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MUM Tables of Contents: 0405060708091011121314

Proceedings of the 2011 International Conference on Mobile and Ubiquitous Multimedia

Fullname:Proceedings of the 10th International Conference on Mobile and Ubiquitous Multimedia
Editors:Qionghai Dai; Ramesh Jain; Xiangyang Ji; Matthias Kranz
Location:Beijing, China
Dates:2011-Dec-07 to 2011-Dec-09
Standard No:ISBN: 978-1-4503-1096-3; ACM DL: Table of Contents; hcibib: MUM11
Links:Conference Website
Augmented visualization with natural feature tracking BIBAFull-Text 4-12
  Gábor Sörös; Hartmut Seichter; Peter Rautek; Eduard Gröller
Visualization systems often require large monitors or projection screens to display complex information. Even very sophisticated systems that exhibit complex user interfaces do usually not exploit advanced input and output devices. One of the reasons for that is the high cost of special hardware. This paper introduces Augmented Visualization, an interaction method for projection walls as well as monitors using affordable and widely available hardware such as mobile phones or tablets. The main technical challenge is the tracking of the users' devices without any special equipment or fiducial markers in the working area. We propose to track natural features of the display content with the built-in camera of mobile devices. Tracking the visualized scene allows pose estimation of the mobile devices with six degrees of freedom. The position and orientation information is then used for advanced interaction metaphors like magic lenses. For a group of experts who are analyzing the data in front of the same screen, a personal augmented view of the visualized scene is presented, for each user on his/her personal device. The prototype Augmented Visualization System achieves interactive frame rates and may lead to a greatly enhanced user experience. The paper discusses the design and implementation questions and illustrates potential application scenarios.
MultiKit: a user interface toolkit for multi-tag applications BIBAFull-Text 13-22
  Robert Hardy; Enrico Rukzio; Matthias Wagner; Paul Holleis
This paper documents MultiKit: a toolkit that supports the development of sophisticated user-interfaces for applications using Near Field Communication (NFC). The usage of the toolkit is exemplified using three implemented prototypes, each with significant differences. These differences highlight the complexities involved in producing such NFC applications, and the benefits of a toolkit that can adapt to varying interface types. As the toolkit is tailored to NFC technology, NFC-specific features are explored. These include switching between dynamic (e.g. projection) and static interfaces (e.g. posters), and interface generation from NFC tag descriptions.
When multi-touch meets streaming BIBAFull-Text 23-32
  Zimu Liu; Yuan Feng; Baochun Li
With the advent of mobile devices with large displays, it is intuitive and natural for users to interact with an application on a mobile device using multi-touch gestures. In this paper, we propose that these multi-touch gestures can be streamed on-the-fly among multiple participating users, making it possible to engage users in a collaborative or competitive experience. Such multi-touch streams, featuring very low streaming bit rates, can be rendered on receivers to precisely reconstruct the states of an application. We present the challenges, system framework, embedded algorithm design, and real-world evaluation of TouchTime, a new system that has been designed from scratch to facilitate the streaming of multi-touch gestures among multiple users. By seamlessly combining local computation on mobile devices and services from the "cloud," we explore the design space of suitable mechanisms to represent and packetize multi-touch gestures, and of practical protocols to transport concurrent live multi-touch streams over the Internet. Specifically, we propose an auction-based reflector selection algorithm to achieve the minimal end-to-end delay in a live multi-touch streaming session. To demonstrate TouchTime, we have developed a new real-world music composition application -- called MusicScore -- using the Apple iPad Programming SDK, and used it as our running example and experimental testbed to evaluate our design choices and implementation of TouchTime.
