Provide Multimedia Services Research Articles

Control-level call differentiation in IMS-based 3G core networks

The 3GPP-defined IP Multimedia Subsystem is becoming the de facto standard for IP-based multimedia communication services. It consists of an overlay control and service layer that is deployed on top of IP-based mobile and fixed networks, in order to enable the seamless provisioning of IP multimedia services to 3G users. Service differentiation, which implies the network's ability to distinguish between different classes of traffic (or service) and provide each class with the appropriate treatment, is an important aspect that is considered in 3G networks. In this article, we present a critical review of existing service differentiation solutions and propose a new control-level call differentiation solution for IMS-based 3G core networks. The solution consists of a novel call differentiation scheme, enabling the definition of various categories of calls with different QoS profiles. To enable the support of such profiles, an extended IMS architecture, relying on two adaptive resource management mechanisms, is proposed. Furthermore, simulations are used to evaluate the system performance. Compared to existing service differentiation solutions, our solution offers several benefits, such as: flexible QoS negotiation mechanisms, control over many communication aspects as means for differentiation, and a dynamic and adaptive resource management strategy.

Topology-based Multicast Scheduling for On-Demand Multimedia Service Provisioning

In this paper, a dynamic scheduling scheme is proposed for delivery of on-demand multimedia contents (e.g. movies) for internet service providers (ISP) that receive requests for different available contents from the customers for near future delivery. Each ISP is interested in assigning the available resources to the requests in such a way that the delivery time remains lower than a threshold, and also the profit is maximized. Regarding the diversity of customers in terms of their willingness to pay, there exists a group of budget-constrained receivers who are ready to wait longer. Therefore, since the ISP dynamically receives the requests for future delivery, postponing transmission of videos to some customers can provide the opportunity to increase the profit by reducing cost of distribution paths via multicast cost sharing. So, it can be profitable to postpone transmitting the content for some receivers (who cannot be clustered into cost saving multicast groups in the current transmission period) in hope for receiving more requests until the next transmission period, and consequently sharing the cost with a larger number of receivers. We propose a heuristic algorithm for topology-based multicast scheduling problem to find cost efficient multicast groups in each transmission period. Performance of the proposed algorithm is evaluated and compared with a popularity-based scheduling algorithm for a wide range of parameters via extensive simulation experiments.

Novel Radio Link Buffer Management Schemes for End-User Multi-class Traffic in High Speed Packet Access Networks

The requirement to provide multimedia services with QoS support in mobile networks has led to standardization and deployment of high speed data access technologies such as the High Speed Downlink Packet Access (HSDPA) system. HSDPA improves downlink packet data and multimedia services support in WCDMA-based cellular networks. As is the trend in emerging wireless access technologies, HSDPA supports end-user multi-class sessions comprising parallel flows with diverse Quality of Service (QoS) requirements, such as real-time (RT) voice or video streaming concurrent with non real-time (NRT) data service being transmitted to the same user, with differentiated queuing at the radio link interface. Hence, in this paper we present and evaluate novel radio link buffer management schemes for QoS control of multimedia traffic comprising concurrent RT and NRT flows in the same HSDPA end-user session. The new buffer management schemes—Enhanced Time Space Priority (E-TSP) and Dynamic Time Space Priority (D-TSP)—are designed to improve radio link and network resource utilization as well as optimize end-to-end QoS performance of both RT and NRT flows in the end-user session. Both schemes are based on a Time-Space Priority (TSP) queuing system, which provides joint delay and loss differentiation between the flows by queuing (partially) loss tolerant RT flow packets for higher transmission priority but with restricted access to the buffer space, whilst allowing unlimited access to the buffer space for delay-tolerant NRT flow but with queuing for lower transmission priority. Experiments by means of extensive system-level HSDPA simulations demonstrates that with the proposed TSP-based radio link buffer management schemes, significant end-to-end QoS performance gains accrue to end-user traffic with simultaneous RT and NRT flows, in addition to improved resource utilization in the radio access network.

