课程名称︰高等计算机网络
课程性质︰资工系选修
课程教师︰逄爱君
开课学院：电机资讯学院
开课系所︰资讯工程学系
考试日期（年月日）︰2025/06/06
考试时限（分钟）：180
试题 :
1. Wireless Link Characteristics
1.1 What do SNR and BER stand for? (5 pts)
1.2 Please elaborate on the SNR, BER, and PHY relationship. (5 pts)
1.3 How does "rate adaptation" work in 802.11? (5 pts)
2. Code Division Multiple Access (CDMA)
2.1 Please describe how CDMA works. (5 pts)
2.2 Please elaborate on why "orthogonal code" and "power control" are needed
for CDMA. (5 pts)
3. Please elaborate on the evolution path from 2G, 3G, 4G and 5G cellular net-
works. (10 pts)
4. Satellite Communications:
4.1 Please compare GEO, MEO, and LEO in terms of transmission rate, trans-
mission latency, and applications. (5 pts)
4.2 Why is an inter-satellite link needed? How does it work? (5 pts)
5. Please describe "Confidentiality", "Authentication", "Message Integrity",
and "Access and Availability" for network security. (5 pts)
6. Public-Key Cryptography, RSA, Message Digest
6.1 Can RSA be used for encrypting data in practice? Why or why not? (5 pts)
6.2 Please elaborate on the digital signature process conducted by Public-
Key Cryptography. How does it work? (5 pts)
7. Please elaborate on the security hole of "Man-in-the-middle" attack. (5 pts)
8. SSL vs. IPSec
8.1 Why is IPSec called "Blanket Coverage"? (5 pts)
8.2 Please compare SSL with IPSec. (5 pts)
9. Client Buffering
9.1 Why do we need client buffering for multimedia networking applications?
Please draw a figure to explain. (5 pts)
9.2 Please elaborate on the initial playout delay tradeoff for client buf-
fering. (5 pts)
9.3 How to adaptively adjust the playout delay caused by client buffering
for VoIP? (10 pts)
10. What is network dimensioning? (5 pts)