10 research outputs found
Penggunaan LTE sebagai Media Interoperabilitas Antar Generasi Komunikasi Nirkabel yang Berbeda
Penelitian dilakukan pada potensi pendekatan interoperabilitas serta mobilitas inter-teknologi menggunakan Long Term Evolution (LTE) antara generasi yang berbeda pada komunikasi nirkabel. Fokus penelitian adalah pendekatan ini dapat digunakan dalam layanan operasi penyebaran, integrasi teknologi akses, kontinuitas layanan dan proses migrasi secara halus ke LTE dengan memaksimalkan penggunaan jaringan cakupan yang telah ada. Salah satu kriteria interoperabilitas paling penting adalah penyerahan latensi. Menggunakan NS2 simulator, ditampilkan bahwa LTE (4G) menyediakan latensi yang lebih sedikit bila dibandingkan dengan generasi lain dari sistem komunikasi nirkabel untuk lingkungan homogen. Dari hasil simulasi didapatkan handover latency untuk GPRS adalah 4s, untuk IEEE 802.11b adalah 4s, untuk IEEE 802. 16e adalah 3s dan untuk IEEE 802.16j ditemukan 1s
An Adaptive Multimedia-Oriented Handoff Scheme for IEEE 802.11 WLANs
Previous studies have shown that the actual handoff schemes employed in the
IEEE 802.11 Wireless LANs (WLANs) do not meet the strict delay constraints
placed by many multimedia applications like Voice over IP. Both the active and
the passive supported scan modes in the standard handoff procedure have
important delay that affects the Quality of Service (QoS) required by the
real-time communications over 802.11 networks. In addition, the problem is
further compounded by the fact that limited coverage areas of Access Points
(APs) occupied in 802.11 infrastructure WLANs create frequent handoffs. We
propose a new optimized and fast handoff scheme that decrease both handoff
latency and occurrence by performing a seamless prevent scan process and an
effective next-AP selection. Through simulations and performance evaluation, we
show the effectiveness of the new adaptive handoff that reduces the process
latency and adds new context-based parameters. The Results illustrate a QoS
delay-respect required by applications and an optimized AP-choice that
eliminates handoff events that are not beneficial.Comment: 20 pages, 14 figures, 4 table
A Survey on Handover Management in Mobility Architectures
This work presents a comprehensive and structured taxonomy of available
techniques for managing the handover process in mobility architectures.
Representative works from the existing literature have been divided into
appropriate categories, based on their ability to support horizontal handovers,
vertical handovers and multihoming. We describe approaches designed to work on
the current Internet (i.e. IPv4-based networks), as well as those that have
been devised for the "future" Internet (e.g. IPv6-based networks and
extensions). Quantitative measures and qualitative indicators are also
presented and used to evaluate and compare the examined approaches. This
critical review provides some valuable guidelines and suggestions for designing
and developing mobility architectures, including some practical expedients
(e.g. those required in the current Internet environment), aimed to cope with
the presence of NAT/firewalls and to provide support to legacy systems and
several communication protocols working at the application layer
Support infrastructures for multimedia services with guaranteed continuity and QoS
Advances in wireless networking and content delivery systems are enabling new challenging provisioning scenarios where a growing number of users access multimedia services, e.g., audio/video streaming, while moving among different points of attachment to the Internet, possibly with different connectivity technologies, e.g., Wi-Fi, Bluetooth, and cellular 3G. That calls for novel middlewares capable of dynamically personalizing service provisioning to the characteristics of client environments, in particular to
discontinuities in wireless resource availability due to handoffs. This dissertation proposes a novel middleware solution, called MUM, that performs effective and context-aware handoff management to transparently avoid service interruptions during both horizontal and vertical handoffs. To achieve the goal, MUM exploits the full visibility of wireless connections available in client localities and their handoff implementations (handoff awareness), of service quality requirements and handoff-related quality degradations (QoS awareness), and of network topology and resources available in current/future localities (location awareness). The design and implementation of the all main MUM components along with extensive on the field trials of the realized middleware architecture confirmed the validity of the proposed full
context-aware handoff management approach. In particular, the reported experimental results demonstrate that MUM can effectively maintain service continuity for a wide range of different multimedia services by exploiting handoff prediction mechanisms, adaptive buffering and pre-fetching techniques, and proactive re-addressing/re-binding
Multimedia
The nowadays ubiquitous and effortless digital data capture and processing capabilities offered by the majority of devices, lead to an unprecedented penetration of multimedia content in our everyday life. To make the most of this phenomenon, the rapidly increasing volume and usage of digitised content requires constant re-evaluation and adaptation of multimedia methodologies, in order to meet the relentless change of requirements from both the user and system perspectives. Advances in Multimedia provides readers with an overview of the ever-growing field of multimedia by bringing together various research studies and surveys from different subfields that point out such important aspects. Some of the main topics that this book deals with include: multimedia management in peer-to-peer structures & wireless networks, security characteristics in multimedia, semantic gap bridging for multimedia content and novel multimedia applications