Recent Research Subjects
Our research group has designed and developed a network simulator for realistic evaluation of mobile network systems and protocols, called MobiREAL. MobiREAL simulator enables developers to specify realistic behavior of mobile nodes, and provides a framework to simulate both the behavior of mobile nodes and wireless communication among them interactively. For details, please visit MobiREAL HP (http://www.mobireal.net)
We consider situations where many persons are simultaneously injured in disaster such as earthquakes and train accidents, and propose an advanced electronic triage system for sensing physical condition of those injured persons and collecting their sensed data in ad-hoc wireless communication. The triage system presents dynamic change of injured persons' location and physical condition on monitors in real time.
Recently, considerable research work has been focused on applying ad hoc wireless networking technology to moving vehicles on roads. It has been suggested that ad hoc communication can be used to propagate information related to traffic jams and accidents. We focus our research on efficient data exchange for acquiring local traffic information and detecting dangerous vehicles on roads and/or highways cooperatively.
We present a range-free ad-hoc localization algorithm called UPL (Urban Pedestrians Localization), for positioning mobile nodes in urban district where location seeds are assumed to be deployed sparsely due to deployment-cost constraints. Each mobile node in UPL relies on location information received from its neighboring mobile nodes in order to estimate its area of presence. We also present an off-line algorithm called TRACKIE (TRACe reproduction algorithm with Keypoint Iterative Estimation) to estimate trajectories of mobile nodes using ad-hoc communication.
We propose a protocol to construct a degree-bounded delay sensitive overlay multicast tree called MODE (Minimum-delay Overlay tree construction by DEcentralized operation). We also propose a new middleware, which supports implementation and evaluation of Application Layer Multicast (ALM in short) protocols in real environments. As an example, we have implemented ALMI, NARADA, NICE and OMNI as ALM protocols, and compared their performance on PlanetLab.
Recently, it is required to develop a methodology to effectively design a complex system in a shorter time that performs efficiently and still meets the required specification such as real-time constraints. To cope with such a problem, we are developing a technique using parametric model checking, to derive automatically a condition formula for design parameters. Moreover, we are studying on analysis, performance evaluation, and cost- and power-optimized automatic synthesis of communication structure of System-on-Chip (SoC) and/or Network-on-Chip (NoC).