Comparison With Other Integrated Data and Power Standards
PoE provides both data and power connections in one cable, so equipment doesn't require a separate cable for each need. For equipment that does not already have a power or data connection, PoE can be attractive when the power demand is modest. For example, PoE is useful for IP telephones, wireless access points, cameras with pan tilt and zoom (PTZ), and remote Ethernet switches. PoE can provide long cable runs e.g. 100 m (330 ft) and deliver 12 W of galvanically isolated power. PoE-plus provides even more power.
There are competing data and power technologies. The Universal Serial Bus (USB) provides both data and power, but it is designed for short cables with a maximum length of 5 m (16 ft) and provides less than 2.5 W of non-isolated power. It is less expensive than PoE, and works well for low power peripherals such as a computer mouse, a headset/microphone or a serial port. Some peripherals, such as speakers, scanners and printers, need more power than USB can provide. IEEE 1394 (FireWire) is similar to USB but can provide substantially more power (45 W) at a distance of 4.5 m. On the other hand, USB peripherals can operate using very little power; while maintaining an Ethernet connection uses a significant amount of power.
If a device already has power available but no data link, then PoE may not be attractive. A wireless data connection such as IEEE 802.11 may be more economical than running a data cable for the device. Alternatively, there are power line communication technologies that can use power cables for transmitting data. Using some power line modems may be more economical than running a cable.
When data rate and power requirements are both low, other approaches may be viable. Mobile phones, for example, use batteries for power and antennas for communication. Remote weather sensors use very low data rates, so batteries (sometimes supplemented with solar power) and custom wireless data links are used.
Depending on the application, some of the advantages with PoE over other technologies may be:
- Inexpensive cabling
- Fast data rate
- No batteries required
- Peer-to-peer network access. Once a device is connected to the network, it is accessible to many users.
Read more about this topic: Power Sourcing Equipment
Famous quotes containing the words comparison with, comparison, integrated, data, power and/or standards:
“What is man in nature? A nothing in comparison with the infinite, an all in comparison with the nothing—a mean between nothing and everything.”
—Blaise Pascal (1623–1662)
“In everyone’s youthful dreams, philosophy is still vaguely but inseparably, and with singular truth, associated with the East, nor do after years discover its local habitation in the Western world. In comparison with the philosophers of the East, we may say that modern Europe has yet given birth to none.”
—Henry David Thoreau (1817–1862)
“Science is intimately integrated with the whole social structure and cultural tradition. They mutually support one other—only in certain types of society can science flourish, and conversely without a continuous and healthy development and application of science such a society cannot function properly.”
—Talcott Parsons (1902–1979)
“This city is neither a jungle nor the moon.... In long shot: a cosmic smudge, a conglomerate of bleeding energies. Close up, it is a fairly legible printed circuit, a transistorized labyrinth of beastly tracks, a data bank for asthmatic voice-prints.”
—Susan Sontag (b. 1933)
“Of Heaven of Hell I have no power to sing,
I cannot ease the burden of your fears,
Or make quick-coming death a little thing,
Or bring again the pleasure of past years,”
—William Morris (1834–1896)
“A generation which has passed through the shop has absorbed standards and ambitions which are not of those of spaciousness, and cannot get away from them. Everything with them is done as though for sale, and they naturally have in view the greatest possible benefit, profit and that end of the stuff that will make the best show.”
—Alexander Herzen (1812–1870)