what are the differences between modulation and multiplexing?
357712
modulation is simply affecting a frequency by altering its waveshape such as with a microphone. Multiplexing is dividing a frequency between 2 or more input signals...I.E. having 2 or more microphones riding on the same frequency but totally independant of each other. Phone lines are multiplexed to contain more than one phone conversation.
957101
None really - thats why digital signalling has taken over, now we have the technology. A analogue signal attenuates over distance and if you amplify it you also amplify the noise and interference. Digital signals also attenuate but can be repeated, which leaves the unwanted part of the signal behind.
1124548
Whichever one you want. Not really any differences. I got a $59.00 one from best buy or somewhere, handles 4 at a time, I only have 1, never a problem yet. I have a linksys unit.
228993
Okies so you want to know about baud.. Actually when we transmit a signal.. each signal can carry from 1 to multiple bits depending on the kind of voltage level available to us. So the no of bits carried by a signal at a time is baud. So 9600 baud in hyper terminal means it will send 9600 bauds, no of bits depend on underlying physical layer. \n\nParity is a technique for knowing wether the packet I transmitted is correct or not suppose my signal is 1101 then even parity is sendin no of 1 is even or odd if its even i attach one at end so my packet becomes 11010 becase no of 1 is odd.\n\nFlow control means wether the sender and reciever should agree on some buffer limit or the sender can send as many bits it wants to send without thinking abut the recievers capability.\n\nstop bit is a bit added at the end of message to represent the message is terminating.\n\n8 data bits is that the windowing used in flow control will be 8 bit large.\n\nHope it pacifies ur thrust or u can ping me up at vinod_recj@yahoo.com
522363
you can use a fm modulator
200277
Are you asking for the mathematical representation of a frequency modulated signal (FM)?  If so, it is:\n\nXc(t)=Ac*cos[omegaC*t + fDelta*X(t)]\n\nWhere t is time, Xc is the the modulated carrier, Ac is the amplitude of the carrier, omegaC is the frequency of the carrier (in radians per second), fDelta is the modulation index (amount of frequency change allowed), and X(t) is the message.\n\nSee chapter 5 of reference in "source(s)".
182016
Multiplexing: The process by which two or more signals are transmitted over a single communications channel\nSynchronization: The coordination of a sending and receiving device, so that both simultaneously send and receive data at the same rate\nMulticasting: The ability to transmit multiple standard-definition programs simultaneously using a single digital broadcast channel
297960
TDM, or time division multiplexing is a scheme to encode several analog signals through one communications channel.\n\nLet's say that you have three telephone conversations.  An encoder, known as a multiplexer, will combine the three by switching very rapidly through all three conversations.  This is called multiplexing.  \n\nLet's say that the multiplexing speed is 66kHz, which translates roughly to 15 microseconds to complete one multiplex cycle (one divided by 66kHz).  The first 5 microseconds, conversation 1 is switched onto the line, the second 5us, conversation 2 is switched onto the line, and the third 5us conversation 3 is switched onto the line.  The cycle then repeats itself over and over.\n\nIf you listened to the communications line, it would sound like you were listening to three conversations simultaneously, like they were blended together.\n\nNow, on the other end of the communications line, a decoder, called a demultiplexer sorts out the three conversations with a precise clock and a time base signal that is added in at the multiplexing process.  So it sorts out the three conversations and seperates them into the three original channels by doing the switching in the exact opposite of the multplexer by again making the switch every 5us.   \n\nVoila, time switching combines three phone conversations over one set of wires.\n\nIn cellular phones, there is a scheme known as TDMA, or time division, multiple access.  This is similar concept, but it coordinates multiple cell phone's transmitters to accomplish the same thing, but over radio instead of wires.
252949
It's basically one way to encapsulate data.  If you send a 1 MB transmission it is chopped into smaller bits so that it can be sent efficiently.  One way to do this is frame relay, another way is ATM.
826878
All radio transmissions can be considered analog even the digital ones like FSK, PSk,QAM, since the carrier is sinsoidal which is analog, however the data are digital so they change the carrier characteristic in discrete way. in mobile systems such as GSM the type of modulation is GMSK (gausian minimum shift keying), which is a special type of FSK (frequency shift keying), in FSK the frequency of the carrier is alternating between two values, each frequency represents a logic state (digital), which can be processed by the mobile circuitry. again the FSK is an FM signal whith the message being digital (binary)
191965
Biggest difference is price and available speed packages.\n\nCable usually allows larger bandwidth at much higher prices.\nDSL allows reasonably large bandwidth for normal useage at reasonable prices.
441194
Optical losses in a single mode optical fiber are smaller than in a multi mode optical fiber.  Therefore single mode fibers have more bandwidth and are used for a signal transmission over long distances.
871400
Because up to a few years ago it was always the easiest and cheapest method to transmit and receive broadcasts with.  The first system invented (discovered ?) by Marconi was an analogue system and it has stayed that way since.  \n\nActually, the terms 'analogue' and 'digital' only apply to the modulation methods used;  once the modulated signal leaves the radiating antenna it travels as an analogue electro-magnetic wave through space regardless of which type of modulation is used.
479254
A modulator is used to impress the information from a single source upon a radio wave or other system carrier, such as the process that happens when you play a VCR through channel three of your TV. The audio and video program are modulated onto a high frequency radio wave which can be received by your TV (demodulated). A radio wave can easily pass through space unlike the baseband video and audio signals.\n\n   A multiplexer may be thought of as a time sharing system in which several program sources are alternately routed to an output. An example of this would be in security systems where the pictures from several cameras are combined to be seen on one monitor screen.\n\n   Modulation has a 'one to one' relationship, as well as does its inverse, 'demodulation'. Multiplexing has a 'many to one' relationship. Its inverse, demultiplexing, has a 'one to many' relationship useful for extracting the various original signals.\n\nWK
655068
Actually most of todays satellites use dual polarization. Its not unlike vertical and horizontal polarization of basic radio antennae down here. Some of the earlier sat tv systems had a parobolic dish that would mechanically change polarization to get the other 12 of 24 channels on the satellite system. Multiplexing is another technique that provides more channels.
227946
MB/s is how many megabytes (each byte is 8 bits long) a device can transmit or receive per second. Generally, this unit is used when copying files or burning CDs, for example.\n\nMbits/s is how many megabits is sent or received per second by a device. Used when talking about network speeds at all.
617845
Let's try a slightly different explanation.  A Decoder is used to change a pattern of voltage pulses or digital signals into a different pattern with a smaller pulse width.  Generally, a Decoder and Coder pair are used to place data from different sources into the same circuit.  The decoder simply breaks out these signals to multiple circuits.\n\nA mux/demux pair performs a similar task for analog or sinusoidal signals.  Generally, the digital signals coming in to a multiplexer will have a specific frequency assigned to it the multiplexer mixes these different frequencies together into a composite signal.  On the other end the signals reach a demux, or de-multiplexer.  Here the different frequencies are broken out into different digital signals.\n\nDave Cooke