Active Coordination in Ad Hoc Networks

The increasing ubiquity of mobile devices has led to an explosion in the development of applications tailored to the particular needs of individual users. As the research community gains experience in the development of these applications, the need for middleware to simplify such software development is rapidly expanding. Vastly different needs of these various applications, however, have led to the emergence of many different middleware models, each of which approaches the dissemination of contextual information in a distinct way. The EgoSpaces model consists of logically mobile agents that operate over physically mobile hosts. EgoSpaces addresses the specific needs of individual agents, allowing them to define what data is to be included in their operating context by means of declarative specifications constraining properties of the data items, the agents that own the data, the hosts on which those agents are running, and attributes of the ad hoc network. In the resulting coordination model, agents interact with a dynamically changing environment through a set of views, custom defined projections of the set of data objects present in the surrounding ad hoc network. This paper builds on EgoSpaces by allowing agents to assign automatic behaviors to the agent-defined views. Behaviors consist of actions which are automatically performed in response to specified changes in the view. Behaviors discussed in this paper encompass reactive programming, transparent data migration, automatic data duplication, and event capture. Formal semantic definitions and programming examples are given for each behavior

Using EgoSpaces for Scalable, Proactive Coordination in Ad Hoc Networks **PLEASE SEE WUCSE-03-11**

The increasing ubiquity of mobile devices has led to an explosion in the development of applications tailored to the particular needs of individual users. As the research community gains experience in the development of these applications, the need for middleware to simplify such software development is rapidly expanding. Vastly different needs of these various applications, however, have led to the emergence of many different middleware models, each of which approaches the dissemination of contextual information in a distinct way. The EgoSpaces model consists of logically mobile agents that operate over physically mobile hosts. EgoSpaces addresses the specific needs of individual agents, allowing them to define what data is to be included in their operating context by means of declarative specifications constraining properties of the data items, the agents that own the data, the hosts on which those agents are running, and attributes of the ad hoc network. The resulting model is one in which agents interact with a dynamically changing environment through a set of views, custom defined projections of the set of data objects present in the surrounding ad hoc network. This paper builds on EgoSpaces by allowing agents to assign automatic behaviors to the agent-defined views. Behaviors consist of actions which are automatically performed in response to specified changes in the view. Behaviors discussed in this paper encompass reactive programming, transparent data migration, automatic data duplication, and event capture. Formal semantic definitions are given for each behavior. Since performance is a real concern in the ad hoc environment, this paper also presents protocol implementations tailored to each behavior type

Context Aware Computing for The Internet of Things: A Survey

As we are moving towards the Internet of Things (IoT), the number of sensors deployed around the world is growing at a rapid pace. Market research has shown a significant growth of sensor deployments over the past decade and has predicted a significant increment of the growth rate in the future. These sensors continuously generate enormous amounts of data. However, in order to add value to raw sensor data we need to understand it. Collection, modelling, reasoning, and distribution of context in relation to sensor data plays critical role in this challenge. Context-aware computing has proven to be successful in understanding sensor data. In this paper, we survey context awareness from an IoT perspective. We present the necessary background by introducing the IoT paradigm and context-aware fundamentals at the beginning. Then we provide an in-depth analysis of context life cycle. We evaluate a subset of projects (50) which represent the majority of research and commercial solutions proposed in the field of context-aware computing conducted over the last decade (2001-2011) based on our own taxonomy. Finally, based on our evaluation, we highlight the lessons to be learnt from the past and some possible directions for future research. The survey addresses a broad range of techniques, methods, models, functionalities, systems, applications, and middleware solutions related to context awareness and IoT. Our goal is not only to analyse, compare and consolidate past research work but also to appreciate their findings and discuss their applicability towards the IoT.Comment: IEEE Communications Surveys & Tutorials Journal, 201

LUNES: Agent-based Simulation of P2P Systems (Extended Version)

We present LUNES, an agent-based Large Unstructured NEtwork Simulator, which allows to simulate complex networks composed of a high number of nodes. LUNES is modular, since it splits the three phases of network topology creation, protocol simulation and performance evaluation. This permits to easily integrate external software tools into the main software architecture. The simulation of the interaction protocols among network nodes is performed via a simulation middleware that supports both the sequential and the parallel/distributed simulation approaches. In the latter case, a specific mechanism for the communication overhead-reduction is used; this guarantees high levels of performance and scalability. To demonstrate the efficiency of LUNES, we test the simulator with gossip protocols executed on top of networks (representing peer-to-peer overlays), generated with different topologies. Results demonstrate the effectiveness of the proposed approach.Comment: Proceedings of the International Workshop on Modeling and Simulation of Peer-to-Peer Architectures and Systems (MOSPAS 2011). As part of the 2011 International Conference on High Performance Computing and Simulation (HPCS 2011

The Quest for Scalability and Accuracy in the Simulation of the Internet of Things: an Approach based on Multi-Level Simulation

This paper presents a methodology for simulating the Internet of Things (IoT) using multi-level simulation models. With respect to conventional simulators, this approach allows us to tune the level of detail of different parts of the model without compromising the scalability of the simulation. As a use case, we have developed a two-level simulator to study the deployment of smart services over rural territories. The higher level is base on a coarse grained, agent-based adaptive parallel and distributed simulator. When needed, this simulator spawns OMNeT++ model instances to evaluate in more detail the issues concerned with wireless communications in restricted areas of the simulated world. The performance evaluation confirms the viability of multi-level simulations for IoT environments.Comment: Proceedings of the IEEE/ACM International Symposium on Distributed Simulation and Real Time Applications (DS-RT 2017