Delay-Aware and Energy-Efficient IoT Task Scheduling Algorithm with Double Blockchain Enabled in Cloud-Fog Collaborative Networks

Since fog nodes are resource-constrained and imperfectly trusted heterogeneous devices, guaranteeing a real-time response to IoT tasks while optimizing system energy consumption remains a significant challenge. To overcome this, we first propose a double blockchain-enabled cloud-fog collaborative task scheduling architecture. Second, a task scheduling model is constructed to optimize system energy consumption and task deadline violation time while adhering to the IoT task response time restriction. Finally, two blockchain-enabled task scheduling algorithms are developed: the reputation-based priority-aware algorithm (DB_RP) and the accelerated ant colony system algorithm (DB_AACS). Extensive experiments are conducted to assess the proposed algorithm in four dimensions: task completion rate, system makespan, system energy consumption, and task deadline violation time. The experimental results demonstrate that the proposed algorithm is superior to existing literature, and the acceleration strategy in DB_AACS is effective.