Natural disasters, such as earthquakes, can cause severe destruction and create havoc in the society. Buildings and other structures may collapse during disaster incidents causing injuries and deaths to victims trapped under debris and rubble. Immediately after a natural disaster incident, it becomes extremely difficult for first responders and rescuers to find and save trapped victims. Often searches are carried out blindly in random locations, which delay the rescue of the victims. This paper introduces a Smartphone Assisted Disaster Recovery (SmartDR) method for post-disaster communication using Smartphones. SmartDR utilizes the device-to-device (D2D) communication technology in Fifth Generation (5G) networks, which enables direct communication between proximate devices without the need of relaying through a network infrastructure, such as mobile access points or mobile base stations. We examine a scenario of multi-hop D2D communication where smartphones carried by trapped victims and other people in disaster affected areas can self-detect the occurrence of a disaster incident by monitoring the radio environment and then can self-switch to a disaster mode to transmit emergency help messages with their location coordinates to other nearby smartphones. To locate other nearby smartphones also operating in the disaster mode and in the same channel, each smartphone runs a rendezvous process. The emergency messages are thus relayed to the functional base station or rescue centre. To facilitate routing of the emergency messages, we propose a path selection algorithm, which considers both delay and the leftover energy of a device (a smartphone in this case). Thus, the SmartDR method includes: (i) a multi-channel channel hopping rendezvous protocol to improve the victim localization or neighbour discovery, and (ii) an energy-aware multi-path routing (Energy-aware ad-hoc on-demand distance vector or E-AODV) protocol to overcome the higher energy depletion rate at devices associated with single shortest path routing. The SmartDR method can guide search and rescue operations and increase the possibility of saving lives immediately aftermath a disaster incident. A simulation-based performance study is conducted to evaluate the protocol performance in post-disaster scenario. Simulation results show that a significant performance gain is achievable when a device utilizes the channel information for the rendezvous process and the leftover energy for routing path selection. Our results show that peer discovery in multi-channel D2D environment can be significantly improved when channel quality information is considered in CH sequence design. Moreover, selecting a routing path based on LoE of a device and the standard deviation of residual energy of a path, can not only enhance the network lifetime, but also reduce the chance of network being partitioned.

诸如地震之类的自然灾害会造成严重破坏并给社会造成破坏。在灾难事件中，建筑物和其他建筑物可能倒塌，导致被碎片和瓦砾困住的受害者受伤或死亡。自然灾害事件发生后，急救人员和救援人员立即很难找到并救出被困的受害者。通常在盲目位置进行盲目搜索，这延迟了对受害者的营救。本文介绍了使用智能手机进行灾后通信的智能手机辅助灾难恢复（SmartDR）方法。SmartDR利用第五代（5G）网络中的设备到设备（D2D）通信技术，该技术可以在附近的设备之间进行直接通信，而无需通过网络基础结构进行中继，例如移动接入点或移动基站。我们研究了多跳D2D通信的场景，受困受害者和受灾地区其他人员携带的智能手机可以通过监视无线电环境来自我检测灾难事件的发生，然后可以自动切换到灾难模式进行传输紧急帮助消息及其位置会协调到附近的其他智能手机。为了定位也在灾难模式和同一通道中运行的其他附近智能手机，每个智能手机都运行一个集合点过程。紧急消息因此被中继到功能基站或救援中心。为了方便紧急消息的路由，我们提出了一种路径选择算法，该算法同时考虑了延迟和设备（在这种情况下为智能手机）的剩余能量。从而，SmartDR方法包括：（i）多通道跳频会合协议，以改善受害者的定位或邻居发现，以及（ii）能量感知多路径路由（能量感知特设按需距离矢量或E-AODV）协议，以克服与单个最短路径路由相关联的设备上更高的能量消耗率。SmartDR方法可以指导搜索和救援操作，并增加在灾难事件发生后立即挽救生命的可能性。进行了基于仿真的性能研究，以评估灾难后场景中的协议性能。仿真结果表明，当设备将通道信息用于会合过程并将剩余能量用于路由路径选择时，可以实现显着的性能提升。我们的结果表明，在CH序列设计中考虑信道质量信息时，可以大大改善多信道D2D环境中的对等发现。而且，基于设备的LoE和路径的剩余能量的标准偏差来选择路由路径，不仅可以延长网络寿命，而且可以减少网络划分的机会。