CN101207290B - System and method for power supply of Ethernet - Google Patents
System and method for power supply of Ethernet Download PDFInfo
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- CN101207290B CN101207290B CN200710300819XA CN200710300819A CN101207290B CN 101207290 B CN101207290 B CN 101207290B CN 200710300819X A CN200710300819X A CN 200710300819XA CN 200710300819 A CN200710300819 A CN 200710300819A CN 101207290 B CN101207290 B CN 101207290B
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Abstract
A system and method for discovering a cable type and resistance for Power over Ethernet (PoE) applications. Cabling power loss in PoE applications is related to the resistance of the cable itself. A PHY can be designed to measure electrical characteristics (e.g., insertion loss, cross talk, length, etc.) of the Ethernet cable to enable determination of the cable resistance. The determined resistance can be used in powering decisions and in adjusting power budgets allocated to power source equipment ports.
Description
Technical field
The present invention relates to the method for network layout system, more particularly, relate to the system and method for the type of cable of a kind of discovery POE (PoE) application.
Background technology
IEEE 802.3af PoE standard is provided for through the Ethernet wiring power being transferred to the power consumption equipment framework of (powed device is called for short PD) from power-supply device (PSE).In this PoE handles, at first carry out effective Equipment Inspection.Whether this testing process identification power-supply device is connected with an effective equipment with the non--PoE available devices of guaranteeing that this power does not offer.
After finding effective PD, PSE selectively carries out the power classification.IEEE 802.3af has been the PD device definition five kinds of power classes.The completion of power classification processing can make the PSE management, and these will be transferred to the power of each PD that links to each other with this PSE.Can be used for specific PD if discern specific power stage, then PSE can be the suitable power of this PD distribution.If do not carry out power division, then can use default categories, wherein, PSE will provide the power of whole 15.4W to particular port.
For effective operation of PSE, the power budget that management is assigned to each coupled PD is very important.In the high coverage rate (Broad Reach) of PoE is used (wherein, PD links to each other with the PSE of use greater than the Ethernet cable of 100 meters (for instance, 300-500 rice)), the management of power budget is more important.The total amount of power that usually, can be assigned to each PD receives the restriction of PSE capacity.Therefore, need a kind of like this mechanism, make PSE can discern the accurate quantity of power that each port is answered budget.
Summary of the invention
The invention provides a kind of system and/or method that control transmission is given the power of power consumption equipment that be used for, carried out representing fully and describing in conjunction with at least one width of cloth accompanying drawing, and in claim, obtained more complete elaboration.
According to an aspect of the present invention, a kind of POE system comprises:
The power consumption equipment detection components is used for the existence of detection equipment, and said power consumption equipment links to each other with power-supply device through Ethernet cable;
The cable detection assembly is used to measure the electrical characteristic of said Ethernet cable; And
Power controller, the type of the said Ethernet cable that is used for pointing out based on the electrical characteristic of said measurement is controlled the power division of said power-supply device port.
Preferably, said cable detection assembly is measured the insertion loss of said Ethernet cable.
Preferably, the said cable detection assembly cross-talk of measuring said Ethernet cable.
Preferably, said cable detection assembly is measured the length of said Ethernet cable.
Preferably, said power controller distributes based on the type and the length power controlling of said Ethernet cable.
Preferably, said power controller is controlled said power division based on the resistance of the definite said Ethernet cable of the said type of using said Ethernet cable.
Preferably, said power controller is based on the access control power division of said Ethernet cable.
Preferably, said power controller identification is assigned to the power budget of said port.
According to an aspect of the present invention, a kind of POE method comprises:
In case through Ethernet cable power consumption equipment is connected to the power-supply device port, just confirms the type of said Ethernet cable according to the electrical characteristic of measuring; And
Distribute power budget to said power-supply device port, the power budget of said distribution is based on said definite type of said Ethernet cable.
Preferably, saidly confirm to comprise the insertion loss of measuring said Ethernet cable.
Preferably, saidly confirm to comprise the cross-talk of measuring said Ethernet cable.
Preferably, said type confirms to comprise whether definite said Ethernet cable is the 3rd type of Ethernet cable.
Preferably, said distribution power budget is based on said definite type and said definite length of said Ethernet cable.
Preferably, said method further comprises the resistance that the said definite type of using said Ethernet cable and said length measured are confirmed said Ethernet cable.
According to an aspect of the present invention, a kind of POE method comprises:
Confirm the type of the Ethernet cable of connection power supply unit and power consumption equipment based on the electrical characteristic of the said Ethernet cable of measuring; And
Determine whether power to be provided based on said definite type to said power consumption equipment.
Preferably, said power confirms it is the Ethernet wiring to greater than 100 meters.
Preferably, said power confirms it is in the POE additional application, using the 3rd type of cable distribution.
Preferably, said power confirms to be based on the length of the said Ethernet cable of being discerned.
