1 poe plus enabling ip convergance over twisted pair cabling
TRANSCRIPT
1
PoE Plus
Enabling IP convergance over twisted pair cabling
2
PoE Plus
Definition
Standards
Advantages/Drawbacks
Modelling
Cabling Options
Benefits of higher graded Cabling
3
PoE : what is it?
Power over Ethernet describes any system to transmit electrical power along with data over standard twisted-pair cable in an Ethernet network.
The IEEE802.3af standard provides the capability to deliver both power (max 12.95W) and data over standard ethernet Cat.3/Cat.5 cabling.
4
Working principle
5
USB/Firewire/PoE
Technology USB2
Firewire 800
(IEEE1394a)
PoE PoE Plus
Power transmitted
(W)5 45 12.95 25
Max length(m)
5 4.5 100 100
Data Rate 480 Mb/s 800 Mb/s 1 Gb/s 10 Gb/s?
connector
Cross section
6
Actual applications
Power supply <13W
IP phone
Webcam
Wifi Accesspoint
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Future applications?
Charge of a laptop
Providing both power supply and internet connection in trains and planes
Peripheral devices : screen, printer, home theatre…
Power backup for PC
Power supply for specific PC
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Examples of power consumption
Power needed Application
13-20W
Wifi MIMO
Biometric Access Control
Thin Clients
20-30W
RFID Readers
Video IP Phones
PTZ IP Cameras
Wimax Base Stations
Industrial Sensors
30-40W
Workgroup switches
Point of Sales
Information Kiosks
40-50W Ultraportable Laptops
50-70W Notebook Laptops
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Advantages
Advantages :
Only one cable to carry datas and power
Up to 100m
Ethernet connector standard (RJ45) is widespread
Compatible with Gigabit Ethernet (1000BASE-T)
centralized backup power
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Challenges and Answers
Learn from the challenges at the beginning and how they have been answered
Data cables are not made for this use (copper conductors are too thin, 24 AWG = diameter of 0.5106 mm)
Higher power levels over thin copper cables lead to temperature rise in cables What are the limits ?
Do we need new cables?
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Nexans Thermal Modell
3D Modelling Project in Nexans Research Center, France
Bundle 19 cables Cat6 FTP modelling
Current : 350 mA per wire
Bundle 19 cables Cat6 FTP modelling
Current : 350 mA per wire Ambient temperature = 24°C
Thermal conductivities (W/m.K) :
- air : 0.025
- copper : 400
- aluminium : 160
- insulation : 0.3
- PVC sheath : 0.1
- cross : 0.4
Thickness of alu screen : 25µm
Radiation emissivity : 0.8
Convection coefficient : 3
Parameters
Ambient temperature = 24°C
Thermal conductivities (W/m.K) :
- air : 0.025
- copper : 400
- aluminium : 160
- insulation : 0.3
- PVC sheath : 0.1
- cross : 0.4
Thickness of alu screen : 25µm
Radiation emissivity : 0.8
Convection coefficient : 3
Parameters
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Nexans Modelling Results (1)
Heating of Ethernet cable depending on the category
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Nexans Modelling Results (2)
Heating of a bundle of cat5e ethernet cables
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Nexans Modelling Results (3)
Comparison with experimental results
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24
29
34
39
44
49
54
59
0 0,5 1 1,5
Current per wire (A)
Tem
pera
ture
(°C)
T layer1
T layer1 - Comsol
19
24
29
34
39
44
49
54
-0,1 0,1 0,3 0,5 0,7 0,9 1,1 1,3 1,5
Current per wire (A)
T layer2
T layer2 - Comsol
19
24
29
34
39
44
49
0 0,5 1 1,5
Current per wire (A)
Temp
eratur
e (°C)
T sheath
T sheath - Comsol
Experimental results are given with an precision of +/- 5°C
- Power of 1A results in ~10° temperature rise in a bundle of 19 cables
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Results for Cat5e UTP cable (Worst Case)
0
5
10
15
20
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5
Current per wire (A)
Max
Tem
per
atu
re Incr
ease
(°C
)
bundle 169bundle 127bundle 91bundle 61bundle 37bundle 19bundle 71 cable
Cat 5e UTP - 2 pairs energizedAmbient temperature: 24°C Thermal conductivities [W/(m.K)] sheath (PVC) 0.1 insulation 0.3 copper 400 air 0.025 aluminium 160Radiation emissivity: 0.8
Convection coefficient: 3 [W/(m2.K)]Conductor diameter: 0,52 [mm]
Cat5e UTP usable if bundle size <100
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ISC SC25 / POE Ad Hoc Result
ISO SC25 Temp. Rise Data provided to IEEE
For 100 cable bundles Cat5 UTP minimum: all pairs energised
Temp Rise (in °C)
allowed current (mA) per pair
5° 420
7.5° 550
10° 600
12.5° 680
15° 720
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IEEE Choice
Maximum acceptable Temperature Rise = 10°
Max maximum rating for cable = 60°
Max temp for equipment / ambient temperature = 45 ° = 15° Max.