Real world responses to interactive gesture based public displays BIBAFull-Text 33-39
  John Hardy; Enrico Rukzio; Nigel Davies
Today, one does not have to travel far to find examples of digital signage, yet the adoption of interactive gesture based public displays remains quite rare. Subsequently, not much is known about them despite a large array of potential advantages. This paper contributes to our understanding of how people perceive, respond to and interact with such displays outside the controlled environment of a research lab. Unlike other works which have focused on isolated aspects of in-lab interaction, we present a detailed examination that addresses a wide range of responses to such a display -- including those who ignore them completely. To facilitate our study we created an experimental coarse gesture based software suite and then deployed the system along with associated applications as part of an existing large scale public display network. Using this as a base, we executed four studies designed to passively observe the reactions of passers-by and followed these up with a fifth controlled experiment that compared the effectiveness of two different kinds of gesture in the context of menu item selection. To conclude, we present our key-findings and highlight possible avenues of further study for the future of gesture based digital signage.
iShake: mobile phones as seismic sensors -- user study findings BIBAFull-Text 43-52
  Mari Ervasti; Shideh Dashti; Jack Reilly; Jonathan D. Bray; Alexandre Bayen; Steven Glaser
The "iShake" system uses smartphones as seismic sensors to measure and deliver ground motion intensity parameters produced by earthquakes more rapidly and accurately than currently possible. Shaking table tests followed by field trial with approximately 30 iShake users were implemented to evaluate the reliability of the phones as seismic monitoring instruments and the functionality of the iShake system. In addition, user experiences were investigated with 59 iShake users, who provided feedback through a mobile questionnaire. Research included participative planning with a focus group to design and conceptualize how to improve iShake for future use. The shaking table tests demonstrated that cell phones may reliably measure the shaking produced by an earthquake. The performed user studies led to important guidelines for the future development and improvement of the iShake system. User studies also provided understanding of how iShake could best provide value to its users. The iShake system was shown to have great potential in providing critical information and added value for the public and emergency responders during earthquakes. Value creation for other users and first response through user-generated data was seen as a great source of motivation and commitment for active use of the system.
The consumption of integrated social networking services on mobile devices BIBAFull-Text 53-62
  Yanqing Cui; Mikko Honkala
Some mobile devices automatically fetch content from social networking services and integrate it into the device user interface. In this paper, we explore how people consume integrated social networking services in a field study with an innovative aggregator named Linked Internet UI Concept, or LinkedUI. Twenty users completed the field study. We logged their activities and performed user interviews. The study reveals two main use cases: habitual checking where users frequently glanced at the integrated services at short intervals; and serendipitous content discovery where they come across some content when performing other tasks. The study also reveals that the users only attended to a small proportion of the full content set, such as content recently published and content from selected contacts. This indicates the user need of quick access to relevant content.
Extending the reach of infrastructure by utilizing node mobility BIBAFull-Text 63-72
  Yu Zhen; Xu Jingdong; Wu Ying
With the advantage of high bandwidth and low cost, WLAN is widely regarded as an appealing technology for wireless access. However, WLAN only provides very limited coverage which is no more than hundreds of meters, making users experience intermittent connectivity when they move near Wi-Fi access points (AP). To fill in the gaps between APs, we present a new framework, which combines infrastructure composed of APs with the concept of DTN to improve network performance. In particular, when a mobile client has moved out of the reach of the infrastructure, our framework predicts the trajectory of this client and lets the APs in the proximity identify suitable relay nodes among the mobile clients that happen to visit those APs. If some passing by mobile clients have a chance to encounter the target client soon, the corresponding AP(s) will transfer the data destined to the target client to those mobile clients, in the hope that they will accomplish the delivery in a "store-carry-forward" fashion. In this way, the target client may be able to receive data even before it arrives at an AP. Our evaluation shows that our framework fairly improves the performance in terms of both delivery delay and delivery ratio, with controlled overhead.
Towards a holistic approach for mobile application development in intelligent environments BIBAFull-Text 73-80
  Stefan Diewald; Luis Roalter; Andreas Möller; Matthias Kranz
"There's An App For That" -- but how do we actually develop them? While smartphones and tablet PCs are getting more and more popular and their application scenarios are growing, we still develop them using only a standard integrated development environment. Although context-based services and apps do, next to network connectivity, require lots of sensor data, the tools for providing realistic sensor data during development are still immature.
