Figure 2 (all data are acquired from [22]) shows the success rate and flooding
rate (number of transmissions divided by n) for quorum-based schemes for
n=100 nodes in the network, respectively. The thickness of each column (p)
and row (s) is varied from 1 to 2. The average number of neighbors of each
node (k) is varied from 4 to 12. As we can see, a quorum-based scheme can
achieve high success rate with low energy cost. It is an energy e?±cient method
to deal with the transaction of data accessing.
Fig. 2. Performance of the quorum method.
242
0
0.2
0.4
0.6
0.8
1
1.2
4 5 6 7 8 9 10 11 12
degree k
success rate
p=s=1 p=s=2
0
0.1
0.2
0.3
0.4
0.5
0.6
4 5 6 7 8 9 10 11 12
degree k
flooding rate
p=s=1 p=s=2
The quorum method has another advantage when all networks move dynamically
together in a given direction, such as a rescue team or army. Because
the correlation among nodes within each quorum is almost stable, less tra?±c
is needed to maintain neighbor information than other methods.
3 Information Dissemination
WSNs aim at disseminating information to querying nodes as soon as possible.
Since WSNs are designed in a distributed fashion, sensors have to make decisions
based on its local information. They have no idea about which node will
ask to consume produced information in the future. Obviously, if all recently
sensed data are broadcasted throughout the whole network, all consumers are
sure to get one copy.
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