Applications consisting of messaging, voice, and video are used to provide situational awareness to decision makers and emergency responders in high criticality crisis scenarios such as disaster management. Here, ad hoc wireless networks are often quickly provisioned to provide the necessary connectivity to support these applications. Applications ill prepared to deal with the constant fluctuation of available bandwidth will stall or fail and contribute to mission failure. Our algorithm, D-Q-RAM (Distributed Quality of Service (QoS) Resource Allocation Model) allows applications to satisfy their specific QoS expectations in dynamically fluctuating networked environments by incorporating a distributed optimization heuristic that results in near optimal adaptation without the need to know, estimate, or predict available bandwidth at any moment in time. This paper describes our approach for managing that optimization heuristic in a manner that is decentralized, that is network routers are unaware of the semantics of the applications, and the applications can arbitrate among competing signals from numerous network routers and select an appropriate QoS level which results in an improved overall global utility of available network bandwidth.

Demand for real-time video in law enforcement, emergency and first responder situations has been in rapid growth. Further, different users will have different requirements which, depending on their needs, may change over time. At some times, a user may require high frame rate to detect motion, while at other times the user may be more concerned with resolution for object recognition. In this paper we describe our model for quantifying Quality of Experience (QoE) and managing Quality of Service (QoS) that incorporates end user or mission needs. We describe our distributed utility-based QoS optimization technique, D-Q-RAM and show how it can be used to make QoS trade-offs in response to mission needs to maximize QoE. We experimentally demonstrate QoS optimized trade-offs as user preferences shift between resolution and frame rate in a live 802.11 ad hoc wireless network. The results show the ability to meet all individual user needs, changing or not, while minimizing the impact on other users.

In high criticality crisis scenarios, such as disaster management, ad hoc wireless networks are quickly assembled in the field to support decision makers through situational awareness using messaging-, voice-, and video-based applications. These applications cannot afford the luxury of stalling or failing due to overwhelming bandwidth demand on these networks as this could contribute to overall mission failure. This paper describes an approach for satisfying application-specific Quality of Service (QoS) expectations operating on ad hoc wireless networks where available bandwidth fluctuates. The proposed algorithm, D-Q-RAM (Distributed QoS Resource Allocation Model) incorporates a distributed optimization heuristic that results in near optimal adaptation without the need to know, estimate, or predict available bandwidth at any moment in time.

Software components and the technology supporting component based software engineering contribute greatly to the rapid development and configuration of systems for a variety of application domains. Such domains go beyond desktop office applications and information systems supporting e-commerce, but include systems having real-time performance requirements and critical functionality. Discussed in this paper are the results from an experiment that demonstrates the ability to predict deadline satisfaction of threads in a real-time system where the functionality performed is based on the configuration of the assembled software components. Presented is the method used to abstract the large, legacy code base of the system software and the application software components in the system; the model of those abstractions based on available architecture documentation and empirically-based, runtime observations; and the analysis of the predictions which yielded objective confidence in the observations and model created which formed the underlying basis for the predictions.

The goal of the 5th Workshop on Open Source Software Engineering is to bring together researchers and practitioners for the purpose of building a roadmap of the ways in which various computing application spaces have been impacted by open source software and also by open source development methods, tools and organizational structures.

Building on the success of "Making Sense of the Bazaar" and "Meeting Challenges and Surviving Success" - the 1/sup st/ and 2/sup nd/ Workshops on Open Source Software Engineering (ICSE 2001 and ICSE 2002)-this workshop ("Taking Stock of the Bazaar') brings together researchers and practitioners for the purpose of discussing the diverse array of techniques - as well as supporting tools and social/organizational contexts which can be observed in the domain of open source software.

The question of which design methods are appropriate for component-based development (CBD) is complicated by different understandings of the end objectives of CBD. A further complication is different understandings of what is meant by "component." These differences lead to entirely distinct classes of design problem. The aim of this tutorial is to, first, outline the different classes of design problem that span these differing interpretations of CBD, and, second, to outline the required methodological responses to these design problems.

The question of which design methods are appropriate for component-based development (CBD) is complicated by different understandings of the end objectives CBD. A further complication is different understandings of what is meant by "component." These differences lead to entirely distinct classes of design problem. The aim of this tutorial is to, first, outline the differing interpretations of CBD, and, second, to outline the required methodological responses to these design problems.

This paper makes pragmatic recommendations for the maintenance of complex COTS-based systems. We first enumerate the issues that can arise in systems that rely on COTS products, whether in operational systems themselves or in the support systems used to create, modify, or test operational systems. We then suggest principles by which maintenance practice for such systems can be facilitated, particularly for those safety-critical systems for which significant risk is present if they fail. These principles aim at making explicit, during system creation, the COTS-related development practices upon which successful system maintenance will subsequently depend. They also depend on a reasonable means of determining, during system maintenance, how much risk is acceptable in using new releases of COTS products. Copyright © 2000 John Wiley & Sons, Ltd.

Members of the COTS-based system initiative at the Software Engineering Institute have developed the Generic Enterprise Ensemble (GEE), a generic approach to building distributed, transaction based, secure enterprise information systems (EIS). GEE is a tool to help in the selection of technologies and architectural choices when building enterprise information systems. Enterprise JavaBeans/sup TM/ (EJB) is a specification from Sun Microsystems for an application server based on Java technology. a comparison is made between GEE based solutions and off-the-shelf solutions based on the EJB specification.

More and more organizations are using intranets and even the Internet as the communications media for important data. However, such communications media are inherently insecure and subject to hijacking. To secure these connections, mechanisms must be built on top of the underlying communications facilities. We discuss one such security mechanism and describe an implementation using common object request broker architecture (CORBA) based interceptors.

This paper provides an overview of isolating and overcoming faults in COTS-based systems. It describes a method and mechanisms that are useful for maintainers and integrators that are tasked with maintaining complex systems from heterogeneous sources. While all readers may find value in this report, it is expressly aimed at a technical audience. The method described in this paper has been used on various systems. Three uses of the method are described in the paper. Copyright © 1999 John Wiley & Sons, Ltd.

This paper provides an in-depth technical study about a COTS-based information system made up of several commercial components. In particular, this paper provides detail on the activities needed to make the system functionally useful. While all readers may find value in this report, it is expressly aimed at a technical audience. The organization that performed the work described herein is not named, nor are the specific commercial products. All of them, however, are common products, and the work is very typical of the type of effort that integrating and tuning a COTS-based information system can entail.