   Developing, testing, debugging and evaluating those next-generation context-based apps require sensor data from the mobile device -- acceleration, motion, light, sound, camera and many more sensors are available. Though, the existing development tools do seriously limit application developers by not providing the data at all or only on a very limited scale. Especially for indoor environment applications such as indoor navigation, seamless interaction between public and private displays and activity recognition and monitoring, realistic sensor data are needed and simulation support during the development phase is essential.
   In this paper, we present our work towards a holistic approach for mobile application development in intelligent environments. At the example of the Android mobile device platform, we show how our approach can facilitate more effective and realistic means for mobile application development.
Supporting children with special needs through multi-perspective behavior analysis BIBAFull-Text 81-84
  Florian Alt; Andreas Bungert; Bastian Pfleging; Albrecht Schmidt; Meindert Havemann
In past years, ubiquitous computing technologies have been successfully deployed for supporting children with special needs. One focus of current research has been on post-hoc behavior analysis based on video footage where one or multiple cameras were used to review situations in which children behaved in a certain way. As miniaturized cameras as well as portable devices are becoming available at low costs, we envision a new quality in supporting the diagnosis, observation, and education of children with special needs. In contrast to existing approaches that use cameras in fix locations, we suggest to use multiple mobile camera perspectives. In this way observation data from fellow classmates, teachers, and caregivers can be considered, even in highly dynamic outdoor situations. In this paper we present MuPerBeAn, a platform that allows multi-perspective video footage from mobile cameras to be collected, synchronously reviewed, and annotated. We report on interviews with caregivers and parents and present a qualitative study based on two scenarios involving a total of seven children with autism (CWA). Our findings show that observing multiple mobile perspectives can help children as well as teachers to better reflect on situations, particularly during education.
A MIP-P2P based architecture for application mobility BIBAFull-Text 85-93
  Dan Johansson; Andreas Åhlund; Christer Åhlund
Mobility exists in many shapes; when migrating a running application (code, states and data) from one device to another, one has achieved application mobility. In this article we combine this mobility type with context awareness, defining context awareness supported application mobility (CASAM) as when using context in the act of moving an application between hosts during its execution, to provide relevant information and/or services, where relevancy depends on the user's task. We identify and present five CASAM challenges, that are used to create requirements for a CASAM architecture. A proposal for an architecture, building on peer-to-peer (P2P) technology in combination with mobile IP, is then presented, addressing the identified challenges, providing a decentralized framework for global application mobility. As such, our architecture differs from earlier centralized and/or locally bound solutions for application mobility.
Easy access to recommendation playlists: selecting music by exploring preview clips in album cover space BIBAFull-Text 94-99
  Arto Lehtiniemi; Jukka Holm
This paper studies the idea of selecting music by exploring preview clips in an album cover space. In the implemented prototype, the user listens to representative audio clips until the preferred musical style has been found, and the corresponding song is then used as a seed song for generating a new playlist of music recommendations. The prototype was evaluated by 40 Finnish participants. In the initial interview, the concept was seen as an innovative and a fast way to explore different types of music without deeper musical knowledge, and it was said that the beauty of the concept is the instant feedback that the user gets when moving in the album cover space. In the longer-term use, the prototype was considered to be less fun and it would have benefited from the possibility to search for individual songs or listen to full albums. Still, the majority of the participants would have wanted to continue using the prototype to complement their other music player applications.
