used cable modem

. Let us now focus our attention on modems that provide communication between a user and an Internet Service Provider (ISP) over the PSTN. Traditionally, the PSTN has been viewed as an analog network. However, in reality, the PSTN has become an almost entirely digital network. In most cas..

This is the simplest type of modem to install because you don't have to open the computer. External modems have their own power supply and connect with a cable to a computer's serial port. The telephone line plugs into a socket on the rear panel of the modem..

These modems, designed for portable computers, are the size of a credit card and fit into the PC Card slot on notebook and handheld computers. These modems are removed when the modem is not needed. Except for their size, PC Card modems are like a combination ..

For amore efficient use of PSTN, we treat it as what is really is an almost entirely digital network that is nonlinear...

The simplest approach to the design of modems is to treat the entire PSTN as a linear analog network. [Note that PSTN is almost entirely due to the use of pulse-code modulation (PCM) for the transmission of voice signals.]..

When a modem first makes a connection, you will hear screeching sounds coming from the modem. These are digital signals coming from the computer to which you are connecting being modulated into audible sounds. The modem sends a higher-pitched tone to represent the digi..

Use the table to find the ratio of the Cable TV subscribers in the year 2000 to 1990. => 1 : 34 or 34 : 25 or 25 : 34 or 1 : 25..

. Aluminium is a lightweight metal with a density of 2.7 g cm - 3 . Al can be easily extruded through dies to form various shapes. It is used for making angles used in windows. Aluminium cables are used to transmit electric current. Al alloys are used..

The smallest conductor used in standard open-wire telephone circuits is No. 12B and S. gauge. A line of such construction will have a loss of approximately 0.06 db per mile. Cable circuits, on the other hand, make use of conductors not larger than No. 19, and a typical..

The transmission lines used in telephony are of two kinds: open- wire and cable. The open-wire lines are gradually being superseded by cable construction, either overhead or underground, for two principal reason..