A transmission control SCTP for real-time multimedia streaming

Multimedia streams over the Internet have a strict playback delay time, i.e., multimedia data arriving after the playback time cannot be played by the receiver and they are discarded. In this paper, we introduce a transmission control SCTP (TC-SCTP) which has a transmission control sub-layer (TCSL) in which the multimedia streaming server determines whether data can be played in the receiver before sending the data and decides whether to send data messages or not. In addition, TCSL employs differentiated retransmission policy depending on the type of multimedia. We evaluate the performances of SCTP, partial reliability (PR)-SCTP, and TC-SCTP via ns-2 simulator. The simulation results demonstrate that the TC-SCTP protocol can decrease the amount of transmissions and increase the video decodable ratio, compared with other protocols.     

CyVOD: a novel trinity multimedia social network scheme

How to comprehensively explore, improve and deploy multimedia social networks (MSNs) has become a hot topic in the era of emerging pervasive mobile multimedia. More and more MSNs offer a great number of convenient tools, services, and applications for multimedia contents including video and audio that users share willingly and on demand. However, concerns with digital rights management (DRM)-oriented multimedia security, as well as the efficiency of multimedia usage and sharing are meanwhile intensified due to easier distribution and reproduction of multimedia content in a wide range of social networks. The paper proposes a comprehensive framework for multimedia social network, and realized a cross-platform MSN prototype system, named as CyVOD, to support two kinds of DRM modes. The proposed framework effectively protects copyrighted multimedia contents against piracy, and supports a more efficient recommendation system for its better handling of the tradeoff between multimedia security and ease of use.     

一种面向多对象多媒体应用的同步控制方法

多对象多媒体应用允许多路媒体同时呈现,其同步控制比较复杂,可分为传输过程中与呈现过程中的同步。然而现有的同步方法忽略了媒体在最后呈现过程中的同步,也没有考虑各媒体对象之间的同步要求差异。针对以上问题,为视频点播提出了一种在应用层上控制多对象多媒体同步呈现质量的方法。在采用多级缓冲门限实现媒体内同步反馈控制的基础上,依据主要媒体对象的呈现时间戳,在每一个呈现场景内调整次要媒体对象的呈现速率,从而实现媒体间的同步呈现。实验结果表明该方案能够有效地提高同步质量,且媒体间的同步性能平均提高28.45%。     

UAVS通信网切换管理方案设计与分析*

针对UAVS通信网中的切换管理问题,提出了融合滞后余量与门限结合的切换判决方法、基于UAV节点自主决策的紧急切换控制策略和GCM-FIFO信道分配方案的切换管理方案.相关理论分析表明,该切换管理方案解决了UAVS通信网中节点高移动性、切换业务量高但信道数有限以及由于中继机节点遭遇威胁而带来的紧急切换等问题.     

A mobile multimedia content handoff scheme based on proxy mobile IPv6 for VR/AR

Multimedia Tools and Applications - This paper proposes a novel mobile multimedia content handoff scheme for a content delivery network (CDN) based on proxy mobile IPv6 (PMIPv6). PMIPv6 is a...     

FHMIPv6网络中快速的乒乓切换方案

针对现有移动网络中乒乓切换问题导致的高切换延迟的情况,提出一种在FHMIPv6网络基础上的快速的切换方案.该方案提出了切换的门限阈值以及隧道状态,门限阈值决定切换发生的起点,隧道间的状态则根据需要快速激活或终止通信链路.方案优点是当移动节点在边界区域来回切换时,提供快速切换机制,减少了切换时延,合理地处理新旧AR通信隧道激活,睡眠以及终止,合理地利用带宽资源,在降低时延上保证了一定的服务质量(QoS).通过实验仿真验证了该切换方案对减少时延的有效性.     

A producer mobility support scheme for real-time multimedia delivery in named data networking

Multimedia Tools and Applications - Named Data Networking (NDN) is a network architecture for the Future Internet, and can cooperate with the Internet of Things (IoT) to tackle problems existing in...     

