What is multiplexing and demultiplexing? Explain.
Describe Time division, Frequency division and Wavelength division multiplexing.
What is ADSL? How does it use multiplexing?
Discuss the differences between different types of wireless telephone systems.
Multiplexing is a method where analog and digital message signals together combines to become one. Multiplexing is widely used in communication application such as telegraphy and shares expensive resources.
De-multiplexing process is meant for performing the reverse process of multiplexing. It is used for the extraction of original channels used on the receiver side.
Time Division Multiplexing:
It includes a process where each individual input stream involve the sequencing group of bits and bytes one after another in a way that they must be sent to indented user. If the whole process is carried out appropriately even then the receiving device is not able to recognize that some of the circuit time has been used for serving another logical communication path. Suppose the airport develop an application that requires four terminals to connect to its central computer. Each terminal is communicated at 2400 bits. So, rather than using four terminals to perform this action; the airline can install a multiplexer.
Frequency Division Multiplexing
The frequency division multiplexing combines various digital signals into one medium by sending signals at different frequencies. The most common example of Frequency Division Multiplexing is Cable Television where one cable connection reaches to customer by only one cable but the provider of this service provides multiple channels to its receivers
Wavelength Division Multiplexing
It is a technology that uses multiple optical signals with different wave lengths of laser light. This technique provides bidirectional communication.
ADSL depends on the Advanced Signal Processing to send so much information through twisted pair cables used in telephone lines. Long telephone lines may attenuate signals at 1 MHz (the outer edge of the band used by ADSL) by as much as 90 dB, forcing analog sections of ADSL modems to work very hard to realize large dynamic ranges, separate channels, and maintain low noise.