Reliable signal reception and attenuation control are critical to improving the performance of low-power wide area networks (LPWANs), especially in hybrid systems integrating LoRa and satellite communications. This study analyzes the effect of Graham’s algorithm in hybrid LoRa-satellite networks using NEO-M8N GPS-enabled TTGO nodes deployed in mesh in hindered environments. Implementation of the algorithm optimized inter-node connectivity, reduced signal attenuation, and improved satellite availability. A superior packet delivery ratio (PDR) was observed with the Graham algorithm. In addition, power consumption per minute was stabilized and battery life was extended. Through mathematical modeling and experimental validation, it is confirmed that Graham improves the energy efficiency and robustness of the network, enhancing the performance of hybrid LPWAN systems.

This paper presents a comprehensive Stochastic Petri Net (SPN) model for evaluating energy availability in multi-microgrid systems, integrating photovoltaic (PV) generation, battery storage, and distribution networks. The proposed framework addresses the inherent uncertainties of renewable energy sources (RES), dynamic load demands, and operational transitions between grid-connected and islanded modes. By leveraging SPNs, the model captures the probabilistic behavior of microgrid components, enabling precise assessment of steady-state and instantaneous availability metrics. A Reliability Block Diagram (RBD) further extends the analysis to cooperative microgrid networks, quantifying the collective ability to meet contractual energy commitments under shared surplus scenarios. Simulation results, validated using the CIGRE LV benchmark network, demonstrate the model’s efficacy in identifying reliability bottlenecks, optimizing maintenance strategies, and enhancing system resilience. The study highlights the SPN’s versatility in modeling complex interactions across residential, industrial, and commercial microgrids, providing actionable insights for sustainable energy system design.

Satellite communications have become an everyday aspect of our daily lives, and the current focus on satellite telecommunications is expected to continue to grow and gain greater prominence. On the other hand, implementing scheduled and unscheduled maintenance practices is essential to improving the availability and reliability of satellite systems. This paper presents a stochastic availability model designed through a Stochastic Petri Net (SPN) that considers the aging of satellites, offering support for infrastructure planning by integrating both scheduled and unscheduled maintenance considerations. Additionally, this research includes two case studies. The first case study explores an availability model that ignores the influence of aging, establishing a baseline of availability and second with aging. This baseline will be compared with the results obtained from the proposed SPN model, which incorporates the effects of aging. In this way, the behavior of both non-aging and aging variables can be analyzed to make contributions through the SPN that helps understand the availability of satellite systems.