Enabl
i
n
g
Technolo
gi
es for W
i
reless E-Bus
i
nes
s
ABC
Weidong Kou
Yelena Yesha (Eds.)
Wi
th 141 F
ig
ures and 15 Table
s
Technologies
for Wireless
E-Business
Enabling

c
We
i
don
g
Ko

u
C
hinese State Ke
y
Laborator
y
of ISN
2
South Taibai Road
Xi an, Shaanxi, 710071
’
a
P
eo
p
les Re
p
ublic of China
Y
elena Yesh
a
D
epartment of Computer Sc
i
ence and
E
lectr
i
cal Eng
i

neer
i
ng
U
n
i
vers
i
ty of Maryland Balt
i
more County
1
000 H
i
lltop C
i
rcl
e
B
alt
i
more, Maryland 21250, US
A
yeyes
h
a@um
b
c.e
d
u

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SPIN: 10959497

Foreword
T
he ke
y
messa

g
e that we have for readers is that wireless is bloomin
g
. The
f
ollowing statistics can show rea
d
ers that this is definitely true:
y
A
ccordin
g
to Strate
gy
Anal
y
tics and UK-based Portio Research, at the
end of 2005 there were over 2.1 billion
m
obile subscribers in the world.
B
y t
h
e en
d
of 2006 t
h
e mo
bil
e su

b
scr
i
b
ers w
ill
reac
h
to t
h
e
l
eve
l
of
2.5 billions, and this fi
g
ure is expected t
o
in
c
r
e
a
se
t
o

c
l

ose
t
o
4
b
illi
o
n
by 2012. The worldwide mobile phone penet
ration is predicted to easily
t
t
p
ass t
h
e 50% mar
k

b
y t
h
e en
d
of 2009.
y
The Ministr
y
of Informat
i
on Industr

y
of China reported that at the en
d

o
f 2005, the number of mobile subscr
i
bers in the country was close to
4
00 m
illi
ons. It
i
s pre
di
cte
d
t
h
at
b
y t
h
e en
d
of 2006, t
h
e num
b
er o

f

mobile subscribers in China can reach 440 millions. In addition, the
n
umber of short messages sent in China in 2005 was over 300 billions,
a
nd the associated revenue was close to
$
4 billion US dollars.
y
A
ccordin
g
to LaNetro Zed based in Madrid of S
p
ain, at the end of
2005, West Euro
p
e has over 270 millions of wirele
s
s subscribers.
G
ermany
i
s t
h
e
l
argest mar
k

et for mo
b
il
e p
h
ones
i
n Europe, w
i
t
h
74.1
million users, and it has a penetration rate of 90%; Ital
y
is the secon
d

l
argest market in Europe, with over 65.3 million mobile subscribers
a
n
d
a penetrat
i
on rate of 114%, t
h
e
hi
g
h

est
i
n t
h
e wor
ld
; t
h
e Un
i
te
d

K
in
g
dom has 64 million subscribers and a mobile phone penetration
r
ate of 106%; the
p
enetration ra
t
e
in Finland stands at 100
%
with
n
ear
l
y 5.2 m

illi
on su
b
scr
ib
ers.
y
I
n 2005 t
o
tal n
u
m
be
r
o
f m
ob
il
e
se
r
v
i
ce

subsc
ri
be
r

s
in R
uss
ia ha
s

grown by 70 percent and reached 125.8 million, according to a recent
r
eport
i
n 2006 from
A
C&M consu
l
t
i
ng
b
ureau.
y
A
ccordin
g
to Mobile Marketin
g
Ass
o
c
iation, in the
U

nited States the
n
umber of wireless subscribers was over 200 millions. The data on the
M
o
bil
ep
h
one
di
scuss.com Forums s
h
ows
th
at 66% of US
h
ouse
h
o
ld
s
o
wn cell
p
hones.
y
I
n Canada
,
with the number of subscribers to wireless

p
roducts an
d

s
erv
i
ce tota
li
ng c
l
ose to
1
3.9 m
illi
on
b
y m
id
-2004, a
l
most 43% o
f

Canadians now have access to a wireless device. B
y
the end of 2005,
it was estimated that this number is probably over 50%.
y
Gl

o
b
a
l
w
i
re
l
ess serv
i
ce revenue
i
s
e
x
pecte
d
to r
i
se 11% to
$
623.9
b
illion. The
g
lobal wireless service industr
y
is expected to
g
enerate

$
800 billion in revenue in 2010, with emerging markets accounting
for a
b
out 42% of t
h
e tota
l
.
y
W
orldwide shi
p
ments of mobile
p
hones reached a record 242 million
un
i
ts
i
n Q4 2005, surpass
i
n
g
t
h
e pr
e
vi
ous pea

k
of 200 m
illi
on un
i
ts
i
n
Q
4 2004, accordin
g
to iSuppli. For all of 2005, 813 million units were
s
hi
pp
ed, u
p
14% from 713 million in 2004.
T
he list of statistics can
g
o on and on. The rapid
g
rowth in the number of wireless
s
ubscribers along with the emergence of new wireless technologies such as 3G
an
d
W
i

-F
i
, a
ll
ow
i
ng for
hi
g
h
er transm
i
ss
i
on rates w
ill

l
ea
d
to an exp
l
os
i
on of new
e-business applications and services generally
referred to as “wireless e-business”.
y
Wi
re

l
ess e-
b
us
i
ness a
ll
ows peop
l
e to con
d
uc
t

b
us
i
ness w
i
re
l
ess
l
y w
i
t
h
out p
h
ys

i
ca
l
connectivit
y
. A variet
y
of different d
e
v
ices can be used for wireless e-business,
i
ncluding mobile phones, pagers, palm-
p
owered
p
ersonal c
o
mp
uters (PCs),
p
ocket
PCs,
l
aptop computers, an
d
ot
h
er mo
bil

e
d
ev
i
ces or
d
ev
i
ces connecte
d
to t
h
e
w
ir
e
l
ess
n
e
t
wo
rk
s.

Because w
i
re
l
ess e-

b
us
i
ness
h
o
ld
s t
h
e prom
i
se to res
h
ape t
h
e way
b
us
i
nesses
conducted, and because it has a hu
g
e customer base, the advanta
g
es of wireless
e
-business are endless. The key is that people can break free from spatial an
d

tempora

l
constra
i
nts an
d
commun
i
cate an
d
transact
i
n
b
us
i
ness anyt
i
me an
d

an
y
w
h
ere. However, t
h
ere are a num
b
er of
g

reat c
h
a
ll
en
g
es,
i
nc
l
u
di
n
g
pro
bl
ems of
s
ustaining connectivity, l
i
mited resources such
a
s limited bandwidth and limited
f
requency spectrum, as we
ll
as t
h
e
i

ssues of secur
i
ty an
d
pr
i
vacy
i
n a w
i
re
l
ess
e
nv
i
ronment. To a
dd
ress t
h
ese pro
bl
ems an
d

i
ssues,
h
u
g

e efforts
h
ave
b
een ma
d
e
to develop a variety of
e
nabling technologies, in
c
luding new wireless communi-
cat
i
on tec
h
no
l
og
i
es, w
i
re
l
ess secur
i
ty, w
i
re
l

ess app
li
cat
i
on protoco
l
s, mo
bil
e
p
a
y
ment protoco
l
s, mo
bil
e
d
ata mana
g
emen
t
, mo
bil
e a
g
ents, mo
bil
e pa
y

ment,
mobile computin
g
, mobile services, a
n
d
RFID technolo
g
ies. Drs. Weidon
g
Kou
an
d
Ye
l
ena Yes
h
a
h
ave e
di
te
d
t
hi
s
b
oo
k,
w

i
t
h
ass
i
stance from t
h
e c
h
apter
contr
ib
utors to cover t
h
ese tec
h
no
l
o
gi
es.
I
b
e
li
eve t
hi
s
i
s an exce

ll
ent
b
oo
k
for
b
us
i
ness managers, e-
b
us
i
ness
d
eve
l
opers,
aca
d
em
i
c researc
h
ers, un
i
vers
i
t
y

stu
d
ents, professors, an
d
profess
i
ona
l
consu
l
tants
to acquire comprehensive knowled
g
e on en
a
blin
g
technolo
g
ies for the bloomin
g
w
i
re
l
ess e-
b
us
i
ness. I

hi
g
hl
y recommen
d
t
hi
s
b
oo
k
!
Ro
b
ert May
b
erry
Vi
ce Pres
id
ent
,
Sensors an
d
Actuators
I
BM Software Grou
p

VI

Foreword
Table of Contents
1 Introduction to Enabling Technologies for Wireless E-Business
W
. Kou and Y. Yesha

1
1
.1 Intro
d
uct
i
on 1
1.
2 A
bou
t T
his
B
ook
3
R
e
f
erences 5
2 Fundamentals o
f

Wi
reless

C
ommun
i
cat
i
ons
D. Shen an
d
V.O.K. L
i

7
2.1 Intro
d
uct
i
on
7

2.2 Global S
y
stem for Mobile Communication 7
2.3
G
enera
l
Pac
k
et Ra
di

o
S
erv
i
ce 15
2.4 Code Division Multiple Access S
y
stems 22
2.5
S
ummar
y
41
Re
f
e
r
e
n
ces
41
3 Wireless Securit
y

4
4
3.1 Intro
d
uct
i

on 44
3.2 Mobile Certificate 46
3.3 E
lli
pt
i
c Curve Cryptograp
h
y for Mo
bil
e Comput
i
ng 51
3.4 Server Assisted Mobile Securit
y
Infrastructure 62
3.5 Summary 72
R
eferences
7
3
4 Wireless A
pp
lication Protocol
W
. Kou
76
4.1 Introduction 76
4.2 W
i

re
l
ess App
li
cat
i
on Protoco
l
76
4.3 Wireless Application Security 85
4.4
S
ummary 86
4.5 A
pp
endix 86
R
e
f
erences 8
7

W
.
-
B.