Exploiting MIMO Technology for Optimal MBMS Power Allocation

In mobile networks, the provision of rich multimedia services, such as Mobile TV, is considered of key importance. To this end, Multimedia Broadcast/Multicast Service (MBMS)--that was introduced in the Release 6 of Universal Mobile Telecommunication System (UMTS)--is envisaged to play an instrumental role in the proliferation of mobile market. The reason behind the design of MBMS was the need to provide multiple users with the same data at the same time in 3GPP (3rd Generation Partnership Project) cellular networks. Still, MBMS performance is limited by the base stations' transmission power. As an aftermath, efficient power allocation techniques should be implemented so as to ensure the mass provision of multimedia applications to mobile users. This paper proposes a novel mechanism for efficient radio bearer selection during MBMS transmissions. The proposed mechanism is based on the concept of transport channels combination in any cell of the network. Furthermore, the mechanism exploits the performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas and manages to efficiently deliver multiple MBMS sessions. The proposed mechanism is thoroughly evaluated and compared with the radio bearer selection mechanisms proposed by 3GPP.

Satellite-HAP Network Supporting Multilayered QoS Routing in the Sky

The main features of the future mobile communication systems are the provisioning of high-speed data transmissions (up to 1 Gb/s) and interactive multimedia services. For effective delivery of these services, the network must satisfy some strict quality-of-service (QoS) metrics, defined typically in terms of maximum delay and/or minimum throughput performances. According to this general vision, the integration of different layered networks play one of the most important roles in the telecommunication systems; for this reason, the paper explains the potential role of an integrated satellite-high-altitude platform (HAP) terrestrial system proposing a new multilayered inter-HAP-satellite routing (IHSR) algorithm integrated with an efficient admission control scheme in order to guarantee an adequate QoS to multimedia traffic connections. The performance of the overall architecture is evaluated through intensive simulations comparing the proposed algorithm with a previous classical routing scheme under several traffic load scenarios and network dimensions. The obtained results demonstrate the goodness of the proposed strategy in terms of handled active connections and inter-HAP link utilization.

멀티미디어 서비스 품질 제어를 위한 QoS 파라미터와 QoE 요소간의 연동 제어 시스템 설계

본 논문에서 우리는 차세대 통합망 환경에서 다양한 멀티미디어 서비스를 이용하는 서비스 이용자의 체감 품질이 저하될 경우 체감 품질과 관련된 QoS 파라미터를 네트워크 계층에서 제어함으로써 품질 만족도를 향상시킬 수 있는 품질 연동 제어 시스템을 제안한다. 제안된 시스템은 RTCP와 같은 제어 패킷을 통해 네트워크 계층의 QoS 파라미터 정보를 수집하고 이 수집된 정보를 이용하여 멀티미디어 서비스의 QoE를 평가한다. 이렇게 평가된 QoE와 응용계층에서 측정된 QoE와 비교하여 기준값보다 낮을 경우 품질 저하로 판단하고 이와 관련된 QoS 파라미터 도출 및 각 파라미터의 상대적 중요도를 결정한다. 결정된 정보를 토대로 QCS는 서비스 품질 제어 시스템(SCS)에서 각 라우터 및 스위치에 적용하는 정책(policy)의 기반이 될 수 있는 QoS 제어값 정보를 생성하여 SCS로 전송한다. 이런 제안된 시스템을 통해 서비스 및 네트워크 사업자들은 서비스 특성 및 네트워크 상황을 고려하여 서비스 이용자에게 향상된 품질의 멀티미디어 서비스를 제공할 수 있다. In this paper, we propose a quality interworking control system to enhance user's quality satisfaction in NGN environment by controling QoS parameters related with QoE in network layer when service user's QoE using variance multimedia service is poor. The proposed system gathers QoS parameter information in network layer through control packet such as RTCP, and evaluates QoE of multimedia service using these QoS parameter information. Comparing the evaluated QoE with the measured QoE in application layer, QCS judges quality degradation, deduces related QoS parameters and decides relative importance of each parameter when QoE is lower than threshold value. QCS generates QoS control values which is based on routing and switching policy in service quality control system(SCS) and forwards them to SCS. Through this proposed system, service and network providers can provide multimedia services of enhanced quality to service users taking account of service characteristic and network performance.

