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CONVERGED INFRASTRUCTURE
for remote powering , and was backwards compatible to 15.4 W PoE .
In 2010 , the HDBaseT alliance introduced Power over HDBaseT ( PoH ). HDBaseT was developed to deliver video , audio and control over 100Mb Ethernet and power . PoH is based on the 802.3at standard , and adapted to enable delivery of up to 100W using all four pairs of a data cable . Cisco also developed its own PoE solution in 2011 UPOE – Universal PoE , which sourced up to 60W i . e . double PoE +. Again , all four pairs of a Cat5e cable were used enabling up to 51W at the device .
This opened up PoE to new devices such as IP Turrets , VDI terminals , compact PoE switches , Health Care systems , LED lighting & Building Management Gateway devices , enabling a great deal of infrastructure convergence and paving the way for smart buildings . Manufacturers of many devices have been quick to seize on the benefits of PoE and UPOE manufacturing partners include BT , Samsung and LG .
In 2013 , IEEE announced the intention to create a new standard : 802.3bt . The goal was a standard for PoE , also using all four pairs and supporting 10GBASE-T . The standard when published will define two new levels of PoE : Type 3 for up to 60W and Type 4 for up to 100W . 100W opens up PoE to new applications such as next generation WiFi , Digital Signage , point-of-sale devices , laptops & larger displays . Publication of 802.3bt is expected early next year .
" While PoE will undoubtedly continue to evolve and support a greater range of devices and applications , many of the next generation of powered devices will require higher wattage "
The evolution of PoE Up until 2009 , power was limited to 12.95Watts ( PD – Power at the Device ) as can be seen in the infographic above . PoE was therefore limited in use to powering mainly three types of devices :
• VoIP phones
• Wireless Access Points
• Fixed IP Cameras
The IEEE has been pivotal in facilitating the progress of PoE . The original PoE standard IEEE 802.3af was adopted in 2003 and standardised at 15.4 W ( PSE – Power Sourcing Equipment ) of DC power , supporting 10BASE-T and 100BASE-T . Power was delivered over two of the four twisted pairs of a category 3 cable or better .
With demands for increased power to enable a wider range of PoE devices , still primarily VoIP phones , Wireless Access Points and PTZ cameras , in 2009 the IEEE introduced 802.3at and was known as the PoE + standard . Power was increased to 30W ( PSE ) - 25.5W at the device while supporting up to 1000BASE-T over a 100m category 5e or 6 channel . The standard still only used two of the four pairs
Maintaining safety and performance While PoE will undoubtedly continue to evolve and support a greater range of devices and applications , many of the next generation of powered devices will require higher wattage . At increased power draw and over multiple bunched cables , design considerations regarding temperature of cables must be factored in . The appropriate cabling needs to be deployed to avoid adverse effects on performance . Cabling standards bodies and manufacturers have conducted many studies to address safety and performance issues . High temperatures can increase insertion loss and consequently impact performance or require reduction of the designed channel length permitted .
Temperature can also impact bit error rates and increase power dissipation in the cabling . TIA and ISO are working in tandem with IEEE , and have updated standards to address cabling recommendations in relation to supporting 4-pair PoE to 802.3bt . ISO / IEC TS 29125:2017 Information Technology ( Telecommunications Cabling Requirements for Remote Powering of Terminal Equipment ) and the TIA equivalent , TSB-184-A ( Guidelines for Supporting Power Delivery Over Balanced Twisted-Pair Cabling ) both offer guidance on maximum bundle size for different category cables based on installation conditions and the maximum power delivered . More consideration will need to be given to both the temperature rating of the cable , the ambient temperature and the potential rise above ambient ( restricted to 15 ° C in TIA standards ).
Measures to mitigate performance degradation risks include :
• Designing to the latest TIA or ISO standards and respecting bundle size accordingly
• Installing cables on open rather than closed containment wherever possible e . g . cable basket
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