Difference Between FDM and TDM

Hello, friends, I hope you all are doing great. In today’s tutorial, we will discuss the Difference Between FDM and TDM. There are 2 commonly used techniques for multiplexing and the first one is TDM and the second one is TDM. The basic difference between them is that in FDM numerous signals are transferred with different frequency slots. While in TDM signals are transferred through different time slots.

Multiplexing is a technique through which numerous signal is transmitted in a common channel. In today’s post, we will have a detailed look at both FDM and TDM to compare them and find their differences. So let’s get started with Difference Between FDM and TDM.

Table of Contents

FDM

It is the method through which the net bandwidth of a single is parted in different frequency levels and every band has its on signal.
It helps to convert a single medium used for transmission to make different mediums.
It sends data in parallel combination

The practical example of this method is radio signal transmission and tv transmission.
There is cable tv is also an example through which numerous channels are operated.
It uses analog multiplexing techniques.
It does not need any synchronization.
Its circuit arrangement is complicated.
There is crosstalk is existing.
In a telephone system, it is used to transmit calls over multiple users.
There is a similar technique to this called wavelength division multiplexing that uses optic fiber for communication
The full form of FDM is Frequency Division Multiplexing.
Its propagating delay is sensitive.
Its efficiency is less.
Its price is high.

TDM

The method that allows the transmission of numerous signals of data through the common line in different time slots is called TDM.
Its full form is Time Division Multiplexing.
It is a digital technique that operates on the time in place of frequency to distinguish data from another form of data.
It is used to transmit 2 or more two signals through a single source.
It is employed when the bit ratio of the signal source is larger than the signal sent.
It was the first time used in the nineteenth century for telegraphy.

It required synchronization.
Its circuit is less complicated than the FDM.
In this signal transmission, there is no need for crosstalk.
Its efficiency is larger than the FDM.
Its price is less than FDM.
It is normally used for digital signal but also work for the analog signal
In this module, the time domain is parted in different time slots having a certain value.
In this signal transmission, a digital multiplexing technique is used.
It has two types

Synchronous TDM

Asynchronous TDM

Synchronous TDM vs Asynchronous TDM

Feature	Synchronous TDM	Asynchronous TDM
Timing	All slots are synchronized with common clock signals	Every slot is independent and nonsynchronized.
Slot allocation	Slots are allocated for certain time intervals	Slots are allocated on a first-come, first-served basis.
Overhead	it needs overhead for synchronization maintain	There is no need for overhead is required for synchronization.
Efficiency	It is best for high-bandwidth, continuous data streams.	it is good for bursty and intermittent data streams.
Example	T1 and E1 lines in telephony.	Ethernet LAN comes with many devices sharing a link.

FDM vs TDM

Feature	FDM	TDM
Basic principle	it divides the frequency bandwidth of the channel	It divides the time of the channel
Channel usage	Every signal uses a distinct frequency band	Every signal employs complete bandwidth in its turn.
Multiplexing	It is Frequency-division multiplexing.	It is Time-division multiplexing.
Demultiplexing	Every signal is separated through the use of a bandpass filter	In this module, every signal is separated through time slot allocation
Data rate	It can support high data rates	It is best for low to medium data rates
Efficiency	It is not effective since some bandwidth lost	It is efficient as the time slot is completely used
Overhead	It needs less overhead for synchronization.	It needs overhead for synchronization.
Application	The analog system such as radio and tv broadcasting	It is used in digital systems such as telephony and LANs.
The capacity	it supported larger users	Since it has time slot allocation so used for limited users.
Synchronization	It does not need signal transmission separately	Itg nee signals are transmitted in sequence
Complexity	It is less complicated since has separate frequency bands	It is completed due to time slot allocation
Cost	It can be costly due to the requirements of many bands	It is less costly due to the simple structure
Latency	It has less latency since signals are transmitted at the same time	It has high latency due to sequential transmission
Interference	Interference exists between different bands.	Interference can exist between different time slots.
Flexibility	it is not flexible as frequency bands are fixed	It is flexible as time slots can be allocated randomly
Resilience	It is resilient to channel noise and distortion	It is less resilient to channel noise and distortion
Examples	Its common examples are Analog broadcast systems like FM radio and TV.	Its examples are Digital telephony, ATM networks, and Ethernet.