Lee
T
able of Contents

5 RFID Technolo
gi
es and Appl
i
cat
i
ons
D. Kou, K. Zhao, Y. Tao and W. Ko
u
.

89

5.1 Introduction 89
5.2
C
omponents 92
5.3 Middleware Technology 99
5.4
S
tan
d
ar
d
s 102
5.5 Summar
y
107
Re
f

e
r
e
n
ces
108
6

S
o
f
tware In
f
rastructure
f
or
C
ontext-Aware Mob
i
le
C
omput
i
n
g
C.L. Wang, X.L. Z
h
ang, N. Be
l
aramani

,
P.L. Siu
,
Y. C
h
ow
,

and F.
C
.M. Lau
109

6
.1 Introduction 10
9
6
.2 Context-aware Mo
bil
e Comput
i
n
g
Infrastructure 111
6
.3 A Case Stud
y
– The Sparkle Pro
j
ect 115

6
.4
S
ummar
y
128
References 12
9

7
Data Mana
g
ement for Mobile Ad-Hoc Networks
F
. Perich
,
A. Joshi
,
an
d
R. Chirkova

132
7
.1 Introduction 132
7
.2 Ori
g
ins of Mobile Peer-to-Peer Computin
g

Model 133
7
.3 Challenges 135
7
.4 Peer-to-Peer Data Mana
g
ement Model 156
7
.5 Future Work 169
7
.6
S
ummar
y
170
R
e
f
erences 171
8
Mobile Agents: The State of the Art
B. Yang an
d
J. Li
u

1
77
8.1 Intro
d

uct
i
on 1
77
8.2 System Facilities 178
8.3 M
i
grat
i
on an
d
P
l
ann
i
ng 180
8.4 Communication an
d
Interoperability 184
8.5 Secur
i
ty 190
8.6 Summary 194
Re
f
erences 197
VII
I
Table of Content
s

9 Mult
i
agent
C
ommun
i
cat
i
on
f
or e-Bus
i
ness us
i
ng Tuple
S
paces
H
.F. Li
,
T. Ra
d
hakrishnan, an
d
Y. Zhan
g
.
199
9
.1 Intro

d
uct
i
on 1
99
9.2 Com
p
utation and Tu
p
le S
p
aces 200
9.3 Examp
l
es of A
g
ent Coor
di
nat
i
on
i
n e-Commerce 204
9.4 A Tuple Space Based Framework for A
g
ent
C
ommun
i
cat

i
on 207
9.5 A Case Stu
dy

i
n e-Commerce Us
i
n
g
Tup
l
e Spaces 217
9.6 Summary 230
R
e
f
e
r
e
n
ces
231
10 Mob
i
le Pa
y
ment
Y
. Liu, X. Cao, and L. Dan

g

233

1
0
.
1 Intr
oduc
ti
o
n

233
1
0.2
Ch
aracter
i
st
i
cs 233
1
0.3 A
g
ents 236
1
0.4 Secur
i
ty for Mo

bil
e Payment 244
1
0.5 Summar
y
251
Re
f
erences 252
11 Mob
i
le
C
ontent Del
i
very Technolog
i
es
Y
. Yang, an
d
R. Yan
253

1
1
.
1 Intr
oduc
ti

o
n

253
1
1.2 Short Message Service 253
1
1
.
3 M
u
ltim
ed
ia M
essa
g
in
g
Service 262
1
1.4 Transcoding Techni
q
ues 275
1
1.5
S
ummar
y
292
Re

f
erences 292
12 Mobile Services Computing
L
. Zhang, B. Li, an
d
Y. Song
2
99
1
2.1
W
e
b

S
erv
i
ces
O
verv
i
ew 299
1
2.2 Extending Web Services to Mobile Services 299
1
2.3
G
enera
l

Arc
hi
tecture of Mo
bil
e
S
erv
i
ces 303
1
2.4 Two General A
pp
roaches to Develo
p
Web/Mobile Services 306
1
2.5 Case Stu
d
y – WAS
(
W
i
re
l
ess A
l
arm System
)
306
1

2.6 Summar
y
309
Re
f
erences 310
IX
T
a
bl
e of
C
ontents
13 Location-Aware Services and its Infrastructure Su
pp
ort
Y. Chen and D. Liu
3
12
1
3.1 Introduction 312
1
3.2 Location Operatin
g
Reference Model and Infrastructure 313
1
3.3 Location Server 317
1
3.4 Movin
g

Ob
j
ect Databases 322
1
3.5 Spat
i
a
l
Pu
bli
s
h/
Su
b
scr
ibe
En
gi
ne 326
1
3.6 Related Works 330
1
3.7
S
ummary 332
R
e
f
e
r

e
n
ces
332
14 Mobile Commerce and Wireless E-Business A
pp
lications
S
.
S
on
g

335

1
4.1 Introduction 335
1
4.2 Mobile
C
ommerce 336
1
4.3 Wireless e-Business A
pp
lications 344
1
4.4 Case Stud
y
354
1

4.5 Summary 359
References 35
9

G
lossar
y
361
A
bout the Editor
s
371
C
ontr
i
butor
s
3
7
3
,

X
I
n
d
ex 379
1 Introduction to Enabling Technologies for Wireless
E-Business
*+

*
+
Department of E
l
ectr
i
ca
l
Eng
i
neer
i
ng an
d
Computer Sc
i
ences, Un
i
vers
i
ty of Mary
l
an
d
,
B
altimore Count
y
, USA
1.1 Introduction

W
ireless e-business allows
p
eo
p
le to communicate and transact in business vi
a

wireless technolo
gy
, without ph
y
sical connectivit
y
, such as wires or cablin
g
.
W
ireless e-business uses m
a
n
y
devices, includin
g
mob
i
le phones, pa
g
ers, palm-
p

owered
p
ersonal com
p
u
t
ers (PCs),
p
ocket PCs, la
p
to
p
com
p
uters, and other mo-
b
ile devices or devices connec
t
ed to the wireless networks.
A
dvancements in wireless
t
echnologies hold the pro
m
ise to reshape the way
b
us
i
nesses con
d

ucte
d
.
Wi
t
h
w
i
re
l
ess tec
h
no
l
og
i
es, peop
l
e can
b
rea
k
free from spa
-
ti
a
l
an
d
tempora

l
constra
i
nts, as t
h
ey are a
bl
e to use t
h
ese tec
h
no
l
og
i
es to wor
k

anyw
h
ere an
d
anyt
i
me. W
i
t
h
w
i

re
l
ess e-
b
us
i
ness, compan
i
es can
l
ocate
i
nventory
i
tems, an
y
time, an
y
where; emer
g
enc
y
units are able to res
p
ond in real time; an
d

u
niversities are able to mana
g

e communications across campuses. The rapi
d

g
rowth in mobile telephony in recent years has provided a strong model for the
ado
p
tion of undeterred wireless e-busi
n
ess. A number of consulting firms have
made various estimations on the growth
o
f the number of mobile
p
hone users
wor
ld
w
id
e. T
h
ese est
i
mat
i
ons are certa
i
n
l
y conf

i
rme
d

b
y t
h
e
h
uge
i
ncrease
i
n t
h
e
num
b
er of mo
bil
e p
h
one users
i
n C
hi
na
–

th

e country current
l
y
h
as over 300 m
il
-
li
on mo
bil
e p
h
one users, more t
h
an t
h
e ent
i
re popu
l
at
i
on of t
h
e USA. T
h
e rap
id

tran

si
t
io
n fr
o
m f
i
x
ed
to mo
bil
e te
l
ep
h
on
y
w
ill
a
l
most certa
i
n
ly

b
e fo
ll
owe

d

by
a
si
m
il
ar trans
i
t
i
on from con
d
uct
i
n
g

e
-
b
us
i
ness t
h
rou
gh

d
es

k
to
p
com
p
uters v
i
a
phy
s
i
ca
l
connect
i
v
i
t
y
to
wi
re
l
ess e-
b
us
i
ness t
h
rou

