To build a new broadband community, we have many options to choose from, including Ethernet access solutions, ADSL access solutions, Cable Modem and HFC network solutions, and fiber access solutions. Faced with these access schemes, how do we choose? Different schemes have different application occasions. Let us first look at the characteristics of several access schemes.
High-speed Ethernet solution
In the broadband access technology, Ethernet has become the most widely used local area network transmission method. It uses baseband transmission and realizes 10M / 100M / 1Gbps network transmission through twisted pair and transmission equipment. The development of Ethernet access technology has now become quite mature, from the original shared 10Mbps transmission technology on the coaxial cable to the current transmission technology and switching technology of 100Mbps or even 1Gbps on twisted pair and optical fiber. Certainly Ethernet technology will continue to develop at a faster rate.
advantage:
· The technology is mature, and already has a huge network foundation and long-term experience and knowledge;
· Wide range of applications, compatible with all popular operating systems;
· Good performance-price ratio, strong expandability, easy installation and high reliability.
Disadvantages:
· For communities that have already been built, it is necessary to re-wire the network structure, which is troublesome, especially for users in high-end communities, which may be unacceptable.
ADSL access solution
ADSL is a relatively mature one of many DSL technologies at present, and it is an asymmetric DSL technology. The so-called asymmetric means that the uplink rate of the subscriber line is different from the downlink rate. On the user's loop, a loaded telephone line is used to transmit information asymmetrically at high speed. ADSL was not originally designed for broadband access, but for applications such as high-speed data communication and interactive video. ADSL access uses an ADSL modem at the user end to transmit data over a telephone line. It uses a frequency above 40KHz to transmit data, but it is still used to transmit voice below 40KHz. Therefore, using ADSL can always connect to the Internet without affecting the use of the phone.
advantage:
· Can make full use of the existing telephone network to reduce construction and maintenance costs, and has no impact on the telephone business.
Disadvantages:
· Higher requirements on line quality, when the line quality is not high, it will affect the use and it is difficult to promote it;
The data transmission rate is relatively slow compared to other broadband access technologies.
Cable Modem and HFC network solutions
Cable Modem and HFC are a method of using the cable TV network to achieve user broadband data access. The solution is to use optical cables for spatial division of uplink and downlink signals for independent transmission. After the optical contacts, the coaxial cable uses a frequency division system for common cable transmission. The system terminal CM completes the upstream and downstream signal processing of the data signal. HFC is the earliest type of broadband access technology that has matured and entered the market. It has the characteristics of broadband and relatively economical. HFC can provide 60 analog broadcast TVs, at least 2 telephones per household, and data services up to 10 Mbit / s in an optical node coverage area of ​​about 500 households. .
advantage:
· The cable modulator does not rely on ATM technology, but directly adopts IP technology;
· No need to re-wire, only the original line is modified to reduce costs;
· Equipment management, billing, security, bandwidth management, etc. have advantages.
Disadvantages:
· At present, the selectivity and maturity of products cannot be compared with Ethernet technology.
0-10V/PWM/RX Dimming Driver
Drivers with dimming capability can dim the LED light output over the full range from 100% to 0%. Dimming drivers can dim LEDs by reduction in the forward current, pulse width modulation (PWM) via digital control, or more sophisticated methods. Most dimming drivers operate using the PWM method. With this method, the frequency could range from a hundred modulations per second to as high as hundreds of thousands of modulations per second, so that the LED appears to be continuously lighted without flicker.
At present, the most commonly used LED dimming power: LED thyristor dimming power, LED 0 / 1-10V dimming power, PWM dimming power supply. Other dimming works by controlling the current and voltage, the frequency of the output to achieve the LED dimming function.
10V Dimmable Led Driver,Led Pwm Driver,Constant Current Driver Dimmable
ShenZhen Fahold Electronic Limited , https://www.fahold.net