Description of drawings
Other advantage and characteristic in order to explain that above-mentioned method and the present invention obtain with reference to the specific embodiment shown in the accompanying drawing, are described in further detail the present invention at preceding brief description.Should be appreciated that these accompanying drawings only are exemplary embodiments of the present invention, can not regard the restriction to its scope as,, will do more concrete and detailed description and explanation the present invention through the use of following accompanying drawing:
Fig. 1 shows the sketch map of POE (PoE) system implementation example;
The circuit block diagram that it is model that Fig. 2 A and 2B show with this PoE system;
Fig. 3 shows the flow chart that PoE handles;
Fig. 4 shows the sketch map of the connector at media relevant interface link (medium dependent interface link) middle part;
It is right that Fig. 5 shows the cable that can shorten in the line side and the transceiver side of transformer;
Fig. 6 shows and can realize the sketch map to the PoE system of PSE transmission cable characteristic information from PHY;
Fig. 7 shows the flow chart to the process of PSE transmission cable characteristic information from PHY;
Fig. 8 shows the sketch map of the embodiment of the insertion loss measurement that is used for the 3rd and 5 type of cable;
Fig. 9 shows the sketch map of the near-end crosstalk test that is used for the 3rd type and the 5th type cable.
Embodiment
Below gone through various embodiment of the present invention.Need be appreciated that the discussion of embodiment only for purposes of illustration.Those skilled in the art know, under the situation that does not break away from the spirit and scope of the present invention, can use other element and configuration.
Fig. 1 shows POE (PoE) system implementation example.As shown in the figure, the PoE system comprises the power-supply device (PSE) 120 to power consumption equipment (PD) 140 through-put powers.PSE is that the voltage that is connected across by application between the center branch road of transformer provides to the power of PD transmission, emission (TX) line that carries in this center branch road and the Ethernet cable to reception (RX) line to linking to each other.Two TX and RX are to being used for the data communication between Ethernet PHY 110 and 130.
Shown in Fig. 1 was further, PD 140 comprised 802.3af module 142.This module comprises can make PD 140 and the electronic component of PSE 120 according to IEEE 802.3af standard traffic.PD 140 also can comprise pulse bandwidth modulation (PWM) DC that is used for power controlling FET 146: DC controller 144, and then firm power is provided to load 150.Two types load is arranged usually: pure resistive loads (lamp for instance) and by DC: the constant power load that the DC power controller is supplied with.The application relates generally to DC: the constant power load that the DC power controller is supplied with.
150 power delivery can be by the circuit Fig. 2 A as model from PSE 120 to load.As shown in the figure, power supply provides voltage V to circuit
PSE, this circuit comprises that first parallel resistance is to (R
1, R
2), load resistance R
LOAD, and second parallel resistance is to (R
3, R
4).At this, first parallel resistance is to R
1, R
2Represent the right resistance of TX line, and second parallel resistance is to R
3, R
4Represent the right resistance of RX line.
Resistance R
1, R
2, R
3And R
4Resistance by the type of Ethernet cable and length decision.Especially, resistance R
1, R
2, R
3And R
4Has certain resistance value/length by Ethernet cable type (for instance, the 3rd, 5,6 type etc.) decision.For example, for the 3rd type of Ethernet cable, resistance R
1, R
2, R
3And R
4Resistance be about 0.2 Ω/rice.Like this, for 100 meters the 3rd type of Ethernet cable, resistance R
1, R
2, R
3And R
4In each resistance be 20 Ω.In this example, parallel resistance R
1, R
2Resistance be equivalent to 10 Ω, and parallel resistance R
3, R
4Resistance also be equivalent to 10 Ω.Generally speaking, the all-in resistance (R of Ethernet cable
Cable) value is 10 Ω+10 Ω=20 Ω.The PoE circuit model of simplifying can comprise the individual cable resistance value R shown in Fig. 2 B
Cable
In IEEE 802.3af standard, the alternative classifying step of carrying out the power classification of identification PD of PSE.Following table 1 shows 5 PD classification that IEEE 802.3af standard is supported.
| Classification | Use | The minimum output power of PSE | The maximal input of PD |
| 0 | Acquiescence | 15.4W | 0.44 to 12.95W |
| 1 | Optional | 4.0W | 0.44 to 3.84W |
| 2 | Optional | 7.0W | 3.84 to 6.49 |
| 3 | Optional | 15.4W | 6.49 to 12.95W |
| 4 | Reserve | Like classification 0 operation | Reserve |
Table 1
As shown in the figure, the minimum output power of the PD categorised regulation PSE of classification 0 (acquiescence) and classification 3 is 15.4W.For the equipment of more lower powered PD such as classification 1 and classification 2, the minimum output power of PSE is that separate provision is 4.0W and 7.0W.Yet optional, the identification of correct PD power classification make PSE only budget at the required power of each port.This has increased PSE provides ability from power to one group of coupled PD effectively.
A characteristic of the present invention is, can use the measurement of one or more characteristics of Ethernet cable to influence the operation of PoE system.In one embodiment, the characteristic of measurement can be used for discerning the type and/or the length of Ethernet cable.The resistance that then, can the type and/or the length of the Ethernet cable that recognizes be used to estimate Ethernet cable.And then use the resistance estimated value of Ethernet cable to assess the power loss in the cable, this power loss influence is assigned to the power budget of specific PSE port.
