Matthew Gillen

QoS enabled dissemination of managed information objects in a publish-subscribe-query information broker

Net-centric information spaces have become a necessary concept to support information exchange for tactical warfighting missions using a publish-subscribe-query paradigm. To support dynamic, mission-critical and time-critical operations, information spaces require quality of service (QoS)-enabled dissemination (QED) of information. This paper describes the results of research we are conducting to provide QED information exchange in tactical environments. We have developed a prototype QoS-enabled publish-subscribe-query information broker that provides timely delivery of information needed by tactical warfighters in mobile scenarios with time-critical emergent targets. This broker enables tailoring and prioritizing of information based on mission needs and responds rapidly to priority shifts and unfolding situations. This paper describes the QED architecture, prototype implementation, testing infrastructure, and empirical evaluations we have conducted based on our prototype.

Dynamic Policy-Driven Quality of Service in Service-Oriented Systems

Service-oriented architecture (SOA) middleware has emerged as a powerful and popular distributed computing paradigm due to its high-level abstractions for composing systems and hiding platform-level details. Control of some details hidden by SOA middleware is necessary, however, to provide managed quality of service (QoS) for SOA systems that need predictable performance and behavior. This paper presents a policy-driven approach for managing QoS in SOA systems. We discuss the design of several key QoS services and empirically evaluate their ability to provide QoS under CPU overload and bandwidth-constrained situations.

Beyond line-of-sight information dissemination for Force Protection

Force protection capabilities have emerged as necessary for operations such as Village Stability Operations and Forward Operating Base security. Current Force Protection Kits include a rich set of sensors that can be monitored from a core operator station. This paper describes ongoing research to extend the reach of Force Protection capabilities as part of an integrated, network-centric system to protect mobile troops on patrol, to include sensors beyond the organic Force Protection perimeter, and to enable the automated, selective transfer of information to and from kit locations. These extended Force Protection capabilities are enabled by a highly-mobile, vehicle mounted information management system providing beyond line-of-sight publish-subscribe capabilities, sensor data archiving, video storage and retrieval, and data ferrying across long distances.

Integrated information and network management for end-to-end Quality of Service

Publish-subscribe-based Information Management (IM) services provide a key enabling technology for net-centric operations. This paper describes technology for Quality of Service (QoS) and Internet-Protocol-based Airborne Networking features for IM services. Enhancing IM services with airborne networking features improves effectiveness in combined tactical and enterprise networks with mobile airborne and ground-based embedded platforms interacting with enterprise systems in command and control operations.

Fault Tolerance in a Multi-Layered DRE System: A Case Study

Dynamic resource management is a crucial part of the infrastructure for emerging distributed real-time embedded systems, responsible for keeping mission-critical applications operating and allocating the resources necessary for them to meet their requirements. Because of this, the resource manager must be fault-tolerant, with nearly continuous operation. This paper describes our efforts to develop a fault-tolerant multi-layer dynamic resource management capability and the challenges we encountered, some due to the fault tolerance requirements we needed to meet and others due to characteristics of the resource management software. The challenges include the need for extremely rapid recovery; supporting the characteristics of component middleware, including peer-to-peer communication and multi-tiered calling semantics; supporting multiple languages; and the co-existence of replicated and non-replicated elements. Making our multi-layer dynamic resource manager fault-tolerant required simultaneously overcoming all of these challenges, presenting a significant fault tolerance research challenge.

Quality of Service in us air force information management systems

Warfighters in todays asymmetric engagements need access to mission-critical information no matter when and where it becomes available. Information Management Services (IMSs) based on publish-subscribe-query services have emerged as an important enabler of tactical information dominance in combined tactical and enterprise military situations. IMSs support information brokering and dissemination between decoupled information producers and consumers, for both future (publish-subscribe) and historical (publish-archive-query) information. To support operations in dynamic environments, IMSs require Quality of Service (QoS) capabilities to ensure prioritized delivery of mission-critical information, to mediate conflicting demands for information brokering and dissemination resources in constrained situations, and to adapt IMS operations to changing missions, roles, and priorities. This paper describes a set of QoS management services, QoS Enabled Dissemination (QED), that provide policy driven, dynamic, aggregate QoS management across the users of IMSs. The paper describes the QED prototype implementation and experimental results illustrating the improvement of QED over a non-QoS enabled IMS baseline.

