The Impact of Higher Power PoE++ on Twisted-Pair Structured Cabling in Modern Building Design

Transcription

1 The Impact of Higher Power PoE++ on Twisted-Pair Structured Cabling in Modern Building Design

2 Agenda Introduction What is it & What is coming? The Impact Why is it important? Recommendations & Summary

3 PoE Power over Ethernet 802.3af Standard PoE Type 1: 15.4/12.95W Published in Watts Powering Watts Powered 2 Pair Powering Alternative A (1-2, 3-6 pairs), Alternative B (4-5, 7-8 pairs) 350mA per pair 802.3at Enhanced PoE or PoE+ - Type 2: 34.2/25.5W Published in Watts Powering 25.5 Watts Powered 2 Pair Powering Alternative A (1-2, 3-6 pairs), Alternative B (4-5, 7-8 pairs) 600mA per pair 802.3bt PoE++ Type 3: 60/51W Started late 2013 expected ratification late 2017/early Watts Powering 51W Powered Alternative naming 4PPoE, Cisco UPoE (non standard) 600mA per pair (all pairs) 802.3bt PoE++ - Type 4: 100/70W Expected ratification late 2017/early Watts Powering 71W Powered Alternative naming 4PPoE, Cisco UPoE (non-standard) 900mA per pair (all pairs)

4 Power over Ethernet - Applications

5 Power over Ethernet Current Design Considerations Mandatory Two Pair Powering Current Type 2 operation requires Class D, or better, cabling as specified in ISO/IEC 11801:1995 with the additional requirement that channel DC loop resistance shall be 25 Ω or less. These requirements are also met by Category 5e or better cable Two alternatives exist A & B and are determined by pairs energised. A PSE device shall implement Alternative A, Alternative B, or both. While a PSE may be capable of both Alternative A and Alternative B, PSEs shall not operate both Alternative A and Alternative B on the same link segment simultaneously

6 Power over Ethernet Alternative A 1,2 & 3,6 Alternative B 4,5 & 7,8

7 Power over Ethernet What does 802.3bt PoE bring? As we have said, current Type 2 operation requires Class D (Category 5E), or better. At this time prior to ratification this is till the same Class D or better However, we are now energising all 4 pairs So do we now look towards a higher Class of Link? Which do we choose? A PSE device determines upon handshake with the end device what the power level is, based upon the end device s requirement. 2.5 & 5GB Ethernet will also be supported The End Device Equipment may determine the cable type selection

8 Power over Ethernet Other Developments Cisco UPoE 60 Watts, 4 Pair Powering Recommending Category 6 A HDBase-T 100 Watts, 4 Pair Powering HD AV application Limits on Bundle Sizes Limits on Distance Only Supports 100Mb Ethernet Type 4 PPoE operation possibly adopted by HDBase-T Alliance *Current Standards STILL say Class D or higher Category 5E*

9 Future Strategies Mitigation Strategies could be required Containment Designs will be influenced Maximum link length may be affected All cabling has in the past been designed to operate at 20 C what does this mean for legacy cabling adopting PoE++? Does a diverse approach to cabling types look likely? Multiple types for different disciplines Cat 6A more applicable for High PoE equipment? CCS has done more independent testing of all cable types to establish capabilities Results have varied from complete failures in extreme conditions to no problems with others The main issue is HEAT

10 Power over Ethernet The Effects of Heat Heat is a major factor in favour of specifying Screened Solutions There will be many Mitigation Strategies outlined in TR EN Some may include: Shorter horizontal cable runs Use of Mid-span devices Shorter final cables Reduced bundles sizes Larger Containment Fields Segregated/Separated Containment Fields This will effect the design dramatically

11 Power over Ethernet The Effects of Heat

12 Power over Ethernet The Effects of Heat

13 Power over Ethernet The Effects of Heat The impact of this could mean that systems installed to handle a 90m PL could: Only deliver 80m or less whilst still being standards compliant Performance could fluctuate depending on devices in use.

14 Power over Ethernet Philosophies Summary and Recommendations so far All Testing to date has shown certain key factors have influence: Insulated/Unventilated spaces perform worse Conductor Size Cable Size So Consider: Specifying Screened Cables Loose Lay of cable is beneficial Containment size could be critical Standards Compliance now will be a factor in the future

15 Thank You Any Questions?