Roel Ocampo

ContextWare support for network and service composition and self-adaptation

A crucial prerequisite for building context-aware networks is an integrated infrastructure for sensing, processing, managing and disseminating network context information to network entities and user-facing applications. This requirement is especially important in ambient networks, a class of networks that exploit the inherent heterogeneity seen in todays wireless networks in order to share diverse resources and services across different but cooperating networks. We discuss ContextWare, our architectural solution for making ambient networks context-aware, and present a programmable approach to its realization. We relate some of our experiences in building and validating a prototype and demonstrating its support for network and service composition, as well as self-adaptation, using a reference scenario.

Self-Management of Context-Aware Overlay Ambient Networks

Ambient networks (ANs) are dynamically changing and heterogeneous as they consist of potentially large numbers of independent, heterogeneous mobile nodes, with spontaneous topologies that can logically interact with each other to share a common control space, known as the ambient control space. ANs are also flexible i.e. they can compose and decompose dynamically and automatically, for supporting the deployment of cross-domain (new) services. Thus, the AN architecture must be sophisticatedly designed to support such high level of dynamicity, heterogeneity and flexibility. We advocate the use of service specific overlay networks in ANs, that are created on-demand according to specific service requirements, to deliver, and to automatically adapt services to the dynamically changing user and network context. This paper presents a self-management approach to create, configure, adapt, contextualise, and finally teardown service specific overlay networks.

Towards distributed hash tables (De)composition in ambient networks

When different wireless networks come in close proximity there is often a need for them to logically combine, or compose. We focus on a known research problem particularly in Ambient Networks (ANs), where hetero-geneous Distributed Hash Tables (DHTs) contained in these wireless networks need to merge or divide as a result of these dynamic (de)composition processes, respectively. We present two novel DHT (de)composition models for ANs, known as absorption and gatewaying, that are designed to handle (de)composition of DHTs in different AN network environments, with minimal disturbance to existing member nodes.

Service-aware Overlay Adaptation in Ambient Networks

Developing service-aware self-adaptation systems in heterogeneous and rapidly changing wireless networks such as ambient networks is a challenging issue. Key research areas are adaptation policy definition, network context monitoring, and adaptation policy enforcement. In this paper, we present the ambient virtual pipe platform (AVPP) - that provides a flexible approach towards the creation and management of self-adaptation service-aware overlays in ambient networks

Self-Management in Ambient Networks for Service Composition

This paper describes the concepts and challenges of self-managing management-layer network composition and service composition in Ambient Networks. A set of requirements are identified. This paper describes the concept of Ambient Virtual Pipe (AVP), which is an autonomic, secure, QoS-assured, self-adapted context aware management service overlay network that provides a secure and QoS-assured environment for AN service composition. The AVP is supported through a programmable platform, and is capable of dynamic deployment of new management services.

Autonomic Management of Context-Aware Ambient Overlay Networks

Ambient networks (ANs) introduce a new dynamic and flexible architecture for fixed and mobile networks. The environment is dynamic since they consist of various mobile nodes and flexible since ANs can compose and decompose dynamically and automatically with other ANs. The AN architecture must be sophisticatedly designed to support such high level of dynamicity, heterogeneity and flexibility. Composition and decomposition is performed at the network-level but since the network topology may change, the service delivery should also be adapted accordingly. Indeed, new services should be user-centric. In this paper, for delivering services adapted to the dynamically changing user and network context, we promote the use of service specific overlay networks in ANs that are created on- demand according to specific service requirements. This paper presents an autonomic approach to create, configure, adapt, contextualize, and finally teardown those context-aware overlay networks.

Towards a Context Monitoring System for Ambient Networks

This paper presents a novel network context monitoring system, known as the context monitoring system (CMS), that is designed to accommodate the rapidly changing network context requirements and network context availability in dynamically (de)composing ambient networks (ANs). CMS is designed to support dynamic deployment, activation, and (re)configuration of context sensors in ANs in an efficient and scalable way, and to locate available distributed network context in a scalable and distributed manner once context sensors are deployed, in order to support subsequent efficient and scalable network context retrieval.

Secure Bootstrapping of Distributed Hash Tables in Dynamic Wireless Networks

Existing research work on Distributed Hash Tables (DHTs) assume that, prior to actually establishing a DHT, large number potential member nodes would come together at one point and at one place, and would all agree on the characteristics of the DHT to-be-established. This paper presents DHT bootstrapping, which is a novel approach to enable secure, efficient and scalable deployment of DHTs in wireless networks, in particular in wireless networks with time-varying topology. Our solution is not restricted to a particular type of DHT implementation.

Flow context tags: Concepts and applications

Context awareness can help build dynamic networks by enabling them to automatically adapt to the user’s activities, computational environment, and network conditions. Our approach in building context-aware networks uses flow context: information about the intrinsic and low-level characteristics of flows, as well as the nature of the applications, devices, and the activities, intentions, preferences or identities of the users that produce or consume them. We tag network flows with their associated context, enabling the information to be shared and acted upon within the network and end-devices. We establish the conceptual framework behind this approach and present some application scenarios, particularly in mobility and QoS adaptation.

Contextualisation of Management Overlays in Ambient Networks

Next generation services requiring adaptability to network and environment changes can be created with the use of flexible, self and service adaptable management overlays. This paper presents such a management overlay, the ambient virtual pipe (AVP) in ambient networks. Contextualisation of an AVP enables it to achieve service adaptation in response to changes in context information. Contextualisation is achieved through interactions with ContextWare, an infrastructure which collects, manages and disseminates context. The contextualisation of the AVP and the architecture and components of ContextWare, are presented along with a proof of concept prototype