1. TAXI
Region
Campus
City
In-Building
Figure 1

2. Figure 2 USA market millions 1995 2000 10 20 30 40 50 60 70 80 90 10010 20 30 40 50 60 70 80 90
100
Internet users
paging subs
laptop users
cellular + PCS subs
annual laptop sales
dedicated wireless
data subs
millions
Figure 2

3. Figure 3 LOCAL AREA PACKET SWITCHING WIDE AREA CIRCUIT SWITCHING User
Bit-Rate
(kbps)
Ethernet
FDDI
ATM
100 M
Polling
Packet
Radio
1st gen
WLAN
2nd gen
wired- wireless
bit-rate "gap"
1970
2000
1990
1980
.01 .1 1 10
100
1000
10,000
100,000
YEAR
WIDE AREA CIRCUIT SWITCHING
14.4
digital
cellular
28.8 modem
ISDN
9.6 modem
2.4 modem
2.4 cellular
32 kbps
PCS
9.6 cellular
wired- wireless
bit-rate "gap"
Figure 3

4. Figure 4

5. Figure 5 Received Signal Power (dB) dB With Respect to Average Value
0.5
0.5l
1.5
-30
-20
-10 10 1
t, in seconds 30 20
x, in wavelength
Received
Signal
Power
(dB)
Figure 5

6. Figure 6 Received Signal Power (dB) log (distance) With path loss and
shadow fading
Received
Signal
Power
(dB)
With path loss, shadow
fading, and Rayleigh fading
With path loss
log (distance)
Figure 6

7. Hierarchical
Star
Peer-to-Peer
Figure 7

8. BASE
STATION
Figure 8