Fault Tolerant Approaches for Distributed Real-time and Embedded Systems

Fault tolerance (FT) is a crucial design consideration for mission-critical distributed real-time and embedded (DRE) systems, which combine the real-time characteristics of embedded platforms with the dynamic characteristics of distributed platforms. Traditional FT approaches do not address features that are common in DRE systems, such as scale, heterogeneity, real-time requirements, and other characteristics. Most previous R&D efforts in FT have focused on client-server object systems, whereas DRE systems are increasingly based on component-oriented architectures, which support more complex interaction patterns, such as peer-to-peer. This paper describes our current applied R&D efforts to develop FT technology for DRE systems. First, we describe three enhanced FT techniques that support the needs of DRE systems: a transparent approach to mixed-mode communication, auto-configuration of dynamic systems, and duplicate management for peer-to-peer interactions. Second, we describe an integrated FT capability for a real-world component-based DRE system that uses off-the-shelf FT middleware integrated with our enhanced FT techniques. We present experimental results that show that our integrated FT capability meets the DRE systems real-time performance requirements for both the responsiveness of failure recovery and the minimal amount of overhead introduced into the fault-free case.

Dynamic Policy-Driven Quality of Service in Service-Oriented Information Management Systems

SOA middleware has emerged as a powerful and popular distributed computing paradigm because of its high‐level abstractions for composing systems and encapsulating platform‐level details and complexities. Control of some details encapsulated by SOA middleware is necessary, however, to provide managed QoS for SOA systems that require predictable performance and behavior. This paper presents a policy‐driven approach for managing QoS in SOA systems called QoS enabled dissemination (QED). QED includes services for: (1) specifying and enforcing the QoS preferences of individual clients; (2) mediating and aggregating QoS management on behalf of competing users; and (3) shaping information exchange to improve real‐time performance. We describe QEDs QoS services and mechanisms in the context of managing QoS for a set of Publish‐Subscribe‐Query information management services. These services provide a representative case study in which CPU and network bottlenecks can occur, client QoS preferences can conflict, and system‐level QoS requirements are based on higher level, aggregate end‐to‐end goals. We also discuss the design of several key QoS services and describe how QEDs policy‐driven approach bridges users to the underlying middleware and enables QoS control based on rich and meaningful context descriptions, including users, data types, client preferences, and information characteristics. In addition, we present experimental results that quantify the improved control, differentiation, and client‐level QoS enabled by QED. Copyright

Information Ubiquity in Austere Locations

Abstract In todays world, connectivity is increasingly taken for granted. Wireless networks, cell towers, and satellites provide ubiquitous connectivity through a number of devices. However, in austere locations constant connectivity cannot be assumed, e.g., due to the remoteness of the area, due to a disaster or combat situation, or due to insecurity or lack of access to available communications. This paper describes a system, Marti, which the authors have been developing and demonstrating that can provide inter-connectivity and access to information in austere locations. Marti is rapidly deployable and interoperates with a large number of existing devices and client applications.

A secure content network in space

We present a content network architecture for a cluster of satellites flying in low Earth orbit. The cluster uses a dynamic wireless network to interconnect the satellites and has an intermittent link to the ground. Even though a cluster of satellites fly in formation, their relative positions can vary widely, and occasionally the cluster can disperse and regroup in order to avoid obstacles or to affect a better arrangement. The network, therefore, is a MANET with elements of a disruption tolerant network. Further, data security is a fundamental concern. Our approach is to layer a content network over the wireless network, supporting multiple qualities of service and multiple independent levels of security.