With reference to the flow chart of figure 3, can understand general process of the present invention.As shown in the figure, this process starts from step 302, measures one or more characteristics of Ethernet cable at this.In one embodiment, this measuring process can be used as the part that the PHY of the electric property of Ethernet cable analyzes and carries out.For example, measuring process can be used as echo that PHY carries out and removes the part of convergence process (echo cancellation convergence process) and carry out.
In one embodiment, one or more characteristics of those Ethernet cables that can measure in step 302, this characteristic is to make the PoE system estimate those characteristics of the resistance of Ethernet cable better.At this, the estimation of actual cable resistance can make the actual power dissipation of PoE system estimation cable.In one embodiment, PHY can be designed for insertion loss, cross-talk and the length characteristic that measurement can be confirmed Ethernet cable.
In step 304, after the measurement of completion to one or more characteristics of Ethernet cable, then the PoE system can confirm the type and the length of Ethernet cable.In one embodiment, can confirm the type of cable of Ethernet based on insertion loss, cross-talk and the length of the Ethernet cable that measures.These measurements to Ethernet cable can make the PoE system confirm for example whether Ethernet cable is the 3rd, 5,6 or 7 type of Ethernet cable.
Should be appreciated that different type of cables has different relevant resistances.For example, the resistance of the 3rd type of Ethernet cable is about 0.2 Ω/rice, and the resistance of the 5th type of Ethernet cable is about 0.1 Ω/rice.In case confirmed the type and the length of Ethernet cable in step 304, then the PoE system can confirm its influence to the PoE system in step 306.
Below will introduce type and the length information of the cable specific effect to the PoE system in detail, this influence can change along with application.Be that the PoE system can use the type and the length information of cable in this characteristic of the present invention in dynamic setting or operating process.For example, can use the type and the length diagnosis Ethernet cable of the Ethernet cable of identification, determine whether and to confirm power budget of regulating specific PSE port or the like to the PD power supplied.
For the type of describing the Ethernet cable of having discerned and the multiple mode of effect length PoE system, to consider and reached first application relevant with traditional P oE system, said PoE system is supported by IEEE 802.3af standard.In this is used, the type of cable and length confirm to can be used for discerning resistance R
Cable(referring to Fig. 2 B).
In the circuit model in Fig. 2 B, comprise DC: DC transducer, load R at this PD
LCan receive firm power P
L, and visible voltage V
LBe positioned at its input.Because the P of load
LFix P
L=I*V
L, be electric current through entire circuit at this I.The power loss of cable can be P
Loss=I
2* R
Cable
When the minimum output power of the 15.4W that specifies PSE, IEEE 802.3af standard supposition PD links to each other with the PSE of the 3rd type of cable that uses 100m.The resistance of 100 meters the 3rd type of cable is about 20 Ω.When electric current is restricted to 350mA, owing to the power loss P of worst condition
Loss=(350mA)
2* 20 Ω=2.45W.The worst condition power loss of this 2.45W be between the minimum output power of PSE and the maximum power that PD obtains difference (just, 15.4W-12.95W=2.45W).
According to the present invention, can be based on the Ethernet cable type confirm to regulate and distribute worst condition power budget to the PSE port.Especially, under the situation of other additional information that does not have the PoE system, the identification of Ethernet cable type can obtain the accurate power loss and estimate.For example, suppose that measurement features points out that PD is to use the 5th type of cable to link to each other with PSE rather than uses the 3rd type of cable to link to each other with PSE.Suppose that as the worst condition of 350mA the resistance of cable will be estimated as 10 Ω of the 5th type of cable, rather than 20 Ω of the 3rd type of cable as 100m and electric current even use cable length.This resistance reduces half the confirming and will cause power loss to reduce half to 1.225W, and correspondingly, the 1.225W power of saving then can be used for reducing the power budget that is assigned to this port, therefore increases the capacity of PSE effectively.
Through the length of cable is confirmed to confirm to combine with its type, can obtain accurate power loss more and estimate.Use additional circuit length information, can the resistance of the cable 100m from worst condition further be reduced.For example, suppose that the type of cable is confirmed as the 5th type, and the length of cable is further confirmed as 50m.In this example, the resistance of the 5th type of cable can further reduce half the to 5 Ω.The power loss of the 5th type of cable of this 50m then is Pl
Oss=(350mA)
2* 5 Ω=0.6125W.Correspondingly, the power of the 2.45W-0.6125W=1.8375 of saving then can be used for reducing the power budget that is assigned to this port.Should be appreciated that the advantage of confirming to provide aforesaid power save of independent cable length.Typically using cable length to confirm in the PoE application (for instance, being lower than 100 meters) though legacy system has been conceived, the use cable length confirms it is distinguishing characteristics of the present invention in greater than 100 meters PoE application.
In above-mentioned example, independent type of cable confirm or combine Ethernet cable length confirm to can be used for reducing the power budget that is assigned to the PSE port.Therefore the identification of type of cable provides than the more significant advantage of the identification of independent circuit length.Be to desirable that the acquisition of these advantages does not need any out of Memory of system.If out of Memory is available for system, can generates more detailed power loss and calculate.
