Wednesday, May 30, 2012


Okay, so now, I'm gonna review how data are transmitted. 시작!  :D

1. Analog & Digital

These two signals will carry out two process on conversion:
  • Analogue to digital = modulation
  • Digital to analogue = demodulation

To make it simple, the conversion of analogue to digital is merely because digital signal is the language of the computer. Here is one example of these two conversion:
 i don't quite understand myself..  =="

2. Bandwidth

To put it simple, the higher the bandwidth, the faster the data to be delivered. Example? Take broadband for instance. 1Mbps and 1Gbps, which one is faster? Easy, right?  :)

3. Serial and Parallel

Another form of transmission. Serial is where the data is transmitted bit by bit within a long single path. It is used for a short communication. Meanwhile, parallel is where the functions the same- one bit at a time but using different path. Parallel transmission is faster and being used for more telecommunication.

here's a nice example
4. Transmission timing
You have to know how data is transmitted synchronously (organised by block) , asynchronously (data with bits specified), and i synchronously (data send at the same time as other data).

5. Transmission flow

The process of exchanging can be done in three operation style:

  • Simplex
  • Half-duplex
  • Full-duplex

The simplex operation is when the data is transmitted in one direction only. As much as I understand about it, the role of transmitter and receiver are fixed.

For example, when you are watching television or listening to the radio where you as the receiver only got to understand the message or information without reacting back to the sender.

The half-duplex operation is when the transmission can flow in two direction but never at the same time. The nearest example is the walkie talkie.
The full-duplex operation is when both station can transmit and receive the information simultaneously. it is usually consist of two simplex channel, for example the the online chatting.

That is all. Seriously, I can't understand these things. But, I will try my best.  :)


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