iPOJO flow:a declarative service workflow architecture for ubiquitous cloud applications

The growth of innovative services backed up by various sensors and devices provides an unprecedented potential for ubiquitous computing applications and systems. However, in order to benefit from the recent developments, the current service middleware technology needs a catch-up of being able to fully support interactions among the services. OSGi is considered as a viable service framework solution due to its ability to deal with the dynamism inherent with ubiquitous cloud environments. iPOJO has also emerged as a service component model that simplifies the development of OSGi applications. However, the technology runs short of providing adequate support to foster declarative service compositions of realistic interaction topologies. Noticing this deficiency, we propose an iPOJO component-based service workflow architecture, named iPOJO Flow, where component services can easily be composed together to form realistic, complicated applications. Along with the architectural design, the paper also introduces a new DSL to specify service workflow topologies in a declarative way. The effectiveness of our proposed approach is validated through a prototype demonstration, comparative design analysis, and performance experiments

Enabling End-To-End Orchestration of Multi-Cloud Applications

The orchestration of application components across heterogeneous cloud providers is a problem that has been tackled using various approaches, some of which led to the creation of cloud orchestration and management standards, such as TOSCA and CAMP. Standardization is a definitive method of providing an end-To-end solution capable of defining, deploying, and managing applications and their components across heterogeneous cloud providers. TOSCA and CAMP, however, perform different functions with regard to cloud applications. TOSCA is focused primarily on topology modeling and orchestration, whereas CAMP is focused on deployment and management of applications. This paper presents a novel solution that not only involves the combination of the emerging standards TOSCA and CAMP, but also introduces extensions to CAMP to allow for multi-cloud application orchestration through the use of declarative policies. Extensions to the CAMP platform are also made, which brings the standards closer together to enable a seamless integration. Our proposal provides an end-To-end cloud orchestration solution that supports a cloud application modeling and deployment process, allowing a cloud application to span and be deployed over multiple clouds. The feasibility and the benefit of our approach are demonstrated in our validation study

IoT-DDL—Device Description Language for the “T” in IoT

We argue that the success of the Internet of Things (IoT) vision will greatly depend on how its main ingredient—the “thing”—is architected and prepared to engage. The IoT’s fragmented and wide-varying nature introduces the need for additional effort to homogenize these things so they may blend together with the surrounding space to create opportunities for powerful and unprecedented IoT applications. We introduce the IoT Device Description Language (IoT-DDL), a machine- and human-readable descriptive language for things, seeking to achieve such integration and homogenization. IoT-DDL explicitly tools things to self-discover and securely share their own capabilities, entities, and services, including the various cloudbased accessories that may be attached to them. We also present the Atlas thing architecture—a lightweight architecture for things that fully exploits IoT-DDL and its specifications. Our architecture provides new OS layers, services, and capabilities we believe a thing must have in order to be prepared to engage in IoT scenarios and applications. The architecture and IoT-DDL enable things to generate their offered services and self-formulate APIs for such services, on the fly, at power-on or whenever a thing description changes. The architecture takes advantage of widely used device management, micro-services, security, and communication standards and protocols. We present details of IoT-DDL and corresponding parts of the thing architecture. We demonstrate some features of IoT-DDL and the architecture through proof-of-concept implementations. Finally, we present a benchmarking study to measure and assess time performance and energy consumption characteristics of our architecture and IoT-DDL on real hardware platforms

An Efficient Service Propagation Scheme for Large-Scale MANETs

This paper proposes a new scheme for efficient dissemination and discovery of service information in mobile ad hoc networks. By extending Bloom filter-based service summarization scheme, our discovery middleware layer also encodes distance to services in summarization filters. By having the distance information gradually attenuated during its propagation, our proposal enables faster discovery of services with a limited amount of advertisement traffic. Categories and Subject Descriptors C.2.1 [Computer-Communication Networks]: Networ

Supporting Seamless Mobility for P2P Live Streaming

With advent of various mobile devices with powerful networking and computing capabilities, the users' demand to enjoy live video streaming services such as IPTV with mobile devices has been increasing rapidly. However, it is challenging to get over the degradation of service quality due to data loss caused by the handover. Although many handover schemes were proposed at protocol layers below the application layer, they inherently suffer from data loss while the network is being disconnected during the handover. We therefore propose an efficient application-layer handover scheme to support seamless mobility for P2P live streaming. By simulation experiments, we show that the P2P live streaming system with our proposed handover scheme can improve the playback continuity significantly compared to that without our scheme

An Adaptive Buffering Scheme for P2P Live and Time-Shifted Streaming

Recently, P2P streaming techniques have been a promising solution to a large-scale live streaming system because of their high scalability and low installation cost. In P2P live streaming systems, however, it is difficult to manage peers’ buffers effectively, because they can buffer only a limited amount of data around a live broadcasting time in the main memory and suffer from long playback lag due to the nature of P2P structures. In addition, the number of peers decreases rapidly as the playback position moves further from this time by performing time-shifted viewing. These situations widen the distribution of peers’ playback positions, thereby decreasing the degree of data duplication among peers. Moreover, it is hard to use each peer’s buffer as the caching area because the buffer area where the chunks that have already been played back are stored can be overwritten at any time by new chunks that will arrive soon. In this paper, we therefore propose a novel buffering scheme to significantly increase data duplication in buffering periods among peers in P2P live and time-shifted streaming systems. In our proposed scheme, the buffer ratio of each peer is adaptively adjusted according to its relative playback position in a group by increasing the ratio of the caching area in its buffer as its playback position moves earlier in time and increasing the ratio of the prefetching area as its playback position moves later. Through extensive simulations, we demonstrate that our proposed adaptive buffering scheme outperforms the conventional buffering technique considerably in terms of startup delay, average jitter ratio, and the ratio of necessary chunks in a buffermap