Dalam sistem HFC digunakan signal sinusoid analog untuk membawa informasi. Signal yang mengandung informasi, umumnya mempunyai energi rendah sehingga perlu ditmpangkan pada suatu signal sinusoid berenergi tinggi yang disebut sebagai carrier, agar informasi tersebut dapat dikirimkan menempuh jarak yang jauh. Menurut IEEE, modulasi adalah proses dimana suatu karakteristik dari signal carrier divariasi dengan sinyal pemodulasi. signal pemodulasi ini adalah signal yang mengandung informasi sinyal hasil modulasi disebut signal termodulasi. Karakteristik signal carrier yang divariasikan umumnya adalah amplitudo, frequensi dan fasa.

Berdasarkan standard DOCSIS versi 1.0 , ada beberapa tekhnik modulasi yang dapat digunakan baik untuk arah upstream maupun untuk arah downstream. untuk arah downstream dapat digunakan tekhnik modulasi 64-QAM dan 256 QAM. Sedangkan untuk upstream dapat digunakan modulasi QPSK dan 16-QAM.

The internet has become even faster. Gone are the days of sluggish dial-up connections. Cable modems offer a way for you to use your cable connection to get high-speed internet access.

How do cable modems work?

First of all, data and information from the internet comes over the coaxial cable, the same cable that is used to give you a television signal if you have cable television. Coaxial cables have the ability to store a large amount of data, so there is plenty of room for both your television and internet.

The cable modem is what allows you to have both cable television and high-speed internet access on the same coaxial cable. There are several parts of a cable modem, and they each serve a different function. The tuner is the portion that receives the internet signal from the cable and then moves the signal to the demodulator. The demodulator takes the signal and the data that is on it and coverts it into a digital form that can eventually be read by the computer. Some cable modems also have a modulator, which takes the signal and converts it back to a form that can be transmitted back out into the coaxial cable.

High-speed internet access gives you a lot of freedom. You no longer need to tie up a phone line in order to have an internet connection. They also allow you to get and receive data at a faster rate because a coaxial cable has a lot of space, despite the fact that you also use the cable to get a cable television signal.

In order to enjoy high-speed internet access, you will need a cable modem. Understanding how the modem works will help you make the best choices, in terms of price and function, when purchasing one.
Cable Modems provides detailed information on Cable Modems, Installilng Cable Modems, Cable Modem Reviews, Uncapping Cable Modems and more. Cable Modems is affiliated with Computer Cables.

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