ActiveEthernet

1、Brief introduction POE (Power Over Ethernet) refers to the existing Ethernet cabling infrastructure Cat.5 do not make any changes to the case, for a number of IP-based terminals (such as IP telephones, wireless LAN access point AP, network cameras etc.) to transmit data signals at the same time , bu

2、t also to provide DC power supply such equipment technology . POE technology to ensure the normal operation of the existing network to ensure the safety of the existing structured cabling while minimizing costs+. PoE is also known as LAN-based power supply system (PoL, Power over LAN) or Active Ethe

3、rnet (Active Ethernet), sometimes referred to as Power over Ethernet , which is using the existing transmission standard Ethernet cable to simultaneously transmit data and the latest standard specification of electric power , and to maintain compatibility with existing Ethernet system and user . IEE

4、E 802.3af standard is based on the new standard Ethernet POE power supply system , which increases the relevant standard power supply via the network cable directly on the basis of IEEE 802.3 , the expansion of the existing Ethernet standards , is the first international on power distribution standa

5、rds.+ + work process+ When PSE supply terminal device arranged in a network , POE Power over Ethernet working process is as follows. +1. Detection A beginning , PSE equipment in the port output low voltage cable terminal until it detects a connection to a support IEEE 802.3af standard powered end de

6、vices.+ 2. PD Premises Equipment Category When the receiving end device detects the PD , PSE device may be classified as a PD , and PD devices needed to assess this power loss.+ 3. Start Power In a configurable time ( generally less than 15s) start period , PSE equipment starting from a low voltage

7、power supply to the PD device , providing up to 48V DC power supply. +4. Power Supply To provide a stable and reliable 48V DC to PD device , the device does not meet the PD across 15.4W power consumption. +5. off If the PD device is disconnected from the network , PSE will quickly ( generally within

8、 300 400ms of ) stopping power for the PD device , and repeat the detection process to detect the cable terminal is connected PD devices.+ + Leveraging the ubiquity of standard Ethernet and IP technologies, an active Ethernet network installs the associated network electronics at the subscriber netw

9、ork edge instead of the CO or head-end. Such devices can be configured to be deployed on a pole, vault, fiber strand or even in an MTU/MDU basement. While the cost per subscriber in a PON-based network becomes more economical with more subscribers, a standard OLT (optical line terminal) can only sup

10、port up to 32 subscribers in a serving area. This means that to serve one more customer, a carrier has to bear the expense of another OLT. Alternatively, an active network can run over longer distances and can be built out on a pay-as-you-grow basis by providing each subscriber with 100 Mbps to 1 Gb

11、ps of dedicated bandwidth.+ +PON and Active Ethernet AdvantagesPON is more flexible+Optical network can be point-to-point or split in the field+Outside plant architecture can be active or passive+Standard supports legacy services : RF video and TDM+Can be deployed in areas with limited fiber cable o

12、r conduit+Consumes much less CO space and 1/3 as much power at the CO +Supports TDM based T1s required for delay and latency sensitive servicesAE is better suited to business+Fiber network is dedicated point-to-point+Better suited for very high bit rate service (100mbs+) to medium and large business

13、es , ultra broadband residential+Optical reach 40 km and beyond+Layer 2 only model favored by businesses+ubiquity+n. 普遍存在；到处存在+If experiments show the road is short and easy then it would be a strong argument for the ubiquity of life in space. +如果实验表明这是很容易简便的，它将成为“宇宙中生命是普遍存在的”最有力的证据。+Today, confront

14、ed with the ubiquity of the internet, we need a whole new set of skills to navigate the information-laden environment we inhabit. +今天，面对着无处不在的互联网，我们需要一整套新的技术为我们在我们所栖居的这个满载信息的环境中导航。+vault +n. 拱顶；撑竿跳；地下室+vi. 跳跃；成穹状弯曲+vt. 做成圆拱形；撑竿跳过+pole vault 撑竿跳高 ; 撑杆跳高 ; 撑杆跳 ; 撑杆跳高+But a year later, at the world cha

15、mpionships in Australia, she won a gold medal on the vault and signaled her dominance of the apparatus. +然而一年以后的澳大利亚世锦赛上，程菲在跳马项目上摘取了金牌，并开始宣称自己在该项目上的统治地位。+Extrapolating current trends, some forecasters predict that Chinas economy will vault ahead of Americas in 15 years. +一些预言家根据目前的趋势推断，中国经济将在未来的15年来跳跃到美国的前面去。+str