The latest iteration of IEEE 802 standard promises to provide more Power over Ethernet (PoE) than ever before. Simultaneously, the established devices are getting increasingly efficient and new low-power devices are entering the market every day.
This convergence is enabling a host of new devices to be powered via ethernet cables, giving a huge boost to the smart building and the wider Internet of Things in Buildings (BIoT). It all starts with a yearlong effort to assess rapidly diversifying ethernet bandwidth needs around the world.
The IEEE 802.3 standard’s initial approval came about in 1983, long before the connectivity revolutions currently taking place had been envisioned. It was 20 years later when PoE first emerged as an IEEE 802.3af standard in 2003, at that time power output was only 13 W at 350 mA and could only be transferred over a distance of 100 m. This was sufficient for powering certain VoIP systems and CCTV cameras, as well as RFID and some types access control.
The 2003 standard was not strong enough to power video conferencing, Wi-Fi routers, pan-tilt-zoom or heated cameras, and door interlock systems, which require greater current, but in 2009, the IEEE ratified the 802.3at iteration, which increased power to 25.5 W at 600 mA and brought a host of new devices into the PoE bracket. Many more devices, however, require even more power and remained tethered to the 120-V AC mains. The upcoming version, 802.3bt, offers a maximum power output of about 90 W, which accommodates many more types of devices.
802.3bt has come at just the right time to give a boost to the IoT, as the proliferation of connected devices reaches new levels. The number of devices that will be able to be powered by technology outlined in the upcoming PoE standard is also much greater because of the increased efficiency of the devices themselves. All manner of sensors will become easier to install, for example, encouraging buildings and cities to make their spaces more aware, while devices for access, security, environmental control and other applications will all get a boost from enhanced PoE.
“The diversity of demands on Ethernet networks has exploded in the years since the first IEEE 802.3 Ethernet Bandwidth Assessment report was published in 2012, and now it is time to reassess industry’s current and foreseeable bandwidth needs around the world,” said John D’Ambrosia, chair of the IEEE 802.3 Industry Connections New Ethernet Applications Ad Hoc. “I am excited to learn more about the use-case models that are unfolding and emerging applications that are taking shape worldwide.”
In fact, it could be said that the smart building is the main beneficiary and even the key target of the latest standard. In addition to the benefit offered by increased power via ethernet cables, PoE also allows every device to have its own IP address, which is fundamental for buildings that manage thousands of sensors and other devices from a central management system. This is all just about the implementation of the standard, of course, the technology itself has been around for some time.
Linear Technology, for example, which is now part of Analog Devices, developed its 90 W LTPoE++ technology almost a decade ago. LTPoE++ has been successfully utilized with the company’s controllers since then. It was actually said to be a driving force behind the development of IEEE’s 802.3bt standard. With efficiency greater than 94%, LTPoE++ based PD controllers have been meeting the needs of high-power applications such as wireless data systems, outdoor security cameras, and public information displays, among other things.
By releasing a standard these new PoE capabilities can better serve the ever-growing needs of data networks around the world. New application areas are constantly being considered that might leverage IEEE 802 standards in their networks from wireless, through twisted-pair cabling, to fiber-optic cabling solutions. With the 802.3bt evolution, IEEE hopes to better address the needs of all of these areas, based upon their fair, open and transparent development process.
“As with all technology advances, 802.3bt will need to prove it can deliver on its promise while handling more dc power than its predecessors, while keeping heat generation in check, along with other potential problems,” says Barry Manz contributing editor for Electronic Design. “However, thanks to IoT, there’s no shortage of “things” that PoE can power in the coming years.”