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5.5 Computational Results
We have chosen a WSN consisting of 10 sensors to test our proposed sched-
uling model, and ASAP and ALAP algorithms. Table 5.1 illustrates the exe-
cution times for 10 sensors that comprise the WSN.
We ran two experiments over the WSN, where in both experiments we
assumed that one base station was available to receive all the transmissions
from the 10 sensors. In the first experiment, the base station is restricted
to receive one transmission at a time, where in the second experiment; we
relaxed to five transmissions at a time. In the second experiment, we also
assumed that the five transmissions arrived at different frequency channels
to avoid collisions.
In Figures 5.6 and 5.7 we illustrated the ASAP and ALAP outcomes from
our program for experiment 1. All scheduled tasks by the two schedules
were executed in 12 states (the number of rows from top to bottom), where
10 and 1 tasks are executed in state 1 at ASAP and ALAP respectively. By
looking at the ALAP schedule in Figure 5.7, we noticed that fewer tasks are
executed in parallel than in the ASAP schedule.
In Figures 5.8 and 5.9 we illustrated the ASAP and ALAP outcomes from
our program for experiment 2, where the BS could receive five transmissions
at a time. All scheduled tasks by the two schedules are executed in four states,
where 10 and 5 tasks were executed in State 1 at ASAP and ALAP respectively.
By looking at both ASAP and ALAP schedules in Figure 5.8 and Figure 5.9 we
noticed that the number of tasks were executed in parallel about the same but
at different States. At State 2, the 10 tasks were scheduled by both algorithms;
at state 5, the 5 tasks were scheduled by both algorithms.
Figures 5.10 through 5.13 depict the timing diagrams for the first experi-
ment and second experiment respectively. The
x
-axis represents the time
TaBLe 5.1
Tasks' Execution Times
Sensor
Sense Time
Process Time
Transmit Time
1
2
2
5
2
6
4
2
3
3
3
4
4
3
2
1
5
5
5
5
6
10
10
10
7
1
2
3
8
2
1
5
9
6
4
2
10
3
3
4
