an imbalance between the first channel and the second channel; and
adjusting an operation of the power sourcing equipment in delivering power to the powered device in response to the determination.
2 . The method of claim 1 , wherein the measuring comprises measuring an impedance of the first channel and the second channel.
3 . The method of claim 2 , wherein the determining comprises determining a difference in impedance between the first channel and the second channel.
4 . The method of claim 1 , wherein the imbalance is an inductive or capacitive imbalance.
5 . The method of claim 1 , further comprising generating a message that reports the determined imbalance.
6 . The method of claim 1 , wherein the adjusting comprises compensating for the imbalance.
7 . The method of claim 1 , wherein the adjusting comprises limiting an operation of the power sourcing equipment to a delivery of power to the powered device over two wire pairs.
8 . The method of claim 1 , wherein the measuring comprises measuring one or more characteristics of magnetics in the first channel.
9 . The method of claim 1 , wherein the measuring comprises measuring one or more characteristics of a connector in the first channel.
10 . The method of claim 1 , wherein the measuring comprises measuring one or more characteristics of a patch cable that is different than the network cable.
11 . The method of claim 1 , wherein the measuring comprises measuring using a physical layer device.
12 . The method of claim 1 , wherein the measuring comprises measuring using a power sourcing equipment.
13 . The method of claim 1 , wherein the measuring comprises determining a category type of Ethernet cabling of the network cable.
14 . A power sourcing equipment, comprising:
a port for delivering power to a powered device via four twisted wire pairs in a network cable; and
a controller that is configured to receive diagnostic information based on measurements of one or more characteristics of a first channel that includes a first of the four twisted wire pairs in a network cable, and one or more characteristics of a second channel that includes a second of the four twisted wire pairs, determine whether the received diagnostic information indicates an imbalance between the first channel and the second channel, and adjust an operation of the power sourcing equipment in delivering power to the powered device in response to the determination.
15 . The power sourcing equipment of claim 14 , wherein the measurements are impedance measurements.
16 . The power sourcing equipment of claim 14 , wherein the controller is configured to generate a message that reports the determined imbalance.
17 . The power sourcing equipment of claim 14 , wherein the controller is configured to compensate for the imbalance.
18 . The power sourcing equipment of claim 14 , wherein the controller is configured to limit an operation of the power sourcing equipment to a delivery of power to the powered device over two wire pairs.