7,698 research outputs found
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Error resilient video transcoding for robust inter-network communications using GPRS
A novel fully comprehensive mobile video communications
system is proposed in this paper. This system exploits
the useful rate management features of the video transcoders and
combines them with error resilience for transmissions of coded
video streams over general packet radio service (GPRS) mobileaccess
networks. The error-resilient video transcoding operation
takes place at a centralized point, referred to as a video proxy,
which provides the necessary output transmission rates with the
required amount of robustness. With the use of this proposed
algorithm, error resilience can be added to an already compressed
video stream at an intermediate stage at the edge of two or more
different networks through two resilience schemes, namely the
adaptive intra refresh (AIR) and feedback control signaling (FCS)
methods. Both resilience tools impose an output rate increase
which can also be prevented with the proposed novel technique in
this paper. Thus, an error-resilient video transcoding scheme is
presented to give robust video outputs at near target transmission
rates that only require the same number of GPRS timeslots as
the nonresilient schemes. Moreover, an ultimate robustness is
also accomplished with the combination of the two resilience
algorithms at the video proxy. Extensive computer simulations
demonstrate the effectiveness of the proposed system
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Ubiquitous Internet in an integrated satellite-terrestrial environment: The SUITED solution
yesThe current Internet architecture appears to
not be particularly suited to addressing the
emerging needs of new classes of users who wish
to gain access to multimedia services made available
by ISPs, regardless of their location, while
in motion and with a guaranteed level of quality.
One of the main objectives of so-called nextgeneration
systems is to overcome the limitations
of todayÂżs available Internet by adopting an
approach based on the integration of different
mobile and fixed networks. The SUITED project
moves in this direction since it aims at contributing
to the design and deployment of the global
mobile broadband system (GMBS), a unique
satellite/terrestrial infrastructure ensuring
nomadic users access to Internet services with a
negotiated QoS. A description of the main features
of the GMBS architecture, characterized
by the integration of a multisegment access network
with a federated ISP network is given in
this article. The GMBS multimode terminal is
schematically described, and an overview of the
so-called QoS-aware mobility management
scheme, devised for such a heterogeneous scenario,is provided
Service Platform for Converged Interactive Broadband Broadcast and Cellular Wireless
A converged broadcast and telecommunication
service platform is presented that is able to create, deliver, and
manage interactive, multimedia content and services for consumption
on three different terminal types. The motivations of
service providers for designing converged interactive multimedia
services, which are crafted for their individual requirements, are
investigated. The overall design of the system is presented with
particular emphasis placed on the operational features of each
of the sub-systems, the flows of media and metadata through the
sub-systems and the formats and protocols required for inter-communication
between them. The key features of tools required for
creating converged interactive multimedia content for a range of
different end-user terminal types are examined. Finally possible
enhancements to this system are discussed. This study is of particular
interest to those organizations currently conducting trials
and commercial launches of DVB-H services because it provides
them with an insight of the various additional functions required
in the service provisioning platforms to provide fully interactive
services to a range of different mobile terminal types
EVEREST IST - 2002 - 00185 : D23 : final report
Deliverable pĂșblic del projecte europeu EVERESTThis deliverable constitutes the final report of the project IST-2002-001858 EVEREST. After its successful completion, the project presents this document that firstly summarizes the context, goal and the approach objective of the project. Then it presents a concise summary of the major goals and results, as well as highlights the most valuable lessons derived form the project work. A list of deliverables and publications is included in the annex.Postprint (published version
3GPP Long Term Evolution: Architecture, Protocols and Interfaces
The evolution of wireless networks is a continuous phenomenon. Some key trends in this changing process include:
reduced latency, increased performance with substantial reduction in costs, and seamless mobility. Long Term Evolution
(LTE) is based on an evolved architecture that makes it a candidate of choice for next generation wireless mobile networks.
This paper provides an overview of both the core and access networks of LTE. Functional details of the associated
protocols and interfaces are also presented
Wireless communication, identification and sensing technologies enabling integrated logistics: a study in the harbor environment
In the last decade, integrated logistics has become an important challenge in
the development of wireless communication, identification and sensing
technology, due to the growing complexity of logistics processes and the
increasing demand for adapting systems to new requirements. The advancement of
wireless technology provides a wide range of options for the maritime container
terminals. Electronic devices employed in container terminals reduce the manual
effort, facilitating timely information flow and enhancing control and quality
of service and decision made. In this paper, we examine the technology that can
be used to support integration in harbor's logistics. In the literature, most
systems have been developed to address specific needs of particular harbors,
but a systematic study is missing. The purpose is to provide an overview to the
reader about which technology of integrated logistics can be implemented and
what remains to be addressed in the future
Proactive TCP mechanism to improve Handover performance in Mobile Satellite and Terrestrial Networks
Emerging standardization of Geo Mobile Radio (GMR-1) for satellite system is
having strong resemblance to terrestrial GSM (Global System for Mobile
communications) at the upper protocol layers and TCP (Transmission Control
Protocol) is one of them. This space segment technology as well as terrestrial
technology, is characterized by periodic variations in communication properties
and coverage causing the termination of ongoing call as connections of Mobile
Nodes (MN) alter stochastically. Although provisions are made to provide
efficient communication infrastructure this hybrid space and terrestrial
networks must ensure the end-to-end network performance so that MN can move
seamlessly among these networks. However from connectivity point of view
current TCP performance has not been engineered for mobility events in
multi-radio MN. Traditionally, TCP has applied a set of congestion control
algorithms (slow-start, congestion avoidance, fast retransmit, fast recovery)
to probe the currently available bandwidth on the connection path. These
algorithms need several round-trip times to find the correct transmission rate
(i.e. congestion window), and adapt to sudden changes connectivity due to
handover. While there are protocols to maintain the connection continuity on
mobility events, such as Mobile IP (MIP) and Host Identity Protocol (HIP), TCP
performance engineering has had less attention. TCP is implemented as a
separate component in an operating system, and is therefore often unaware of
the mobility events or the nature of multi-radios' communication. This paper
aims to improve TCP communication performance in Mobile satellite and
terrestrial networks.Comment: 5 pages, 2 figure
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