Multiplexing Techniques Flashcards
Define Muxing
A process whereby multiple analogue signals or digital data streams are combined into one signal over a shared medium.
Expand and explain IMUX
Inverse Multiplexing. It has the opposite aim to multiplexing, namely to break one data stream into several then transfer simultaneously over several channels.
Expand and explain FDM
Frequency Division Multiplexing. The available transmission frequency range is divided into narrow bands of frequencies, each used for a separate channel or user.
What is a basic unit of FDM systems?
Voice Grade Channel
How are basebands formed?
By multiplexing Voice Grade Channels together.
The multiplexing hierarchy for FDM systems is standardised by who?
International Consultative Committee on Telegraphy and Telephony (CCITT)
Expand and explain TDM
Time Division Multiplexing. Individual channels are automatically allocated to the radio transmitter for a finite period of time.
What may the channel sample in TDM?
A bit, a number of bits or complete characters.
A resultant TDM signal will consist of what?
A sequence of bits or characters, interlaced in time.
Name one key factor that is of importance when producing a TDM baseband.
The VGC must be digitised.
What is a process of sampling channels in a TDM system?
Commutation
What can be used to as a reference to locate channels?
Timing Pulses
What are the advantages/disadvantages of FDM and TDM
FDM - All information is transmitter simultaneously, yiedling a faster throughput.
TDM - Requires a lesser bandwidth than FDM.
Who controls telecommunications standards worldwide, in particular Europe?
European Conference of Postal and Telecommunications Administration (CEPT)
What could be described as a basic building block of the digital signalling hierarchy?
Digital Signalling Level 0 (DS0)
