# New Detection Paradigms to Improve Wireless Sensor Network Performance under Jamming Attacks
## 4 Analysis of Results
In the Extended Mechanism the included nodes are all those with similar performance metrics because they are in the same area of the topology or at the same distance from the collector node. In the Extended Mechanism more nodes can be considered, i.e., the whole set of nodes in the same area in the topology \begin{table}
\begin{tabular}{l c} \hline \hline
**Parameter** & **Value** \\ \hline \multicolumn{3}{c}{**Physical Layer Parameters**} \\ \hline Sensitivity threshold receiver & \(-94\) dBm \\ Transmission power & \(4.5\) dBm \\ Propagation model & Free Space \\ \hline \multicolumn{3}{c}{**MAC Layer Parameters**} \\ \hline Waiting time for ACK packet & \(30\) ms \\ Maximum retransmission number & \(3\) \\ Maximum retry number & \(5\) \\ Maximum number of tries to reach & \(9\) \\ a node from the collector & \(1\%\) \\ Packet error rate & \(1\%\) \\ Average frame length & \(22\) bytes \\ Maximum number of backoffs & \(4\) \\ MAC protocol & IEEE 802.15.4 \\ MAC layer & CSMA/CA \\ \hline \multicolumn{3}{c}{**Network Layer Parameters**} \\ \hline Number of nodes & \(49\) \\ Maximum number of neighbors & \(16\) \\ Discovery neighbor time & \(30\) s \\ Update time neighbors table & \(30\) ms \\ Maximum data rate & \(250\) kbps \\ Routing & Hierarchical \\ Scenario & Static nodes \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Simulation and real network parameters. CSMA/CA, carrier sense multiple access with collision avoidance [31]. with respect to the collector node, which forms a set of nodes with similar performance parameters. The communication to the Extended Mechanism demands higher overhead to the network when the information of performance metrics is gathered, this is because some of the nodes in the groups may not have direct connectivity. In contrast, collecting information within the Connected Mechanism is straightforward. Thus, the latter is a more practical approach, but the former sends the control packet more accurately. Figure 2 shows the results of the proposed Extended Mechanism for identification of jammed nodes for the MPH protocol. The three possible positions of the jammer node are with respect to the collector node and are: near (position [2,2] of the grid matrix of the Figure 2), middle (position [4,4] in the Figure 2) and far (position [7,7] of the grid matrix of Figure 2). These positions are based on Figure 1. The results show in white squares the nodes that remain in the routing tables of their neighbors and in black squares those that are not included as neighbors, while the gray colors represent intermediate conditions (may be also under attack). This Figure has four columns representing four situations in the network: (1) No jamming or normal network conditions, (2) When the jammer node is close to the coordinator, (3) When the jammer node is in the middle of the topology, (4) When the jammer node is in the farthest corner from the coordinator node. The column \"No jamming\" is represented by the nodes in stable state or normal conditions, therefore, the nodes that are grayer indicate the nodes near to the collector node because they constitute a bottleneck in the network. The nodes that remain white are those that do not have their altered performance parameters. When we obtain the performance parameters in the other cases (near, middle and far) with the jammer node, a difference is established and when the difference is very low, almost zero, the squares are clearer (almost whites) and this indicates that they are remaining under their normal operating conditions. Then, when the difference in the performance parameters (energy, retransmissions, and CSMA retries) is high, in the \"near\", \"middle\" and \"far\" columns, these nodes become darker. The above represents that in the last three columns, the darker nodes show the affected nodes according to each of the positions of the jammer node.