The pressure drop (voltage drop) that is connected across on the cable may be defined as V
PSE-V
L=I*R
CableThis equality can be used for calculating as follows the voltage V that obtains the permission of PD place
L:
V
PSE-V
L＝I*R
cable
V
PSE-V
L＝(P
L/V
L)*R
cable
V
PSE*V
L-V
L 2＝P
L*R
cable
V
L 2-V
PSE*V
L+P
L*R
cable＝0
V
L＝[V
PSE+/-SQRT(V
PSE 2-(4*P
L*R
cable))]/2
If V
PSEBe known as 48V, P
LBe 12.95W (maximum power that all PD allow), and R
CableConfirm as 5 Ω (resistance of 50 meters the 5th type of cable), then V
L=(48+/-SQRT (48
2-4*12.95*5))/2=(48+/-45.22)/24=46.61V.Then can use V
PSE-V
L=I*R
CableCalculate electric current, 48V-46.61V=I*5 Ω obtains I=0.278A like this.Total power of PSE is output as 12.95W and adds the power loss in the cable.Power loss in the cable is I in this case
2* R
Cable=(0.278A)
2* 5 Ω=0.39W.In this example, the gross power of PSE port is 12.95W+0.39W=13.34W.The power budget of practicing thrift is 15.4W-13.34W-2.06W.
Further said like this example, IEEE 802.3af standard estimates that to the worst condition of the 3rd type of cable (the cable resistance of its worst condition is 20 Ω) of 100m the power budget that will cause being assigned to port has unnecessary waste.When adding up to the port of all PSE, the waste on the power budget will unnecessarily reduce the actual power capacity of PSE.
Second of the principle of the invention is used the PoE+ that can be applicable to as being supported by following IEEE 802.3at standard and is used.PoE+ uses the Ethernet cable that can be designed to support more high-power PD and the 5th type of supposition use or higher class.PD up to 30W can regard two pairs of PoE+ systems as, and can regard four pairs of PoE+ systems as up to the PD of 56W.Should be appreciated that identity principle is applicable to two pairs or four pairs of systems.Usually, can support to have the more high-power PD of PoE+, making becomes possibility like WiMAX reflector, varifocal band cloud platform camera (pan-tilt-zoom camera), video telephone, Thin Client (thin clients).
In this was used, principle of the present invention at first can be used as diagnostic tool, is used to verify the Ethernet cable that links to each other with the PSE port.In one embodiment, diagnostic tool will be discerned the Ethernet cable type and use this identification to confirm how to control PoE+PD equipment.
In one embodiment, if Ethernet cable is confirmed as the 3rd type of cable, then PSE can refuse for the PoE+PD equipment of this port power to be provided.In another embodiment, this diagnostic tool can be used for expanding the potential application of PoE+PSE.For example, even if this diagnostic tool has confirmed that this PoE+PD equipment uses the 3rd type of cable to link to each other with PSE, this diagnostic tool determines whether that with continuing this PoE+PD equipment still obtains power through the 3rd type of cable.For example, diagnostic tool can be used for verifying this port confirming whether it can adapt to PoE+PD equipment, even be to be connected with this PSE through the 3rd type of cable at this port.This checking can be based on the actual characteristic (for instance, length) of cable, rather than depends on the type (for instance, the 3rd, 5 type etc.) of cable simply.
Even the resistance of the 3rd type of cable is approximately the twice of the resistance of the 5th type of cable, the 3rd type of cable also can use in PoE+ uses in some cases.PSE can use length, the V like the 3rd type of cable
PSE, V
LPower is applied to particular port and makes wise decision to what power budget of this port assignment to whether with the information such as power of PoE+PD.Effectively, the doing of the decision that this is wise PSE identification additional port of sening as an envoy to is laid, and this additional port is laid and can be benefited from PoE+, and do not rely on the characteristic of the Ethernet cable installed is not done wide restriction.
For example, consider such a case, wherein V
PSEBe 50V, P
LBe 15W, and R
CableConfirm as 15 Ω (resistance of 75 meters the 3rd type of cable).Through this group operational factor, can calculate V
L=(50+/-SQRT (50
2-4*15*15))/2=(50+/-40)/2=45V.Then can use V
PSE-V
L=I*R
CableCalculate electric current, 50V-45V=I*15 Ω obtains I=0.333A like this.Power loss in the cable is I
2* R
Cable=(0.333A)
2* 15 Ω=1.66W.In this example, the total power budget of PSE port is 15W+1.66W=16.66W.When this group service conditions was the permission service conditions of the 3rd type of cable, PSE can select the PoE+PD on the 3rd type of cable that power is provided.
Under another kind of situation, if V
PSEBe 50V, P
LBe 20W, and R
CableConfirm as 20 Ω (resistance of 100 meters the 3rd type of cable), then can calculate V
L=(50+/-SQRT (50
2-4*20*20))/2=(50+/-30)/2=40V.Then can use V
PSE-V
L=I*R
CableCalculate electric current, 50V-40V=I*20 Ω obtains I=0.5A like this.No matter power loss (I
2* R
Cable=(0.5A)
2* 20 Ω=5W) whether can accept, the electric current I of 500mA has been higher than the limiting value electric current 350mA of the 3rd type of cable.In this case, PSE can select not that the PoE+PD on the 3rd type of cable provides power.
