## 4 Performance Evaluation  
In order to assess the performance of the proposed approach, several tests have been made using the Network Simulator Version-2 (NS-2) [33] for the evaluation of the proposed HEM scheme and for simulating the BLE-based WN infrastructure. Simulations have been performed making a comparison with an approach without energy management and with the approaches proposed by [PERSON] _et al._[27] and [PERSON] _et al._[28] in which an HEM scheme, based on a WN, for a smart home is introduced. The main differences between the approaches presented in [27] and [28] and the solution presented in this work are that the algorithm introduced both by [PERSON] _et al._ and [PERSON] _et al._ does not take into account the feedback of the consumers, although it is similar to the one presented in this paper, and their considered WN is based on the IEEE 802.15.4 wireless protocol. In this paper, the simulations have been carried out in the same scenario considered by [PERSON] _et al._ and [PERSON] _et al._, in order to have a direct comparison with their HEM scheme. Specifically, the scenario is composed of four loads, represented by a washer, a dryer, a dishwasher and a coffeemaker. The duration and the energy consumption of these appliances are vendor specific; however, the reference values for average load per cycle given in [34] have been used. The washer, the dryer, the dishwasher and the coffeemaker are assumed to consume 0.89 kWh, 2.46 kWh, 1.19 kWh and 0.4 kWh, respectively, while the durations of their cycles are 30, 60, 90 and 10 min. Moreover, an extra load has been supposed whose electricity consumption value varies randomly between 0 kWh and 4 kWh. Therefore, 80% of the load is miscellaneous, and the remaining 20% is related to standby appliances. It is useful to note that peak hours can change both with days and seasons. For this reason, in this paper, the peak hours fall from 8 a.m.-2 p.m., as in the scenario considered by [PERSON] _et al._ and [PERSON] _et al._ As stated in [35], the electricity consumption behavior can be modeled as a Poisson random distribution that is a discrete random distribution. For this reason, even in this paper, the switching on of an appliance has been considered as a Poisson distribution. The switch on requests of appliances have been generated randomly, while the threshold value of power (\(P_{thr}\)), used in the proposed algorithm, has been set to 1 kWh. The simulations' duration has been between 10 days and 210 days (approximately seven months). The first 10 days are spared for warm up. The threshold \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Rule**} & **Antecedent** & **Antecedent** & **Consequent** \\  & **scheduled time** & **consumer feedback** & **scheduled time** \\ \hline
1 & Low & Low & Low \\
2 & Low & Medium & Low \\
3 & Low & High & Medium \\
4 & Medium & Low & Medium \\
5 & Medium & Medium & Medium \\
6 & Medium & High & High \\
7 & High & Low & Medium \\
8 & High & Medium & High \\
9 & High & High & High \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Inference rules for the new scheduled delay. value of delay (\(D_{thr}\)) has been set to 24 h. Regarding the WN, the traffic model, as mentioned above, has been considered as Poisson, and the NS-2 radio propagation model has been chosen as shadowing. On the contrary, as in the simulations of [PERSON] _et al._ and [PERSON] _et al._, the channel bit error rate has not been taken into account. Figure 7 shows the electricity consumption pattern measured in a single day. It is clear that the proposed solution and the approaches of [PERSON] _et al._ and [PERSON] _et al._ shift loads from peak hours to off-peak hours efficiently. It is useful to remark that the percentage of load in peak hours is a ratio between the amount of load in peak hours to the total load. A high value of this ratio results in high electricity charges due to pricing tariffs. In peak hours, in order to provide monetary benefits to the consumer, the approaches reduce the percentage of the load.