# Enhanced Distributed Dynamic Skyline Query for Wireless Sensor Networks
## 3 Basic System Design
### Skyline Query  
A threshold based hierarchical approach has been used in this research to calculate \(DS\) (\(q\), \(r\)). The threshold based hierarchical approach uses the temporal correlation among the sectors and segments of a sector. All the key notations used in this section are listed in the Table 3 to increase reader comfort.  
\begin{table}
\begin{tabular}{c c} \hline \hline \multirow{2}{*}{**Number Node Id**} & **Received Signal** \\  & **Strength Indicator** \\ \hline \(m_{i}\) & \(RSSI_{i}\) \\ \(m_{i}\) & \(RSSI_{i}\) \\ \(m_{i}\) & \(RSSI_{i}\) \\ \(m_{i}\) & \(RSSI_{i}\) \\ \(m_{i}\) & \(RSSI_{i}\) \\ \(m_{i}\) & \(RSSI_{i}\) \\ \(-\) & \(-\) \\ \(-\) & \(-\) \\ \(-\) & \(-\) \\ \(-\) & \(-\) \\ \(-\) & \(-\) \\ \(-\) & \(-\) \\ \(-\) & \(-\) \\ \(-\) & \(RSSI_{i}\) \\ \hline \hline \end{tabular}
\end{table}
Table 2: Member table of a SH node.  
\begin{table}
\begin{tabular}{c c} \hline \hline \multicolumn{1}{c}{**Symbol**} & **Description** \\ \hline \(e_{i}\) & An event at \(SH_{i}\) or segment \(r_{i}\) of a sector \\ \(E\) & A set of events \\ \(\theta_{i}\) & The threshold point of \(SH_{i}\) or Segment \(r_{i}\) \\ \(LDS_{i}\) & The local dynamic skyline of \(SH_{i}\) or Segment \(r_{i}\) \\ \hline \(e_{i}\prec_{(q,r)}e_{j}\) & Event \(e_{j}\) is dominated by event \(e_{i}\) with respect to query point \(q\) and the target region of interest is a circle of radius \(r\) centered at \(q\). \\ \hline \(e_{i}\less_{(q,r)}e_{j}\) & Event \(e_{j}\) is dominated by or equal to event \(e_{i}\) with respect to query point \(q\) and the target region of interest is a circle of radius \(r\) centered at \(q\). \\ \hline \(e_{i}\prec_{(q,r)}E\) & Each event in \(E\) is dominated by event \(e_{i}\) with respect to query point \(q\) and the target region of interest is a circle of radius \(r\) centered at \(q\). \\ \(e_{i}\less_{(q,r)}E\) & Each event in \(E\) is dominated by or equal to event \(e_{i}\) with respect to query point \(q\) and the target region of interest is a circle of radius \(r\) centered at \(q\). \\ \hline \hline \end{tabular}
\end{table}
Table 3: Skyline Notation.  
Figure 7: Segmentation architecture of member nodes inside a sector.  
```
0:\(n\) (total number of sectors (columns)), \(SELF\_NET\_ADDR\)
0:Node (to store the node values), \(L\) (to store the address of left child of each node), \(R\) (to store the address of right child of each node)
1:// Finding the Track (row) number of current sector
2:\(i=(SELF\_NET\_ADDR)/n\);
3:\(index=S\);
4:for\(j=0\) to \(S\)\(-\)\(1\);
5:\(node\) [j] = (\(i,j\))
6:if (\(i\)-\(1\geq 0\))
7:\(L[j]=index\);
8:\(N[index]=(i\)\(-\)\(1,j\))
9:endif
10:\(L_{i}=i\)\(-\)\(11\)
11:while (\(L_{i}\)-\(1\)\(\geq\)\(0\))
12:\(L[index]=index+1\)
13:\(Node[index]=(L_{i}\)\(-\)\(1,j\))
14:\(index\)++
15:\(L_{i}\)\(-\);
16:endwhile
17:\(index\)++
18:if (\(i\)+\(1\)\(<\)\(T\))
19:\(R[j]=index\);
20:\(N[index]=(i\)\(+\)\(1,j\))
21:endif
22:\(R_{i}=i\)\(+\)\(1\)
23:while (\(R_{i}\)+\(1\)\(<\)\(T\))
24:\(R[index]=index\)\(+\)\(1\)
25:\(N[index]=(R_{i}\)\(+\)\(1,j\))
26:\(index\)++
27:\(R_{i}\)++
28:endwhile
29:\(index\)++
30:endfor
```  
**Algorithm 3**Build_Tree(), implemented at each SH.