Hybrid cellular-MANETs in practice: A microblogging system for smart devices in disaster areas

Our dependence on mobile communications continues to grow; however, wireless devices may encounter inadequate coverage due to a variety of shortage and outage circumstances. In particular, in disaster situations, the access to communications is critical for rescue operations while local wireless infrastructure may have suffered damage. In this paper, we demonstrate the concept of hybrid cellular mobile ad hoc network (hybrid cellular-MANET) to extend wireless coverage by showing a fully functioning microblogging system for smartphones and tablets without requiring modifications of the existing wireless infrastructure in an emulated disaster area. Participating devices connect to each other through WiFi radio to form a hybrid cellular-MANET, relaying data off the MANET through the nodes that have sufficient cellular forwarding capability. We have proposed a self-organizing, mobility-aware, multi-path routing protocol (HMANET) to control the data forwarding in the hybrid cellular-MANET. We compare its performance with the classic Hybrid Wireless Mesh Protocol (HWMP) used in the IEEE 802.11s standard in the built microblogging system. Our experimental results show that the HMANET protocol statistically outperforms the HWMP protocol in terms of adaptiveness to role change and mobility in the hybrid cellular-MANET.