High Power PoE. Updating Power over Ethernet Standards for More Power, Speed, and Efficiency

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1 P E R F O R M B E YO N D E X P E C TAT I O N S A B E R K -T E K W H I T E P A P E R High Power PoE Updating Power over Ethernet Standards for More Power, Speed, and Efficiency W W W. B E R K T E K.COM

2 Page Table of Contents The Evolution of PoE... Enhancements for Emerging Applications... Setting the Stage for Next Generation Standards... Understanding the Power-Heat Relationship... The Impact of Higher Power on Cabling... Testing that Replicates the Real World... Impacts to Installation Methods...9 Conclusion... 0

3 High Power PoE Page For over a decade, Power over Ethernet (PoE) and PoE+ have provided organizations with a simple and convenient option for powering devices such as IP phones and low-power cameras. Now, as technology continues to evolve, the structured cabling infrastructure is being used to support an increasingly diverse and power hungry set of devices whose appetites exceed the current capabilities specified by today s PoE+ standard. This paper provides updates on developments in the standards, expected deployment arenas and their respective applications. Further discussions on the impact to structured cabling, and insights to enable planning for future PoE and structured cabling deployments are provided. It is clear that the developing PoE ecosystem will continue to grow through new applications and will be better serviced by cabling with improved power delivery capabilities. The Evolution of PoE PoE first emerged in 00 with the IEEE 0.af standard and was originally built around Category and Category specifications, to deliver approximately watts to a powered device through 0mA of current with Ethernet speeds up to 00Mbps. The standard allowed for delivering power on two combinations of two pairs as two different alternatives Mode A or Mode B (Figure ). However, the standard did not permit power simultaneously over all four twisted pairs. In Mode A, pairs - and - have both power and data flowing over them while pairs - and - are unused. In Mode B, all pairs are utilized, but power and data are separated, with data being carried via pairs - and - and power using - and -. In 009 major changes were made to PoE with the ratification of 0.at. These included specifying Category cabling as the minimum cable grade required to support the new PoE+ standard. With this ratification,. watts and 00mA of current could now be delivered to devices. As illustrated in Figure, all four pairs are utilized to transmit data in order to support 000BASE-T transmission, but Mode A and Mode B power distribution remains consistent with the previous standard. POWER SOURCING EQUIPMENT POWER UNUSED POWER POWER SOURCING EQUIPMENT Mode A + - POWER SOURCING EQUIPMENT + - Figure : 0.af delivers.9w and 0/00BASE-T Mode B Mode A POWER UNUSED RX RX TX TX POWER UNUSED UNUSED POWER SOURCING EQUIPMENT Figure : 0.at delivers W and 000BASE-T Mode B

4 Page Figure : High Power PoE Applications Enhancements for Emerging Applications In the intervening years since the last update, non-standardized solutions have been developed to address specific challenges. For example, some solutions may deliver continuous power without the IEEE specified handshake or perhaps require additional converters at the device. Others may deliver 0 watts over four pairs, maintain compatibility with 0.at, and yet not be 0.at standards-compliant due to the explicit exclusion of -pair power delivery. Finally, there are the proprietary solutions that deliver higher wattages but are not compatible with the current standardized equipment. In March 0, the IEEE held a Call for Interest focused on evaluating the need to develop a higher power standard. This need has been driven primarily by emerging applications that require power in excess of what is supported by today s standards. The markets with identified needs span today s infrastructures and include areas such as healthcare, retail, building management, IP turrets, thin clients, video conferencing, IP security cameras, and industrial networks. Figure above depicts the overall potential market for high power PoE ports, with especially substantial growth in building management opportunities through 0. Significant growth is also projected for industrial automation and thin clients. Setting the Stage for Next Generation Standards As these opportunities expand, so do the expectations for standardization, which center primarily on delivering as high a power output solution as can be managed. To do this will require increased system efficiencies to address the limitations and shortcomings of a DC power distribution system. Early generations of networking equipment lacked power reserves and were unable to provide the full watts of power across all ports simultaneously, causing issues with large scale deployments. In future developments, this power supply limitation must be mitigated through greater power supply capacities and smarter equipment to ensure an adequate power supply for building management functions. The new standard must also service Ethernet devices such as 0.ac wireless access points that will require additional power as well as faster network speeds. To address this, the IEEE 0.bt task force convened in January 0 to begin the standardization process. Comprised of electronic component and cabling manufacturers, the task force has the responsibility of specifying new levels of power delivery while assuring compatibility with previous generations of equipment. Standardization is still underway, but it is possible to project the form that this technology will