gh
a var
i
et
y
of mo
bil
e
d
ev
i
ces
via wireless communication networks in the near future.
To make wireless e-business work effectively, a variety o
f
enabling technolo
-
g
ies are needed. First, one mus
t
be connected wirelessly. This means that wireless
commun
i
cat
i
ons networ
k
s must
b
e

i
n p
l
ace. From t
h
e f
i
rst commerc
i
a
l
G
l
o
b
a
l
System for Mobile Communication (GSM) net
work launched in 1992 to 3G ser-
t
t
v
i
ces
l
aunc
h
e
d


i
n Hong
K
ong, UK, an
d
Ita
l
y
i
n recent years, w
i
re
l
ess commun
i
ca-
t
i
on networ
k
s
h
ave penetrate
d
a
l
most ever
y
part of t
h

e wor
ld
. T
h
e 2G
/
2.5G an
d

3
G w
i
re
l
ess commun
i
cat
i
on s
y
stems are t
h
e cornerstones of w
i
re
l
ess commun
i
ca
-

t
i
ons. In a
ddi
t
i
on, t
h
ere are ot
h
er w
i
r
e
l
ess networ
k
s, suc
h
as W
i
-F
i
, W
i
-Max,
Bluetooth, and infrared. Wireless securit
y
i
s


c
r
uc
ial f
o
r
w
ir
e
l
ess

e
-
bus
in
ess.
A
c
-
cessin
g
the Internet, di
g
itall
y
si
g
n

i
n
g
e-commerce transactions, authentication, and
W. Kou and Y. Yasha
*
ISN Nat
i
ona
l
Key La
b
oratory, X
idi
an Un
i
vers
i
ty, X
i
’an, C
hi
n
a
2

W
. Kou an
d
Y. Yes

ha
e
ncr
y
pt
i
on of transact
i
on
i
nformat
i
on, a
ll
t
hese

wi
r
eless

e
-
busi
n
ess
a
c
t
ivi

t
ies
n
eed

s
ecurity. However, given that wireless e-businesses broadly use mobile devices
s
uch as mobile phones, and that these devices have strict processing requirements
and storage limitations of wireless environments, ubiquitous wireless security
tec
h
no
l
og
i
es must
b
e rea
d
y to sat
i
sfy t
h
ese requ
i
rements an
d
overcome t
h

ese
li
m
i
-
tat
i
ons. To ena
bl
e mo
bil
e Internet app
li
ca
ti
ons, app
li
cat
i
on env
i
ronment an
d
var
i-
ous app
li
cat
i
on protoco

l
s are nee
d
e
d
. I
n
1997
,
Er
i
csson
,
Motoro
l
a
,
an
d
No
ki
a
f
orme
d
a forum for creat
i
n
g
suc

h
protoco
l
s. As a resu
l
t, t
h
e w
i
re
l
ess app
li
cat
i
on
p
rotoco
l

(
WAP
)
, a su
i
te of emer
gi
n
g
s

tan
d
ar
d
s,
h
as
b
een
d
ef
i
ne
d
. T
h
e WAP
i
s
d
e
-
sig
ne
d
to ass
i
st t
h
e conver

g
ence of t
w
o
fast-
g
row
i
n
g
networ
k
tec
h
no
l
o
gi
es,
namely, wireless communications and the Internet. The convergence is based on
the rapidly increasing numbers of mobile phone users and the dramatic effect of e
-
b
us
i
ness over t
h
e Internet. T
h
e com

bi
nat
i
on of t
h
ese two tec
h
no
l
og
i
es w
ill

h
ave a
bi
g
i
mpact on current e-
b
us
i
ness pract
i
ce,
a
n
d


i
t w
ill
create
h
uge mar
k
et potent
i
a
l
.
To
b
e a
bl
e to connect
m
obil
e peop
l
e to t
h
e
i
nformat
i
on an
d
app

li
cat
i
ons t
h
e
y

nee
d
— an
y
t
i
me an
d
an
y
w
h
ere, to a
ll
ow p
e
o
p
l
e to
h
ave computat

i
on capa
bili
t
i
es
an
d
networ
k
resources at
h
an
d
, an
d
to move t
h
e wor
k
p
l
ace to an
y
p
l
ace, support
-
i
n

g
t
h
e
b
roa
d
est spectrum of mo
bil
e net
w
or
k
s an
d
a w
id
e arra
y
of
d
ev
i
ces on t
h
e
client side, necessar
y
wireless middlewa
r

e
software and mobile data mana
g
emen
t

are essential. When a mobile user moves with a handheld mobile device and con-
nects to a wireless network, how one can
e
n
su
r
e
that th
e

co
nn
ec
ti
o
n
w
ill n
o
t
be

l
ost w

hil
e t
h
e user moves out of t
h
e
r
ange of t
h
e w
i
re
l
ess networ
k
t
h
at can reac
h
?
Roam
i
ng from one w
i
re
l
ess networ
k

i

nto
a
not
h
er
i
s t
h
erefore a
d
es
i
re
d
feature fo
r

w
i
re
l
ess e-
b
us
i
ness app
li
cat
i
ons.

Mo
bil
e content
d
e
li
ver
y
tec
h
n
o
l
o
gy

d
ea
l
s w
i
t
h

d
e
li
ver
i
n

g
t
h
e
digi
ta
l
contents to
mo
bil
e
d
ev
i
ces w
i
t
h

li
m
i
te
d
comput
i
n
g
an
d

stora
g
e resources. For examp
l
e,
i
f a
digi
ta
l
p
h
oto
i
s too
l
ar
g
e to f
i
t
i
nto t
h
e
m
emor
y
of a mo
bil

e p
h
one
,
t
h
en for t
h
e
mobile user to see the
p
hoto, one must convert the ori
g
inal di
g
ital
p
hoto into one
o
f a
s
mall
e
r
s
iz
e
that
c
an fit int

o
t
h
e mobile phone. This convertin
g
process is
called transcodin
g
.
W
h
en a mo
bil
e user
i
s
l
ocate
d

i
n a p
l
ace w
h
ere t
h
e
b
us

i
nesses are c
l
ose to
hi
m,
t
h
ese
b
us
i
nesses may w
i
s
h
to
i
nform t
h
e user on e
i
t
h
er serv
i
ces or pro
d
ucts ava
il

-
a
bl
e at a spec
i
a
l
pr
i
ce, w
hi
c
h
t
h
e user m
igh
t
b
e
i
ntereste
d

i
n. T
h
e tec
h
no

l
o
gy
ena
-
bli
n
g
suc
h
a capa
bili
t
y
i
s ca
ll
e
d

l
ocat
i
on-aware tec
h
no
l
o
g
y

, w
hil
e re
l
ate
d
serv
i
ces
ar
e

c
a
lled

loc
at
io
n-a
w
ar
e

se
r
vices.

To transact wireless e-business, mobile pa
y

ment is essential. Without mobile
p
a
y
ment, wireless e-business is
n
ot
g
oin
g
to be successful
a
s
p
eo
p
le need to col-
l
ect the pa
y
ment when the
y
conduct e-business an
y
time and an
y
where. Mobile
p
ayment needs wireless security to ensure secure authentication and data confi
-

dentiality. In addition, restriction of
m
o
bile devices and wireless communications
must be considered while making the payment.
W
i
re
l
ess e-
b
us
i
ness a
l
so nee
d
s mo
bil
e a
g
ent tec
h
no
l
o
gy
. A mo
bil
e a

g
ent s
y
stem
i
s a p
l
atform t
h
at can create,
i
nterpret, execute, transfer, an
d
mana
g
e a
g
ents. T
h
e
a
bili
t
y
to trave
l
, w
hi
c
h


di
st
i
n
g
u
i
s
h
es mo
bil
e
ag
ents from ot
h
er
ty
pes of a
g
ents, a
l-
l
ows them to move to a new host and then to take advanta
g
e of bein
g
in the same
e
nvironment to interact with each other locall

y
.
1
Introduction to Enabling Technolo
g
ies for Wireless E-Business 3
M
obile Web service is an extension
o
f Web service technolo
gy
. A Web service
i
s a software system
d
es
i
gne
d
to support
i
nteropera
bl
e mac
h
i
ne-to-mac
hi
ne
i

nter
-
a
ct
i
on over a networ
k
. It
i
s a stan
d
ar
d
comput
i
ng un
i
t over
th
e Internet. T
h
ere are
th
ree tec
h
no
l
og
i
es to ma

