What does the ADSL modem mean? often have netizens to consult this problem, ADSL modem is a modem, commonly known as "cat", users of ADSL broadband after (telephone line internet), must use ADSL modem this equipment, can normal internet.
Why do you use ADSL Modem?
ADSL Broadband is the transmission of signals through telephone lines, and the telephone line can only transmit "analog signal", but the computer can recognize and deal with the "digital signal", there is a problem, "digital signal" is not directly transmitted through the telephone line, to solve this problem, You have to use the ADSL modem (modem).
The function of ADSL modem
ADSL Modem (Modem) The main role, so that digital signals on the computer can be transmitted on the telephone line. The working principle of ADSL modem is this:
1, the computer has access to the Internet request, the modem will first computer digital signal into analog signals, and then through the telephone line to the broadband operator's server.
2, the broadband operators there are similar "ADSL Modem" equipment, will receive the analog signal into digital signals, and then transmitted to the Internet.
3, the user needs to receive the data on the Internet is, the digital signal on the Internet will first be transmitted to the broadband operator's server, the server will be the user needs to receive the digital signal into the analog signal, and then transmission through the telephone line to the user's ADSL modem, modem to receive the analog signal into digital signal , and finally transmits it to the user's computer.
Therefore, when the user handles ADSL broadband (telephone line) Internet, must install an ADSL modem (modem) can normal Internet, if the lack of modem, then the computer is unable to access the Internet through the telephone line.
When broadband ADSL broadband, broadband operators (Telecom, Unicom) will provide a free ADSL modem to the user, but if the use of broadband, the modem needs to be returned to the broadband operators. Of course, some local broadband operators to provide the modem will charge a certain fee, in short, different regions, the policy is not the same.