Value Chain Analysis

CH 1

Review Questions

1.What are general trends in the mobile market?

2.What are important differences between 3G and 4G mobile networks?

3.What advantages does 4G offer to mobile users?

4.What advantages does 3G offer to mobile operators?

5.What are the requirements of LTE?

6.What is the 3GPP? What is 3GPP2? Give example of standards.

7.Distinguish between the following: GSM, GPRS, WCDMA, HSDPA, HSUPA, HSPA+, LTE, cdmaOne, cdma2000, EV-DO, UMB, WiMax, 802.16

8.Distinguish Release 99, Rel 4, Rel 5, Rel 6, Rel 7, Rel 8, Rel 9, Rel 10, Rel 12.

9.What are implications of the following in LTE : OFDM, MIMO, Flat IP, EPC, scalable bandwidth, spectral efficiency, simplified RAN, low PAPR.

10.Who are the major 4G operators in Australia? What 4G networks do they operate?

11.Distinguish person-to-person, content to person, business connectivity and location based services ?

CH2

Review Questions for Tests

•  Draw the LTE architecture showing (a) network elements , (b)  external entities to which the network connect to (c) all the interfaces. Circle new  elements.
• State the functions of eNodeB, SGW, PGW, MME, PCRF, HSS, LIG, MLS, SPR.
• State one function of S1-MME, S1-U, X2, S6a, S10, S11,S13, S5, S8, Sgi, Gx. 
• What are some important differences between the following 3G and LTE concepts.

• 3G and LTE network architecture (EPS). 
• UTRAN and eUTRAN. 
• Packet Core Network and evolved Packet Core (EPC)  
• NodeB and eNodeB. 
• SGSN and SGW. 
• GGSN and PGW. 
• User plane in LTE and control plane in LTE 
• Physical links in LTE and logical links in LTE

1. What are some advantages and disadvantages of the following concepts in LTE  (a) MME Pooling (b) X2 interface c) flat architecture 
2. Briefly explain the backhauling network concept used in LTE between eNodeB and EPC.

CH3

Review Questions for Session 3

1. What is modulation? Why is there a need for modulation? What types of modulation are used in LTE? 

2. What is the relationship between channel quality and modulation type? 

3. What is QAM? Explain "One symbol is identified by a Q and an I value" 

4. Distinguish between the terms baud rate and bit rate? 

5. Draw the constellation diagram for the QPSK and 16-QAM? What are the similarities and differences between these schemes?

6. Why does QPSK outperform 16-QAM in noisy channels?

7. What is encoding? Why is it performed? What are typical coding rates of LTE? 

8. Explain the figure on Slide 12. 

9. What are important differences between TDD and FDD? 

10. How does LTE provide spectrum(Carrier freq) and bandwidth flexibility? 

11. What are some similarities and differences between FDMA, TDMA, CDMA, OFDMA? 

12. What is a sub-carrier? What is transmitted in a subcarrier? 

13. What is a resource block? How many subcarriers within a RB? 

14. Why are guard bands used in FDM? What are the disadvantages of guard bands? 

15. How has OFDMA adaopted the FDM concept? 

16. What is the relationship between sub carrier spacing and symbol duration?

17. Explain Figure in Slide 25. How does OFDMA minimize ICI.

18. What types of sub-carriers are used in LTE? What is the purpose of each sub-carrier? 

19. What is effect of multipath on OFDMA? 

20. Distinguish between ICI and ISI? How are  ICI and ISI minimzed? 

21. What is the cyclic prefix? Why is there a need for cyclic prefix?  What types of cyclic prefix are used in LTE? What is the impact of using a cyclic prefix? 

22. Explain Slide 31 and Slide 32. 

23. What are the advantages and disadvantages of OFDMA? 

24. What are the differences between OFDMA and SC-FDMA. 

25. Show from first principles that in LTE downlink the maximum, composite (all users) raw bit rate  is 100 Mbps for 20 MHz spectrum for Normal CP. Use the data in Slide 43. 

CH4

Review Questions for Tests

• Briefly explain the following (using suitable diagrams if possible):  Radio frame, sub-frame, slot, cyclic prefix (CP), extended cyclic prefix, useful symbol duration, symbol, resource element, resource block, physical resource block (PRB), Reseource Element Group (REG), TTI, transport block (TB).
• What are the main differences between TDD and FDD radi frame format? 
• In terms of subframe allocations, what are advantages of LTE TDD over LTE-FDD.
• Why is there a need for pilots in the uplink and downlink (DwPTS)? 
• Briefly explain how each of the following is used in an LTE network. Do NOT define the terms 

• RRC  b) PDCP c) RLC d) MAC  e) PHY 

1. What information is used by the MAC layer for downlink scheduling? 
2. What are important differences between the following concepts in LTE 

• Physical channel, logical channel and transport chanel. 
• User plane and control plane
• PDU vs SDU
• RRC_Connected state vs RRC_Idle state
• BCCH, PCCH, CCCH, DCCH and MCCH 
• DTCH and MTCH 
• Mobility management and paging 
• Unicast and multicast 
• Transparent Mode (TM) vs Unacknowledged Mode(UM)  vs. Acknowledged Mode (AM)
• Physical channel and physical signal. 
• PDSCH vs PDCCH vd PBCH
• CQ vs Rank Indicator (RI) vs Precoding Matrix (PMI)

1. Explain how UE assists in scheduling in the LTE uplink and downlink.
2. How is the size of the transport (TB) determined)? 
3. Go through the tutorial question as well. 

5.

What processes takes place when 

• a) UE is switched on before a initial network attach request.
• b) During the initial attach 
• c) Random access procedure 

Briefly explain the following (using suitable diagrams if possible). What/Why/How/Where/When 

a) Radio bearers b) Synchronization c) Random access procedure d)Attach procedure e) Scheduler  

f) data transmission in DL g) data transmission in UL 

Briefly explain how each of the following is used in an LTE network. Do NOT define the terms 

Cell ID, CQI, HARQ, PDCCH, SRB,  PRACH, C-RNTI, DM-RS, SRS

What are important differences between the following concepts in LTE