EASWARI ENGINEERING COLLEGE QUESTION BANK
Subject: EC 1013/ WIRELESS NETWORKS Class: VIII Sem ECE Period: Even Semester of AY 2010-2011 Name of Faculty member(s): Mrs.D.Vydeki Mr.C.Gnan a rak-aIsam UNIT PART – A
The CDPD system used GMSK to provide a data rate of 19.2Kbps over a 30KHz channel, find the bandwidth efficiency of the system. [Nov 2009] 2. What type of access technologies are used for the following systems? (a) AMPS (b) GSM (c) IMT 2000 (d) EDGE [Nov 2009] 3. What are the advantages of UWB pulse transmission? [May 2009] 4. Write short notes on OOK modulation. [May 2009] 5. How is a wireless network different from a wired network? State at least two differences. [Nov 2008] 6. What is the special requirement involved, while integration of voice and data traffic is carried out? [Nov 2008] 7. What is multi carrier modulation? [May 2008] 8. What do you understand by ultra wideband technology? [May 2008] 9. Name five design consideration in selecting a modulation scheme for a wireless networks. 10. Why is out of band of radiation an important issue in designing modulation scheme? 11. Why is PPM used with IR communication instead of PAM? 12. Name four space diversity techniques. 13. What are the advantages of high efficiency voice band modems? 14. Draw the structure of DFE. 15. Define ACI. 16. What are the types of diversity? 17. Draw the structure of adaptive MLSE receiver. 18. Draw the structure of linear transversal equalizer. 19. In an OFDM modem with 48 channels, each channel uses 16QAM modulation. If the overall transmission rate is 10 Mbps. What is the symbol transmission rate per channel? 20. What are the sectored antennas? How they are useful in combating multipath? 21. What are the popular access schemes for data networks? Classify them. 22. What is the difference between the access technique of IEEE802.3 and IEEE 802.11? 23. What is the difference between performance evaluations of voice oriented fixed assignment and data oriented random access? 24. What is the difficulty of implementing CSMA? CD in a wireless environment? 25. Explain about CSMA. 26. Explain about hidden terminal problem. 27. Explain about capture effect. 28. Write down the formula for Nidle. 29. Sketch the operation of CSMA protocol. 30. Define: a. persistent b. non persistent c. 1-persistent d. p-persistent 31. Draw the frame structure of movable boundary frame polling system 1.
Difference between ALOHA and slotted ALOHA. 33. Explain about space diversity. 32.
PART – B
Define the time diversity, frequency diversity and space diversity. [Nov Explain how diversity is used in rake receiver. (16) 2009] 2. Explain how to integrate voice in data oriented network. Also explain a method to cope with voice packet jitter. (16) [Nov 2009] 3. (i) Explain the multicarrier, multisymbol, multirate OFDM Modulation followed in broadband modems for higher speeds. [ 8] (ii) Illustrate Frequency Hopping Spread Spectrum and Direct Sequence Spread Spectrum with suitable examples. [8] [May 2009] 4. (i) Discuss the modulation schemes followed in high speed modems for spread spectrum technology. [8] (ii) Explain the time diversity techniques of DSSS and the RAKE receiver.[8] [May 2009] 5. (i) What are the considerations needed in the design of wireless modems? Substantiate.(10) (ii) What is UWB pulse transmission? Describe the salient features.(6) [Nov 2008] 6. (i) Discuss about frequency diversity and space diversity techniques. Compare & contrast them. (12) (ii) What is the maximum throughput of a pure ALOHA network with a large number of users and a transmission rate of 1 Mbps? What is the throughput of a TDMA network with the same transmission rate? (4) [Nov 2008] 7. With necessary diagrams explain the different types of Random access methods of Mobile Data Services. [May 2008] 8. List out the different types of diversity techniques and explain each with necessary diagram. [May 2008] 9. Explain the following: (16) a. bandwidth efficiency b. power efficiency c. out of band of radiation d. UWB pulse transmission 10. What is OFDM? Explain about multicarrier, multisymbol and multirate OFDM. (16) 11. Why we are going for diversity? Explain the time diversity using rake receiver and traditional modems & equalizers. (16) 1.