영상 처리를 이용하여 주변 환경 센서를 관리하기 위한 유비쿼터스 홈 네트워크 시스템

Abstract A home network provides users with a variety of information services. The kind and quality of the services can be substantially enhanced by utilizing a variety of data from sensors. However, home networks currently limit their potential by focusing on providing multimedia services rather than services utilizing sensor data. Outdoor electronics are frequently made in a form that emphasizes only certain limited functions in contrast to home appliances. Thus, sensors with one or two functions rather than many can be used in outdoor systems and their use will be more economical than using sensor nodes indoors with more complex home appliances. In this study, we chose to work with motion sensors as they have many potential uses, and we selected a parking lot control system with to use the motion sensors. This parking lot control system was implemented and applied as part of a home network. For this purpose, we defined and implemented a protocol to manage the network in a ubiquitous sensor network environment for the wireless home network in this study. Although a network management system in a Ubiquitous Sensor Network (USN) related to this study is being advanced for other projects, the protocol interface and message system have not yet been clearly defined for use in a general purpose network or in an extension into heterogeneous kinds of networks, communication support, etc. Therefore, USN network management should be conducted for management of faults, composition, power, and applications. To verify the performance of the protocol interface designed in this study, we designed and implemented the necessary units (sensor nodes, sensor gateway, and server) for each network section and, with them, proved the validity of this study 요 약

Personalized multimedia touristic services for hybrid broadcast/broadband mobile receivers

This paper presents the topology of a multimedia tourism service that targets mobile devices equipped with broadband and either multicast or broadcast access capabilities. Multicast / Broadcast access is used to handle the delivery of multimedia data to many simultaneous users in the service area. The solution adopted is based on existing standards for mobile TV services, but introducing features that enable the provision of generic multimedia services on top of mobile hybrid broadband and broadcast networks. Furthermore, this paper shows how to use standardized interfaces originally defined for interactive mobile TV broadcasting to build personalized mobile multimedia services that do not deal with TV contents or are not necessarily coupled to a mobile TV service bundle.

Development of portable intelligent gateway system for ubiquitous entertainment and location-aware push services

Intelligent gateway systems have evolved to seamlessly offer location-aware and multimedia services, allowing multi users to roam among multi service domains. In the past decade intelligent gateways have been implemented to support context-aware multimedia services with network convergence and service reasoning mechanisms in multi domains. However, recent researches have to consider multiple events and service management according to the user's movements and requirements. Therefore, we propose a Portable Intelligent Gateway System (PIGS) to offer seamless device-independent multimedia services and location-aware push services. Using heterogeneous network convergence and utilizing cooperation between other gateways, the PIGS interconnects users (user devices) who want to be offered multimedia services and Service Providers (SPs). Furthermore, our system dynamically offers differential services to multiple users with respect to the user, device and location characteristics. The PIGS also collects events using embedded sensors and generates events used for service configuration along with service predictions by using light-weight middleware. In this paper we implement real testbed, a house and a car, and verify the effectiveness of the service reconfiguration. The portable gateway structure using the PIGS achieves a 22% faster service response time in comparison to a fixed gateway-based structure.

A Service-Oriented Platform for Ubiquitous Personalized Multimedia Provisioning

As multimedia contents are becoming widely used in ubiquitous computing environments among many application fields, e.g., education, entertainment, and live surveillance, the demand of personalized access to these contents has increased dramatically. The provisioning of ubiquitous personalized multimedia services (UPMSs) is a challenging task, which involves a lot of heterogeneous entities ranging from objects, devices to software. In this work, we propose a three-layer software platform, called UPmP to support efficient development and deployment of UPMSs. It fulfills the core functionalities for ubiquitous personalized multimedia provisioning including service management, multimedia recommendation, adaptation, and delivery. We adopt service-oriented approach in building the platform. The enabling technologies such as component representation, service lifecycle management, platform configuration, and service composition are described in detail. The experimental results show that the UPmP is flexible to be configured under different settings.

Building a framework for a partnership business model

Value in the business model concept is traditionally described from the perspective of end-customers. We argue that this is not sufficient in today's competitive multichannel environment. We utilise a transactional perspective and extend the notion of exchange of value and resources to the firm's partners. The developed partnership business model construct is introduced and its usability to analyse interfirm cooperation related to provision of IP multimedia communication services is examined empirically. The goal is to find out why an operator would be a preferred channel for service delivery, and what would make their partnership business model attractive from the partners' perspective. The results suggest that partners evaluate the attractiveness of the business model of an operator in terms of value and resources. The partnership business model construct provides a valuable perspective to companies who have to consider how to attract good partners to stay competitive.