In another embodiment, suppose P
LBe 15W, and R
CableConfirm as 20 Ω (resistance of 100 meters the 3rd type of cable), and V
LBe known as 43V.Should be appreciated that, can use multiple communication mode, like some form of layer 2 communication, with V
LBe sent to PSE from PD.In this case, can use I=P
L/ V
L=15W/43V=0.349A calculates electric current.In this case, PSE can select to PoE+PD power to be provided through the 3rd type of cable.
Shown in these examples, whether PSE can to providing power to make wise decision through the 3rd type of cable to PoE+PD.This dynamic process is a far reaching, and the classification of whole the 3rd type of laying can not be got rid of from the PoE+PD that supports in classification.Though above provides example seldom, will be appreciated that the PoE+ system can use the information of its available any amount, detect the 3rd type of potential cable and lay.Usually, information available is many more, verifies that the 3rd type of cable can be used for PoE
+The possibility of using is big more.
Traditional P oE+ laying based on the 5th type of cable also can benefit from principle of the present invention.When considering the power budget that is assigned to the PoE+PSE port especially like this.
Lay for traditional 802.3af, the worst condition power loss of cable is P
Loss=(350mA)
2* 20 Ω=2.45W.This worst condition power loss is based on the electric current restriction of the 350mA of each PD, and this electric current restriction is because 20 Ω resistance of cable and patch panel restriction and the 3rd type of Ethernet cable.In PoE+ that can double electric current used, for example the power loss of the 5th type of cable can be P
Loss'=(700mA)
2* 10 Ω=4.9W=2*P
LossShown in this brief calculation, the power loss/rice during PoE+ lays can be the twice that traditional 802.3af lays, even makes cable resistance descend 50%.Because this reason, in the process of the worst condition power loss that reduces port, the identification of the 5th type of cable length can cause more significant power budget saving.For example, if the length of cable is confirmed as 25m, the power loss that then can calculate electric current and be 700mA is 1.225W.This is starkly lower than the power loss of the 4.9W when the length of the 5th type of cable of supposition is 100 meters.Certainly, when use as about above-mentioned V
PSE, P
LAnd R
CableWhen estimating actual current, the power loss of the estimation in this cable can further reduce.
In addition, power loss is calculated in the type of cable information that also can from PoE+ lays, obtain and is benefited.At this, confirm that whether ethernet type is superior to the resistance estimation that the 5th type of cable (for instance, the 6th or 7 type of cable) will be used to reduce cable, therefore further reduces the power loss of estimating.
It is that PoE high coverage rate (PoE-BR) is used that the 3rd of the principle of the invention is used.In PoE-BR used, PD can be connected with the PD with the above Ethernet cable of 100m.For example, definable PoE-BR uses to support up to 500m or farther distance.
In PoE-BR uses, confirm that the Ethernet cable type will provide simple benefit in expansion existing P oE uses.Consider, for example provide the 802.3af of the worst condition of power to use through the PD that surpasses on the 3rd type of cable of 100m.In this worst condition was used, the resistance of cable was about 20 Ω.If replace with the 5th type of cable, meeting under the condition that resistance is 20 Ω so, more low-resistance the 5th type of cable can allow longer length.For example, the 5th type of cable supposing worst condition comprises the connector that is positioned at media relevant interface (MDI) link middle part.As shown in Figure 4, the connector that is positioned at media relevant interface (MDI) link middle part can be incorporated into the middle part of MDI link through inclusion, wall outlet or the analog of cross connect system.In this case, the resistance of Ethernet cable is about 12.5 Ω.Estimate that according to this under the situation of the resistance that meets 20 Ω, the length of the 5th type of cable can expand to 100m*20/12.5=160m.Like this, even without any operation information of PoE system, the simple identification of type of cable can cause to apart from the PD greater than 100m power being provided.
Usually, the increase of distance between PSE and the PD (for instance, up to 500m) has caused potential operation wider in the PoE-BR system.This range of operation makes uses the worst condition operational factor to provide system specifications to become difficult more.For example, suppose that the PoE-BR standard supports the 3rd type of cable.When being in this situation, the resistance of cable can be appointed as 20 Ω-100 Ω.Significantly, during like the listed power budget of table 1, the cable resistance of supposing 100 Ω worst conditions is unpractical in identification.Owing to when the resistance of cable is designated as 10 Ω-50 Ω, also need allow the 5th type of cable standard.
Therefore characteristic of the present invention is, part is laid based on specific port at least, for the PD in the PoE-BR application provides power.For example, suppose V
PSEBe 51V, PD will consume constant 12.95W, and the voltage of PD is 37V, in this case, can calculate electric current I=P like this
L/ V
L=12.95W/37V=0.34A.Then can calculate the maximum resistance R of cable like this
Cable=(V
PSE-V
L)/I=(51V-37V)/0.34A=41 Ω.
Has maximum resistance R
Cable=41 Ω, PoE-BR system can confirm then whether specific port adapts to such laying.For example, if definite use is the 3rd type of cable, the PD that reaches 205 meters that then can adjust the distance provides power.Similarly, if definite use is the 5th type of cable, the PD that reaches 410 meters that then can adjust the distance provides power.
