Always Connected Things: Building Disaster Resilience IoT Communications Maintenance of communications during disasters is still a serious challenge due to power loss and equipment damage. An additional emergency communication usually needs a lot of investment and becomes a burden in normal. Since IoT devices become more and more important for human life, billions of connected devices become a great opportunity for building communications to resilient emergencies. In this paper, we present AWCT, a novel communication framework to support consistent communications with IoT devices in normal and emergency. In the AWCT framework, we design an orchestration of the lowpower widearea network (LPWAN) and ad hoc networks to build standby communication during emergencies. Meanwhile, we also optimize the cost of the AWCT framework by leveraging the standby time and battery capability. We test the AWCT framework with small testbed and extensive simulations. Evaluation results show that our work has great potential for building future disaster resilience IoT.

Communication Aspects of the Integration of Wireless IoT Devices with Distributed Ledger Technology The pervasive need to safely share and store information between devices calls for the replacement of centralized trust architectures with decentralized ones. DLTs are seen as the most promising enabler of decentralized trust, but they still lack technological maturity, and their successful adoption depends on the understanding of the fundamental design tradeoffs and their reflection in the actual technical design. This work focuses on the challenges and potential solutions for an effective integration of DLTs in the context of the Internet of Things (IoT). We first introduce the landscape of IoT applications and discuss the limitations and opportunities offered by DLTs. Then we review the technical challenges encountered in the integration of resourceconstrained devices with distributed trust networks. We describe the common traits of lightweight synchronization protocols, and propose a novel classification rooted in the IoT perspective. We identify the need for receiving ledger information at the endpoint devices, implying a twoway data exchange that contrasts with the conventional uplinkoriented communication technologies intended for IoT systems.