A Dynamic Service Lookup and Discovery Scheme using a Self-Organizing Overlay Network for Indoor Location-Based Service

REACTION 2012. 1st International workshop on Real-time and distributed computing in emerging applications. December 4th, 2012, San Juan, Puerto Rico.Indoor location-based service (LBS) has various challenges, including that of numerous service lookups being requested concurrently and frequently from several locations, and that the network infrastructure needs to support high scalability, such as inserting or deleting network nodes anytime and anywhere. In general, indoor LBS resources are generally located in close proximity to the requested point. However, a traditional centralized LBS system needs to maintain a geographical map of the entire building or complex in its central server, which can cause low scalability and traffic congestion. This paper presents a self-organizing and fully distributed indoor LBS platform through regional cooperation among devices, and a service lookup algorithm that searches for the shortest physical path to the service resource. An evaluation of the performance of the proposed platform has been compared to the traditional centralized method regarding the service turnaround time according to the number of concurrent lookup increases.This work was supported by the IT R&D program of MKE/KEIT. [10041145, Self-Organized Softwareplatform(SOS) for welfare devices

Optimization of a Self-Stabilizing Role Assignment Algorithm for Actuator/Sensor Networks

La tesi si pone come obiettivo quello di proporre un algoritmo ottimizzato per l'assegnamento di ruoli nelle reti di sensori e attuatori. L'algoritmo è costituito da uno stack ti protocolli self-stabilizing che basa direttamente sull'interfaccia radio. Partendo dal basso lo Spanning Tree struttura la rete ad albero eleggendo dunque un root node. Basandosi su questa struttura il secondo livello dello stack implementa un paradigma di comunicazione gerarchico di tipo publish/subscribe, tramite cui ogni nodo notifica verso il root node le proprie funzionalità. In cima allo stack il Role Assignment analizza i ruoli richiesti dalle applicazioni per poter girare e, dinamicamente, provvede ad assegnarli ai nodi in base alle loro funzionalità. La tesi espone dunque l'implementazione dell'algoritmo per Network Simulator 2 (NS2) e i grafici ottenuti, riferenti agli indici di maggiore interesse