5 Page take. It is anticipated that higher power -pair solutions will be developed along with -pair delivery configurations as shown in Figure. The use of all four pairs in the cable for POWER SOURCING EQUIPMENT the highest levels of power delivery will increase efficiency by cutting the potential delivery losses in half. With these parameters in mind, the standardization bodies have a number of complex goals set before them. First, the standard must exhibit backward compatibility with the previous generations of the PoE standards, IEEE 0.af and 0.at. Additionally, the new standard must support 0GBASE-T operation with possible new speeds such as.gbps and Gbps to enable wireless access points that are aggregating the traffic of multiple users and multiple devices. Finally, this technology will need to utilize all four pairs simultaneously in order to maximize power distribution efficiencies. An initial objective of delivering a minimum of 9 watts to the powered device was adopted in order to deem the project successful. However, the growing deliverable list has become quite diverse and complicated through the initial course of draft development. There are two primary active components as defined within the standard. The power sourcing equipment (PSE) represents the end span switches or mid-span injectors Figure : A proposed -pair power delivery solution while the powered device (PD) represents the device at the opposite end such as a camera, thin client or building management device. There are now 9 proposed classes for the PSE ranging from watts to 90 watts, as illustrated in Table. Due to cabling losses, the minimum available power at the PD is slightly less. (Note: Class 0 and Class are grouped together because they are required to deliver the same W to the powered device. Class 0 can be declared or used as a default state when the powered device does not indicate its classification. It is presumed that an undeclared device will need the maximum W.) Class Table : Power Sourcing Equipment Classifications Min Power from PSE (Watts) Min Guaranteed Available Power at PD (Watts) 0 and In order to further maximize power delivery or energy conversation, the task force is considering the complexities of evaluating the cabling losses in each link. Specifically in the case of short links, the PSE may conserve and repurpose the power for other links, or allow a PD on a short link to reserve and utilize the unused power that is budgeted for a full 00-meter length deployment. These system design characteristics give added importance to the development of cabling specifically designed for use in multiple applications with the goal to improve overall system efficiencies. For the delivery of power and data, higher grades of cable will provide the best performance and efficiencies.

6 Page Understanding the Power-Heat Relationship While the IEEE standard is in development, several manufacturers and technical consortiums are working to establish the boundaries of technical feasibility. It has been demonstrated in a lab environment that it is possible to supply at least 0 watts over a 00-meter 0GBASE-T link. However, increasing power delivery increases current flow, resulting in an increase in heat generation within the cabling infrastructure. It is expected that this increased power delivery will significantly impact cable bundle temperatures, and the de-rating factors originally recommended in 009 in the TIA TSB-: Guidelines for Supporting Power Delivery Over Balanced Twisted-Pair Cabling will need to be revised. As a result, the standards bodies of TIA, ISO and CENELEC are investigating the impact of delivering an average of amp per pair within the cable and revising their recommendations. In general, cable temperature rise with PoE deployment is a function of several factors:. Gauge Size: Larger copper conductor reduces the resistance and allows for easier current flow, generating less heat.. Twist Rate per Inch: Higher categories of cable generally have increased pair twist rates. This increased twist rate creates a longer electrical path per given cable length, as depicted by Pair A in Figure. This results in increased resistance to current flow and increased heat generation.. Current: As current increases, so does heat generation.. Thermal Insulation/Diffusion: This refers to the ability to shed or disperse the generated heat to the outside environment. Cables unable to cool will increase in temperature until equilibrium is reached.. PoE Deployment Density: Heat generation increases as the number of PoE drops increase within a pathway. A B A B Figure : Increasing twists (Pair A vs. Pair B) increase DCR The Impact of Higher Power on Cabling There are three major reasons for an interest in heat: environmental heat loading to the facility, safety, and the impact to electrical performance. Environmental heat loading This can be a fairly straightforward calculation as it is based upon the number and length of the drops in conjunction with the cable unit resistance and electrical current traversing the pairs. Deploying large amounts of high power PoE may increase the HVAC requirements for a facility and raise the average ambient and peak temperatures experienced by the cabling. Safety Excessive temperatures from heating may lead to melting insulation and the immediate failure of infrastructure components. However, elevated temperatures also age components at a faster rate, and the jackets and insulations may become brittle when exposed to elevated temperatures for extended periods. This may result in cracking or segments of insulation falling off the cable. Flame retardant properties may also be reduced as vital components within the compounds degrade or evaporate. Cables have temperature ratings, such as 0 or C, which are designed to ensure their operation over their lifetime. However, failing to account for thermal gain from PoE deployments may drive a cable above its safety listing when installed in a hot environment. Given the increased current load and the increased heat generation that comes along with it, those specifying cabling infrastructures should consider cabling with rating of at least C, particularly for those areas with an already elevated ambient operating temperature. Electrical Performance Heat increases the losses within the cable and reduces the effective reach of copper cabling, making a 00-meter reach with minimally compliant cable unobtainable. Therefore ambient conditions as well as thermal gains must be considered when calculating length reductions for system operations.