A novel server-side proxy caching strategy for large-scale multimedia applications

Nowadays, server-side Web caching becomes an important technique used to reduce the User Perceived Latency (UPL). In large-scale multimedia systems, there are many Web proxies, connected with a multimedia server, that can cache some most popular multimedia objects and respond to the requests for them. Multimedia objects have some particular characteristic, e.g., strict QoS requirements. Hence, even some efficient conventional caching strategies based on cache hit ratio, meant for non-multimedia objects, will confront some problems in dealing with the multimedia objects. If we consider additional resources of proxy besides cache space, say bandwidth, we can readily observe that high hit ratios may deteriorate the entire system performance. In this paper, we propose a novel placement model for networked multimedia systems, referred to as the H^k/T model, which considers the combined influence of arrival rate, size, and playback time to select the objects to be cached. Based on this model, we propose an innovative Web caching algorithm, named as the ART-Greedy algorithm, which can balance the load among the proxies and achieve a minimum Average Response Time (ART) of the requests. Our experimental results conclusively demonstrate that the ART-Greedy algorithm outperforms the most popular and commonly used LFU (Least Frequently Used) algorithm significantly, and can achieve a better performance than the byte-hit algorithm when the system utilization is medium and high.     

蓝牙技术的快速连接转移模式

由于一个移动设备所属的微微网只有10 m距离,因此就有可能发生频繁的连接转移.连接转移需要移动设备与新的基站之间建立连接,这在频跳系统中是费时的过程,这种状态将引起许多连接的丢失从而影响网络性能.提出了一种新的模式用来改善连接转移的性能.模拟的结果显示,提出的模式显著的减少了连接转移的延时.     

DAI based wireless sensor network for multimedia applications

In Wireless Multimedia Sensor Network (WMSN), the time critical and delay sensitive applications like video, audio, image demands high bandwidth and transmission resources. The provision of Cognitive Radio (CR) can effectively utilize the available spectrum in the most appropriate way to provide high bandwidth in the Wireless Sensor Network (WSN) environment as Cognitive Radio sensor network (CRSN). The CR features are applicable in WMSN paradigm with required changes in transmission parameter for bandwidth hungry multimedia applications. In this paper, we propose an approach for setting up a cost-efficient and higher data rates communication in Wireless Multimedia Cognitive Radio Sensor Network (WMCRSN). The process analyses power allocation for sensor nodes by dynamic channel modelling and allocates power using multi-agent based Distributed Artificial Intelligence (DAI) in WMCRSN applications. The novelty in the approach lies in analyzing the real-time spectrum sensing outputs system for high data rate wireless multimedia applications. The DAI makes the process of power allocation in a smart way for having low latency based intra and inter cluster communication between sensor nodes. The performance parameters of the network, i.e. probability of detection and false alarm with the modelled error rates are presented. The mathematical analysis and simulation results justifies the feasibility and merits of the proposed method over conventional methods.

     

Management of virtual network resources for multimedia applications

The Internet is the primary means for multimedia content sharing, playing a central role in the lifestyle of users. As a consequence, in the past few years, the traffic demand for access and edge networks has increased (video stream downloading, videoconferencing or even the broadcasting of video streams through the Internet), since multimedia applications have strict requirements, including high bandwidth, small amount of loss and low delay. To address this scenario, the edge as a service (EaaS) paradigm arises as a suitable approach to increasing the quality of Internet access. The EaaS uses network virtualization and software-defined networks to improve the resource utilization and manageability. Within this context, this article proposes a framework to manage the virtual network resource (VNR) according to the multimedia application characteristics, and not only the network requirements. Additionally, a study about the relationship between quality of experience (QoE) and VNR availability was performed to be used as a basis for a proposed resource allocation adjustment mechanism. Experiments using real multimedia traffic under distinct scenarios demonstrate the effectiveness of the proposed framework to ensure the QoE of users through the management of the VNR.     

An efficient resource allocation scheme for multimedia applications in MANET

A Mobile Adhoc Network (MANET) is collection of mobile nodes and communicates using wireless network without having any fixed infrastructure. This paper proposes an algorithm used to allocate the resources for multimedia applications using mobile agent technology in MANET. In addition to that, it allocates the resources for hand-off applications and new applications.     