Explain about space and frequency diversity. ` (16) 13. Explain about random access method? (16) 14. Explain about integration of voice traffic. (16) 12.
UNIT - II PART – A
What is the formula to find number of simultaneous users? [Nov 2009] 2. What is meant by overlaid cell concept in cell splitting? [May 2009] 3. Mention the circumstances that prefer temporary channel borrowing in cellular networks. [May 2009] 4. What is an Ad-hoc network topology? [Nov 2008] 5. What is cell splitting? [Nov 2008] 6. Define co-channel and adjacent channel interference. [May 2008] 7. What is ping-pong effect? [May 2008] 8. Name any three advantages of an infrastructure topology over an adhoc network topology. 9. Compare single hop and multihop networks topologies. 10. Name the five different cell types in the cellular hierarchy and compare them in terms of coverage area antenna site. 11. Why is hexagonal cell shape preferred over square or triangular cell shape to represent the cellular architecture? 12. Name five architecture methods that are used to increase the capacity of an analog cellular system without increasing the number of antenna sites. 13. Explain the following: a. Cell splitting b. Cell sectoring c. Cell partitioning 15. Explain how smart antennas can improve the capacity of cellular network. 16. What are channel allocation techniques? 17. Explain the terms FCA, DCA, HCA. 18. Compare FCA and DCA. 19. Define channel borrowing technique and give its types. 20. Define mobility management. 21. Name the two important issues in mobility management. 22. What is location management? What are the three components? 23. Name three paging mechanisms. 24. Explain about paging. 25. Explain three traditional handoff techniques? 26. Difference between mobile controlled and mobile assisted hand off? 27. Difference between centralized and distributed power control. 1.
What are the two steps in hand off? 29. What are the privacy and authentication requirements of wireless networks? 30. How are public key and secret key algorithms different? 31. Explain the importance of key sizes in the security of an encryption algorithm? 32. What is challenge response scheme? 33. What are the parts in location management? PART – B 1. (i)With necessary diagram s explain the mobility management process. (8) (ii) Discuss on the power control mechanisms of wireless networks. (8) [Nov 2009] 2. Explain how cell splitting and Lee’s micro cell zone concept improves [Nov the capacity of a cellular system. 2009] 3. Assume that we wanted to deploy an analog FM AMPS system with half band of 15KHz rather than the existing 30KHz. Also assume that in analog FM, the carrier - to - interference ratio (C/I) requirement is inversely proportional to the square of the bandwidth (4 time increase in C/I for dividing the band into two). 28.
(i) What is the required C/I in dB for the 15MHz channel if the required C/I for the 30KHz systems in 18dB? [4] (ii) Determine the frequency reuse factor N needed for the implementation of this 15KHz per user analog cellular system. [ 4] (iii) If a service provider had a 12.5MHz band in each direction (up link and downlink) and it would install 30 antenna sites to provide its service, what would be the maximum number of simultaneous users (capacity) that the system could support in all cells? Neglect the channels that are used for control signaling. [4] (iv) If we use the same antenna sites but a 30KHz per channel system with N=7 (instead of the 15KHz) what would be the capacity of the new system? [4] [May 2009] 4.
