answersLogoWhite

Top Answer
User Avatar
Wiki User
Answered 2008-08-30 07:19:08

Multiplexing and multiple access

Modern telephone networks allow bandwidths in their channels that are much larger than those is needed for a digitalized telephone channel. Basically, a number of channels share a common transmission medium with the aim of reducing costs and complexity in the network. Multiplexing is defined as the process by which several signals from different channels share a channel with greater capacity. When the sharing is carried out with respect to a remote resource, such as a satellite, this is referred to as multiple access rather than multiplexing. There are various ways of performing this sharing:

# FDM/FDMA (Frequency Division Multiplexing/Frequency Division Multiple Access): Assigns a portion of the total bandwidth to each of the channels. # TDM/TDMA (Time Division Multiplexing/Time Division Multiple Access): Assigns all of the transport capacity sequentially to each of the channels. # CDMA (Code Division Multiplexing Access): In certain circumstances it is possible to transmit multiple signals in the same frequency and at the same time, with the receiver being responsible for separating them. This technique has been used for years in military technology, and is based on extending the spectrum of the signal and reducing the transmission power. # PDMA (Polarization Division Multiple Access): Given that polarization can be maintained, the polarization direction can be used as a multiple access technique, although when there are many obstacles noise can make it unsuitable, which is why it is not usually used in indoor installations. Outside, however, it is widely used to increase transmission rates in installations that use microwaves. # SDMA (Space Division Multiple Access): With directional aerials, the same frequency can be re-used provided the alignment of the aerials is correctly adjusted. There is a great deal of interference but this system lets frequencies obtain a high degree of reusability.

001
๐Ÿ™
0
๐Ÿคจ
0
๐Ÿ˜ฎ
0
๐Ÿ˜‚
0
User Avatar

Your Answer

Still Have Questions?

Related Questions

What is the difference between multiplexing and demultiplexing?

MULTIPLEXING is used to take a signal and send it out to many DE multiplexing perform the opposite


What is the difference between frequency division multiplexing and freq division multiple access?

The basic difference between fdm and fdma is that fdm is used in wired system where as fdma is used in wireless communication.


What is the difference between upward and downward multiplexing?

upward and downward ultiplexing


Difference between switching and multiplexing?

Multiplexing-Combining all the inputs into one output. Switching-Taking one input to the output, at a time/frequency


What advantages does TDM have over FDM in a circuit switched network?

TDM and FDM are multiple access techniques used for multiplexing number of signals into a single single for bandwidth saving. FDM is older technique of multiplexing whereas TDM is relatively a newer technique of multiplexing. TDM advantage over FDM is that it offers bandwidth saving and there is low interference between the signals that are being multiplexed.


What are the advantages does tdm have over fdm in circuit switching network?

TDM and FDM are multiple access techniques used for multiplexing number of signals into a single single for bandwidth saving. FDM is older technique of multiplexing whereas TDM is relatively a newer technique of multiplexing. TDM advantage over FDM is that it offers bandwidth saving and there is low interference between the signals that are being multiplexed.


What is the difference between statistical time division multiplexing and synchronous time division multiplexing?

the major difference between both is that the time slot is not same for each sending device. the wastage of capacity of the multiplexed channel is solved by asynchronous or statistical time division multiplexing. In synchronous Time division multiplexing their is under utilization of capacity of multiplexed channel. This way cost to multiplex per character increases.


What is the relationship between multiplexing and modulation?

What is the relationship between multiplexing & modulation


What is the difference between teaching approach and techniques?

It is the difference between strategy and tactics. The approach defines goals, and the techniques describe methods.


Difference in modern and traditional techniques of managerial control?

difference between modern and traditional techniques of controlling


What is the difference between double cropping and multiple cropping?

what is difference between single double and multiple cropping


What is the difference between time division switching and space division switching?

Space division multiplexing uses spacing to separate channels in a communications link. These separations may be done by frequency, insulation, or distance (spacing). Time division multiplexing is one way of doing the spacing separation. Space division multiplexing may use other techniques, such as TDM, FDM, etc., to maintain separation so that the conversations do not collide with each other.


Explain the difference between tdm and fdm with suitable examples?

TDM means time-division multiplexing. It is a type of digital channel. While on the other hand FDM means frequency-division multiplexing.


What is the difference between an upward multiplexing and down-ward multiplexing When they are needed?

If only one network address is available on a host, all transport connections on that machine have to use it. When a TPDU comes in, some way is needed to tell which process to give it to. This situation, called upward multiplexing. While if a user needs more bandwidth than one virtual circuit can provide, a way out is to open multiple network connections and distribute the traffic among them on a round-robin basis. This modus operandi is called downward multiplexing.


What is the difference between sword fighting techniques and knife fighting techniques?

about two feet


Difference between link and channel in multiplexing?

In multiplexed system n-lines (channels) share bandwidth of one link


Advantage of TDM over FDM?

TDM and FDM are multiple access techniques used for multiplexing number of signals into a single single for bandwidth saving. FDM is older technique of multiplexing whereas TDM is relatively a newer technique of multiplexing. TDM advantage over FDM is that it offers bandwidth saving and there is low interference between the signals that are being multiplexed.


What is the difference between finding a factor and finding a multiple?

a factor is what you multiply by a multiple is the answer


What is the difference between precision and non-precision casting techniques?

nothing


What is the difference between tae kwon do and karote?

Basically, the biggest difference between Tae Kwon Do and Karate is that Tae Kwon Do is more focused on foot techniques (about 60%-70%) and Karate is focused more on hand techniques.


What is the difference between the third and the sixth multiple of 8?

24


How do infection rates and renal deterioration compare between conduit and continent techniques?

There is little difference in infection rates or in renal deterioration between the conduit surgical techniques and the continent techniques. The patient's preference becomes important.


What is the differences between multiplexer and de multiplexer?

multiplexer combines several individual signals into a single signal.demultiplexer separates a single signal into several individual signals.There are many types of multiplexing, a few are:time domain multiplexingfrequency domain multiplexingdigitally coded multiplexingetc.


What is the difference between a mailbox and a pipe in RTOS?

these are techniques to make student to go mad


What is the difference between worst case and best case scenario of sorting techniques?

good


Still have questions?