Multi-hop broadcast for data transmission of traffic congestion detection BIBAFull-Text 100-108
  Yuwei Xu; Ying Wu; Jingdong Xu; Lin Sun
Nowadays, urban traffic congestion has become a global phenomenon, resulting in a lot of negative effects both on economy and ecology. Thus, the detection of road congestion in cities is a highly urgent problem to be solved by scientists throughout the world. One new promising approach is the utilization of vehicular ad-hoc networks (VANETs). In this paper, we focus on the data transmission in the detection applications and propose a novel broadcast method, restricted multi-hop broadcast (RMB), to improve the congestion detecting ability of road side unit (RSU). Furthermore, two strategies are presented as the optimization of RMB. In order to validate RMB, we make experiments in a realistic traffic scenario. Simulations show that RMB works efficiently and expands the detection range of RSU significantly.
Video summarization with semantic concept preservation BIBAFull-Text 109-112
  Zheng Yuan; Taoran Lu; Dapeng Wu; Yu Huang; Heather Yu
A compelling video summarization should allow viewers to understand the summary content and recover the original plot correctly. To this end, we materialize the abstract elements that are cognitively informative for viewers as concepts. They implicitly convey the semantic structure and are instantiated by semantically redundant instances. Then we analyze that a good summary should i) keep various concepts complete and balanced so as to give viewers comparable cognitive clues from a complete perspective ii) pursue the most saliency so that the rendered summary is attractive to human perception. We then formulate video summarization as an integer programming problem and give a ranking based solution. We also propose a novel method to discover the latent concepts by spectral clustering of bag-of-words features. Experiment results on human evaluation scores demonstrate that our summarization approach performs well in terms of the informativeness, enjoyability and scalibility.
Carpe diem: exploring user experience and intimacy in eye-based video conferencing BIBAFull-Text 113-122
  Kaisa Väänänen-Vainio-Mattila; Katja Suhonen; Tina Gonsalves; Martin Schrader; Toni Järvenpää
Technology-mediated communication including mobile phone and video conferencing on PC enable increasing bandwidth for everyday interactions between remote people. The effectiveness and social presence with traditional video conferences have been studied rather extensively. Our research arose from the motivation of exploring how intimacy and emotional engagement between people can be supported by alternative types of image-based communication tools. We constructed a video conferencing system with near-eye displays, where the users could only see one of each others' eyes. The goal was to explore how such unusual eye-based display of the other person would make people feel during conversations. We conducted an explorative user study in a laboratory context with five pairs of users to understand their experiences with this system. The results show that this kind of mediated communication between remote partners can cause a variety of experiences, such as "interesting", "surprising", "tranquil" or "pleasantly strange". Overall, the full-screen display of the eye clears off distractions from the discussion and thus can help make the discussion more intimate and focused on the moment. We envision that a novel system like this could become a communication tool for everyday life, including mobile situations where it's possible for two people to stop for a while to focus on one another.
Dynamic scheduling of a mixture of scalable IPTV and VoD traffic over wireless home networks BIBAFull-Text 123-126
  Tiantian Guo; Jianfei Cai; Mingsheng Gao; Chuan Heng Foh
Unlike most of the existing studies on video streaming over WLANs, which usually focus on only one type of video streams, either stored videos or live videos, in this paper we propose a dynamic scheduling method for transmitting a mixture of live and stored videos over WLANs. In particular, we dynamically estimate the future IPTV traffic information based on the past. Our proposed dynamic scheduling algorithm allows VoD traffic to be transmitted not only at a later time but also in advance so as to provide more flexibility to serve the overall traffic to achieve a better QoS. The ns-2 simulations verify the effectiveness of the proposed approach.
A universal approach that makes legacy online content location-based BIBAFull-Text 127-133
  Basil Hess; Anar Gasimov; Juliana Sutanto
The growing popularity of location-based services for mobile smartphones requires web content to be assigned with location tags. In this paper we propose a simple yet powerful approach that assigns location information tags to online content that hasn't been originally assigned with such. The novel method first assesses if the content has any location-based relevance and then assigns one or more location tags to it. It is a user-centric approach. This means that instead of analyzing the content itself, it uses the locations from where the content has been accessed from. It is hence universally applicable for any type of legacy online content, like text, pictures or videos. Finally we present a case study with a non location-based question and answer platform, to which we apply our approach and build a location-based, mobile system.