We have installed cellular system with 100 sites, a frequency reuse factor of N=7, and 500 overall two-way channels: (i) Give the number of channels per cell, total number of channels available to the service provider, and the minimum carrier-tointerference ratio (C/I)of the system in dB [4] (ii) To expand the network, we decide to create an underlay-overlay system where the new system uses a frequency reuse factor of K=3. Give the number of cells assigned to inner and outer cells to keep a uniform traffic density over the entire coverage area. [4]
Answer the above two questions with N=12. [8]
[May 2009]
5. (i) Find out the expression for signal to interference ratio in a cell. (ii) Compare peer-to-peer and multihop adhoc topologies. [Nov 2008] 6. (i) What is channel borrowing? Explain. (4) (ii) Discuss about DCA and it’s various types. (8) [Nov 2008] (iii) What is FCA? Explain. (4) 7. (i) With necessary diagram explain how the capacity is increased by using directional antennas for cell sectoring and cell splitting.[10] (ii) Explain the concept of channel borrowing and dynamic channel allocation. [6] [May 2008] 8. (i) With necessary diagram explain the generic handoff management process. (ii) Discuss on power saving mechanism in Wireless Networks. [May 2008] Explain the two fundamental types topologies used in the wireless networks? (16) 10. Comparison of adhoc and infrastructure topologies. (16 ) 11. Explain the concept of cellular topology and cell fundamentals with examples. 12. (16) 13. Explain in detail about capacity expansion technique. (16) 14. Explain in detail about channel allocation technique. (16) 15. Comparison of FCA and DCA. (16) 16. What are the parts available in location management and explain in detail. (16) 17. What is meant by handoff? What are the issues available in hand off management? Explain with neat diagram. (16) 18. Discuss about power control mechanism with example. (16) 21. Explain in detail about security in wireless networks. (16) 9.
UNIT - III PART – A What are the difference between the 802,11a and HIPERLAN-2? [Nov 2009] 2. Draw the packet frame format of WATM. [Nov 2009] 3. Is CDMA an access method or an air-interface? Justify your answer. [May 2009] 4. What is meant by 'capacity on demand' principle in GPRS networks? [May 2009] 5. What is meant by HAN? [Nov 2008] 6. What is wireless ATM? [Nov 2008] 7. Why is power control important in CDMA? [May 2008] 8. List out the four layer involved in SMS. [May 2008] 9. Difference between registration and call establishment? 10. What are the reasons to perform handoff? 11. Difference between network decided and mobile assisted handovers? 12. Difference between logical and physical channel? 13. Name five most important logical channels in GSM 14. What are the stack layers? 15. Three types of bursts. 16. Three types of control channels. 17. What is IS-95? 18. What are the bandwidth and chip rates used in WCDMA and how they compare with cdma-one? 19. How many physical channels are available in each IS-95 carrier? What type of coding separates these channels from one another? 20. Name the forward and reverse channels used in IS-95? 21. Difference between Walsh codes and cdma-one forward and reverse channels? 22. What are the bit rates of the data services supported by IS-95? 23. Why is power control important in CDMA? 24. What forward channels are involved in IS-95 for power control? 25. Why are several pilot channels monitored in IS95? When does a pilot channels from a base station move from an active set to a candidate set? 26. Sketch handoff threshold in WCDMA? 27. What are the new elements added to the GSM infrastructure to support GPRS? 28. How does GPRS provides a variety of data rates? 29. Name the connectionless and connection oriented services provided by the GPRS 30. What is GPRS-136? How does it differ from GPRS? 1.
31. What is the importance of the framing structure in GSM? 32. What is the difference between registration and establishment? 33. Name three sub systems in the GSM architecture. 34. What are VLR and HLR and why we need them?
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PART – B Draw the GSM prortocol architecture & explain the call establishment [Nov 2009] in GSM using the logical channels. (16) 2. Expalin the forward & reverse channels of WCDMA. (16) [Nov 2009] 3. (i) Explain the GSM services & the reference architecture of GSM cellular networks. (10) (ii) Explain the registration mechanism to support a mobile environment. (6) [APR 2009] 4. (i) Explain the IS-95 CDMA forward channel in detail. (6) [May (ii) Explain the IS-95 CDMA reverse channel in detail. (10) 2009] 5. (i) Discuss in detail with block diagram IS-95 CDMA forward channel. (12) (ii) What are the bit rates of the data services supported by IS-95. (4) [Nov 2008] 6. Discuss in detail about GPRS. (16) [Nov 2008] 7. List & explain the four mechanisms that are embedded in all voice oriented wireless networks that allow a mobile to establish & maintain connection with the network. (16) [April 2008] 8. (i) Describe the different logical channel used in the GSM network. (8) (ii) With necessary diagram explain the GPRS system architecture. (8) [April 2008] 9. What are the mechanisms available to support mobile environment? (16) 10. Draw the protocol architecture of GSM and explain in detail. (16) 11. Explain in detail about IS-95 CDMA forward channels? (16) 12. Explain in detail about IS-95 CDMA reverse channels? (16) 13. Explain in detail about IMT-2000. (16) 14. What is GPRS? Explain in detail about GPRS. (16) 15. Explain in detail about SMS and mobile application protocol. (16) 1.