k
e We
b
serv
i
ce wor
k
, name
l
y, We
b
Serv
i
ces Descr
i
pt
i
o
n

L
an
g
ua
g
e
(
WSDL
)
, S

i
mp
l
e O
bj
ect Access Protoco
l

(
SOAP
)
, an
d
Un
i
versa
l
De-
scr
i
pt
i
on, D
i
scover
y
, an
d
Inte
g

rat
i
on
(
UD
D
I
)
. W
i
t
h
WSDL, a
l
e
g
ac
y
s
y
stem can
b
e wrappe
d
w
i
t
h
a stan
d

ar
d

i
nterface an
d

b
ecomes a We
b
serv
i
ce. SOAP, on t
h
e
other hand,
p
rovides a standard connec
t
ion amon
g
those Web services so tha
t

communications amon
g
them can be carried out. UDDI is a re
g
istration server,
which is available for the convenience of publishin

g
and retrievin
g
Web services.
Accor
di
ng to t
h
e
i
nformat
i
on
i
n UDDI servers, consumers of We
b
serv
i
ces are
a
bl
e to o
b
ta
i
n essen
ti
a
l


k
now
l
e
d
ge so as to ensu
r
e t
h
at t
h
e serv
i
ces meet t
h
e
i
r re-
qu
i
rements. Mo
bil
e We
b
serv
i
ce exten
d
s
W

e
b
serv
i
ce w
i
t
h
cons
i
de
rat
io
n
s

o
f m
o
-
bili
t
y
, w
i
re
l
ess secur
i
t

y
, restr
i
ct
i
on of mo
bil
e
d
ev
i
ces, an
d
mu
l
t
i
mo
d
a
li
t
y
.
R
a
di
o Frequenc
y
I

d
ent
i
f
i
cat
i
on
(
RFID
)
i
s a not-qu
i
te-new w
i
re
l
ess tec
h
no
l
o
gy

t
hat has a wide ran
g
e of applications from automaticall
y

collectin
g
hi
g
hwa
y
tolls,
i
dentif
y
in
g
and tracin
g
products and mana
g
in
g
suppl
y
chain, to controllin
g
access
t
o buildin
g
s and offices. A minimum RFID s
y
stem consists of an RIFD ta
g

, a
n
RFID reader, and a computer host. Each RFID tag holds a microchip surrounded
by a printed antenna and
p
rotected between laminates,
w
hich can be
p
asted to
a

product. The chip on the RFID tag holds data in its memory that can identify a
m
anufacturer, a part
i
cu
l
ar pro
d
uct mo
d
e
l
, an
d
an
i
n
di

v
id
ua
l
pro
d
uct. An RFID
rea
d
er
i
s a
d
ev
i
ce to rea
d
t
h
e ta
g
at a
di
stance. Ra
di
o waves from t
h
e rea
d
er

hi
t t
h
e
t
a
g
w
i
t
h
enou
gh
power for
th
e ta
g
to retransm
i
t t
h
e
d
ata
b
a
ck
t
o
t

he
r
e
a
de
r
.
T
he
host com
p
uter
p
rocesses the data and
pa
sses them to business a
pp
lications.
G
iven a number of market demands and needs, includin
g
societal shifts towar
d
a more mobile workforce,
g
eo
g
raphical
m
obilit

y
amon
g
corporate individuals,
criticality of time and effective decision making within narrow windows of o
pp
or-
t
unities, increasing need for remote commu
n
i
cation, com
p
utin
g
and collaboration,
i
ncreasing availability of wireless connections at affordabl
e
rates, new and im
p
or
-
t
ant requ
i
rements for mo
b
il
e comput

i
ng support suc
h
as
i
nte
lli
gent mo
bil
e agents,
an
d
mo
bil
e
k
now
l
e
d
ge networ
ki
ng, part
ic
ul
ar
l
y, g
i
ven a c

l
ose to one
billi
on mo-
bile phone users (if not
y
et exceeded), which is a hu
g
e potential customer base fo
r

wireless e-business, we can certainl
y
sa
y
that wireless e-business is ver
y
promis-
i
n
g
and will have a ver
y
bri
g
ht future.
1.2 About This Book
A
s
d

o
i
ng e-
b
us
i
ness w
i
re
l
ess
l
y
i
s
b
ecom
i
ng
a
new tren
d
an
d
as t
h
ere
i
s a
h

uge
d
eman
d
from
b
us
i
ness execut
i
ves an
d
managers, tec
h
no
l
og
i
ca
l
pract
i
t
i
oners, stu-
d
ents, an
d
teac
h

ers w
h
o w
i
s
h
to
k
now
h
ow e-
b
us
i
ness can
b
e
d
one w
i
re
l
ess
l
y, an
d

w
h
at t

h
e tec
h
no
l
o
gi
es to support w
i
re
l
ess e
-
b
us
i
ness are, t
hi
s
b
oo
k

i
s a response to
thi
s
d
eman
d


by
prov
idi
n
g
rea
d
ers w
i
t
h
compre
h
ens
i
ve
i
nformat
i
on on ena
bli
n
g

t
ec
h
no
l

o
gy
for w
i
re
l
ess e-
b
us
i
ness. T
h
e tar
g
et au
di
ence of t
hi
s
b
oo
k

i
nc
l
u
d
es
e

-business develo
p
ers, busin
e
s
s mana
g
ers, academ
i
c
researchers, universit
y

s
tu
d
ents, professors, an
d
profess
i
ona
l
con
s
u
l
tants. T
hi
s
b

oo
k
can a
l
so
b
e use
d
fo
r

e-
b
us
i
ness c
l
asses an
d
tra
i
n
i
n
g
courses.
W
e
h
ave

i
nv
i
te
d

l
ea
di
n
g
experts
i
n var
i
o
u
s
countr
i
es an
d
re
gi
ons,
i
nc
l
u
di

n
g
U
SA, Canada, Hon
g
Kon
g
, Taiwan, and China, to contribute to this book. From
w
ireless communication fundamentals to
w
ireless a
pp
lications, the book covers
the major subjects related to
e
nabling technologies f
o
r
wireless e-business, includ-
ing wireless security, mobile agents, mobile payment, mobile computing, mobile
data management, location-based ser
vices, software infrastructure, wireless appli-
r
r
c
at
i
on protoco
l

, an
d
RFID tec
h
no
l
og
i
es.
Ch
apter 2 presents a
b
r
i
ef
i
ntro
d
uct
i
on of t
h
e fun
d
amenta
l
s of w
i
re
l

ess commu
-
ni
cat
i
ons,
i
nc
l
u
di
n
g
a var
i
et
y
of ce
ll
u
l
ar stan
d
ar
d
s, suc
h
as GSM, GPRS, IS-95,
cd
ma2000, an

d
UMTS.
C
hapter 3 deals with mobile security
i
ssues with the int
r
i
nsic restrictions that
a
re inherent in the mobile devices and the wireless environment, and
p
ossible
practical solutions that can be used to overcome those restrictions, including the
wi
re
l
ess equ
i
va
l
ent of pu
bli
c
k
ey cryptosystem an
d
e
lli
pt

i
c curve cryptograp
h
y, an
al
ternate approac
h
to convent
i
ona
l
pu
bli
c
k
ey cryptograp
h
y, w
h
i
c
h

i
s su
i
ta
bl
e for
a

pp
li
cat
i
ons un
d
er resourc
e
-constra
i
ne
d
con
di
t
i
ons.
W
AP
i
s a su
i
te of emer
gi
n
g
stan
d
ar
d

s to e
n
abl
e mo
bil
e Internet app
li
cat
i
ons.
T
h
e
W
AP stan
d
ar
d
s
h
ave
b
een create
d
as a resu
l
t of t
h
e
W

AP Forum t
h
at was
forme
d

i
n June 1997
by
Er
i
csson, Motoro
l
a, an
d
No
ki
a. T
h
e WAP Forum
i
s
d
e
-
si
g
ned to assist the conver
g
ence of t

w
o fast-
g
rowin
g
network technolo
g
ies,
n
amel
y
, wireless communications and the Internet. Chapter 4 presents a detailed
introduction to WAP, includin
g
the application environment and various
p
roto
-
c
o
l
s.
C
h
apter 5 focuses on a very
h
ot w
i
re
l

ess tec
h
no
l
ogy, RFID, w
hi
c
h

h
as a
h
uge
potent
i
a
l

i
n manag
i
ng pro
d
ucts an
d
peop
l
e, part
i
cu

l
ar
l
y
i
n t
h
e areas of supp
l
y
ch
a
i
n mana
g
ement, manufactur
i
n
g
, asset m
a
n
a
g
ement, pro
d
uct trac
i
n
g

