37,160 research outputs found
Network support for multimedia applications using the Netlets architecture
Multi-party multimedia networking applications such as e-commerce, distributed data analysis, Internet TV and advanced collaborative environments feature stringent end-to-end Quality of Service (QoS) requirement and require globally distributed user groups to be interconnected. The variety of delivery requirements posed by such applications are best satisfied using highly customised networking protocols. Hence, a demand for networks to migrate from the current fixed service model to a more flexible architecture that accommodates a wide variety of networking services is emerging.
New approaches are required in order to build such service oriented networks. Active networking is one such approach. Active networks treats the network as a programmable computation engine, which provides customised packet processing and forwarding operations for traffic flowing through network nodes. User applications can download new protocols into network elements at runtime, allowing rapid innovation of network services. This thesis makes the case for employing mobile agents to realise an active networking architecture, and describes such an architecture called the Netlets architecture. Netlets are autonomous, mobile components which persist and roam in the network independently, providing predefined network services.
This thesis presents the design and implementation of the Netlet node and the service deployment m echanisms that are required to distribute Netlet services in the network. Using the Netlet toolkit, variety of network services were designed to provide network support for multimedia applications in the Internet. A service was implemented to enhance the working of the RSVP protocol in order to provide robust end-to-end QoS support even when the network is only partially QoS provisioned. A scalable and reliable multicast protocol was implemented using the unicast communication model that accommodate heterogeneous receiver terminals. Another service integrates client-side server selection support into web sessions established over the Internet. A service was also developed which provides QoS signalling support to legacy applications.
It is shown that these Netlet services are of practical value using performance measurements to assess Netlet responsiveness. Netlet based solutions maybe deployed using existing technologies to provide support for a wide range of multimedia applications in the Internet. The Netlets architecture has thus been shown to allow value-added services to be added to existing networks. By optimising the Netlet architecture implementation, this may be extended to services operating on high-speed (1Gb/s and upwards) links. It thus shows promise as an architecture for building the next generation of active networking solutions
The Design of a System Architecture for Mobile Multimedia Computers
This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies
Hybrid Satellite-Terrestrial Communication Networks for the Maritime Internet of Things: Key Technologies, Opportunities, and Challenges
With the rapid development of marine activities, there has been an increasing
number of maritime mobile terminals, as well as a growing demand for high-speed
and ultra-reliable maritime communications to keep them connected.
Traditionally, the maritime Internet of Things (IoT) is enabled by maritime
satellites. However, satellites are seriously restricted by their high latency
and relatively low data rate. As an alternative, shore & island-based base
stations (BSs) can be built to extend the coverage of terrestrial networks
using fourth-generation (4G), fifth-generation (5G), and beyond 5G services.
Unmanned aerial vehicles can also be exploited to serve as aerial maritime BSs.
Despite of all these approaches, there are still open issues for an efficient
maritime communication network (MCN). For example, due to the complicated
electromagnetic propagation environment, the limited geometrically available BS
sites, and rigorous service demands from mission-critical applications,
conventional communication and networking theories and methods should be
tailored for maritime scenarios. Towards this end, we provide a survey on the
demand for maritime communications, the state-of-the-art MCNs, and key
technologies for enhancing transmission efficiency, extending network coverage,
and provisioning maritime-specific services. Future challenges in developing an
environment-aware, service-driven, and integrated satellite-air-ground MCN to
be smart enough to utilize external auxiliary information, e.g., sea state and
atmosphere conditions, are also discussed
Reconfigurable Mobile Multimedia Systems
This paper discusses reconfigurability issues in lowpower hand-held multimedia systems, with particular emphasis on energy conservation. We claim that a radical new approach has to be taken in order to fulfill the requirements - in terms of processing power and energy consumption - of future mobile applications. A reconfigurable systems-architecture in combination with a QoS driven operating system is introduced that can deal with the inherent dynamics of a mobile system. We present the preliminary results of studies we have done on reconfiguration in hand-held mobile computers: by having reconfigurable media streams, by using reconfigurable processing modules and by migrating functions
The Road Ahead for Networking: A Survey on ICN-IP Coexistence Solutions
In recent years, the current Internet has experienced an unexpected paradigm
shift in the usage model, which has pushed researchers towards the design of
the Information-Centric Networking (ICN) paradigm as a possible replacement of
the existing architecture. Even though both Academia and Industry have
investigated the feasibility and effectiveness of ICN, achieving the complete
replacement of the Internet Protocol (IP) is a challenging task.
Some research groups have already addressed the coexistence by designing
their own architectures, but none of those is the final solution to move
towards the future Internet considering the unaltered state of the networking.
To design such architecture, the research community needs now a comprehensive
overview of the existing solutions that have so far addressed the coexistence.
The purpose of this paper is to reach this goal by providing the first
comprehensive survey and classification of the coexistence architectures
according to their features (i.e., deployment approach, deployment scenarios,
addressed coexistence requirements and architecture or technology used) and
evaluation parameters (i.e., challenges emerging during the deployment and the
runtime behaviour of an architecture). We believe that this paper will finally
fill the gap required for moving towards the design of the final coexistence
architecture.Comment: 23 pages, 16 figures, 3 table
Lessons learned from the design of a mobile multimedia system in the Moby Dick project
Recent advances in wireless networking technology and the exponential development of semiconductor technology have engendered a new paradigm of computing, called personal mobile computing or ubiquitous computing. This offers a vision of the future with a much richer and more exciting set of architecture research challenges than extrapolations of the current desktop architectures. In particular, these devices will have limited battery resources, will handle diverse data types, and will operate in environments that are insecure, dynamic and which vary significantly in time and location. The research performed in the MOBY DICK project is about designing such a mobile multimedia system. This paper discusses the approach made in the MOBY DICK project to solve some of these problems, discusses its contributions, and accesses what was learned from the project
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