Data Communication Flashcards
What is meant by data communication?
Data communication is a transmission of data from one place to another using electronic means.
How is data transferred in data communication?
Data is transferred through transmission medium such as cable wireless system micro system satellite system etc.
Data communication system may consist of __________ and ______________.
Hardware and software
How is data transmitted from one system to another system
Data is transmitted electronicly.
Data communication between computer to the internet?
Tere communication between computer and internet would be computer connecting to the internet using a dam in which uses establish a communication between a pc and hundreds of computers on the internet
How is data transmitted in telecommunications ?
In telecommunication there is a mix of both data (digital) and voice (analogue)
Define data
Raw fox and figures given to the computer as an input is called data.
What is information?
Process to form of data.
In what forms does data exist?
Data can be in the form of text numbers graphics sounds and videos.
By what method data is more convenient to move out process in data communication?
By translating into a form that is convenient
Define data transmission?
Process of transporic data between two or more devices
What is the signal?
It is an electrical or electromagnetic current used for carrying data from one device or network to another.
What is the other name of data transmission?
Digital transmission
What are transmission media
Mediums through which data send or received such as cables or wireless media like microwave infrared and satellite
Name types of waves
Mechanical waves (sound) requires medium
Electromagnetic waves require no medium (light)
What are analogue signals
Continue signals that vary overtime
What is analogue data transmission
Transfer of data from one place to another in the form of analogue signals that transfer voice data over telephone line.
What is used in analogue signal instead of on and off
Variations between the Waves
Examples of analog signals
Light waves, sound waves, radio waves
In continuous way there is a _______ and _______ values
High and low
What exist between high and low values
Variety your values in continuous wave
Disadvantage of analogue signals
They are prone to impairments over a distance
What are digital signals
I discrete signals that used binary values to represent data and are discontinuous
What does one and zero mean
One means on why zero means off
What does digital signal transmit
It transmits binary data based on 2 digits
How does computer except and process data
In digital form
How does duster signal perceive information
It passes information as a string of impulses
What is low pulse and high pulse
Low pulse or no pulse indicate zero while high pulse it detects 1
What does a modem do
Madam converts analogue signals to digital signals and vice versa
On a destal image what are pixels represented as
Pixels are represented as on and off and combined together to create this till images
List components of a communication system
Sender
Receiver
Message
Protocol
Transmission medium
What is the sender
Device or person that sends data
Other names of sender
Transmitter or source
What is the receiver
It is a device that receives data
Other names of receiver
Sink or destination
What is message
The actual data being transmitted
What is the protocol
Sarproof that govern data communication
What does protocol represent
Agreement between communicate and devices
What will happen without a proper protocol
Devices maybe connected but they cannot communicate with each other
What does protocol include
Error detection synchronization signaling and authentication in communication system.
Define transmission medium
Path through Which message is transmitted
What is feedback
Important components of communication system that help centre to analyse and confirm the correct interpretation of message by the receiver
List properties of a good communication system
Delivery accuracy and timelines
What is meant by delivery
It means that the send data should be delivered to the receiver
What is meant by accuracy
Receive data must be exact to the send data
What happens to altered data
Alter data in transmission and left uncorrected are unusable
What must happen if there is any error during data transmission
Data must be retransmitted
Explain timelines
It means that the data sent must be delivered in time
What happens if data is late
If the data is transmitted late then the data become useless
What is jitter
Property of the communication system that refers to the variation in the packet arrival time
Name modes of data communication
Synchronous and asynchronous
What is synchronous data transmission
Transmission of data as a continuous stream typically in blocks all frames without any gaps
Define asynchronous transmission
Method by data is sent bite by bite and each bite is sent individually with intervals
How is data transmitted in synchronous data transmission
Data is transmitted block by block or word by word
What special device is used in synchronous transmission
Synchronised clock is required to schedule the transmission of information
In what way is data transmitted with synchronous transmission
Large blocks of piles are transmitted at regular interval without any start stop signals
What is the requirement of synchronous transmission
The sending and receiving devices must be synchronised
Compare cost of synchronous and asynchronous transmission
Synchronous transmission requires expensive equipment while a synchronous transmission maybe cheaper
List advantages of synchronous transmission
It was greatest speed and accuracy
Other name of asynchronous transmission
Start stop transmission
Why is it called start / stop transmission
Because communication can start anytime and stop anytime
How is data sent in asynchronous transmission
Did a sentence small independent chunks
What is parity
Additional bed included at the end of each by two allow error checking
How is a receiver alerted
To alert the receiver about arrival of new bite and extra bit zero called start with is added at the beginning of each group of bits and one cold stop bit is appended at the end of each byte
Can timing be used in acrony transmission
Tere Siva cannot use the timing as it has no knowledge me the next bite will arrive
What is the speed of asynchronous transmission
It is lower and in efficient than synchronous
Advantage of a synchronous transmission
Simple to implement and is ideal for scenarios were data is regularly transmitted
List properties of asynchronous transmission
Start and stop bitch are used to identify when data begins and ends
No synchronisation is required
Lower efficiency due to start and stop bits
How is error checked
Asynchronous transmission and checks error bite
What transmission mods are used in real time data transmission where minor delay is not acceptable
Isochronous
Name types of transmission medium
Guided media and unguided media
What is guided media
Guided media uses physical path to transmit signals
What is unguided media
Undered media transmit signals through air without any physical path
Other name of guided media
Wired communication are boundary transmission media
What is other name of unguided media
Wireless communication or unbounded transmission media
Which media provides direction to the signal
Guided media
List different guided medias
Twisted pack cable coaxial cable and fiber optic cable
