Skip to main content

Difference in between Time division multiplexing (TDM) and Frequency division multiplexing (FDM)

Difference in between TDM and FDM:


This page on FDM versus TDM describes difference between FDM and TDM multiplexing. FDM is the short form of frequency division multiplexing and TDM is the short form of time division multiplexing.
In FDM each signal is modulated onto different unique RF carrier frequency and all carrier frequencies are separated significantly so that bandwidth of the signals do not overlap in frequency domain.
Difference in between TDM and FDM
Figure: Difference in between TDM and FDM
   "Time-division multiplexinin telecommunications for telegraphy systems in the late 19th century, but found its most common application in digital telephony in the second half of the 20th century."
                        


      In telecommunications, frequency-division multiplexing (FDM) is a technique by which the total bandwidth available in a communication medium is divided into a series of non-overlapping (guard band provided) frequency sub-bands, each of which is used to carry a separate signal. These sub-bands can be used independently with completely different information streams, or used dependently in the case of information sent in a parallel stream. This allows a single transmission medium such as the radio spectrum, a cable or optical fiber to be shared by multiple separate signals.




Wavelength-division multiplexing (WDM) is a method of combining multiple signals on laser beams at various infared (IR) wavelengths for transmission along fiber optic media. Each laser is modulated by an independent set of signals.
Wavelength-division multiplexing (WDM) Video:




Labels:
Location: Pune, Maharashtra, India

Popular posts from this blog

Multiplexing and Multiple Access

Multiplexing And Multiple Access : Digital Communications Difference between Multiplexing and Multiple Access: Sr.No. Multiplexing Multiple Access 1 “In telecommunications and  computer networks, multiplexing is a process where multiple analog  message signals or digital data  streams are combined into one   signal over a shared medium.” “In telecommunications and computer networks, a channel access method or multiple access  method allows several terminals connected to the same multipoint physical medium to transmit over it and to share its capacity.” 2 The multiplexed signal is transmitted  over a communication channel,  which may be a physical transmission medium. A channel-access scheme is  based on a multiplex method  that allows several data streams  or signals to share the...
Read more

Call Setup GSM Flow

GSM Call Flow (GSM Originating Call) Call Setup GSM Flow Call Setup GSM Flow: •              The MSC sends an Initial Address Message (IAM) to the GMSC. The IAM contains the MSISDN of the called party as the MS dialed it. •              The MSC will also send a Call Proceeding (CALL_PROC) message down to the BSS and this is when the BSS would assign a TCH to the MS, as described earlier •              Based on the dialed number, the GMSC decides where to route the IAM within the PSTN. •              The PSTN will continue to route the IAM until it reaches the correct Switching Center and the call routing is complete. The PSTN will then establish the call circuit and send an Address Complete Message (ACM) back to the GMSC. •              The GMSC then forwards the ACM back to the r...
Read more