многоуровневое название：The Inaccurate Statement Regarding Power Over Ethernet Standards
Введение:
Питание через Ethernet (PoE) has revolutionized the way power is delivered to devices in various applications, such as network switches, IP cameras, and wireless access points. It provides a convenient and cost-effective solution by integrating power and data transmission over a single Ethernet cable. Однако, there is one statement regarding PoE standards that is inaccurate, which will be clarified in this article.
я. Understanding Power Over Ethernet (PoE)
А. Определение и цель:
– PoE refers to the technology that enables devices to receive power and data through an Ethernet cable.
– Its purpose is to eliminate the need for separate power cables, simplifying installation and reducing costs.
Б. Преимущества PoE:
– Flexibility in device placement, as PoE eliminates the dependency on power outlets.
– Ease of installation and maintenance, as PoE eliminates the need for electrical expertise.
– Экономия затрат, as it reduces the overall infrastructure and equipment costs.
II. PoE Standards and Their Importance
А. IEEE 802.3af Standard:
– This standard was introduced in 2003 and provides up to 15.4 watts of power to devices.
– Used primarily for low-power devices such as IP phones, беспроводные точки доступа, и камеры наблюдения.
– Requires only two copper pairs for power and data transmission.
Б. IEEE 802.3at Standard (PoE+):
– Established in 2009 to address the increasing power demands of devices.
– Provides up to 30 watts of power to devices.
– Suitable for devices requiring higher power, such as PTZ cameras, системы контроля доступа, и тонкие клиенты.
– Requires all four copper pairs for power and data transmission.
С. IEEE 802.3bt Standard (4PPoE):
– Recently ratified in September 2018 to meet the power requirements of emerging technologies.
– Provides up to 90 ватт мощности, allowing for the support of high-power devices like LED lighting systems, pan-tilt-zoom cameras, and virtual reality equipment.
– Utilizes all four copper pairs for power and data transmission.
III. The Inaccurate Statement
The inaccurate statement is that \”all PoE standards, including IEEE 802.3af, 802.3в, and 802.3bt, require all four copper pairs for power and data transmission.\” This statement is incorrect.
Объяснение:
While the 802.3at and 802.3bt standards do require all four copper pairs for power and data transmission, the 802.3af standard only necessitates two copper pairs. The 802.3af standard, also known as PoE, is limited to providing up to 15.4 ватт мощности. Поэтому, it can efficiently transmit both power and data using only two copper pairs.
Заключение:
Power over Ethernet standards play a crucial role in delivering power to devices with data transmission over Ethernet cables. Однако, it is important to note that not all PoE standards require all four copper pairs for power and data transmission. The inaccurate statement claiming that all PoE standards require four pairs has been clarified in this article, highlighting the distinct requirements of each standard.
