To address the stability of
436
0 20 40 60 80 100 120 140 160 180
0
2
4
6
8
10
12
Time (seconds)
Data Rate (Mbps)
Linksys
Chapter 18 Unauthorized Sensor Node Identification
(a) Lucent
(b) D-Link
(c) Linksys
Fig. 6. PSD prior to injecting noise.
437
0 50 100 150 200 250
0
100
200
300
400
500
PSD
0 50 100 150 200 250
0
20
40
60
80
100
120
PSD
0 50 100 150 200 250
0
10
20
30
40
50
Frequency(Hz)
PSD
Cherita Corbett, John Copeland, and Raheem Beyah
Fig. 7. PSD and cumulative PSD.
438
0 50 100 150 200 250
0
10
20
30
PSD
Lucent
0 50 100 150 200 250
0
0.2
0.4
0.6
0.8
1
Frequency(Hz)
Cumulative PSD
(a) Lucent
0 50 100 150 200 250
0
2
4
6
PSD
D??’Link
0 50 100 150 200 250
0
0.2
0.4
0.6
0.8
1
Frequency(Hz)
Cumulative PSD
(b) D-Link
0 50 100 150 200 250
0
10
20
30
PSD
Linksys
0 50 100 150 200 250
0
0.2
0.4
0.6
0.8
1
Frequency(Hz)
Cumulative PSD
(c) Linksys
Chapter 18 Unauthorized Sensor Node Identification
the PSD, we repeated experiments with the same RI. The PSD for each RI,
respectively, is similar. A comparison between Figure 7(a) and Figure 8 illustrates
similarity among repeated experiments for the Lucent RI.
We also observed a distinction between RIs when comparing the normalized
cumulative sum (NCS) of the spectrum during the noisy period. The
slope of the NCS of the Linksys RI is almost linear with a modest variation in
the slope over the range of 90Hz to 130Hz (and 190Hz to 210Hz), indicating
that the power spreads (somewhat evenly) across this frequency range.
Pages:
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680