UNIT - IV PART – A How does IEEE 802.11a PHY layer differ from that of IEEE 802.11 PHY [May 2009] layer? 2. State the relationship between HYPERLAN-2 and WATM. [May 2009] 3. Name the five major challenges for implementation of wireless LANs that existed from the beginning of this industry. [May 2008] 4. How do HPNA, DSL, POTs share the telephone wiring? [May 2008] 5. What is the difference between nomadic access and adhoc networking? 6. Name three categories of unlicensed bands used in U.S and compare them in terms of size of the available band coverage. 7. Explain the difference between WLAN and PAN. 8. Name the five major challenges for implementation of wireless LANs compare with one another. 9. Explain the difference between wireless inter-LAN bridges and WLANs 10. What are the differences between IEEE802.11 and HIPERLAN standards? 11. Compare WCAN and WHAN. 12. Why does the military shoe how much of interest in wireless ATM approach? 13. Name three military projects related to broadband wireless local access. 14. Name different alternatives for internet access to the home and different medium for home distribution. 15. What are the difference between LAN and HAN? 16. Explain the specific challenges for the design of HAN. 17. Name the classes of home appliances that are emerging in the networking market. 18. Compare wireless and wired solution for home access and in home distribution. 19. Name four major transmission technique considered for WLAN standards and give the standard activity associated with each of them. 20. Compare OFDM and spread spectrum technology for the WLAN application. 21. Give the physical specification summary of the DSSS and FHSS used by the IEEE 802.11. 22. Difference between probe and beacon signal in 802.11 23. Difference between power control in 802.11 and power control in cellular system. 24. Why an AP in the 802.11 also acts as a bridge. 25. What are the responsibilities of the MAC management sub layer in 802.11? 1.
26. What are the difference between the 802.11a and HIPERLAN-2? 27. Compare packet form ATM and WATM. 28. What are the similarities between HIPERLAN -1 and HIPERLAN-2 29. What are the purpose of scrambler and interleaver in the HIPERLAN-2 modem? 30. What is the purpose of guard time?
PART – B 1. (i) What is PIF, DIF & SIF time interval & how they are used in IEEE 802.11.(8) (ii) Explain the difference between the carrier sensing in 802.11 & 802.3. (8) [NOV 2009] 2. With the required diagram, explain the HYPERLAN 1 architecture & MAC layer. (16) [NOV 2009] 3. (i) Explain the MAC management sublayer in terms of handoff & power management. (8) (ii) Explain the reference model & protocol entities of WATM. (8) 4. (i) Discuss the HYPERLAN-1 PHY & MAC layer in detail. (8) (ii) Discuss the DLC layer of HYPERLAN-2 in detail. (8) [MAY 2009] 5. Discuss elaborately 802.11. (16) [NOV 2008] 6. (i) Discuss in detail about HYPERLAN-1.(12) (ii) In WLAN, discuss about the emergence of unlicensed bands. (4) [NOV 2008] 7. (i) With necessary diagram, explain the HYPERLAN-1 requirements & architecture. (8) (ii) Explain the overview of IEEE 802.11. (8) [APR 2008] 8. Write short notes on (i) HPNA & (ii) Home access network. (8 +8 =16) [APR 2008] 9. (i) Explain the MAC management sublayer in terms of handoff and power management. [8] (ii) Explain the reference model and protocol entities of WATM. [8] [May 2009] 10. (b) (i) Discuss the HIPERLAN-1 PHY and MAC layers in detail. [ 8] [May (ii) Discuss the DLC layer of HIPERLAN-2 in detail. [ 8] 2009] 11. What are the layers available in HYPERLAN-2? explain each layer with suitable diagram. (16) 12. What is HYPERLAN? Explain in detail about HYPERLAN-1. (16) 13. Explain in detail about wireless ATM. (16) 14. Explain in detail about overview, reference architecture, layered architecture of IEEE802.11? (16) 15. Explain in detail about three choices of PHY layer. (16) 16. Explain in detail about MAC sub layer with suitable diagram. (16)
