Showing papers by "Craig Partridge published in 2012"

A secure content network in space

Abstract: 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.

Information dissemination in disadvantaged wireless communications using a data dissemination service and content data network

Abstract: Disadvantaged wireless communications, such as those in fractionated spacecraft systems, need real-time, reliable, and fault tolerant information dissemination from information producers (such as sensors) to information consumers (such as information exploitation, analysis, or command and control systems). Such systems are well-suited to the publishsubscribe paradigm, but cannot afford the large footprint of many publish-subscribe systems and do not provide the underlying high-bandwidth, stable connectivity many publish-subscribe systems assume. Similarly, publish-subscribe systems cannot, by themselves, provide the real-time performance and quality of service needed by many missioncritical and spacecraft applications; they need enforcement and control provided by an underlying network. This paper presents a concept for a dissemination system suited to space-borne platforms that combines a lightweight implementation of the OMG's Data Dissemination Service with a simplified Content Delivery Network. The result is a topic-based publish-subscribe information dissemination service that supports decoupled publishers and subscribers of varying numbers, automated failover, and quality of service (QoS), coupled with a topic-based network that can enforce QoS parameters and efficiently deliver published messages based on the subscriptions registered by consumers.

A concept for publish-subscribe information dissemination and networking

Abstract: Although IP and its overlying protocols, such as TCP and UDP, are ubiquitous, they were originally designed for point-to-point connections between computers in reasonably fixed locations. They are less suited to mobile networks and broadcast communications. In this paper, we present an alternative to IP that is based on a publish-subscribe approach. The approach that we present combines an application publish-subscribe programming model with a content delivery network, which provides several advantages in certain communication environments, including quality of service based on application level needs; efficient support for reliable broadcast; support for disadvantaged, intermittent, and limited communications; and more efficient reliability and fault tolerance. The paper presents our approach, based on a streamlined Data Distribution Service and simplified Content Delivery Network, a motivating example in which the publish-subscribe based distribution and network provides advantages, and a contrast to TCP/IP in the example context.