ELEC 5110/6110 Homework 2 Solution
Problem # 2.5
What is the average call holding time in seconds of a group of circuits that has accumulated 0.4445 Erlangs
of usage in an hour on 330 call attempts with 10 calls over-flowing (i.e., calls not served)?
0.44
Chapter 19
Problem # 5
The hopping rate of 1600 hops per second is used in the Bluetooth that carries 240
bits in one slot packet. If each frame of the HV2 voice packet carries 160 bits of
sample speech, what is the efficiency of packet transmission? How
Chapter 9
Problem1
A digital signaling system is required to operate at 9.6 kbps. If a signal element encodes a 4-bit word,
what is the minimum bandwidth of the channel?
Solution:
R = 2Bw log2M
M = 24
9.6 = 2 Bw log2 24
BW = 1.2 kHz
Problem 2
Given a chan
Chapter 11
Problem 8:
Determine (S/N)o for a spread spectrum system having bandwidth, Bw = 1.2288 MHz,
information rate, R = 9.6 kb/s and (S/N)i = 15 dB. Relate your result to Eb / N0.
Solution:
Gp = 1.2288 x 106 / (9.6 x 103) = 128
(S/N)0 = 10log128 + (S
Q1. Prove that for a hexagonal geometry, the co-channel reuse ratio is given by
Q = 3N , where N = i 2 + ij + j 2 . Hint : Use the cosine law and the hexagonal
cell geometry.
Q2. A cellular service provider decides to use a digital TDMA scheme which can
t
Chapter 17
Problem # 3
A GSM serving 100,000 subscribers in an urban area is to be replaced by a WCDMA
network. In the GSM network each subscriber generate 0.01 Erlangs voice traffic during
busy-hour. Calculate the number of 3-sector cell-sites for the WC
Chapter 8
Problem 10:
Calculate the output of the convolution encoder shown in Fig. 8.8, if the input is 1 0 1 0 0 1 1 (first bit).
g
Rate (r) = 1/2
Constraint length K = 9
X
1
X
2
X
3
c
0
X
4
X
5
X
6
0
X
7
X
8
Shift Register
Information Bits (input)
g
c
Chapter 6
Problem # 1
In a proposed TDMA cellular system, the one-way bandwidth of the system is 40
MHz. The channels spacing is 30 kHz and total voice channels in the system are
1333. The frame duration is 40 ms divided equally between 6 time-slots. The
Chapter 10
Problem 4
In Example 10.1, calculate the SNR ratio when a frequency of 6 GHz is used for the system. At this
frequency use 10 dB for the receiver noise figure.
Solution
= (3 x 108) / (6 x109) = 0.05 m
Lp = 20log[ 0.05/(4 x 10,000)] = -128 dB
P
Chapter 21
Problem # 10
In the HIPERLAN/2 PHY layer 64-subchannels implementation is used. 48
subcarriers are used to information transmission, 4 subcarriers for pilot tones used
for synchronization, and 12 subcarriers reserved for other purposes. The
HIP
Chapter 14
Problem # 1
Which two addresses are used in an IP address?
netid and hosted
Problem # 2
What are the maximum number of class A, B, and C network IDs?
Class A: 27 2 = 126
Class B: 214 2 = 16,382
Class C: 221 2 = 2,097,150
We subtract 2 in eac
ELEC 5110/6110 Wireless Networks
Homework 1
Due time: 3:30 PM, Thursday, 02/02/2017
Problem 1. Define the following parameters for a switching network:
N = number of hops between two given end systems
L = message length in bits
B = data rate, in bits per
ELEC 5110/6110 Wireless Networks
Quiz 1
Name
Question 1. List 2 advantages of wireless technologies compared to wired technologies (each in a
couple of words):
Answer: Convenience; deployed faster than fixed service; no cost for cable plant; mobility
Ques
ELEC 5110/6110 WIRELESS NETWORKS
Lecture 10
Wireless Ad Hoc Networks
Dr. Yihan Li
Dept. of Electrical & Computer Engineering
Auburn University
1
Network Architecture
Infrastructure mode
Ad hoc mode
Mao&Li, Auburn University
2
Ad Hoc Networks
Consist of
SPRING 2015: ELEC 5110/6110 WIRELESS NETWORKS
Tuesday/Thursday 14:0015:15 Broun 125
Instructor:
Dr. Yihan Li, 262 Broun, yli@auburn.edu
Office Hours: T&Th 1:00 pm 2:00 pm; email for appointment or drop by at other times.
Prerequisite: Course ELEC 3400: Co
ELEC 5110/6110 WIRELESS NETWORKS
Lecture 11
Bluetooth and IEEE 802.15
(Chapter 15 in the textbook, only materials covered in
the slides are required)
Dr. Yihan Li
Dept. of Electrical & Computer Engineering
Auburn University
1
Wireless Personal Area Networ
ELEC 5110/6110 Homework 6 Solution
Problem 1
12.3
Home address, care-of address, lifetime.
Problem 2
12.4
Home address, home agent address, MAC address, lifetime.
Problem 3
See Slides 10~16.
Problem 4
See Section 6.7.2 (p.553-554) in Computer Networking,
ELEC 5110/6110 Homework 5 Solution
8.20
b.
c.
a.
8.22 a. Because only one frame can be sent at a time, and transmission must stop until an
acknowledgment is received, there is little effect in increasing the size of the message if
the frame size remains t
ELEC 5110/6110 WIRELESS NETWORKS
Lecture 9
Wireless LAN and IEEE 802.11
(Sections 13.1, 14.1, 14.2 & 14.3 in the textbook)
Dr. Yihan Li
Dept. of Electrical & Computer Engineering
Auburn University
1
LAN Extension
Wireless LAN linked into a wired LAN on sa
Chapter 4
Problem # 4
A digital signaling system is required to operate at 9.6 kbps. If a signal element encodes
4-bit word, what is the minimum bandwidth of the channel?
Solution # 4
(a) R = 9.6 kbps; M = 24 = 16
R 2 Bw log 2 M
9.6 2 Bw log 2 2 4
B w 1.2