TEST1 REVIEW QUESTIONS (10/22/2010)
1. What are the differences between wireless and wireline networks
2. What are the differences between different wireless media
3. What are the differences between centralized and ad-hoc wireless networks
4. List different types of cellular wireless network elements and their functions
5. List differences between soft and hard handoff
6. What are the SDU functions – select/combine -distribute?
7. List differences between macro and micro mobility?
8. Describe procedures and steps (with an example) in micro-mobility management
9. List four handoff algorithms and explain the benefits and disadvantages of each one of them
10. What is a ping-pong effect during micro-mobility. How do you avoid this
11. Compare wireless network elements (see the list below for more details) with wire line network components like access devices, access router, edge router, core router, gateways Comparison in terms of functions, bandwidth, physical distance and session setup
a. Mobile Station
b. Base Transceiver System
c. Base Station Controller
d. Mobile Switching Center
e. Packet Inter-Working Function
12. What are the differences between wireless and wire line networks in terms of
a. QoS
b. Transmission rates
c. OA & M (Operation, Administration & Maintenance)
d. Security
13. Give examples for bandwidth for
i. BTS-BTS
ii. BTS-BSC
iii. BSC-BSC
iv. BSC-MSC
v. MSC-MSC
14. Different the steps in handoff process between two base stations (describe with an event flow.
15. We want to provide a cellular communication service to downtown Dallas.
i. Total available spectrum: 100Mhz
ii. Bandwidth needed per user: 30Khz
iii. Frequency reuse factor = 5
Calculate the no. of subscribers you can support if you have 20, 40, 60 BTSes (all the three cases). Give crisp answers (numerical wherever applicable) to each case. Clearly state any assumptions
20 BTS / 40 BTS / 60 BTSNo. of subscribers
16. State two differences between shared memory and pipe
17. Shmget(1024,2048,0644|IPC_CREAT): In this method, what is the size of shared memory being allocated and what are the permissions being given.
18. Shmat(shmid,(void *)0,SHM_RDONLY): In this method, where shmid is the shared memory Id. In the given method there are three parameters, what does the second and third parameters convey? And what is the return value of the given method?
19. What is the method to be used to destroy the shared memory segment? Specify along with parameters.
20. What do you do if there are any concurrency issues(multiple updates at a time) in shared memory?
21. What do you mean by blocked read and write in pipes?
22. What are the differences between full duplex and half duplex pipes?
23. State two benefits and limitations of pipes
24. Can we use pipes to establish a communication between two processes on two different machines? If yes how
25. Name two messages (just name them) used for handoff between BS—BS/MSC and two messages used for origination and termination of phone calls (MS-BS-MSC)
26. Name two messages (just name them) used for call setup between MS—BS and two messages used for origination and termination of phone calls (BS-MS)
27. What are the forward and reverse control channels (just list them)
28. What is the approximate size of the RF frame
29. What is the difference between “blank & burst” and “dim and burst” in signaling/control messages
30. What is a frequency reuse factor ? How do you use it
31. List three kinds of registrations
32. What is the difference between micro and macro mobility
33. What is the difference between soft and hard hand off
34. List and explain two performance parameters during hand off
35. Explain the difference between close loop and open loop power control