Including some tolerance finally 10° Temperature Rise accepted
Leads to limitation to 25 Watts
10° TR equals 600 mA
using 57 Volts 24/25 Watts Limitation (using 2-pairs only)
50 Watts target only achievable with 4 pairs but this is patented technology
No licenses available (PowerDesign)
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IEEE Standards
The existing standard : IEEE802.3af (PoE)
48V DC over two pairs of cat3/cat5 ethernet cable
400mA per pair
12.95W (with losses)
The future standard : IEEE 802.3at (PoE Plus)
Uses the up to four pairs of cat5e cable
57V DC
600mA per pair
Up to 25.5W
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ACHIEVEMENT
FINALLY:
POE PLUS is possible with ALL Copper LAN Cables !! IEEE Standard based on worst case CAT5e UTP
No need for ‚thick‘ cables
Big Achievement:
Run POE PLUS and IP Convergance over existing LAN cabling
..but some cabling can support it better than others..... Get around some limitations and compromises made to enable worst case
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Benefits of better cable
Let us look into benefits of better cabling. This would potentially allow
Limit the temperature rise (and save energy for cooling(?))
Tolerate higher power levels (some equipment oversubscribes)
To use larger bundles than 100 cables or even “bundles of bundles”
Tolerate environments at higher temperature without reaching the 60° limit when using PoE+
Keep maximum distances (100m)
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POE /P 2 pairs
Temperature Rise per cable grade remember to double temperature rise due to 4 pairs (IEEE) instead of 2 pair (used
in comparison these chart) Almost linear behaviour from 2-4 pair!!!
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Temp Rise per Cable Grade
Approximate Temperature Rise in 127 cable bundles
2 pairs energised with 0.35A per wire
~4 pairs energised with 0.35A per wire
IEEE standard
LANmark-5 UTP 6.25 14°
LANmark-6 UTP ~4.5 10°
LANmark-5 FTP 3.5 8°
LANmark-6 F2TP ~3 7°
LANmark-7 S/FTP 2.5 6°
LANmark-7A S/FTP AWG23
1.6° 4°
LANmark-7A S/FTP AWG22
1.1° 3°
Difference between AWG 23 and AWG 22 cables is 1° !!
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Acceptable Ambient Temperature
Maximum Peak Ambient Temp compatible with
POE +
~4 pairs energised with 0.35A per wire
Acceptable Peak Temp from Cabling Point of
view(Operating range)
UTP Cat.5 14° 46°
LANmark-6 UTP 10° 50°
LANmark-5 F1TP 8° 52°
LANmark-6 F1TP 7° 53°
Cat.7 S/FTP 6° 54°
LANmark-7A 4° 56°
LANmark-7A 1500 3° 57°
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Tolerate higher power levels
0
5
10
15
20
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5
Current per wire (A)
Max
Tem
per
atu
re Incr
ease
(°C
)
bundle 169bundle 127bundle 91bundle 91 AWG22bundle 61bundle 61 AWG22bundle 37bundle 37 AWG22bundle 19bundle 19 AWG22bundle 7bundle 7 AWG221 cable1 cable AWG22
Cat 7 SFTP - 2 pairs energizedAmbient temperature: 24°C Thermal conductivities [W/(m.K)] sheath (HFFR) 0.4 insulation 0.3 copper 400 air 0.025 aluminium 160 (40µm)Radiation emissivity: 0.8 Convection coefficient: 3
[W/(m2.K)]Conductor diameter: 0,59 [mm] 0,64 [mm] AWG22
Cat7A cable would allow to run ~ double power level
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Larger Bundle Size
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 201 7 19 37 61 91 127 169 217 271 331 397 469 547 631 721 817 919 1027 1141 1261
Relation of Cabling Grade and Size of Cable Bundle
0
5
10
15
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
No of layers in bundle
Max
Tem
pera
ture
Incr
ease
(°C)
Cat6 UTP
Cat5 FTP
Cat6 FTP
Cat7 S/FTP
Cat.7A S/FTP
Cat7A AWG22
Cat.6 UTP Extrap.
Cat.5 FTP Extrap.
Cat.6 FTP Extrap.
Cat.7 Extrap.
Cat.7A Extrap.
Cat.7A AWG22 Extrap.
Estimation of 4 pairs energizedAmbient temperature: 24°C
AWG 2310 bundels = 331 cables
AWG 2210 bundels = 331 cables
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Impact on distance
UTP Insertion Loss
Reduces by -0.6%/degree C
Example: +10° for UTP 90m - 6% = 84,6 m link length
Example: 60° for UTP 90m - 24% = 68,4 m link length
FTP Insertion Loss
Reduces by -0.2%/degree C
Example: +10° for FTP 90m - 2% = 88,2m link length
Example: 60° for FTP 90m - 8% = 82,8 m link length
All International Standards specify insertion loss requirements at 20° C and have quantified a small increase of attenuation of less than 0.2%/degree C for shielded cable and up to 0.6%/degree C for unshielded cable.
In High Temp envronments use higher cable grade to ensure 100m distance (application dependend f.ex. Cat5 app over Cat6 cabling)
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Impact for Office Cabling
High Impact estimated for Office Cabling where a frequent use of POE/P can be expected
Devices like VoIP Telephones, Sensors, Printers, thin clients, new generation laptops require pontially fully energised large bundles of cabling
Bundles Size in horizontal cabling = typically 100 FD, often larger than 100 cables
1 Floor of 50 users equals 150 cables at 3 drops /users
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Summary
POE/P is a key technology to enable IP Convergence
Cat5e UTP cabling is required as a minimum
10° temperature rise at 600mA per pair
Max. bundle size = 100
Better cabling Higher Grade (Cat 6 and Cat7) or shielded cable allows to
Lowering the expected temperture rise
Use larger bundles sizes
Tolerate higher power level
Save energy for cooling in comms rooms
Enable full distance of 100m