Cable length information can be used for confirming the power loss of cable.For example, if confirm that the 5th type of cable is 400 meters, suppose that its resistivity is 10 Ω/rice, the resistance of cable is about 40 Ω so.Then rated output loss P like this
Loss=(340mA)
2* 40 Ω=4.62W.The total power budget of this port is 12.95W+4.62W=17.57W so.
By on know that because PoE-BR uses the distance range served, the power budget of its port can be done bigger variation.For example, if what use is 120 meters the 5th type of cable, the resistance of cable is about 12 Ω so.Rated output loss P like this
Loss=(340mA)
2* 12 Ω=1.39W.The total power budget of this port is 12.95W+1.39W=14.34W.Under both of these case, (just, 17.57W-14.34W) benefit that basic worst condition hypothesis is brought is observed rather than depended on to clear type and/or the length to cable of difference table to the 3.23W of power budget.
Since during PoE-BR uses cable resistance in a big way, the minimum voltage of PD can decrease with respect to traditional 802.3af PoE.For example, the minimum voltage of supposing PD is low to moderate 30V.When type of cable and length were known, the value of this 30V can be used for verifying the laying of given port.Should be appreciated that, compare that to start voltage, PD has higher requirement with minimum voltage.In the process of start, PD maybe be occurred and whole power can not be obtained, the voltage of PD is almost identical with PSE like this.
Suppose V
PSE=50V, P
L=12.95W, and R
Cable=45 Ω (resistance of 450 meters the 5th type of cable).For this group operational factor, can calculate V
L=(50+/-SQRT (50
2-4*12.95*45))/2=(48+/-30)/2=30.5V.Calculating V
LAfterwards, the PoE-BR system can be according to the definite voltage V that calculates of minimum voltage so
LWhether available.In this case, V
L=30.5V is higher than minimum limit value, so the PoE-BR system can verify this port under these service conditionss.About being assigned to the power budget of this port, the PoE-BR system can use V
PSE-V
L=I*R
CableCalculate electric current, 50V-30.5V=I*45 Ω obtains I=0.433A like this.Power loss in the cable can be calculated I like this
2* R
Cable=(0.433A)
2* 45 Ω=8.44W.So, the total power budget of PSE port is 12.95W+8.44W=21.39W in this example.
Use principle of the present invention, can be minimized in the excessive negative effect of using worst condition resistance in the PoE-BR link.At first, practice thrift the power budget that is assigned to particular port, therefore increased the total capacity of PSE.Secondly, when the worst condition that uses cable resistance was estimated, PSE can verify the port laying that is excluded.
By on can know that one or more characteristics of measuring Ethernet cable make the resistance of PoE system estimation Ethernet cable, and finally estimate the actual power dissipation of Ethernet cable.For the ease of such estimation, more such characteristics of Ethernet cable can be measured by the PoE system, as inserting loss, cross-talk, length etc.The insertion loss of Ethernet cable, cross-talk, measurement of length are to be used for estimating cable resistance and and then to estimate the example of characteristic of the power loss of cable.
Usually, different type of cables are inserted loss in the standard definition that certain frequency range meets himself.Different decay takes place according to the type of cable in the signal of telecommunication that on cable, transmits.Inserting loss is the function of frequency and cable length, to all fine definition of each type of cable.In order to confirm type of cable, the PoE system can send with predetermined frequency component one, a plurality of or continuous impulse in cable.At receiving terminal, decay magnitude (magnitude attenuation) and phase distortion can be measured by the PoE system, then these information and cable length are made up to confirm type of cable.
In one embodiment, can close link partner (link partner), and cable is broken off line side or opposite (transceiver) side from transformer.In this case, but all retroeflection is to the transmitting terminal with identical polar in nearly all subsidiary pulse, and these pulses will be experienced the insertion loss corresponding to the cable length of twice.Fig. 8 shows the example of the insertion loss of the 3rd type of cable can be used for measuring 100m and the 5th type of cable.
In another embodiment, can close link partner, and cable is shortened line side or opposite (transceiver) side from transformer.As shown in Figure 5, be shorter than A-at this A+.In this case, but all retroeflection is to the transmitting terminal with opposite polarity in nearly all subsidiary pulse, and these pulses will be experienced the insertion loss corresponding to the cable length of twice.
In another embodiment, can close link partner, and with two cables to from another to breaking off and shorten, to constitute a loop (A+ shorten to B+ and A-shortens to B-) for instance.This can realize in line side or opposite (transceiver) side of transformer.In this case, nearly all subsidiary pulse all can postback the right transmitting terminal of difference, and these pulses will be experienced the insertion loss corresponding to the cable length of twice.
In another embodiment, can temporary unlatching link partner to send predetermined pulse.In this case, these pulses will be experienced the insertion loss corresponding to cable length.
Cross-talk is similar to the insertion loss, and different type of cables meets the cross-talk standard that himself defines in the certain frequency scope.It is right to adjacent line that the signal of telecommunication that on cable, transmits injects different noises according to the type of cable.Cross-talk is the function of frequency and cable length, to all fine definition of every kind of type of cable.In order to confirm type of cable, system can send with predetermined frequency component one, a plurality of or continuous impulse in cable.At receiving terminal, decay magnitude and phase distortion can be measured by system, then these information and cable length are made up to confirm type of cable.