, an
d
secu
-
ri
t
y
access contro
l
.
An exten
d
e
d
form of mo
bil
e comput
i
n
g
, name
ly
, context-aware mo
bil
e comput
-
in
g
, is investi
g

ated, and the issues
in building soft
ware infrastructure for support-
t
t
in
g
this paradi
g
m are discussed in Chap. 6.
C
h
apter 7 presents an overv
i
ew of c
h
a
ll
enges ar
i
s
i
ng
i
n t
h
e area of mo
bil
e
d

at
a

m
anagement an
d
surveys ex
i
st
i
ng so
l
ut
i
ons, w
i
t
h
emp
h
as
i
s on
d
ata management
i
n mo
bil
e a
d


h
oc networ
k
s
. Var
i
ous c
h
a
ll
enges re
l
ate
d
to
d
ata management
i
n mo
-
bil
e a
d

h
oc networ
k
s
,


i
nfor
m
a
t
i
on
di
scover
y

i
n
dy
nam
ic
networ
k
s
,
an
d
tra
di
t
i
ona
l
d

ata mana
g
ement
i
ssues, suc
h
as transact
io
na
l
support or cons
i
stenc
y
amon
g

d
at
a

obj
ects, are
di
scusse
d
, an
d
po
s

s
ibl
e so
l
ut
i
ons to t
h
ese c
h
a
ll
en
g
es are propose
d
.
T
he topic of mobile a
g
ents is the focus of Cha
p
. 8.
A
ft
e
r a
b
ri
e

f intr
oduc
ti
o
n
of

the concept of mobile a
g
ents, the cha
p
ter outlines t
h
e
advanta
g
es and applications
o
f mobile a
g
ents, and presents important technolo
g
ies for implementin
g
mobile
a
gen
t
sys
t

ems.
C
ha
p
ter 9 extends the discussions of
m
obile agents, by presenting how the co
-
o
rdination and information sharing among multiple agents can be done through
t
h
e tup
l
e space-
b
ase
d
coor
di
nat
i
on mo
d
e
l
.
4 W. Kou and Y. Yesh
a
Mobile payment is crucial to wireless e-business, simply because without col-

l
ect
i
ng payment
i
nstant
l
y regar
dl
ess of w
h
ere users are, t
h
e w
i
re
l
ess e-
b
us
i
ness
cannot survive. Chapter 10 presents a variety of
mobile payment technologies.
f
Ch
apter 11
d
ea
l

s w
i
t
h
mo
bil
e conte
n
t

d
e
li
very tec
h
no
l
og
i
es,
i
nc
l
u
di
ng messag-
i
n
g
services technolo

g
ies, such as short messa
g
e service (SMS) and multimedia
messa
g
e service (MMS), and existin
g
transc
o
d
in
g
technolo
g
ies of ima
g
e, video,
audio, and Web pa
g
es.
Web service is an effective techni
q
ue f
o
r
improving business efficiency b
y

automating the collaboratio

n
of heterogeneous information systems. By extending
i
t to the wireless and mobile world, m
a
ny more people can be connected to the enor-
a
a
mous We
b
of
i
nformat
i
on an
d
serv
i
ces, anyw
h
ere an
d
anyt
i
me. C
h
apter 12
p
resents mo
bil

e serv
i
ces, w
hi
c
h

i
s
th
e next
di
rect
i
on of
W
e
b
serv
i
ce.
C
ha
p
ter 13
p
resents the Location Operatin
g
REference (LORE) model, includ
-

i
n
g
domains of location operation semantic, privac
y
and securit
y
, mana
g
ement
and location-aware a
g
ent. To suppor
t
the rich sets of location-aware wireless a
p-
plications, based on the LORE model, an
infrastructure – Location-Based Services
n
(
LBS) middleware—can be built, which has three key components: location
s
erver, moving object database, and spatial pub/sub engine.
T
h
e
b
oo
k
conc

l
u
d
es w
i
t
h
C
h
ap. 14,
i
n w
hi
c
h
m
o
bil
e commerce
,

h
or
i
zonta
l

w
i
re

l
ess e-
b
us
i
ness app
li
cat
i
ons, an
d
vert
i
ca
l
w
i
re
l
ess e-
b
us
i
ness app
li
cat
i
ons are
id
ent

i
f
i
e
d
an
d
pr
e
sente
d
w
i
t
h
case stu
di
es.
T
h
e rea
d
ers can use t
h
e structure of t
h
e
b
oo
k

effect
i
ve
ly
. If t
h
e
y

h
ave no
b
ac
k-
g
roun
d

k
now
l
e
dg
e of w
i
re
l
ess commun
i
c

at
i
ons, t
h
e
y
can t
h
en rea
d
c
h
apters of t
hi
s
b
oo
k
sequent
i
a
lly
;
i
f t
h
e
y
are a
l

rea
dy
fam
ili
ar w
i
t
h
w
i
re
l
ess commun
i
cat
i
ons, t
h
e
y
can skip reading Chap. 2. Of course, the readers, if they wish, can always select a
chapter without following a
p
articular order.
Acknowledgments
T
his work is su
pp
orted in
p

art by NSFC grant 90304
0
08 from the Nature Science
Foundation of China and the Do
c
toral Program Foun
d
a
tion gra
n
t
2004071001
f
rom the Ministry of Education of China.
1 Intro
d
uct
i
on to Ena
bli
n
g
Tec
h
no
l
ogi
es for W
i
re

l
ess E-Bus
i
ness 5
1
. W. Kou, Y. Yesha (eds.) (2000) Electronic Commerce Technolo
gy
trends:
C
hallen
g
es and Oppo
r
tunities. IBM, Carlsbad.
2
. W. Kou
(
1997
)
Networ
ki
ng Secur
i
ty an
d
Stan
d
ar
d
s. K

l
uwer, Boston.
3
. W. Kou, Y. Yes
h
a, C. Tan
(
e
d
s.
)

(
2001
)
E
l
ectron
i
c Commerce Tec
h
no
l
og
i
es.
L
NCS 2040. Spr
i
nger, Ber

li
n He
id
e
lb
erg New Yor
k
.
4. M. S
h
er
i
f
(
2000
)
Protoco
l
s for Secure E
l
ectron
i
c Commerce. CRC, Boc
a

Rat
o
n
.
5

. M. S
h
aw, R. B
l
ann
i
n
g
, T. Stra
d
er, A
.
W
hi
nston
(
2000
)
Han
dbook

o
n E
lec
-
t
ronic Commerce. Sprin
g
er, B
e

rlin Heidelber
g
New York.
References
6
W
. Kou an
d
Y. Yes
ha
6
. K. Finkenzeller (2003): RFID-Handbook, “Fundamentals and A
pp
lications
in Contact less Smart Cards and Identification,” 2nd edition, Wiley, New York.
7
. J. E
b
ers
p
ch
er, H. Vö
g
e
l
, C. Bettstetter
(
2001
)
, GSM Sw

i
tc
hi
n
g
, Serv
i
ces an
d

P
rotocols, 2nd edition,
W
ile
y
, New York.
8
. T. Halonen, J. Romero, J. Melero
(
2002), GSM, GPRS and EDGE Perform
-
a
nce, Wile
y
, New York.
ä
2 Fundamentals of Wireless Communications
T
h
e Un

i
vers
i
ty of Hong Kong, Po
k
fu
l
am Roa
d
, Hong Kong
2.1 Introduction
S
i
nce t
h
e
i
ntro
d
uct
i
on of t
h
e f
i
rst generat
i
o
n
ce

ll
u
l
ar networ
k
s
in
the 1980s, there
n
h
as
b
een tremen
d
ous growt
h

i
n w
i
re
l
ess
c
ommun
i
cat
i
ons. In 1
99

2 t
h
e f
i
rs
t

commercial GSM network was launched, which marked the be
g
innin
g
of era o
f

digital cellular net
works. Since 2003, Hutchinson has la
t
t
unched 3G services in Hong
a
a
Kon
g
, UK, and Ital
y
. Toda
y
, wire
l
e

ss communication devices have
p
enetrated
almost every corner of the world and have bec
o
m
e an indis
p
ensable part of our dail
y

l
ife. In this cha
p
ter, we
p
resent a brief overview of 2G/2.5G and 3G wireless
communication systems, with par
ticular focus on security-related aspects.
r
r
2.2 Global System for Mobile Communication
Global System for Mobile Comm
unication (GSM), is currently the most widely
m
m
use
d
w
i

re
l
ess tec
h
no
l
ogy. T
h
e num
b
er of g
l
o
b
a
l
GSM customers
i
s est
i
mate
d
to
b
e over 1
billi
on as of t
h
e f
i

rst quarter of 2004, account
i
ng for over 70% of t
h
e
g
lobal market share.
GSM was
p
ro
p
osed in Euro
p
e (in fact, the initials were ori
g
inall
y
derived from
Groupe Special Mobile) and was under
standardization
r
b
y the European
T
elecommunication Standards Institute
(E
TSI). Currently, the work has largel
y

b

een transferred to third gene
r
ation partnership project (3GPP).
2.2.1
O
verv
i
ew
C
urrent
l
y, GSM operates
i
n frequency
b
an
d
s of 400, 800, 900, 1,800, an
d
1,900
MHz. A GSM channel has a bandwidth of
200 kHz. The modulation scheme is
f
Gauss
i
an m
i
n
i
mum s

