We describe an abstract, generic and extensible ontology, the Rover Context Model Ontology (RoCoMO), which is currently being designed and developed to model and represent context in an intelligent context-aware middleware system, called Rover II. The Rover Context Model (RoCoM) is the underlying context model for Rover II and is centered on four primitives that can be used to represent a situation: entity, event, activity and relationship. The ontology is expressed using the Web Ontology Language (OWL) and includes two components -- RoCoM Core Ontology and the RoCoM Application Ontology. We also illustrate its usage with the aid of a public safety application called M-Urgency that is currently deployed at the UMD campus.

A major challenge of context models is to balance simplicity, generality, usability and extensibility. It is also important that the model be practical and implementable. In pursuit of this goal, this paper proposes a context model, Rover Context Model (RoCoM), structured around four primitives that can be used to represent and model any situation and activity: entities, events, relationships, and activities. It introduces the notion of templates of context for each primitive and describes, albeit briefly, the RoCoM Ontology (RoCoMO). It also describes the design and architecture of an abstract, generic and intelligent context-aware middleware called Rover II. We propose this framework as a solution to address the context problem as a whole, and be usable in many domains. We also illustrate its application with the aid of a context-aware public safety application that is deployed in the UMD campus.

M-Urgency is a public safety system that (1) redefines how emergency calls are made to a Public Safety Answering Point (PSAP) like the 911 system and (2) is designed to be context-aware of the situation in which it is used. M-Urgency enables mobile users to stream live audio and video from their devices to local PSAP along with the audio stream, the real time location and the relevant context information, enabling appropriate and prompt service. This paper presents a new feature, incorporated in M-Urgency, that enables social contribution whereby users in the vicinity of an emergency event can help operation conducted by the emergency personnel through verbal/visual information useful to them or by providing assistance. Our experiments show a very positive response from the participant to the capabilities of our system. In this paper, we also discuss the social implications such as privacy and security for this system.

The importance of information for the appropriate handling of any situation is well recognized. We, as human beings, use context not only to interpret available information, but also to seek additional relevant, missing information. Most information systems, which support human decision-making, process context inadequately. Moreover, when some context is considered, the structure is often so rigid that, but for very restricted applications, such systems are not usable. In order to integrate context-handling capabilities with an information integration system, we need a context model for representing context that can efficiently acquire, maintain and integrate contextual information and make it available to applications on demand. In this paper, we present such a model and describe the design of Rover II, a situation-handling platform which supports integration of context-aware applications. The system manages context by constructing a situation graph which dynamically reflects the relevant situation information. We illustrate the use of Rover II with M-Urgency, a public safety application providing audio and video support for emergency help. This system is being deployed for the University of Maryland campus community of 44 000 students, faculty and staff.

We present a public safety system that (1) redefines how emergency calls are presently made (2) has been designed to be fully context aware. First, we describe Rover 2.0, a context aware framework which caters to the development of mobile applications. The framework uses a paradigm for handling context information, which could be user specific context, combined with the general context of the system and the environment, to provide relevant functions and support to the users through the applications. More importantly, we present M-Urgency, a public safety application, developed on the Rover 2.0 platform that redefines the way an emergency call is made to the PSAP (Public Safety Answering Point). M-Urgency enables mobile users to stream live video from their devices to local PSAP along with the audio stream, the real time location information and any personal relevant information about the caller. We are in the process of deploying the M-Urgency system at the University of Maryland Police Department for a pilot.

The world is seeing two significant trends today -- (a) most of the decisions and actions are performed based on the information available (b) the increasing popularity of smart phones and mobile apps that function in isolated manner. We present Rover 2.0, framework that caters to the development of context-aware mobile applications. As technology is used to augment human capabilities, it is important that the applications should combine the con-text of the end user, the system and the environment, to provide relevant functions and support to the users. Rover 2.0 is an ongo-ing effort and we present here a brief description of its current state. We also present a public safety application called M- Urgency.