Existing two types cross-talk: near-end crosstalk (NEXT) and far-end crosstalk (FEXT).For NEXT, noise injects from one or more local reflectors, and injects from one or more far-end reflectors for the FEXT noise, is that NEXT or FEXT or their combination all can be used for confirming type of cable.Fig. 9 shows the example that can be used for measuring the 3rd type of cable and the 5th type of cable.
In one embodiment, can use domain reflectometer (TDR) directly to confirm cable length.In an optional embodiment, the data that can generate in the measuring process of inserting loss based on the roundtrip of use injection signal are come indirectly definite cable length.At this, the time interval and the cable length that send and receive above-mentioned pulse are linear scale.Just can calculate cable length through propagation velocity and the time interval are multiplied each other, then with its divided by 2 to calculate round trip delay time.
As stated, can use various cable characteristics to confirm type of cable, and and then the resistance and the power loss of definite cable.Should be appreciated that the further feature outside more than describing also can be used for the resistance and the power loss that make the PoE system confirm cable.Do not consider that the measurement data used, PoE system can use this Data Dynamic ground to regulate the configuration of PoE system or some aspect of operation is a far reaching.As implied above, this characteristic of the present invention can be used in the various application.
But Fig. 6 shows the embodiment of the PoE environment 600 of embodiment of the present invention principle.As shown in the figure, environment 600 comprises PHY 630-1 to 630-N, and each PHY all can be connected to Ethernet switch 620.Each PHY can comprise one or more ethernet transceivers, and only only illustrating among the figure, the distribution of a transceiver links to each other with PHY 630-N.Each PHY also can be connected with CPU 610, for brevity, only shows from the single connection of CPU 610 to PHY 630-N.In one embodiment, CPU 610 is integrated on the single chip to 630-N with PHYs 630-1 with Ethernet switch 620.In another embodiment, Ethernet switch 620 is integrated on the single chip and with CPU to 630-N with PHYs 630-1 and opened in 610 minutes, and can communicate by letter with CPU 610 through serial line interface.Also show the PSE 640 that power is provided through the central branch road of the transformer that illustrates in the PoE environment 600.As shown in the figure, PSE 640 links to each other with CPU 610 through the optical isolator 650 of the boundary that is used to insulate.
In order to describe the operation of PoE environment 600 in carrying out principle process of the present invention, can be with reference to the flow chart shown in the figure 7.As shown in the figure, the flow process of Fig. 7 starts from step 702, and at this, the transceiver among the PHY 630-N is measured the line characteristics of the Ethernet cable that links to each other with PHY 630-N.In one embodiment, said measurement is used in the Echo Cancellation aggregation procedure that the echo canceller module of CPU 610 control carries out, confirm to adopt to inserting loss, cross-talk and cable length.In step 704, the line characteristics measured value that transceiver is obtained sends to CPU 610.
Next, in step 706, CPU 610 uses the line characteristics measurement data to confirm type of cable and length.In one embodiment, in step 708, subsequently type of cable and length information are offered PSE 640.At this, it should be noted that PSE can be set confirms the type and the length of cable to use the line characteristics measurement data.
In step 710, no matter type of cable and the length where confirmed, PSE 640 can utilize it to confirm its influence to PoE system configuration and/or operation.This influence is confirmed to consider type of cable and length, and then is considered the resistance and other PoE system parameters such as V of cable
PSE, P
L, V
LDeng combination.Should be appreciated that this impact analysis can realize that this system component can be used for diagnosing Ethernet cable by any such system component, determine whether and to confirm the power budget of the specific PSE port of adjusting etc. to the PD power supplied.Usually, this impact analysis can be based on being transmitted, found by suitable system component or one or more parameters of hypothesis, like cable resistance, cable current, V
PSE, P
L, V
LFor example; One or more parameters can be based on system specifications (for instance; IEEE 802.3af), use measurement data to obtain one and a plurality of calculated values (for instance, obtaining cable resistance) from type of cable and the length confirmed; Or receive from other system component that (for instance, PD is sent to the V of PSE with this parameter information
L).
According to the review to aforesaid description, various aspects of the present invention are obvious for a person skilled in the art.Though more than disclose a plurality of notable feature of the present invention; After having read disclosed the present invention, to those skilled in the art, the present invention may be implemented in a variety of ways or carries out will be conspicuous; Therefore, foregoing description should not regarded the eliminating to other embodiment as.Likewise, should be appreciated that, be for the purpose of description in the term and the wording of this use, and should do not regard limitation of the present invention as.
Claims (10)
1. a POE system is characterized in that, comprising:
The power consumption equipment detection components is used for the existence of detection equipment, and said power consumption equipment links to each other with power-supply device through Ethernet cable;
The cable detection assembly is used to measure the electrical characteristic of said Ethernet cable, and this electrical characteristic comprises insertion loss, cross-talk and the length of said Ethernet cable; And
Power controller is used for confirming based on the electrical characteristic of said measurement the type of said Ethernet cable, the power division of controlling said power-supply device port based on the type and the length of said Ethernet cable.
