# Adaptive Jamming Mitigation for Clustered Energy-Efficient LoRa-BLE Hybrid Wireless Sensor Networks
## 4 Results and Discussion
### Scenario 1: BLE-Based Communication with Cluster-Based Mitigation and a Jammer Node  
In this scenario, the sensor network operates exclusively using BLE, where LPSTK-CC1352R sensors communicate directly with the Laird Sentrius Gateway. A subset of CC1352P sensors is configured as cluster heads based on their energy availability, retransmission rates, and link quality. The jammer node is positioned near one of the CHs to introduce interference, causing packet losses and increased retransmission rates. The goal is to evaluate how the network adapts through cluster reconfiguration, where affected nodes elect a new CH and reroute data through alternative BLE paths. Key metrics evaluated:  
* Retransmission Rate: The number of packet retransmissions before successful delivery. * Energy Consumption: Power usage before and after cluster adaptation. Routing Resilience: The time taken to reestablish a stable BLE communication path after jamming. In the first phase, sensor nodes operate exclusively in BLE mode without any mitigation strategies. Energy consumption data are collected every hour over 24 h to establish a baseline measurement of power usage under normal network conditions. This behavior is described in Figures 2-4. In the second phase, conducted on a separate day, the proposed mitigation algorithm is implemented within the BLE network. The same set of sensor nodes is monitored for energy consumption every hour for another 24-h period. During this phase, the mitigation strategy dynamically adjusts transmission power, reroutes data through alternative paths, and reorganizes network clusters to counteract potential jamming attacks. Comparative analysis between the two datasets allows for the evaluation of the effectiveness of the mitigation strategy in reducing energy consumption while maintaining network stability. Figure 2 illustrates the energy consumption trends for BLE under jamming conditions, both without and with the mitigation algorithm. The results demonstrate that, in the absence of a mitigation strategy, energy consumption increases progressively as jamming intensifies, primarily due to the elevated retransmission rates caused by packet collisions and interference. Without mitigation, affected nodes continue to attempt transmissions, leading to unnecessary energy expenditure. Conversely, when the mitigation algorithm is applied, energy consumption is significantly reduced. This efficiency gain can be attributed to the algorithm's adaptive routing approach, which dynamically reorganizes network clusters and redistributes transmission responsibilities to nodes with higher energy reserves, thereby optimizing power usage. Furthermore, the implementation of intelligent transmission power adjustments minimizes excessive retransmissions and improves network stability. Figure 3 highlights the variation in retransmission rates under similar jamming conditions. The number of retransmissions in the unprotected BLE network remains notably high, particularly during peak interference periods, as the nodes continuously attempt to deliver packets despite heavy congestion in the communication channel. This behavior severely affects overall network efficiency, leading to increased latency and higher energy drainage. However, with the mitigation strategy in place, the retransmission rate drops substantially. This improvement stems from the algorithm's ability to detect jamming zones in real time and reconfigure communication paths accordingly. By selecting alternative routes or temporarily shifting transmission responsibilities to more robust nodes, the system reduces failed transmission attempts, thus alleviating network congestion. Figure 4 presents the resilience of the BLE network, measured as the time required for the network to recover after a jamming event. Without mitigation, the recovery time is prolonged due to the network's inability to promptly adapt to the changing interference landscape.