오버레이 멀티캐스트 및 콘텐츠 전달 네트워크를 적용한 개방형 IPTV 플랫폼

일정 수준의 서비스 품질, 보안, 양방향성, 신뢰성 등을 제공하는 관리된 IP 기반의 네트워크에서 멀티미디어 서비스를 주로 수행하는 IPTV 서비스는 최근 상용화 서비스 제공으로 인해 그 중요성이 증가하고 있다. 그러나 IPTV 서비스 사업자들의 주요 서비스들이 폐쇄형 플랫폼에 의존하고 있어 개인형, 개방형 서비스를 통해 언제, 어디서나, 어떤 디바이스 환경에서도 콘텐츠를 생산하고 동시에 소비하는 IPTV 서비스의 본래 취지를 충족하지 못하고 있다. 본 논문에서는 개방형 IPTV 서비스 플랫폼을 제안하여 개인이나 소규모 사업자가 쉽게 콘텐츠를 생산하고 기존의 IPTV 망에 종속되지 않은 상태에서 서비스를 제공할 수 있는 방안을 제공하였다. 제안된 플랫폼은 제한적인 네트워크 및 프로세스 자원에서 서비스를 지원할 수 있는 오버레이 멀티캐스트 전송 방법과 콘텐츠의 품질을 보장하기 위해 사용하는 콘텐츠 전달 네트워크(Content Delivery Network)와 유사한 전송 방법을 동시에 적용하였다. 제안 IPTV 플랫폼은 성능 시험을 통해 전송되는 콘텐츠의 품질, 콘텐츠 전송량 및 채널 Zapping Time에서 개방형 서비스 플랫폼으로서의 가능성을 보여 주었으며, 향후 지속적인 기능 및 사용자 인터페이스의 개선을 통해 개방형 IPTV 플랫폼을 이용한 IPTV 서비스를 제공할 수 있음을 보여 주고 있다. Recently, the importance of IPTV providing multimedia service over IP based networks managed to provide the required level of quality of service and experience, security, interactivity and reliability has been gradually increasing by the commercialization of its service. However, the original purposes of IPTV service - contents are produced and consumed anytime, anywhere, and over any device at the same time - have not been satisfied by service providers because most services offered by service providers depend on closed IPTV platform. In this paper, we propose an open IPTV service platform that an individual or small company can easily produce contents and offer IPTV service independently from the existing closed IPTV platform.. The proposed IPTV platform exploits overlay multicast scheme to offer reasonable service under the environment where network bandwidth and processor resource are limited. It also uses CDN-like scheme to ensure the quality of transmitted contents. The performance evaluation shows that the proposed IPTV platform has the possibility of being an open IPTV platform considering its results such as the quality of transmitted contents, the transmission rate, the channel zapping time, and so on. It also shows that proposed IPTV platform could be applied to real IPTV service with continuous enhancement of its functions and user interfaces.

Design and implementation of advanced multimedia conferencing applications in the 3GPP IP multimedia subsystem

The IP multimedia subsystem is a key component of 3G networks. It enables the seamless provision of multimedia services to end users. Multimedia conferencing is an important category of multimedia services in IMS, serving as the basis for a wide range of applications including audio/video conferencing, multiparty gaming and distance learning. Floor control is an advanced feature of multimedia conferencing which manages the access to shared resources such as audio and video channels. This article extends the 3GPP architecture to include the design and implementation of advanced multimedia conferencing applications. It separates the floor control server and the media resource function processor, and it also opens up advanced conferencing capabilities. A SIP-based floor server control markup language and a multi-level abstraction API are proposed. The extensions are illustrated by a case study based on the design and implementation of a multiparty multimedia game. An important finding of this article is that tools and technologies for the design and implementation of multimedia conferencing applications in IMS are relatively immature. We therefore caution designers and implementers that they may need to develop additional tools and technologies to complete their projects, just as we did in the work presented in this article.

An improved MBMS power counting mechanism towards long term evolution

One of the key objectives of beyond 3rd generation mobile networks is the realization of enhanced end-user experience through the provision of rich multimedia services. Multimedia Broadcast/Multicast Services (MBMS) framework epitomizes the increasing popularity of such applications and is envisaged to play an instrumental role for the Long Term Evolution (LTE) proliferation in mobile market. For exploiting resource efficiency, MBMS specifications consider the Counting Mechanism which decides whether it is more efficient to deliver MBMS multicast traffic over Point-to-Point (PTP) or Point-to-Multipoint (PTM) bearers. However, the necessity to further improve MBMS resource efficiency and integrate new technologies in the frame of LTE stresses the need for an advanced Counting Mechanism. In this work we propose a novel Power Counting Mechanism for efficient selection of MBMS bearers. The proposed mechanism optimally utilizes power resources and exploits broadband characteristics and performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas used in LTE networks.

