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DARPA ULTRALOG Final Report - Industrial and Manufacturing ...

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7<br />

respectively. In PA-O resources are allocated only at t=0 <strong>and</strong><br />

kept over time while in PA-C periodically (every 100 time<br />

units). PA-C is the resource control mechanism we have<br />

designed.<br />

B. Results<br />

TABLE I<br />

EXPERIMENTAL CONDITIONS<br />

Condition Distribution of P i rt i P i<br />

Con1-1 Deterministic [000 000 000 000 [04 12 04 08<br />

Con1-2 Exponential 200 200 200 200] 02 02 02 02]<br />

Con2-1 Deterministic [100 100 100 100 [04 12 04 10<br />

Con2-2 Exponential 200 200 200 200] 02 02 06 06]<br />

Con3-1 Deterministic [100 100 100 100 [04 12 04 10<br />

Con3-2 Exponential 200 200 200 100] 02 02 20 10]<br />

Con4-1 Deterministic [100 100 100 100 [04 12 04 08<br />

Con4-2 Exponential 200 200 200 200] 02 02 10 02]<br />

Con5-1 Deterministic [100 100 200 200 [04 10 04 08<br />

Con5-2 Exponential 200 200 200 200] 02 02 02 02]<br />

TABLE II<br />

CONTROL POLICIES FOR EXPERIMENTATION<br />

Control policy<br />

Description<br />

RR<br />

Round-Robin allocation<br />

PA-O Proportional allocation - Open loop<br />

PA-C Proportional allocation - Closed loop<br />

Numerical results from the experimentation are shown in<br />

Table III. Lower <strong>and</strong> upper bounds are calculated for each<br />

experimental condition. The network adequacy of each<br />

condition is close to one <strong>and</strong> the proportional allocation policy<br />

can be used effectively for all the conditions.<br />

Proportional allocation policies (PA-O <strong>and</strong> PA-C) shows<br />

significant advantages compared to round-robin allocation in<br />

all the different conditions. The completion time T under<br />

proportional allocation is bounded to T UB <strong>and</strong> close to T LB in all<br />

deterministic conditions (note that the performance of PA-O<br />

<strong>and</strong> PA-C is the same in deterministic environments),<br />

supporting the effectiveness of the resource allocation policy.<br />

Though T UB does not work accurately in stochastic<br />

environments, the performance improves close to T LB when the<br />

proportional allocation is implemented in closed-loop. The<br />

periodic design process alleviates the impacts of stochasticity.<br />

So, we can conclude that the designed control mechanism can<br />

be effectively used even in stochastic environments for the<br />

networks with high adequacy.<br />

The performance differences can be reasoned from resource<br />

utilization as discussed earlier. A node with maximal total CPU<br />

time needs to utilize its resource almost fully to achieve a<br />

performance close to T LB . For example, N 2 is such a node in<br />

Con1-1 (deterministic) <strong>and</strong> Con1-2 (stochastic). Resource<br />

utilization profiles of N 2 are shown in Fig. 4 for Con1-1 <strong>and</strong><br />

Fig. 5 for Con1-2, in which a data point corresponds to the<br />

amount of utilized resource during a control period (100 time<br />

units). In deterministic environment (Con1-1), N 2 utilizes its<br />

resource almost fully under both proportional allocation<br />

Utilization (%)<br />

100<br />

80<br />

60<br />

40<br />

20<br />

PA-O<br />

RR<br />

PA-C<br />

0<br />

0 1000 2000 3000 4000 5000 6000<br />

Fig. 4. Resource utilization of N 2 in Con1-1. In a deterministic environment,<br />

N 2 utilizes its resource almost fully under both proportional allocation policies<br />

(PA-O, PA-C) while underutilizing in initial stage under round-robin<br />

allocation policy (RR).<br />

Utilization (%)<br />

100<br />

80<br />

60<br />

40<br />

20<br />

PA-O<br />

RR<br />

Time<br />

0<br />

0 1000 2000 3000 4000 5000 6000<br />

Fig. 5. Resource utilization of N 2 in Con1-2. In a stochastic environment, N 2<br />

utilizes its resource more under proportional allocation policies (PA-O, PA-C)<br />

compared to round-robin allocation policy (RR), <strong>and</strong> resource utilization<br />

under closed-loop policy (PA-C) is larger than under open-loop policy<br />

(PA-O).<br />

Time<br />

PA-C<br />

TABLE III<br />

EXPERIMENTAL RESULTS<br />

Control policy<br />

RR PA-O PA-C<br />

T LB T UB Adequacy T T LB /T T T LB /T T T LB /T<br />

Con1-1 4800 4820 0.996 5619 0.854 4820 0.996 4820 0.996<br />

Con1-2 4800 4820 0.996 5618 0.854 5021 0.956 4939 0.972<br />

Con2-1 7200 7230 0.996 7612 0.946 7200 1.000 7200 1.000<br />

Con2-2 7200 7230 0.996 7679 0.938 7323 0.983 7252 0.993<br />

Con3-1 6000 6073 0.988 6412 0.936 6012 0.998 6012 0.998<br />

Con3-2 6000 6073 0.988 6408 0.936 6193 0.969 6013 0.998<br />

Con4-1 7200 7228 0.996 7200 1.000 7200 1.000 7200 1.000<br />

Con4-2 7200 7228 0.996 7231 0.996 7109 1.013 7169 1.004<br />

Con5-1 7200 7220 0.997 7810 0.922 7210 0.999 7210 0.999<br />

Con5-2 7200 7220 0.997 7979 0.902 7351 0.979 7319 0.984

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