Maximizing Availability of Content in Disruptive Environments by Cross-Layer Optimization

Abstract

Emerging applications such as search-and-rescue operations, CNS (communication, navigation, surveillance), smart spaces, vehicular networks, mission-critical infrastructure, and disaster control require reliable content distribution under harsh network conditions and all kinds of component failures. In such scenarios, potentially heterogeneous networked components — where the networks lack reliable connections — need to be managed to improve scalability, performance, and availability of the overall system. Inspired by delay- and disruption-tolerant networking, this paper presents a distributed cross-layer monitoring and optimization method for secure content delivery as a first step toward decentralized content-based mobile ad hoc networking. In particular, we address the availability maximization problem by embedding monitoring and optimization within an existing content-distribution framework. The implications of policies at security, caching, and hardware layers that control in-network storage and hop-by-hop dissemination of content then are analyzed to maximize the content availability in disruptive environments. Additional benefits can be obtained by optimizing the control based on continuously observing the response to anomalies caused by cyber-attacks. For example, if excessive (potentially fraudulent) content is injected, the content distribution system can adapt without significantly compromising the availability.