Modeling the co-evolution of behaviors and social relationships using mobile phone data BIBAFull-Text 134-143
  Wen Dong; Bruno Lepri; Alex (Sandy) Pentland
The co-evolution of social relationships and individual behavior in time and space has important implications, but is poorly understood because of the difficulty closely tracking the everyday life of a complete community. We offer evidence that relationships and behavior co-evolve in a student dormitory, based on monthly surveys and location tracking through resident cellular phones over a period of nine months. We demonstrate that a Markov jump process could capture the co-evolution in terms of the rates at which residents visit places and friends.
Accelerate TV-L1 optical flow with edge-based image decomposition and its implementation on mobile phone BIBAFull-Text 144-151
  Botao Wang; Qingxiang Zhu; Hongkai Xiong; Chuanfei Luo
Variational methods are among the most accurate techniques of optical flow computation. TV-L1 optical flow, which is based on L1-norm data fidelity term and total variation (TV) regularization term, preserves discontinuities in the flow field and also can deal with large displacements. However, the TV-L1 optical flow method is inaccurate near edges and computationally intensive. In this paper, we proposed a technique, called Edge-based Image Decomposition (EID), to improve the accuracy in the edge areas and also accelerate the original TV-L1 method. EID improves the performance by decomposing image into edge regions and flat regions, and also assigns computing power discriminatively. We evaluated our algorithm on Middlebury datasets and proved that by applying EID, 30% of run-time can be saved with no loss in accuracy, and with same run-time, 7% of accuracy can be promoted. In addition, we implemented our EID-enhanced TV-L1 optical flow algorithm on mobile phone with Android operating system. Our application calculates the optical flow field between two images and can be used to generate the disparity map and reconstruct 3D scenes.
Cooperative cross-layer transmission for scalable video to resource-constrained receiver BIBAFull-Text 152-155
  Hongjiang Xiao; Qiong Liu; Qionghai Dai
For resource-constrained wireless scenarios, this paper proposes a cooperative cross-layer scheme to improve the performance of scalable video transmission. At the application layer, the extraction parameters of scalable video coding are first optimized to maximize the visual quality and fulfill the resource constraints of decoding capacity and bandwidth. At the link layer, a priority-based cooperative scheduling strategy is further proposed to transmit the video packets of extracted substream. In this strategy, the relay link may substitute for the unreliable direct link if it has a relatively smaller packet error rate (PER). The packet priorities are determined by both the link PERs and the video layers properties. Simulations demonstrate the effectiveness of our proposed scheme.
Integration of QoS and congestion control in multi-hop wireless networks BIBAFull-Text 156-160
  H. C. Mao; Q. S. Guan; G. Wei; B. Y. Guo; S. M. Jiang
The layered protocol architecture lacks of flexibility to support granular QoS requirements for multi-hop mobile wireless networks with limited bandwidth. Meanwhile, research indicates that TCP behaves inefficiently in such networks. Recently Differentiated Queueing Service (DQS) and Semi-TCP schemes have been proposed to provide granular QoS and improve the performance of TCP, respectively. However, the impact of their correlation on the overall network performance has not been investigated when they are implemented in the same protocol stack since their implementations cross transport layer, network layer and data link layer. To this end, this paper integrates DQS and Semi-TCP to investigate the performance in multi-hop mobile wireless networks. The study comes up with some new possible schemes to further improve the overall performance. According to our study, we propose a new algorithm to estimate the latest departure time and a novel handling of overdue packets, as well as an ACK scheme to decrease nodes' contention. Furthermore, we also design the cross-layer architecture for the integrated solution. Simulation results show that the integrated scheme can further improve throughput and reduce delay.
