Data Communication Important Questions For External Exams

Data Communication Important Questions For External Exams

Unit-1

Write short notes on :Protocol Architecture.
Discuss TCP / IP protocol layer architecture and functions in detail.(**)
Write short note on (c) Line Configuration.-5
List and explain transmission impairments.
Write short notes on any two of the following:
(a) Pulse code modulation and delta modulation.

Compare the three basic modulation techniques for transforming digital data into analog signals. (5)
What is pulse stuffing? Explain how it is helpful in design of TEDM. (5)
(b) Explain the concept of Delta Modulation.***
(a) Draw the wave forms and explain the following coding schemes:

(a) Bipolar-AMI (ii) Differential Manchester

Explain Data Communications Interfacing with neat diagrams.
Explain about Amplitude modulation and Angle modulation. 10
Differentiate between Amplitude shift keying, frequency shift keying and phase shift keying. (4)

Unit:2

Write about on error detecting and one error correcting codes. Explain with examples.
Elaborate On data transmission techniques.
Explain the Transmission modes, transmission characteristics and categories of applications of optical fiber. . (5)
Explain the different phases of HDLC with suitable example. (5)
What are the topology options for Fiber channel?
Explain how the Go-Back-N Arq technique can handle different specific cases or contingencies.
Discuss the mechanisms of sliding-window flow control.
State the purpose of ARQ and explain stop and wait ARQ.
Explain HD LC protocol in detail.****
Explain HDLC frame structure.
Explain in-detail Cyclic Redundancy Check (CRC) error detection technique with suitable examples. 10
Write about Line-of-sight Transmission.
A channel has a data rate of 4 kbps and a propagation delay of 20 ms. For what range of frame sizes does stop-and-wait give an efficiency of at least 50% ?

Unit:3 

Give architecture of ATM and explain its logical connections and cells.
Describe Frame relay.
Elaborate on various methods of multiplexing.
Contrast the architecture of a traditional telephone network circuit switch with soft switch architecture. Explain how flexibility has been achieved in soft switch architecture.
Draw the Event timing diagram to bring out differences between circuit switching and packet switching.
What is the need for ATM adaptation layer? What are some of the protocols and services provided by the AAL ? (10)
What are the characteristics of virtual channel convections?
Draw and explain the ATM cell format 5
Explain the concepts of packet switching and how routing is done in packet switching.
Write short notes on any two of the following:
ADSL
Explain in detail about statistical time division multiplexing.
Explain in detail about xDSL.
The difficult problem in the design of a synchronous time division multiplexer is that of synchronizing the various data sources.How can this problem be overcome? Explain with suitable example
What are the advantages and disadvantages of Frame Relay over X.25 ?
What are the different categories and types of services that can handled by ATM network
Give a comparison of the circuit switching, datagram packet switching and virtual circuit packet switching Techniques.

Unit:4

Discuss Ethernet and token ring by giving their frame formats. Explain the significance of each field.
Differentiate Ethernet and token ring.
(c) LANs. Transmission media.
(c) Layer 2 and Layer 3 switches

14. (a) Describe the operation of CSMAjCD.
(b) Write short notes on -virtual LANs.
(b) List various LAN topologies and explain the frame transmission in each LAN
topology. .. 6
ExplainLANprotocolarchitecture.
Explainfunctionsof aBridge. 10
a) Layer 2 switches,

14. (a) Write about layer 2 and layer 3 switches.
(b) Explain briefly about Gigabit ethemet.

16. (a) Explain key elements such as topology, medium access control of LAN.
(I) Bridge protocol architecture (c) Fibre channel topologies

Unit:5

Discuss cellular wireless networks of third generation systems.
Describe IEEE 802.11.
How medium access control is done is wireless LANs?
discuss the architecture and services defined by1 EEE 802.11.
Write short notes on any two of the following:
(a) Frequency hopping spread spectrum and direct sequence spread spectrum.
(b) Typical call between two mobile users within an area controlled by a single MTSO.
Explain Bluetooth architecture.

16. a) Give overview of operation of cellular systems.

15. Write about IEEE 802.11 architecture and services.

17. Write short notes on any two of the following:
(a) HDLC
(b) xDSL
(c) Overview of cellular systems.
Draw and explain the 1EEE 802.11 MAC Frame Format. (3)
What are the advantages and disadvantages of using CDMA for cellular network?