7 Page Testing that Replicates the Real World The complexities of real world installations create an infinite number of possible test scenarios. Today s LAN cables are subjected to a wide range of installation conditions, such as extremely large bundles, covered trays and conduits. Care must be taken not to underestimate the impact of cable heating due to increased power delivery. However, the converse is that the overestimation of temperature rise can lead to the creation of onerous installation or manufacturing requirements, which could limit the potential of the technology and severely curtail its deployment. Cable tested in an environment that resembles a vacuum flask with little outward heat convection shows alarmingly high heat gains, but this scenario does not reflect the installations of today s infrastructure. To accurately determine the effect of heat on a cable s performance, testing scenarios must replicate real-world installation environments as closely as possible. To this end, the TEK Center at Berk-Tek has both modeled and tested the temperature profiles of numerous sizes of cable bundles in preparation and support of the standardization efforts for the next generation of PoE. The TEK Center recently published a Test Report entitled Next Generation Power over Ethernet and Temperature Testing. This report examines temperature rise when power is applied to different types of cable in open and closed trays, in addition to cable inside conduit. The TEK Center evaluated the performance of various types of construction from several different manufacturers, and included Category e through Category a. To avoid confusion, this paper will focus on one representative product from each category tested: Figure : A -cable bundle under test The 9-cable bundle was built from seven bundles of and represents the approximate depth of a loaded cable tray as depicted below in Figure. It should be noted that this bundle would closely approximate the deployment of 0 cables addressing ten fully populated -port patch panels. All bundles were subjected to currents representing various projected power levels of future PoE deployments, and the resultant temperature increases were measured. Thermal gains were calculated by measuring the temperature increase of the inner-most cable after the bundle reached equilibrium (- hours) and comparing it to the recorded ambient temperature. The center of the bundle provides a good approximation of the temperature gradient expected across a fully loaded wire tray. Category e: LANmark-0 TM Category : LANmark TM -000 Category A (unshielded): LANmark TM -0G Category A (foil-isolated): LANmark TM -XTP The testing focused on two bundle sizes of and 9 cables. The quantity (depicted in Figure ) was selected to match testing being done by the industry standards bodies, and because of its approximate size to cable bundles servicing and port panels. Figure : A 9-cable bundle under test

8 Page These results were compared to a TEK Center model for predicted heat generation. Figure below represents the comparison of the highest temperature rise of the various cable constructions with respect to the size of the bundle when carrying 000mA of current across each pair, which closely approximates the conditions of Class power delivery. The model provides a high degree of correlation between the measured and predicted data in this test configuration. In general, as a cable s electrical performance improves, the thermal performance also improves. Specifically, the TEK Center s testing showed:. Higher category cables experienced less temperature rise than lower category cables.. In larger bundles, LANmark-0G (Category UTP) performed similarly to LANmark-000 (Category A UTP). This is attributable to the construction of a Category A UTP cable, specifically its higher twist rate and increased jacket thickness, both of which are needed to meet internal and external crosstalk requirements.. The best solution for high PoE deployment is the foil isolated Category A product, LANmark-XTP. The XTP cable exhibits significantly less temperature increase with 00W PoE deployment. In a 9 cable bundle, the XTP cable is approximately C ( F) degrees cooler than the LANmark-0 Category e cable. This is a significant difference, and will become even more critical as more devices demand higher levels of power delivery over the network. This reduced temperature rise with the XTP cable reinforces its suitability to high power PoE deployment as it helps to ensure the cable reach is maximized under adverse conditions. Center of Bundle Temperature Rise vs. Cable Count at Amp/Pair (00 Watt PoE) Figure : Modeled vs. measured temperature rise of innermost cable in bundle in an open tray

