SCS. PoE Technology. - Milind Tamhane Vice President Manufacturing D-Link (India) Limited D-Link (I) Ltd. All rights reserved.

Transcription

1 SCS PoE Technology - Milind Tamhane Vice President Manufacturing D-Link (India) Limited

2 Introduction Power over Ethernet (PoE) is a revolutionary technology that integrates data and power on standard Ethernet wiring. It supplies reliable, uninterrupted power to IP telephones, Wireless LAN and other Ethernet devices via commonly used Cat 5 cable infrastructure. PoE saves time and money by avoiding the complexity and expense involved in the installation of separate Ethernet infrastructure, power cabling and AC outlets. It even doubles as an Uninterrupted Power Supply (UPS) for individual devices, and along with added installation simplicity, significantly enhances network reliability

3 Advantages

4 Applications

5 IEEE 802.3af Standards This standard governs the functioning of PoE Devices. Provides 48 volts DC over two out of four available pairs on a Cat 5 cable with a maximum current of 400 milliamperes for a maximum load power of 15.4 watts. This permits its use not only with 10BASE-T and 100BASE- TX, which use only two of the four pairs in the cable, but also with 1000BASE-T (Gigabit Ethernet), which uses all four pairs for data transmission.

6 PoE process PD Detection is performed to decide whether the terminal is PoE enabled PD Classification determines PD s consumed power level prior to its ignition Gradual Startup to avoid data interference of high frequencies Real-Time Protection & Power Management during operation to ensure system safely PD Disconnection is followed by a fast power shutdown

7 Classes of operation

8 Architecture

9 Cabling Schematic

10 Endspan schematic

11 Midspan schematic

12 What about higher power requirements???

13 PoE Plus IEEE recommended the creation of a task force to study the enhancements to PoE PoE is governed by IEEE 802.3af standard IEEE 802.3at born to create PoE Plus

14 IEEE 802.3at objectives At least 30W power supplied to the PD (As much as economically feasible) Backward compatible to IEEE 602.3af Support for Gigabyte Midspan Potential support for 10 Gigabit Ethernet (802.3an) PoE plus PDs that require more than 12.95W to operate must give indication to user when connected to 802.af PSE PoE plus PDs that require 12.95W or less to operate must be able to be powered by an 802.af PSE PD MIB to be created

15 IEEE802.3at agreements Cabling: Cat 5e required Voltage: PSE voltage from 50V to 57V DC ( for 802.3af standards PSE voltage from 44V to 57V DC) Current level: 720mA assuming cable temp=45c or less (for 802.3af standards current levels between 350mA to 400mA ) Power Feeding: 2-pairs and 4-pairs possible 2-pairs Medium Power: PSE 36W o/p, PD 29.5W i/p (for 802.3af standards 2-pairs Medium Power: PSE 15.4W o/p, PD 12.95W i/p) 4-pairs High Power should be based on 2x2-pairs: PSE 72W o/p, PD 59W i/p Detection: 25K signature resistance not changed Port startup: parameters not modified PD delays consumption of power above 12.95W Classification Classic Method enhancement: 2-Event Classification Layer-2 Classification Method: 1000Base-T Midspan in scope of IEEE Base-T Midspan power interface can be Type A (4,5,7,8) or Type B (1,2,3,6)

16 IEEE802.3at Schedule Nov-2004: Study Group Created Jul-2005: IEEE802.3 recommended creation of Task Force Sep-2005: IEEE802.3at Power over Ethernet Enhancements Task Force Created Mar-2007: Orlando, FL (plenary) last meeting Draft 0.1 available at_d0p1.pdf May-2007: Geneva, Switzerland (interim) next meeting Q2 2008: Official Expected Completion of work Q3 2008: Estimated completion of work

17 Concluding remarks! There is no doubt that the PoE technology is going to transform the way electrical equipment is powered in the most economical way. Why not become an early adapter yourself, and start using IEEE 802.3af Power over Ethernet?

18 Thank You!!! Any Questions???