Smartphone-based 3D in-building localization and navigation service BIBAFull-Text 161-164
  Yang Yu; Nengqiang He; Zhihua Li; Yong Ren; Xinheng Wang
In this paper, we present a 3D indoor navigation service system based on smartphones. To achieve an accurate indoor navigation system in a multi-storey building, it is necessary to determine the storey where the user is. By attaching an atmosphere pressure sensor on smartphones, the altitude information of the user can be obtained, and then, the storey where the user is can be calculated indirectly. With the information of storey, we project localization anchor nodes, e.g. WiFi-AP, of different storeys onto the storey where the user is, and calculate their projection distances based on received signal strength (RSS). To utilize the projection distance in 2D localization algorithms, the systematic error deviation from the storey deviation can be reduced. In addition, we develop a software running in a smartphone to implement our localization method, and provide a smartphone navigation service in our office building. Experimental results show that our method is more accurate than the traditional triangle localization method.
Digifieds: insights into deploying digital public notice areas in the wild BIBAFull-Text 165-174
  Florian Alt; Thomas Kubitza; Dominik Bial; Firas Zaidan; Markus Ortel; Björn Zurmaar; Tim Lewen; Alireza Sahami Shirazi; Albrecht Schmidt
Traditional public notice areas (PNAs) are nowadays a popular means to publicly exchange information and reach people of a local community. The high usability led to a wide-spread use in stores, cafes, supermarkets, and public institutions. With public displays permeating public spaces and with display providers and owners being willing to share parts of their display space we envision traditional PNAs to be complemented or even replaced by their digital counterparts in the future, hence contributing to making public displays a novel communication medium. In this paper we report on the design and development of Digifieds (derived from digital classified), a digital public notice area. We deployed and evaluated Digifieds in an urban environment in the context of the UbiChallenge 2011 in Oulu, Finland over the course of 6 months. The deployment allowed the users' view to be studied with regard to the envisioned content, preferred interaction techniques, as well as privacy concerns, and to compare them against traditional PNAs.
FunSquare: first experiences with autopoiesic content BIBAFull-Text 175-184
  Nemanja Memarovic; Ivan Elhart; Marc Langheinrich
Public displays are becoming a ubiquitous resource in the urban environments due to significant price drops of large LCD panels. However, most public displays are still displaying simple advertisements in the form of slide shows or movie clips, instead of offering locally customized content that resonates with passers-by. So far, creating such customized content has been expensive. As a possible solution we present the concept and architecture for autopoiesic content, i.e., self-generative content that is automatically created by matching local context information with regular scheduled information into content that is highly localized. In this paper we report on the design, operation, and user experience of FunSquare -- an application that uses autopoiesic content to present localized "fun facts" in order to strengthen the feeling of community.
CLIO: blending the collective memory with the urban landscape BIBAFull-Text 185-194
  Dimitrios Ringas; Eleni Christopoulou; Michail Stefanidakis
This paper presents the methodology and outcomes of the Collective City Memory of Oulu study that we conducted in order to research whether it is feasible to embed community shared memories in the physical landscape of a city exploiting deployed public computing infrastructure. Personal memories that contribute to the collective memory in time are altered or lost with their carries and along with them a part of the culture of a city is lost; ubiquitous computing technologies today could allow us to capture and preserve collective memory, as well as to blend it into the urban landscape. CLIO is an urban computing system that allows people to form and interact with the collective memory; we deployed it at Oulu exploiting the city's infrastructure and we monitored how people interact with it and conducted a number of user trials. Findings support our statements that the collective memory of a city can be blended into the urban landscape and that people perceive it as a way of preserving aspects of the city culture.
