A decoder takes n inputs and produces 2^n outputs. An encoder takes 2^n inputs and produces n outputs.
A multiplexer selects one line from many lines. The inverse of selection is distribution. A demux essentially transmits data from one line line to 2^n possible output lines. The output line is determined by n select lines. In short, a multiplexer selects an input line, a demultiplexer selects an output line.
The differences between these two circuits is subtle, as far as I can tell. A demux simply selects an output line, nothing more. It's a glorified switch. A decoder takes n inputs, and uses those inputs to determine which of the 2^n output lines is high. This is the difference, I think. A decoder is designed to simply keep one line high. A demux is designed to set one output equal to the input (whether it be high, low, or a changing signal).
An encoder refers to a device that is used to change a signal or data into a code. Whereas a Multiplexer or mux is a device which performs multiplexing or it takes information from more than one channels and outputs into a single channel. Thus a multiplexer is basically a kind of encoder where its function is to combine multiple inputs into one output.
An electronics multiplexer will select an output by a digital code. a mechanical multiplexer will select an out by a mechanical switch of sort possibly driven by a motor
Statistical multiplexer does not reserve time slots or frequencies. Instead, it dynamically allocates bandwidth only when it is needed.
Physically a multiplexer usually looks like a box of some sort. More important is what is inside. The inside of a multiplexer contains a switch or switches, a power supply, and the electronic circuits to manage the system. One link is to informative datasheets for a couple of multiplexer Integrated Circuits from which much can be learned about multiplexer characteristics. There are many, many more kinds of multiplexer ICs.
multiplexer.
Which has more number of input, It can be obtained by cascading two or more multiplexer with less nunber of inputs.
What is the difference between a data card and an usb modem?
yes
Nothing. They are both modems (MOdulator/DEModulator).
A USB modem plugs into your USB port.A "normal" modem plugs into your RS232 port or your parallel port.
a wireless router is needed when internet modem doesn't have wireless capability.
Port speed is how fast the computer talks to the modem. Modem speed is how fast the modem talks across the phone line to the other modem.
An electronics multiplexer will select an output by a digital code. a mechanical multiplexer will select an out by a mechanical switch of sort possibly driven by a motor
An internal modem is housed within the main computer. An external modem is on the outside of the computer and connected to the computer with a cable.
There is a difference if you are using a low quality router. For good routers you will not notice any difference. Usually there is no difference at all.
Telephone is Cat3 while the cable coming form the modem is Cat5
Usually a cable modem is about 30 mbps and DSL can up to 768 kbps.
An encoder refers to a device that is used to change a signal or data into a code. Whereas a Multiplexer or mux is a device which performs multiplexing or it takes information from more than one channels and outputs into a single channel. Thus a multiplexer is basically a kind of encoder where its function is to combine multiple inputs into one output.