Such modeling can provide a clear understanding
of the key design tradeo?®s underlying such mechanisms, and give an
insight into how protocol parameters should be optimized to provide e?±ciency
in terms of energy savings or latency improvements, or other relevant metrics.
We should caution, however, that the first order protocol analysis methodology,
which emphasizes tractability, abstraction, and simplicity, is by no
397
Bhaskar Krishnamachari
(a)
(b)
Fig. 6. Performance of Search with Replication.
398
10
0
10
1
10
2
10
3
10
4
10
2
10
3
10
4
10
5
10
6
Number of Replicas
Total Cost of Replication and Search
fq = 0.1
fq = 1
fq = 10
10
??’2
10
??’1
10
0
10
1
10
2
0
20
40
60
80
100
120
140
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Ratio of Query Frequency to Event Frequency (f
q
/f
e
)
Optimal Number of Replicas
Chapter 16 Modeling Data Gathering in Wireless Sensor Networks
means a complete substitute for other analytical and experimental tools which
emphasize detail, realism, and sophistication. While such modeling provides
a good starting point for understanding the key design tradeo?®s involved in
parameter selection, it is entirely complementary to other approaches. The
translation of the insights obtained through mathematical analysis into practical
protocols will certainly involve further evaluation through more detailed
simulations, as well as through experiments on a test-bed and real-world implementations.
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