17. What is HAN? Explain about HAN technologies? (16) 18. Explain the following: a. Overview of the LAN industry (8) b. Evolution of the WLAN industry (8)
UNIT - V PART – A Mention the role played by L2CAP in Bluetooth networks. [May 2009] 2. What is the difference between TDOA and TOA in GPS? [May 2009] 3. Differentiate between remote and self positioning system. [May 2008] 4. What are the basic elements of wireless geo-location systems? [May 2008] 5. What is home RF? 6. What is the IEEE 802.15 and what is the relation to the Bluetooth and homeRF? 7. Name the four states that a Bluetooth terminal. 8. Name the three classes of application that are considered for Bluetooth technology? 9. Difference between 802.11 and 802.15. 10. How many different voice services does Bluetooth support? 11. How many different symmetric and asymmetric data services does Bluetooth support? 12. What is the maximum data rate of an overlay bluetooth network? 13. Difference between the implementation of paging and inquiry algorithms in bluetooth? 14. What are the two standard MAC protocols that are combined in the home RF SWAP protocol? 15. Difference between GPS, wireless cellular assisted GPS, and indoor geolocation systems. 16. Differentiate between remote and self positioning systems. 17. Compare mobile centric and network centric geolocation technique in terms of complexity and accuracy. 18. Give some examples of location dependent services. 19. What are the E-911 services and who has mandated these services? 20. What are the basic elements of a wireless geolocation system? 21. Name three major metrics used for location finding. 22. Why are AOA techniques not popular in indoor geolocation applications? 23. Why is RSS not a very good measure of the distance between a transmitter and a receiver? 24. What is Bluetooth? 1.
PART – B (i) Explain the four states that a Bluetooth terminal can take. (8) (ii) What is the difference between the MAC protocol used by Bluetooth & IEEE 802.11. (8) [NOV 2009] 2. Explain the different technologies in Wireless Geolocation. (16) [NOV 2009] 3. (i) Explain the frame format in Bluetooth technology. [8] (ii) Discuss the connection management followed in Bluetooth [May 2009] technology. [8] 4. (i) Explain the wireless geolocation system architecutre. [Marks 8] (ii) Discuss the performance measures for geolocation systems. [Marks 8] . [May 2009] 5. Discuss about (i) IEEE 802.15 WPAN & (ii) Reference architecture of Bluetooth. (8+8=16) [NOV 2008] 6. (i) Compare mobile centric & network centric geolocation techniques in terms of complexity & accuracy. (6) (ii) Discuss in detail about interference between Bluetooth & 802.11. (10) [NOV 2008] 7. Explain the different techniques of technologies for Wireless [May 2008] Geo Location with necessary diagram. 8. (i) With a necessary diagram, explain the protocol stack for Bluetooth and implement the protocol stack of cordless telephone over Bluetooth. [10] (ii) What is IEEE 802.15 and what is its relation with Bluetooth [May 2008] and Home RF? [6] 9. Explain in detail about geolocation standards for E.911 services (16) 10. What are the technologies available for wireless geo location? And explain (16) 11. What is geolocation? And give the architecture of geolocation. (16) 12. Explain about bluetooth technology. (16) 13. Explain in detail about interface between Bluetooth and 802.11. (16) 14. Explain about IEEE 802.5 WPAN and home RF. (16) 1.
Prepared by: 1. Ms. D.VYDEKI
Approved by:
HOD/ECE 2. Mr.C.GNANAPRAKASAM