2. POE according to claim 1 system is characterized in that, the insertion loss of said Ethernet cable, cross-talk, measurement of length are to be used for estimating cable resistance and and then to estimate the power loss of cable.
3. POE according to claim 1 system; It is characterized in that; System sends with predetermined frequency component one, a plurality of or continuous impulse in cable, and measures decay magnitude and phase distortion at receiving terminal, with this metrical information and cable length combination with definite type of cable.
4. POE according to claim 1 system is characterized in that, uses domain reflectometer TDR directly to confirm cable length.
5. POE according to claim 1 system is characterized in that, based on the data of using the roundtrip of injecting signal to generate in the measuring process of inserting loss, comes to confirm indirectly cable length.
6. POE according to claim 1 system is characterized in that, the resistance of the said Ethernet cable that said power controller is confirmed based on the said type of using said Ethernet cable is controlled said power division.
7. a POE method is characterized in that, comprising:
In case power consumption equipment is connected to the power-supply device port through Ethernet cable, just confirm the type of said Ethernet cable according to the electrical characteristic of measuring, this electrical characteristic comprises insertion loss, cross-talk and the length of said Ethernet cable; And
Distribute power budget to said power-supply device port, the power budget of said distribution is based on the said definite type and the length of said Ethernet cable.
8. method according to claim 7; It is characterized in that; System sends with predetermined frequency component one, a plurality of or continuous impulse in cable, and measures decay magnitude and phase distortion at receiving terminal, with this metrical information and cable length combination with definite type of cable.
9. a POE method is characterized in that, comprising:
Based on the definite type that connects the Ethernet cable of power supply unit and power consumption equipment of the electrical characteristic of the said Ethernet cable of measuring, this electrical characteristic comprises insertion loss, cross-talk and the length of said Ethernet cable; And
Determine whether power to be provided based on said definite type and length to said power consumption equipment.
10. method according to claim 9 is characterized in that, said power confirms it is the Ethernet wiring to greater than 100 meters.
Applications Claiming Priority (4)
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| US85333006P | 2006-12-19 | 2006-12-19 | |
| US60/853,330 | 2006-12-19 | ||
| US11/654,023 | 2007-01-17 | ||
| US11/654,023 US7664972B2 (en) | 2006-12-19 | 2007-01-17 | System and method for controlling power delivered to a powered device based on cable characteristics |
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| CN101207290A CN101207290A (en) | 2008-06-25 |
| CN101207290B true CN101207290B (en) | 2012-02-15 |
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| CN2007101602573A Expired - Fee Related CN101345553B (en) | 2006-12-19 | 2007-12-14 | Cable diagnosis system, method and system for configuring Ethernet port |
| CN200710300819XA Active CN101207290B (en) | 2006-12-19 | 2007-12-17 | System and method for power supply of Ethernet |
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| CN2007101602573A Expired - Fee Related CN101345553B (en) | 2006-12-19 | 2007-12-14 | Cable diagnosis system, method and system for configuring Ethernet port |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| RU2594292C2 (en) | 2010-08-30 | 2016-08-10 | Конинклейке Филипс Электроникс Н.В. | Control of power transmission over ethernet set |
| CN102983982B (en) * | 2011-09-05 | 2016-08-03 | 中国电信股份有限公司 | Average voltage distribution method, system and multiport power receiving equipment |
| CN104518819B (en) * | 2013-09-30 | 2017-01-25 | 华为技术有限公司 | Twisted pair category identification method and twisted pair category identification equipment |
| US9832028B2 (en) * | 2014-09-25 | 2017-11-28 | Texas Instruments Incorporated | Automatic power budget management for power-over-Ethernet apparatus |
| US11038307B2 (en) * | 2018-05-25 | 2021-06-15 | Cisco Technology, Inc. | Cable power rating identification for power distribution over communications cabling |
| CN108957127A (en) * | 2018-06-26 | 2018-12-07 | 深圳市易飞扬通信技术有限公司 | Cable quality detecting system, method and cable quality detection device |
| CN111092445B (en) * | 2018-10-24 | 2021-10-26 | 华为技术有限公司 | Signal reliability detection method, PSE chip, CPU chip and PoE device |
| CN113597749B (en) * | 2019-03-20 | 2023-12-26 | 康普技术有限责任公司 | System and method for infrastructure management system based power distribution of power supply devices |
| CN113125877B (en) | 2021-03-02 | 2022-12-06 | 华为技术有限公司 | PD detection equipment for powered device |
| CN115941465A (en) * | 2022-12-02 | 2023-04-07 | 京东科技信息技术有限公司 | Network card configuration method and device, electronic equipment and computer readable storage medium |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US7075283B1 (en) * | 2002-06-07 | 2006-07-11 | Marvell International Ltd. | Cable tester |
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| CN1235347C (en) * | 2002-12-19 | 2006-01-04 | 华为技术有限公司 | Inter face for realizing automatic impedance matching and method thereof |
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| US7075283B1 (en) * | 2002-06-07 | 2006-07-11 | Marvell International Ltd. | Cable tester |
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| CN101345553B (en) | 2013-04-24 |
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