What is PoE?
Power over Ethernet, or PoE, describes any of several standards or ad hoc systems that pass electric power along with data on twisted pair Ethernet cabling. This allows a single cable to provide both data connection and electric power to devices such as Wireless Access Points (WAPs), Internet Protocol (IP) cameras, and Voice over Internet Protocol (VoIP) phones.
There are several common techniques for transmitting power over Ethernet cabling. Three of them have been standardized by Institute of Electrical and Electronics Engineers (IEEE) standard IEEE 802.3 since 2003. These standards are known as alternative A, alternative B, and 4PPoE. For 10BASE-T and 100BASE-TX, only two of the four signal pairs in typical Cat 5 cable are used. Alternative B separates the data and the power conductors, making troubleshooting easier. It also makes full use of all four twisted pairs in a typical Cat 5 cable. The positive voltage runs along pins 4 and 5, and the negative along pins 7 and 8.
Alternative A transports power on the same wires as data for 10 and 100 Mbit/s Ethernet variants. This is similar to the phantom power technique commonly used for powering condenser microphones. Power is transmitted on the data conductors by applying a common voltage to each pair. Because twisted-pair Ethernet uses differential signaling, this does not interfere with data transmission. The common-mode voltage is easily extracted using the center tap of the standard Ethernet pulse transformer. For Gigabit Ethernet and faster, both alternatives A and B transport power on wire pairs also used for data since all four pairs are used for data transmission at these speeds.
4PPoE provides power using all four pairs of a twisted-pair cable. This enables higher power for applications like Pan–Tilt–Zoom (PTZ) cameras, high-performance WAPs, or even charging laptop batteries.
In addition to standardizing existing practice for spare-pair (Alternative B), common-mode data pair power (Alternative A) and 4-pair transmission (4PPoE), the IEEE PoE standards provide for signaling between the power sourcing equipment (PSE) and powered device (PD). This signaling allows the presence of a conformant device to be detected by the power source, and allows the device and source to negotiate the amount of power required or available.
HDCVI technology supports up to 4K ultra high definition resolution. With 4 times the pixels of 1080P, it presents a true-to-life image with impressive clarity that captures even the tiniest of details. As the very first technology to bring 4K-over-coax to the market, HDCVI comes with a complete product portfolio.
HDCVI is an over-coaxial cable video standard that enables long-distance HD video transmission over a wide range of application scenarios at a friendly cost
HDCVI technology can simultaneously transmit 4 signals (audio, video, data, and power) over 1 coaxial cable. HDCVI cameras offer high resolution video, support audio input or built-in mic, and communicate with the HCVR through control signals. Moreover, Power-over-Coax (PoC) technology has been made available for integrated power-supply requirements. HDCVI cameras are able to cover multiple signal acquisitiondemands, further simplifying the installation and deployment of surveillance systems.
PoC, or Power over Coax (coaxial cabling) technology, utilizes a single coaxial cable to transmit both data and power between front-end cameras and back-end video recorders (DVRs), as opposed to using one cable to send power to a camera and another one to transmit data back to recording units.
Based on standard protocol, Hikvision’s PoC technology features long transmission distance. It reduces time and costs on the electrical “prep” work by using plug-and-play products, so camera access and power are available right away. The excellent stability also makes backing up the DVRs and cameras possible by way of uninterruptible power supplies (UPS). PoC technology is widely used in scenarios such as buildings, stores, classrooms, gyms, and gardens, for both new installations and upgrades or renovations with legacy systems.
An intelligent algorithm self-developed by Hikvision that can greatly decrease the bitrate of video based on a standard H.265 codec. Hikvision’s H.265+ is such an optimized video encoding technology based on the standard H.265/ High efficiency Video Coding (HEVC) format.
With H.265+, video quality nearly matches that of H.265/HEVC but reduces the transmission bandwidth and storage capacity required, due to three key technologies — prediction encoding, noise suppression, and flexible bitrate control.
It demonstrates incredible improvements in bandwidth reduction, data storage efficiency, and video content analyses.