초고속통신망에서 DHCP 기반의 IP 할당 분석

최근 정보통신기술은 통신서비스의 공급자들이 개별적으로 구축하여 운영하고 있는 네트워크 시스템에 일관된 자원 및 네트워크의 보안 체계 구축을 도입하고 있다. 그래서 다양한 접속망을 통하여 멀티미디어 통신서비스를 수행한다. 따라서 본 논문에서는 초고속 통신망에서의 DHCP 프로토콜을 기반으로 한 IP 할당 방법을 알아보고, 이를 이용하여 유동 IP를 할당받아 xDSL모뎀, AP, 사용자 PC 등의 부팅 순서에 따라 IP 할당의 성공 또는 실패가 발생할 수 있는 경우를 분석하여 사용자에게 최적의 서비스품질을 제공하고자 한다. Recently, Telecommunication companies have introduced a new network architecture that assigns network resources consistent and protects their systems more secure. Now, they provide multimedia services through various types of access networks. In this study, I'd like to introduce IP address assignment method based on the Dynamic Host Configuration Protocol (DHCP) and find out how success or failure of Ip address assignment will be taken place according to the booting order of xDSL modem, AP and PC.

Current Issues and Future Trends: DVB-RCS Satellite Systems

The telecommunications market is reaching new types of customers who require their applications anywhere and anyway. Therefore, the DVB-RCS standard, which had great success in the fixed version is changing in this direction. The main objective of this work is to give an overview of architectures and technologies that can be used for implementation of a first-generation of advanced mobile satellite systems for the provision of broadband multimedia services.

CONTEXT-AWARENESS AND USER PROFILING IN MOBILE ENVIRONMENTS

The evolution of mobile communication systems to 3G and beyond introduces requirements for flexible, customized, and ubiquitous multimedia service provision to mobile users. One must be able to know at any given time the network status, the user location, the profiles of the various entities (users, terminals, network equipment, services) involved and the policies that are employed within the system. Namely, the system must be able to cope with a large amount of context information. The present paper focuses on location and context awareness in service provisioning and proposes a flexible and innovative model for user profiling. The innovation is based on the enrichment of common user profiling architectures to include location and other contextual attributes, so that enhanced adaptability and personalization can be achieved. For each location and context instance an associated User Profile instance is created and hence, service provisioning is adapted to the User Profile instance that better apply to the current context. The generic model, the structure and the content of this location- and context-sensitive User Profile, along with some related implementation issues, are discussed.

IPTVhome networking via 802.11 wireless mesh networks: an implementation experience

Wireless multimedia home servers are the next generation of home entertainment systems. From a single broadband connection entering home, multimedia data is transmitted to TV and other peripherals using only wireless links. The provision of hiqh quality time-critical multimedia services in indoor environment is very challenging due to high attenuation and multi-path fading caused by the walls and the contention in the shared wireless channel. In this paper, we demonstrate that mesh networking can help improve the service quality of both multimedia and data users, when the video packets are relayed with EDCA priorities based on their importance. Our results on a real wireless mesh network implementation using the new high definition video streaming standard, H.264 verify our hypothesis, where we observe almost no degradation video quality, and very low packet delay and loss rate in the presence of high amount of competing data traffic.

Performance Analysis of WCDMA System for LEO Satellite Channel

In a Low Earth Orbit (LEO) satellite mobile multimedia system, the multiple access scheme should be capable of supporting the necessary features that would facilitate the provision of multimedia services. Wideband Code Division Multiple Access (WCDMA) is an attractive multiple access scheme for mobile multimedia communications based on LEO satellites. In this paper, the performance of WCDMA system over LEO satellite channel is evaluated. The performance is measured in terms of the bit error probability. A mathematical derivation of the bit error probability is presented. A rake receiver with maximal ratio combining is considered in the analysis. The effect of the number of users and the processinggain on the performance of the WCDMA system is investigated.

Multimedia Service Provisioning and Personalization on Grid-Based Infrastructures: Now and the Future

This article identifies key technology components for provisioning multimedia services on grid-based infrastructures and discusses needed research to deal with the demands of next-generation multimedia applications.