Tai-Won Um

IPTV Systems, Standards and Architectures: Part II - Heterogeneous Networks and Terminal-Aware QoS/QoE-Guaranteed Mobile IPTV Service

We describe two main technical challenges in terms of the network and application levels for mobile IPTV service. To support a multimedia- streaming application service over a mobile network environment, we present the IP/MPLS-based NGN architecture with fixed and mobile convergence and its challenge, which is basically to support QoS for mobile IPTV ser vice. To meet the challenges for application source levels, we focus on the relationship of user terminals and video streaming sources to support user-perceived QoE, based on high- quality service between heterogeneous terminals. The techniques to meet these challenges depend on the characteristics of media processing and terminal capabilities, such as LCD panel size, resolution, video coding, and so on, in the heterogeneous network environment. To have a relationship between the two different levels, the significant factors mentioned previously are required to deliver the bandwidth coupled with a user profile to provide QoS/QoE in assured seamless mobile IPTV service on client devices.

A novel fountain code-based mobile IPTV multicast system architecture over WiMAX network

In this paper, we present a novel fountain code-based mobile IPTV multicast system architecture over WiMAX network. In the proposed system, the transmission algorithm at a base station determines the control parameters of a fountain-encoded IPTV multicast stream adaptively to the wireless link states of subscribers in order to provide a stable IPTV service with minimum resource usage on WiMAX network, and the channel grouping algorithm at a server makes near-optimal channel grouping based on channel selection preferences to pursue an effective tradeoff between the channel zapping time and the processing complexity of a subscriber. Finally, experimental results are provided to show the performance of the proposed system.

Mobile SCTP with Bicasting for Vertical Handover

The mobile Stream Control Transmission Protocol (mSCTP) can be used to support IP handover. This paper proposes an extension of mSCTP with bicasting for vertical handover across heterogeneous wireless access networks, in which the data packets of mSCTP are bicast to the old and new IP addresses in the vertical handover region. From the ns-2 simulation results, it is shown that the proposed scheme can provide better performance than the existing mSCTP.

Strengthening trust in the future social-cyber-physical infrastructure: an ITU-T perspective

Evolving toward a knowledge society requires a trusted ICT infrastructure for sharing information and creating knowledge. To advance the efforts to build converged ICT services and reliable information infrastructures, ITU-T has recently started to work on future trusted ICT infrastructures. This article proposes a possible future Social-Cyber-Physical infrastructure that acts as the glue for integrating the physical, cyber, and social worlds with ICT, and outlines proposals toward an effort to find viable solutions for trust related problems while developing advanced technologies from an ITU-T standards perspective along with the trust conceptual model and the trust architectural framework.

Centralized Resource Allocation for Time-Slotted OBS Networks

This paper proposes a centralized control architecture and a time-slot assignment procedure for time-slotted optical burst switched (OBS) networks in which ingress OBS nodes request time-slots necessary to transmit optical bursts, and a centralized control node makes a reply according to the slot-competition result. Our scheme attempts to improve burst contention resolution and optical channel utilization. Analysis and simulation results show that the channel utilization of the time-slotted OBS network is improved markedly at the expense of ingress buffering delay

Performance analysis of a centralized resource allocation mechanism for time-slotted OBS networks

Time-Slotted Optical Burst Switching (TS-OBS) is one of the most promising next-generation transport network technologies. This paper proposes a time-slot assignment procedure using centralized control for TS-OBS networks. Our scheme attempts to improve burst contention resolution and optical channel utilization. Analysis and simulation results show that the channel utilization of the TS-OBS network is improved markedly at the expense of ingress buffering delay.

Event-Driven Trust Refreshment on Ambient Services

Since trust among entities can change according to various conditions, it is necessary for ambient services to determine when and how the trust has to be updated. Therefore, our contribution in this paper is to present: 1) a new definition of trust that can be extended to various domains; 2) a novel method based on social events and patterns to trigger trust refreshment in ambient services; and 3) a web application framework (called SocioScope) for collecting and analyzing data from multiple data sources. Finally, the case study suggests that this proposal could be applied to trust-aware ambient and recommendation systems.

Dynamic resource control mechanism for multimedia overlay transport in NGN

This paper investigates a dynamic resource control mechanism to efficiently deliver NGN multimedia services while supporting quality of service (QoS) requirements and bandwidth flexibility in next generation networks (NGN). The proposed resource control aims to realize the dynamic and automatic setup and release of multimedia resource sessions across heterogeneous transport networks including IP, SONET/SDH, and WDM technologies. It can also provide not only low cost operations but also flexibility for multimedia resource control.

Performance of a Partial Burst Retransmission Mechanism in OBS Networks

We investigate the effects on performance of using a partial retransmission mechanism in optical burst switched (OBS) networks. In our scheme, the lost segments of a burst are retransmitted in the OBS layer. We also propose an optical resource reservation using the partial retransmission mechanism. Our scheme attempts to improve the burst contention resolution and optical channel utilization. Simulation results indicate that the link utilization of the OBS network is improved markedly at the expense of signaling and ingress buffers

Leverage a Trust Service Platform for Data Usage Control in Smart City

In the Internet of Thing, data is almost collected, aggregated and analyzed without human intervention by machine-to-machine communications resulting in raising serious challenges on access control. Particularly in Smart City ecosystems in which multi-modal data comes from heterogeneous sources, data owners cannot imagine how their data is used to extract sensitive information. Thus, there is a critical need for novel access control methods that minimize privacy risks while increase ability of personalized access control. Our solution is to build a trust-based usage control mechanism called TUCON that enables stakeholders to set access control policies based on their trust relationships with data consumers. In this study, we introduce two novel paradigms integrated in the Smart City shared platform: a Trust Service Platform and a Data Usage Control, then bring them together to establish the new mechanism. The conceptual model, the architecture, the formalization, and the practical development of TUCON is described in detail. We also show the roles and the interactions of TUCON components in the Smart City platform. Our contributions lie in a new trust model with a trust computation procedure based on semantic web technologies, a novel trust-based usage control conceptual model including a formalization, a practical expression and an architecture for Smart City systems. We believe this study provides better understanding on both trust and usage control in the Internet of Things and opens several important research directions in the future.