hi
ft
k
ey
i
ng
(
GMSK
)
, w
hi
c
h

i
s a type of cont
i
nuous 7-p
h
ase
mo
d
u
l
at
i
on sc
h
eme.
Si

nce
G
M
S
K
h
as
a
constant amp
li
tu
d
e enve
l
ope,
i
t
i
s
d
es
i
ra
bl
e
f
or s
i
mp
l

e amp
li
f
i
ers. At t
h
e same t
i
me,
i
t
h
as a narrow power spectrum w
i
t
h

l
ow
a
dj
acent c
h
anne
l

i
nterference. T
h
e

d
up
l
ex
i
n
g
sc
h
eme
i
s frequenc
y

di
v
i
s
i
o
n

duplexing (FDD), with the upl
i
nk channel and downlink channels located in
different frequency bands. Since the uplink time slo
t

i
s about three time slots later

t
han the corresponding downlink slot, the mo
b
i
le station
(
MS
)
does not have to send
an
d
rece
i
ve at t
h
e same t
i
me, t
h
us re
d
uc
i
ng system
d
es
i
gn comp
l
ex

i
ty an
d
cost.
D. Shen and V.O.K. Li
8
transmitter, the voice is first digitized and source encoded. Then channel coding
(
convo
l
ut
i
ona
l
co
di
ng
)
an
d

i
nter
l
eav
i
n
g
are app
li

e
d
for error correct
i
on. To
ac
hi
eve conf
id
ent
i
a
li
ty over t
h
e a
i
r
i
nterface, encrypt
i
on
i
s performe
d
. Afte
r

mo
d

u
l
at
i
on, t
h
e user s
i
gna
l

i
s trans
m
i
tte
d
over t
h
e mu
l
t
i
pat
h
fa
di
ng c
h
anne

l
. A
t

the receiver, the received si
g
nal is first demodulated, and then decr
y
pted. Afte
r

deinterleavin
g
and channel
d
ecodin
g
, source decodin
g
is conducted to restore the
sp
eech.
F
i
g. 2.
1
.
Process
i
ng of a vo

i
ce ca
ll
T
ransmitter sid
e
S
peec
h
Digi
t
i
zat
i
on an
d
source co
di
n
g
Interleavin
g
Modula
t
ion
De
m
odula
t
ion

D
e
i
nter
l
eav
i
n
g
Receiver sid
e
S
peec
h
S
ource decodin
g
Channel decoding
B
u
r
s
t
fo
rm
a
ti
on
D
ecryptio

n
M
ultipath fading
channel
E
ncryptio
n
Bu
r
s
t
fo
rm
a
ti
on
Channel codin
g
D. Shen and V.O.K. Li
I
n
Fig. 2.1
,
we
ill
ustrate t
h
e process
i
n

g
of a GSM vo
i
ce ca
ll
. At t
h
e
9
The multi
p
le access scheme of GSM is time division multi
p
le access (TDMA)
with optional frequency hopping. A TDMA frame lasts for 4.615 ms, and is
divided into 8 time slots, corres
p
ondin
g
to a slot time of 576.9
µ
s
. The
g
ross data
rate of a frame is 271 kb
p
s or 33.9
k
b

p
s for a slot. This data rate is e
q
uivalent to
1
56.25 bit
p
eriods in a time slot. There are five types of time slot burst: normal,
we s
h
ow t
h
e structure of a norma
l

b
urst. In a norma
l

b
urst
,
t
h
e f
i
rst t
h
ree
bi

ts are
t
a
il

bi
ts. T
h
e next 57
bi
ts are
d
ata
bi
ts, fo
ll
owe
d

b
y 1 s
i
gna
li
ng
bi
t, 26 tra
i
n
i

ng
bi
ts,
1
s
i
gna
li
ng
bi
t, 57
d
ata
bi
ts, 3 ta
il

bi
ts, an
d
f
i
na
ll
y a guar
d

p
er
i

o
d
of 8.25
bi
ts.
F
ig. 2
.
2
. Structure of a normal time slot burst
T
he TDMA frames are further organized into multiframes. There are two
t
ypes of multiframes: one type consists of 26 TDMA frames
,
another with 51
f
rames. A su
p
erframe has 1326 TDMA frames, which is composed of either fifty-
o
ne 26-frame mu
l
t
i
frames or twent
y
-s
i
x 51-frame mu

l
t
i
frames, an
d

l
asts for 6.12 s.
Th
en 2,038 superframes are
g
roupe
d
as a
hy
perframe, correspon
di
n
g
to a per
i
o
d
o
f

F
i
g
. 2

.
3
.
Or
g
anization of frames
t
here is one base transceiver station (BTS), transmittin
g
and receivin
g
radio
s
i
gna
l
s to
/
from MS. T
h
e ma
i
n tas
k
s for a BTS are:
•
C
h
anne
l

co
di
ng
•
C
i
p
h
er
i
ng an
d

d
ec
i
p
h
er
i
ng
•
B
urst format
i
on, mu
l
t
i
p

l
ex
i
n
g
, an
d
mo
d
u
l
at
i
on
•
Evaluation and o
p
timization o
f
u
p
link and downlink transmissions
3
tai
l
bi
t
s
5
7 data bit

s
1 signaling bit
3
t
ai
l
bi
t
s
8
.
25
- b i
t
g
uard period
26
- bit trainin
g
s
e
q
uenc
e
5
7 data bit
s
Hy
per
f

ram
e
F
ram
e
A
time slot
7
6
5
4
3
2
2
1
1
1
1
1
25
24 25
50
49
50 24
1
50
2046 2047
0
0
0

0
0
S
u
p
erfram
e
2 Fun
d
amenta
l
s of
Wi
re
l
ess
C
ommun
i
cat
i
ons
f
requency correct
i
on, sync
h
ron
i
zat

i
on, access, an
d

d
ummy s
l
ot
b
urst. In Fi
g
. 2.2
,
3 h 28 min 53.760 s. The organization of frames is plotted in
Fi
g
. 2.3.
n
T
h
e ce
ll
u
l
ar structure
i
s a
d
opte
d


i
n GSM, as s
h
own
in
Fi
g
. 2.4
.
In eac
h
ce
ll,
1
0
Fig
. 2.4
.
C
e
ll
u
l
ar networ
k
structure of
GS
M
A n

u
m
be
r
o
f
b
a
se

s
tati
o
n
s
ar
e

co
ntr
o
ll
e
d b
y
one base station controller (BSC).
T
he BTSs and BSC form the base station subs
y
stem. The main responsibilit

y
of a
BSC is to coordinate the handoff o
p
eration. Therefore, a BSC will collect the
measurement report of link quality from each mobile to decide whether a handoff
i
s necessary. A BSC also needs the information of available resources in each
n
e
ighb
or
i
n
g
BTS. Dur
i
n
g
t
h
e
h
an
d
off pro
c
e
ss
,

t
h
e BSC w
ill
coor
di
nate t
h
e ca
ll

trans
i
t
i
on from one BT
S
to an
o
t
he
r
wi
t
h
t
he
i
nvo
l

ve
d
BT
S
an
d
M
S
.
Severa
l
BSCs are furt
h
er contro
ll
e
d

by
t
h
e
mo
bil
e sw
i
tc
hi
n
g

center
(
MSC
)
. T
h
e
MSC monitors the si
g
nalin
g
between the
M
S and the core network, and
p
erforms
s
witchin
g
between the BTS and core network
.
It is also res
p
onsible for resource
mana
g
ement for each BTS.
At the MSC, there are also home location register (HLR) and visitor location
register (VLR). Calls between the mobil
e

networks and fixed networks, e.g.,
p
ublic switched tele
p
hone network (PSTN), integrated service data network
(
ISDN
)
, pac
k
et
d
ata networ
k