9 Page 9 Impacts to Installation Methods In anticipation of moving beyond the delivery of just IP traffic, the TEK Center has been investigating the performance of cables in various installation scenarios. Open tray represents just one instance of many different installation environments. The TEK Center has tested several possible deployment scenarios, including energizing only a portion of the cable bundle, and enclosing the cables in various types of conduit. Each test scenario represents a distinctly different deployment option and has a varying impact upon the resultant temperature. Energizing a Portion of the Cable Bundle To represent a group of power-delivering cables insulated by other cables in a cable tray, the TEK Center built -cable bundles of the various categories and surrounded them with groups of identical -bundle designs to build large 9-cable bundles. Only the center cables were energized with 000mA of current to represent a installation with only an approximate % PoE deployment. Figure 9 shows a conception cross-section of this bundle. The cables under test exhibited a temperature rise when compared to tests of the same categories in -cable bundles in the open tray. The comparative measurements are shown in Table. Again, the LANmark- XTP cable exhibited significantly less temperature rise when compared to standard Category a constructions. Figure 9: Inner cables of 9-cable bundle energized Table : Temperature rise ( C) for the center cable lengths energized with 000mA in a large bundle of 9 cables Cable In Open Tray In Large Bundle % Change HyperPlus e CMP UTP.9.9 % LANmark-000 CMP UTP. 0. 0% LANmark-0G CMP UTP.9 0. % LANmark-XTP CMP UTP.. %

10 Page 0 Testing in Conduit The TEK Center also measured the heat rise of cables placed inside various conduits. In order to approximate a loaded conduit, an 0-cable bundle of HyperPlus e was built and energized with 000mA to measure the impact of conduit installation. The bundle was first built and measured in the open tray for a reference temperature rise. HyperPlus e was selected as a worst case study as the smaller diameter allowed for more cables to be installed in the conduit. Larger cables would reduce the number of cables in the bundle and reduce the overall heat generated making the HyperPlus e the upper bound of expected heat rise. Figure 0 shows the bundle inside. EMT conduit, and Table denotes a - C difference in temperature rise in an open tray versus inside conduit. It is interesting to note that the metallic conduit results in a higher temperature rise instead of acting as a heat sink and helping to disperse heat. This is attributed to the inner non-conductive coating of the conduit acting as an insulating layer preventing heat from dispersing into the ambient environment. Table : Temperature rise for 0 HyperPlus e cable length bundle (000mA) Figure 0: 0 cables measured in conduit HyperPlus e CMP UTP Temp Rise ( C) In open cable tray. In. PVC conduit 9.9 In PVC conduit 0. In. EMT conduit. Conclusion As the ecosystem of powered devices continues to grow, power delivery and heating characteristics will soon join other traditional cable performance parameters as a factor in the selection of cabling. Cabling must be able to ensure the delivery of increasing power and data speeds in adverse conditions over its expected lifetime. To maximize the capabilities and efficiencies of tomorrow s system, the correct cabling infrastructure will need to be implemented. Selecting a higher grade of cabling will reduce heat generation within the cabling infrastructure, minimize the impact to IP traffic traversing the network and reduce the aging effect that heat can have on insulating materials. Over time, as more devices are connected and powered over the network infrastructure, the selected solution employed in the network will have a growing impact on network performance. Cables with temperature listings of at least C will be better suited to resist the aging impacts of elevated ambient temperatures over time. It is important to think about the expected lifespan of the network infrastructure, and the total lifecycle costs of selecting one option over another. In the vast majority of network IT projects, the cabling cost is negligible relative to the total project costs. Yet it can have a very significant impact on your network s performance for years to come. Finally, foil-insulated cables such as the Berk-Tek LANmark- XTP product will provide increased robustness with the best deployment options for PoE due to the minimized thermal gains inherent in its design. Metallic tape on the XTP product allows heat to transfer out of the cable much more efficiently than cable designs without this type of construction. This will allow for maximum ease, performance and flexibility when planning for PoE deployment. The LANmark-XTP product has been specially designed to be Berk-Tek s best performing product for PoE applications.

11 PERFORM BEYOND EXPECTATIONS Contact Information Corporate Headquarters White Oak Road New Holland, PA USA In Canada, please contact: Nexans Canada Inc. 0 Allstate Parkway Markham, Ontario LR 0Z Canada 00-- This stamp certifies that all testing was performed, reviewed, and approved by highly trained, experienced engineers dedicated to studying and developing solutions for future network infrastructures. Located in New Holland, Pennsylvania, The TEK Center at Berk-Tek is comprised of several labs and a technology showcase. By employing industry-leading research, advanced testing procedures, and sophisticated modeling for emerging technologies, the applications and system labs translates expanding network requirements into leading edge cabling solutions that perform beyond the standard. Similarly, to exceed your expectations in real world applications, the materials lab develops advanced proprietary materials and process technologies that result in superior application performance that you can see and hear. The technology showcase displays the results of these labs along with industry-available equipment shown in actual segment usage, such as data center, security, and enterprise spaces. The TEK Center is a part of an extensive global R&D network with similar laboratories found throughout Nexans Inc.