Difference Between Synchronous TDM and Statistical TDM

Parameter	Synchronous TDM	Statistical TDM
Working	In Synchronous TDM data flow of each input connection is divided into units and each input occupies one output time slot.	In Statistical TDM slots are allotted dynamically. i.e. input line is given slots in output frame if and only if it has data to send.
No. of Slots	In Synchronous TDM no. of slots in each frame are equal to no. of input lines.	In Statistical TDM, No. of slots in each frame are less than the no. of input lines.
Buffers	Buffering is not done, frame is sent after a particular interval of time whether someone has data to send or not.	Buffering is done and only those inputs are given slots in output frame whose buffer contains data to send.
Addressing	Slots in Synchronous TDM carry data only and there is no need of addressing. Synchronization and pre assigned relationships between input and outputs that serve as an address.	Slots in Statistical TDM contain both data and address of the destination.

Difference Between TDMA and FDMA

Parameter	TDMA	FDMA
Acronym for	Time Division Multiple Access	Frequency Division Multiple Access
Technology	In TDMA radio spectrum is divided into time slots and in each slot only one user is allowed to either send or receive.	In FDMA individual channels are assigned to individual users. Each user is allocated a unique frequency or band.
Bandwidth Sharing	In TDMA single frequency is shared by several users.	Frequency sharing is not allowed. If FDMA channel is not in use, it can’t be utilized by other user to increase or share capacity.
Transmission Scheme	Data transmission for users in TDMA is not continuous and uses buffer-and-burst method.	FDMA is a continuous transmission scheme and after the assignment of channel, base station and mobile transmit simultaneously and continuously.