RunWithUs: a social sports application in the ubiquitous Oulu environment BIBAFull-Text 195-204
  Felipe Gil-Castiñeira; Antía Fernández-López; Cristina López Bravo; Nerea Cid-Vieytes; David Conde-Lagoa; Enrique Costa-Montenegro; Francisco Javier González-Castaño
Authorities recommend the practice of moderate physical activity to improve health and quality of life, but sometimes it is difficult to find the willpower or the motivation to reserve a few minutes to exercise. In this paper we describe a new tool designed to help users to practice sport and record their achievements, which makes the activity more social (finding friends, sharing results, etc.). Furthermore, this tool has been integrated in the "Ubiquitous Oulu", an intelligent city that provides the building blocks to bring it closer to citizens. In this real-life environment we had the opportunity to assess the technical viability of RunWithUs and to identify the main interests of its potential users.
UBI challenge: research coopetition on real-world urban computing BIBAFull-Text 205-208
  Timo Ojala; Vassilis Kostakos
This paper introduces the UBI Challenge that challenged the global R&D community to design, implement, deploy and evaluate novel applications and services in real world setting atop an open urban computing testbed. The paper first provides a procedural description of the UBI Challenge and then discusses the outcome so far with a special focus on the various issues introduced by the real world setting.
Intermedia: system and application for video adaptation BIBAFull-Text 209-215
  Dong Zhang; Bin Li; Houqiang Li
Video adaptation has been considered as a promising technique to bridge the gap between network status, device capabilities and user preferences in pervasive media applications. However, conventional adaptation framework based on transcoding or multiple pre-transcoding is not competent for accommodating diversified usages and a large number of users. In this paper, the system design of a novel video adaptation system based on Intermediate video description called "Intermedia" is introduced. Intermedia is consist of multiple video signal components, such as texture, motion, structural characteristic, rate control information, ROI, as well as some semantic features. It is off-line generated and stored in the video server or media gateway. Our adaptation system is able to quickly and easily generate required bitstream from Intermedia with very low complexity to fulfill a specific adaptation requirement, e.g., bit-rate conversion, temporal/spatial resolution reduction, video summarization, region-of-interest browsing, and some multi-dimensional adaptation involving both signal level adaptation and semantic level adaptation. The satisfactory performance of our system demonstrates the effective and efficiency of our proposed video adaptation framework.
Muse: a multimedia streaming enabled remote interactivity system for mobile devices BIBAFull-Text 216-225
  Weiren Yu; Jianxin Li; Chunming Hu; Liang Zhong
Recent years we have witnessed the rapid advent of mobile cloud computing, in which remote software is delivered as a service and accessed by mobile device users over the Internet. However, most existing remote display technologies for high motion application (e.g, movie) have defects in latency and bandwidth. In this paper, we designed an adaptive multimedia streaming enabled remote interactivity system, Muse, to utilize remote resources with reduced display update traffic and response latency. A window-aware updating mechanism is designed as an adaptation scheme, which allows users to focus on the current application in use and also enable them to switch between applications on the fly. Besides, a windowed display encoder using H.264 video codec is integrated into the remote frame buffer protocol to achieve high performance in compression to address the high latency limitation of mobile Internet. Experimental results show that the windowed display Muse mechanism can successfully reduce network traffic, loading time and response latency of remote display and interaction. Our system can achieve in average 22fps of 1024*768 desktop multimedia playbacks with good video quality under 1 Mbit/s of bandwidth limitation.
D-cast: DSC based soft mobile video broadcast BIBAFull-Text 226-235
  Xiaopeng Fan; Feng Wu; Debin Zhao
Mobile video broadcasting is a popular application of wireless network. However, the traditional layer based approaches have limited supports to the accommodation of users with diverse channel conditions. The newly emerged Softcast approach provides smooth multicast performance but is not very efficient in inter frame compression. In this work, we propose a new video multicast approach: D-cast. Instead of using conventional close loop prediction (CLP), D-cast is based on distributed source coding (DSC) theory. This helps D-cast to avoid error propagation but still achieve high compression efficiency in inter frame coding. D-cast outperforms softcast 3-5dB in video PSNR while maintaining the similar graceful degradation feature as softcast. In addition, D-cast is efficient in not only narrow band channel but also wide band channel.