What’s So Great About Ethernet?

Ethernet cable has become the universal backbone for residential computing, communications, entertainment and home-control networks. With the advent of Power over Ethernet (PoE) technology that same Ethernet cable is increasingly being used to simultaneously deliver power to digital home devices, from WiFi wireless access points and notebook computers to video surveillance cameras, game consoles and other broadband entertainment products.

PoE improves consumer convenience and energy efficiency by enabling both power and data to be distributed over the same cable. With PoE, the home network's various devices can be located wherever the consumer wants to use them, and not just where power outlets are available.

The same PoE technology that has become the power backbone for business' Voice over IP (VoIP) and wireless data and security networks is now bringing benefits to the broadband digital home.

During 2009, the industry completed its work of enhancing PoE technology so it could support even more devices with higher-power needs. The previous industry-standard technology was limited to delivering 12.95 watts to any given device. However, devices such as video phones, 802.11n WiFi access points and pan-tilt-zoom cameras require 15 to 30 watts.

A group known as the IEEE 802.3at Task Force worked to enhance PoE so that it could power devices requiring up to 25.5 watts. The resulting IEEE P802.3at PoE+ standard also included extensions so powered devices could negotiate their own power requirements. With PoE's new capabilities, it became possible to power WiMAX Subscriber Stations (SS), fiber-to-the-home (FTTH) optical network terminators (ONTs), 3G pico and femto cells and even laptop computers.

Some of these applications require as much as 50 watts. This is also now possible because the latest PoE+ technology can deliver power over all four Ethernet Cat 5 pairs. Four-pair powering enables 60 watts to be delivered with a much more efficient, 600mA current, rather than the 1.2A required for two-pair PoE technology. As a result, for the same 60 watts at the source, 51 watts can be delivered over Cat 5 cable with a four-pair solution, compared with 42 watts for a two-pair solution.

Additionally, this four-pair configuration can be used to power two-pair devices with 30 watts of power, while dissipating up to half the power and consuming almost 15 percent less energy than two-pair solutions - a savings of approximately $25/year per powered device, assuming energy costs of $0.10 per kilowatt hour (KWH).

Hitting Home Technology
PoE has already helped pave the road into the broadband digital home. Today, many telecommunications carriers use PoE to power technologies such as FTTH and WiMAX that provide the entry points for ultra-fast home Internet access. Increasingly, PoE is also being used to power 3G femto cells so they can be deployed on a home's rooftop or in its attic to enhance Internet-access performance and coverage.

Inside the home, PoE can now be used to power the home network's computers, video phones and network cameras, as well as home automation devices. Additionally, PoE can power inkjet printers and supplemental network storage for home multimedia libraries.

Plus, as the power consumption of today's digital consumer electronics products continues to drop, it will be possible to use PoE to power, for instance, a netbook designed with high-performance, low-power CPUs. All the consumer will need is an RJ-45 jack with PoE to power these products.

Once products are connected via PoE, they can be monitored and reset, if necessary, by remotely powering them down and up again. Additionally, the intelligent PoE power network can maintain operation during a power failure by providing backup electricity on a priority basis to the network and selected connected devices. By taking advantage of this capability with high-power PoE+, consumers can plan to keep their desktop computers alive so they can maintain home-network operations during power outages.

WiFi access points have their own particular powering needs. Those featuring IEEE802.11n multiple input multiple output (MIMO) technology, with its multichannel implementations, require approximately 20 watts of power. Smart use of PoE allows consumers to use these access points in a reduced operation mode when only the standard-power PoE mode is available, or in full mode when the high-power PoE technology is present. This allows homeowners to balance coverage versus power when striving for a "green" installation, in which not every port supplies full power.

There are many other "green" PoE opportunities for homeowners and the CE installers who serve them. The technology can be used to set up systems for managing entry/exit lights as an alternative to today's timer systems, with the additional benefit of enabling backup powering schemes for emergency lighting in the home during a power failure.

PoE also is ideal for "smart" lighting and related applications for residences and vacation homes, since there is no need for permitting. The technology is low-voltage and not UL-mandated, and, with the latest high-power capabilities, there are numerous home command and control possibilities. Finally, PoE provides a significantly more efficient alternative to traditional AC-to-DC converter solutions, and offers the opportunity to turn a home's wall outlets into USB plugs for powering all of a home's various electronics devices with significantly less energy drain.

As more and more devices and services are introduced into the next-generation broadband digital home, it is becoming increasingly difficult to power them. The latest high-power PoE technology offers an extremely convenient and efficient powering option, with the added benefits of remote management and backup capabilities, for both wired and wireless networks used for a variety of broadband digital home services and applications.