(
PDN
)
, pu
bli
c
l
an
d
mo
bil
e networ
k

(

PLMN
)
, etc. are
h
an
dl
e
d

b
y a gateway ca
ll
e
d
gateway mo
bil
e sw
i
tc
hi
ng center
(
GMSC
)
. T
h
e
MSC, HLR, VLR, an
d
GMSC are parts of t

h
e networ
k
an
d
sw
i
tc
hi
ng su
b
system.
N
etwork mana
g
ement-related operations, such as administration, securit
y
,
network confi
g
uration and performance mana
g
ement, maintenance, etc. are the
responsibility of the operation
s
ubsystem. The network control functions are
monitored by the operation and m
a
i
ntenance center. The authentication cente

r

(AuC) and e
q
ui
p
ment ide
n
t
ity register (EIR) are related
t
o the security aspects.
More spec
i
f
i
ca
ll
y, t
h
e AuC
i
s respons
ibl
e for aut
h
ent
i
cat
i

on an
d
encrypt
i
on, an
d

th
e EIR stores equ
i
pment
id
ent
i
ty
d
ata. T
h
e networ
k
arc
hi
tecture
i
s
d
escr
ib
e
d


i
n
F
i
g. 2.5.
D. Shen and V.O.K. Li
11
Fig
. 2.5. Networ
k
arc
hi
tecture of
GS
M
HLR and VLR are used to su
pp
ort user mobilit
y
. When an MS is under an
MSC different from its home MSC, the MS
w
ill re
g
ister at the VLR of the MSC.
Th
e VLR w
ill
a

l
so forwar
d
t
h
e user
l
ocat
i
on
i
nformat
i
on to t
h
e HLR. W
h
en t
h
e
MS
i
s ca
ll
e
d
,
i
ts HLR
i

s f
i
rst quer
i
e
d
fo
r

th
e current
l
ocat
i
on.
Th
en t
h
e HLR w
ill
respon
d
w
i
t
h
t
h
e MS’s current
l

ocat
i
on, an
d
t
h
e ca
ll

i
s route
d
to t
h
e v
i
s
i
t
i
ng MSC.
2.2.2 Securit
y
-Related Aspects
In GSM, t
h
e fo
ll
ow
i

n
g
are re
l
ate
d
to secur
i
t
y
:
•
S
u
b
scr
ib
er
id
ent
i
t
y
conf
id
ent
i
a
li
t

y
•
S
u
b
scr
ib
er
id
e
n
t
i
t
y
aut
h
ent
i
cat
i
on
•
S
i
g
nalin
g
information element confidentialit
y

•
D
ata confidentiality
T
hese are described in the following paragraphs.
2 Fun
d
amenta
l
s of
Wi
re
l
ess
C
ommun
i
cat
i
ons
PLMN
& Internet
PSTN
ISDN
PDN
GMSC
OMC
MSC
HLR VLR
AuC

EIR
BSC BSC
BTS
BTS
BTS
BTS
BTS
BTS
A
A
O
Operation
Subsystem
Network and Switching
Subsystem
Base Station
Subsystem
bis
12
In GSM, the user identit
y
is
r
epresented b
y
th
e
int
e
rnati

o
nal m
ob
il
e

subsc
ri
be
r
i
dentit
y
(IMSI) and is stored in the subs
c
riber identit
y
m
o
dule
(
SIM
)
card. The
i
dentity of the MS is rep
r
esented by the internation
a
l

mobile station e
q
ui
p
ment
i
dentity (IMEI). The IMEI is
a
llocated by the equ
i
p
ment manufacturer an
d

registered by the network operator, which is stored in the EIR. Since the SIM card
can
b
e transferre
d

b
etween MS, user serv
i
ce on
l
y re
l
ates to t
h
e SIM car

d
an
d

i
s
not
d
epen
d
ent on a part
i
cu
l
ar MS.
O
b
v
i
ous
ly
,
i
t
i
s not
d
es
i
ra

bl
e to transm
i
t t
h
e IMSI frequent
ly
over t
h
e a
i
r
i
nterface, since user identit
y
is easil
y
disclosed. Therefore, each user is assi
g
ned
a temporar
y
identit
y
called temporar
y
mobile subscriber identit
y
(TMSI), which
i

s actuall
y
used over the radio channel.
T
he association between IMSI and TMSI
i
s stored in the HLR/VLR. In this way
,
a user becomes anonymous over the air
i
nterface. Even if the TMSI is intercepted by an eavesdropper, there is no way
f
or t
h
e eaves
d
ropper to
id
ent
i
fy t
h
e mo
bil
e user, s
i
nce t
h
e IMSI–TMSI
assoc

i
at
i
on
i
s not ava
il
a
bl
e. T
h
e TM
S
I
i
s temporary an
d

h
as on
l
y
l
oca
l

s
i
gn
i

f
i
cance. W
h
enever a user roams to t
h
e area of anot
h
er VLR, a new TMSI
i
s
i
ssued b
y
the VLR, in encr
y
pted form. In this wa
y
, user identit
y
is protected b
y

T
MSI and b
y
encr
y
ption.
W

hen a subscriber is ad
d
ed
t
o
a h
o
m
e
n
e
t
wo
rk f
or

t
he first time, a subscribe
r

authentication key (
Ki
(
(
) is assigned for authentication purposes. This key,
Ki
,
is
s
tored in both the SIM card at the user side and the AuC of the network side.

In GSM, authentication is b
a
sed on the A3 algorithm.
T
he authenti
c
ation
p
rocess
i
s s
h
own
i
n F
i
g. 2.6. After rece
i
v
i
ng an aut
h
ent
i
cat
i
on request, t
h
e AuC of t
h

e
h
ome
networ
k
generates a ran
d
om num
b
er
(
RAND
)
. T
h
e aut
h
e
nt
i
cat
i
on
k
ey K
i
is retrieved
i
f
rom t

h
e
d
ata
b
ase
b
ase
d
on t
h
e user
id
ent
i
ty IMSI. T
h
en a s
i
gnature response
(
SRES
)

i
s ca
l
cu
l
ate

d
from
Ki
and RAND from the A3 algorithm. The RAND is also
i
sent to t
h
e MS. From t
h
e
l
oca
lly
store
d

Ki
and the received RAND, the MS
i
ca
l
cu
l
ates
i
ts own
S
RE
S
va

l
ue an
d
transm
i
t
s
i
t to t
h
e networ
k
. At t
h
e MSC, t
h
e
SRES values from the MS and the AuC are compared: if the two agree, the
subscriber is authenticated. In this aut
h
entication
p
rocess, RAND is transmitted once
f
rom the network to MS, and SRES once from the MS to the network. There is no
e
xp
li
c
i

t exc
h
ange of user
id
ent
i
ty
i
nformat
i
on
b
etween t
h
e MS an
d
t
h
e networ
k
. T
h
e
RAND
i
s generate
d
eac
h
t

i
me on aut
h
ent
i
cat
i
on. T
h
us
i
t
i
s of no use for an attac
k
er
to
r
eco
r
d
t
he
tran
s
m
i
tt
ed
SRES and retransmit some time later, which means the

d
aut
h
ent
i
cat
i
on process
i
s secure a
g
a
i
nst t
h
e rep
l
a
y
attac
k
.
T
h
e
k
e
y
Ki
can

b
e store
d
exc
l
us
i
ve
ly

i
n t
h
e AuC of t
h
e
h
ome networ
k
. W
h
en
a

VLR requests the authentication of a roamin
g
user, a 2-tuple (RAND, SRES) is
computed and forwarded b
y
the HLR to th

e
requestin
g
VLR. This approach can
p
rovide a hi
g
h level of secu
r
it
y
. In this a
u
thentication
p
rocedure,
Ki
is onl
y
stored
i
n t
h
e Au
C
at t
h
e
h
om

e
networ
k
an
d

i
s never trans
m
i
tte
d
to
V
LR.
Thi
s ensures
security when a user roams to the network of
another operator. An alternative
f
opt
i
on
i
s to supp
l
y
K
i to t
h

e request
i
ng VLR. O
b
v
io
us
l
y, t
hi
s approac
h

i
s
l
ess
secu
r
e.
D. Shen and V.O.K. Li
Subscriber Identity Confidentiality
Subscriber Identity Authentication
13

Fi
g. 2.6. Aut
h
ent
i

cat
i
on proce
d
ure
In GSM, user
d
ata are protecte
d

by
encr
y
pt
i
on. Once a user
i
s aut
h
ent
i
cate
d
, t
h
e
c
i
p
h

er
k
e
y
K
c s
h
ou
ld

b
e
g
enerate
d
fo
r
encr
y
pt
i
on an
d

d
ecr
y
pt
i
on.