One-time packet key exchange scheme for secure real-time multimedia applications

To secure multimedia communications, existing encryption techniques usually encrypt the whole data stream using the same session key during a session. The use of the session key confronts with tradeoff problem between session key creation latency and security for the real-time multimedia stream. The main feature of our proposed scheme is to selectively encrypt RTP packets using different one-time packet keys in the same session for real-time multimedia applications. The packet key, which has already been used, will never be reused throughout the same session. The use of the one-time packet key enables to improve security strength of real-time multimedia. To solve the issue of the real-time packet key exchanges related to the timely use of the one-time packet keys, this paper suggests the one-time packet key exchange method that does not need to occur on a packet-by-packet basis.     

Secure multimedia data processing scheme in medical applications

People communicate in a variety of ways via multimedia through the propagation of various techniques. Nowadays, variety of multimedia frameworks or techniques is used in various applications such as industries, software processing, vehicles and medical systems. The usage of multimedia frameworks in healthcare systems makes it possible to process, record and store huge amount of information generated by various medical records. However, the processing and management of huge records of every individual lead to overload the security risk and human efforts. The aim of this paper is to propose a secure and efficient technique that helps the medical organizations to process every record of individuals in a secure and efficient way. The proposed mechanism is validated against various security and processing metrics over conventional mechanisms such as Response Time, Message Alteration Record, Trusted Classification Accuracy and Record Accuracy. The analyzed results claim the significant improvement of proposed mechanism as compare to other schemes.

     

Query based relevant music genre retrieval using adaptive artificial neural network for multimedia applications

Multimedia Tools and Applications - In the case of digital music industry, current major internet stores contain millions of tracks, which complicate search, retrieval and discovery of music...     

Synchronization and handoff management schemes for wireless multimedia systems

This paper presents handoff management schemes for synchronization algorithms for wireless multimedia systems. The synchronization and handoff management schemes allow mobile hosts to receive time-dependant multimedia streams without delivery interruption while moving from one cell to another. They also maintain the correct ordering of the media components, through the execution of the wireless multimedia application by a means of timestamped messages passed among mobile hosts, base stations and servers. The timestamp values are used to compute the delay for each multimedia unit for each server. Furthermore, the proposed schemes always search for a quasi-receiver among the base stations with which the mobile hosts can communicate to synchronize multimedia units. We discuss the algorithms and present a set of simulation experiments that evaluate the performance of our schemes, using message complexity and buffer usage at each frame arrival time. Our results indicate that our schemes exhibit no underflow or overflow within the bounded delivery time.     

一种异构无线网络的垂直切换方案

针对异构网络环境下的垂直切换决策问题,提出了一种使用IEEE802.21 MIH标准进行数据传输的改进TOPSIS切换决策方案。引进了联系数和IEEE802.21 MIH的概念,基于[a+bi]型联系数提出了一种新的权重确定方法以及模糊属性指标表示方法,据此对传统的TOPSIS决策算法进行了改进。基于IEEE802.21 MIH标准对切换过程和数据结构进行了分析和构建。用具体实例对算法的正确性进行了验证并与以往的算法进行了比较分析,结果证明,该算法与以往算法相比更加合理、准确。     

基于SIP的无线网络移动性管理研究

为了使移动设备能在无线IP网络中无缝漫游,无线IP网络必须要能提供有效的移动性管理来支持终端的移动性。基于SIP提出了一种新的应用层移动性管理方案,和已有的移动性管理方案相比,它既支持实时业务的快速切换,减少了切换时的延迟和丢包,也支持非实时业务,而且实现和部署起来比较简单方便。     

基于SIP的无线网络移动性管理研究

为了使移动设备能在无线IP网络中无缝漫游，无线IP网络必须要能提供有效的移动性管理来支持终端的移动性。基于SIP提出了一种新的应用层移动性管理方案，和已有的移动性管理方案相比，它既支持实时业务的快速切换，减少了切换时的延迟和丢包．也支持非实时业务，而且实现和部署起来比较简单方便。