SDBlockEdge: SDN-blockchain enabled multihop task offloading in collaborative edge computing

In recent years, the Internet of Things (IoT) has gained tremendous attention and exponential growth in every domain of life. However, these devices face many challenges due to the limited resources in terms of storage and computation. Collaborative Edge Computing (CEC) is an emerging paradigm that solves these issues where multiple edge devices share computational resources to collaborate and satisfy user requirements. The fundamental issues in CEC are to make an offloading decision while considering the flow scheduling and balancing the load over multiple edge devices. Moreover, the efficient resource allocation of edge nodes is challenging, particularly when IoT devices are more vulnerable and become resource-hungry. The combination of Software Defined Networking (SDN) and Blockchain (BC) can play a vital role in solving the issues mentioned above. This paper presents a token-based resource management mechanism as SDBlockEdge by integrating these two technologies. The programming abstractions and global view of the SDN can help offload decision and flow scheduling, whereas the smart contract mechanism of BC can help control the abnormal behavior of IoT devices. We design the Resource Management Controller (RMC), which collaborates with the SDN controller to keep the record of available resources. It helps for offloading decisions and balancing the load over edge servers, whereas the SDN controller helps consider the less loaded path, while offloading reduces the task completion time. Moreover, the resources are allocated against tokens, and smart contracts are used to pay the cost of these resources. The proposed approach is implemented in Mininet_WiFi and Containernet, where docker hosts act as edge nodes with different IoT devices. The results after the extensive simulation show the effectiveness of the proposed approach.