Kc
is
a
lso
g
enerate
d
from t
h
e secret aut
h
ent
i
cat
i
on
k
e
y

K
i an
d
t
he
RAND
used
f
or


authentication, based on the A8 algorithms. The generation of
Kc
takes
p
lace in
both AuC and MS. The
p
rocedure is
i
llustrated in Fig. 2.7. Afte
r

Kc
is generated,
i
t
i
s use
d

b
etween t
h
e MS an
d
t
h
e BTS for
d
ata protect

i
on. At t
h
e BTS, t
h
e
e
ncrypte
d

d
ata from t
h
e MS are
d
ecrypte
d
.
T
h
erefore,
d
ata protect
i
on
i
n GSM
on
l
y

h
appens over t
h
e a
i
r
i
nterface, an
d

i
s not en
d
to en
d
. T
hi
s
i
s o
b
v
i
ous
l
y not
d
es
i
ra

bl
e for certa
i
n app
li
cat
i
ons.
F
ig
. 2.7
.
C
i
p
h
er
k
e
y

g
enerat
i
on
A3 A3
S
RE
S
S

RE
S
=
?
IMS
I
I
MSI
N
etwor
k
M
S
RAND
K
i
K
K
K
i
K
K
Mobile
K
i
K
K
K
i
K

K
K
c
K
K
K
c
KK
T
o BT
S
Au
C
A8
A
8
RAND
2 Fun
d
amenta
l
s of
Wi
re
l
ess
C
ommun
i
cat

i
ons
Data Encryption
14
Th
e
d
ata encr
y
pt
i
on a
lg
or
i
t
h
m
i
n GSM
i
sca
ll
e
d
A5. A5
i
s a t
y
pe of stream c

i
p
h
er.
T
he encr
y
ption and decr
y
ption b
y
a stream cipher are based on the linear shift
f
eedback re
g
ister (LSFR) and exclusive-or operations. Due to the simplicit
y
of the
operations, stream ciphers have a hi
g
h encr
y
ption and decr
y
ption speed with little
hardware complexity, which is desirable for realtime applications such as voice
communications. The encryption and decry
p
t
ion o

p
erations over the u
p
link are
s
hown in Fig. 2.8. The operations over the d
o
w
nlink are identical.
I
t should be note
d

th
at t
h
e frame num
b
er
i
s requ
i
re
d

in
both encryption and decryption.
n
Fig
. 2.8. Encr

y
pt
i
on an
d

d
ecr
y
pt
i
on over t
h
e up
li
n
k

2.2.3 Problems w
i
th
GS
M
S
ecur
i
ty
A5 has two versions: A5/1 and A5/2.
A
5/1 is a proprietary 64-bit stream cipher,

while A5/2 can be viewed as a weakened version of A5/1. The schematic of A5/1
i
s p
l
otte
d

i
n F
i
g. 2.9. A5
/
1
i
s ma
in
l
y compose
d
of t
h
ree LSFRs of
l
engt
h
s 19, 22,
an
d
23
(

tota
ll
y 64
)
, an
d

d
enote
d
as R1, R2, an
d
R3. T
h
e taps of fee
db
ac
k
for R1
are at t
h
e
bi
t pos
i
t
i
ons of 13, 16, 17, 18
;
for R2 t

h
ey are 20, 21; an
d
for R3at 7, 20,
2
1
,
22. T
h
en t
h
e LSFRs are
all
of max
i
ma
l

l
en
g
t
h
.
In pract
i
ce, most operators e
i
t
h

er use A5
/
2 or no encr
y
pt
i
on at a
ll
. In ot
h
er
w
or
d
s, user
d
ata are usua
lly
u
n
protecte
d
over t
h
e a
i
r, w
h
i
c

h
ma
k
es
i
t ver
y
eas
y
fo
r

an eavesdro
pp
er. Moreover, us
e
r
s
ar
e

u
na
w
ar
e

o
f th
e

current securit
y
le
v
e
l, since
n
etwork o
p
erators do n
o
t a
dve
rti
se
th
e
a
d
o
pted securit
y
method.
T
o make thin
g
s worse, A5 has been d
i
scove
r

ed
t
o

be
in
secu
re.
E
ve
n f
o
r th
e
s
tronger a
l
gor
i
t
h
m of A5
/
1,
i
n a wor
k
s
h
op

h
e
ld

i
n New Yor
k
C
i
ty
i
n year 2000,
it

broken in seconds given sufficient precom
putation time and
m
m
resource. Anot
h
e
r

gi
ven 2–5 m
i
nutes of p
l
a
i

ntext conversat
i
on. T
h
erefore, t
h
e use of encr
y
pt
i
on
in

GSM can make things difficult only for an
amateur eavesdropper but is unable to
n
protect against well-eq
uipped professionals.
q
q
+
+
MS Air interface BTS
frame numbe
r
A
5
plaintext
plaintext
up

lin
k
A
5
K
c
f
rame number
K
c
D. Shen and V.O.K. Li
was announced that A5/1 can be cracked [8]. It was claimed that A5/1 can be
attack on A5/1 has been presented in [9], and it can break A5/1 in a few minutes
15

Fig
. 2.9.
S
c
h
emat
i
c of A5
/
1
Th
ese are not t
h
e on
l

y secur
i
ty f
l
aws
i
n GSM. S
i
nce t
h
e encrypt
i
on
i
s on
l
y
b
etween t
h
e MS an
d
t
h
e BTS, user messages are
i
n t
h
e c
l

ear
i
n f
i
xe
d
networ
k
s. If
an attac
k
er can tap
i
nto a f
i
xe
d
networ
k
, t
h
e encr
y
pt
i
on over t
h
e a
i
r

i
nterface
h
as
n
o s
ig
n
i
f
i
cance.
Anot
h
er secur
i
t
y
feature
i
n GSM
i
s to
hid
e user
id
ent
i
t
y


by
us
i
n
g
TSMI.
However, user anon
y
mit
y
is not alwa
y
s
g
uaranteed. When the user device is to
r
e
g
ister in a new PLMN, the network will requ
e
st the true user identit
y
(e.
g
.,
IMSI
)
, which is transmitted in the clear.
I

n a
ll
, a
l
t
h
oug
h
GSM
i
s
d
es
i
gne
d
w
i
t
h
s
ecur
i
ty features, t
h
eac
hi
eve
d
secur

i
ty
2.3 General Packet Radio Service
Genera
l
pac
k
et ra
di
o serv
i
ce
(
GPRS
)
,
i
s part of ETSI’s GSM P
h
ase 2+
d
eve
l
opment. It can
b
e up
g
ra
d
e

d
from GS
M
wi
t
hou
t
e
xtra
i
nfra
s
tr
uc
t
u
r
e.
2.3.1 Overview
T
he ori
g
inal GSM is essentiall
y
a circ
u
it-switchin
g
technolo
gy

, and GPRS is to
s
upport packet switchin
g
within GSM. Wi
t
h circuit switchin
g
, a ra
d
i
o

c
hann
e
l i
s

ded
i
c
at
ed
t
o
a
use
r
.

E
ve
n
w
h
e
n a
use
r ha
s
n
o

t
raffi
c
t
o

se
n
d
an
d
th
e

c
hann
e

l i
s
n
o
t
utilized, it is still “occupied” by the user and cannot be used by other users. Circui
t

s
witching is more suitable for voice traffic, since voice usually has a continuous
b
it stream. However, circuit switching is
n
ot a
pp
ro
p
riate for
p
acket data due to
l
ow eff
i
c
i
ency an
d

i
nf

l
ex
ibili
ty. T
hi
s
i
s
b
ecause pac
k
et
d
ata usua
ll
y
h
ave a
var
i
a
bl
e
bi
t rate
,
w
hi
c
h

causes an
i
nterm
i
tte
n
t nature
i
n c
h
anne
l
usage.
LSFR
(
R3
)
LSFR
(
R2
)
L
S
FR
(
R1
)
C
loc
k

co
ntr
o
l
I
n
i
t
i
a
l
va
l
ue
s
2
Fundamentals of Wireless Communications
still has flaws that
p
revent the u
s
e of securit
y
-critical applications such as
m
-
commerce.
16
W
ith packet switchin

g
, a channel is occupied onl
y
when there are packets to
s
end. When there is no packet, the channel is released and can be used by othe
r

users. Therefore, packet switching is more efficient in terms of channel use fo
r

p
acket data with bursty traffic. This is because packet switching enables bette
r

resource s
h
ar
i
ng among users.
G
PR
S
a
l
so
i
ntro
d
uces Internet Protoco

l
(
IP
)
an
d
X.25 to t
h
e GSM networ
k
,
whi
c
h
fac
ili
tates t
h
e access of
d
ata networ
k
s, suc
h
as corporate
l
oca
l
area
n

etworks and
p
ublic Internet.
F
urther, two new services are added:
•
P
oint-to-
p
oint (PTP)
•
P
oint-to-multi
p
oint (PMP)
Another feature is that GPRS can su
pp
o
rt much higher data rates than GSM.
T
he classic GSM circuit switched data (CSD) has a connection rate of 9.6 kb
p
s,
whil
e GPRS can reac
h
a spee
d
as
high

as 171
kb
ps. T
hi
s
i
s ac
hi
eve
d
t
h
rou
gh

b
un
dli
n
g
severa
l
GSM c
h
anne
l
s for an MS.
2
.3.2 Network Architecture
In GPRS

,
a few new networ
k
e
l
ements are
i
ntro
d
uce
d

i
nto t
h
e GSM networ
k
. T
h
e
n
etwork architecture of GPRS is
p
lotted in Fi
g
. 2.10. The most important ones are
the new servin
g
GPRS support node (SGSN
)

and the
g
atewa
y
GPRS support node
(
GGSN
)
.
D. Shen and V.O.K. Li
BTS
BTS
BTS
MS
BTS
BTS
BTS
U
A
Gb Gn Gi
m
bis
interface
Base station subsystem
GPRS network
interface
interface interface interface
BSC
BSC
SGSN

GGSN
PLMN
HLR
F
i
g
. 2.10.
G
PRS network architecture