Jeonghwa Lee, Gilsang Yoon, Insik Cho, Changhyeon Chae, Daewon Choi, T. Jung, Cheolsung Kim, I. Hwang, C. You, Daeki Hong
In this paper, we propose and analyze an adaptive modulation system with optimal turbo coded V-BLAST (vertical-bell-lab layered space-time) technique that adopts the extrinsic information from MAP (maximum a posteriori) decoder with iterative decoding as a priori probability in two decoding procedures of V-BLAST scheme; the ordering and the slicing. The result indicates that the proposed systems achieve a better throughput performance than the conventional systems in the whole SNR range. In addition, the simulation result shows that the maximum throughput improvement in each MIMO scheme is respectively about 421 kbps, 545 kbps, and 880 kbps. It is suggested that the effect of the proposed decoding algorithm accordingly gets higher as the number of system antenna increases.
{"title":"Improvement of Iterative Decoding Algorithm in the Adaptive Modulation and Coding System","authors":"Jeonghwa Lee, Gilsang Yoon, Insik Cho, Changhyeon Chae, Daewon Choi, T. Jung, Cheolsung Kim, I. Hwang, C. You, Daeki Hong","doi":"10.1109/CCNC08.2007.156","DOIUrl":"https://doi.org/10.1109/CCNC08.2007.156","url":null,"abstract":"In this paper, we propose and analyze an adaptive modulation system with optimal turbo coded V-BLAST (vertical-bell-lab layered space-time) technique that adopts the extrinsic information from MAP (maximum a posteriori) decoder with iterative decoding as a priori probability in two decoding procedures of V-BLAST scheme; the ordering and the slicing. The result indicates that the proposed systems achieve a better throughput performance than the conventional systems in the whole SNR range. In addition, the simulation result shows that the maximum throughput improvement in each MIMO scheme is respectively about 421 kbps, 545 kbps, and 880 kbps. It is suggested that the effect of the proposed decoding algorithm accordingly gets higher as the number of system antenna increases.","PeriodicalId":183858,"journal":{"name":"2008 5th IEEE Consumer Communications and Networking Conference","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114067583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bomjun Kwon, Tai-Ho Choi, Heejin Chung, Geonho Kim
This paper describes design and implementation of a parallel algorithm that detects scale-invariant keypoints from digital images. Keypoint detection is one of the most important operations in image processing since efficient image matching is possible with it. Image matching is used in many intelligent image processing service, including object/scene recognition, stereo correspondence, motion tracking, and panorama imaging. In this paper, we design a new parallel algorithm of keypoint detection that is suitable for Cell Broadband Engine architecture by converting each subprocess of keypoint detection algorithm into parallel version. The experimental results show that performance of our algorithm increases in proportion to the number of processors utilized, that is, it achieves linear scalability.
{"title":"Parallelization of the Scale-Invariant Keypoint Detection Algorithm for Cell Broadband Engine Architecture","authors":"Bomjun Kwon, Tai-Ho Choi, Heejin Chung, Geonho Kim","doi":"10.1109/CCNC08.2007.235","DOIUrl":"https://doi.org/10.1109/CCNC08.2007.235","url":null,"abstract":"This paper describes design and implementation of a parallel algorithm that detects scale-invariant keypoints from digital images. Keypoint detection is one of the most important operations in image processing since efficient image matching is possible with it. Image matching is used in many intelligent image processing service, including object/scene recognition, stereo correspondence, motion tracking, and panorama imaging. In this paper, we design a new parallel algorithm of keypoint detection that is suitable for Cell Broadband Engine architecture by converting each subprocess of keypoint detection algorithm into parallel version. The experimental results show that performance of our algorithm increases in proportion to the number of processors utilized, that is, it achieves linear scalability.","PeriodicalId":183858,"journal":{"name":"2008 5th IEEE Consumer Communications and Networking Conference","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116469770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BitTorrent is one of the most efficient peer-to-peer content sharing protocols. The authors took part in implementing SymTorrent: a full featured BitTorrent client application for high-end mobile phones based on Symbian OS. Recently, they have also brought the BitTorrent technology to low-end mobile by creating a prototype application, called MobTorrent. Currently MobTorrent supports only content downloading (implementation of upload functionality is ongoing). The target platform of MobTorrent is the S40 platform, which is based on the Java Micro Edition technology. This paper contains a brief overview of the BitTorrent protocol, introduces the applications and outlines the demonstration.
{"title":"BitTorrent at Mobile Phones","authors":"P. Ekler, I. Kelényi, H. Charaf","doi":"10.1109/CCNC08.2007.273","DOIUrl":"https://doi.org/10.1109/CCNC08.2007.273","url":null,"abstract":"BitTorrent is one of the most efficient peer-to-peer content sharing protocols. The authors took part in implementing SymTorrent: a full featured BitTorrent client application for high-end mobile phones based on Symbian OS. Recently, they have also brought the BitTorrent technology to low-end mobile by creating a prototype application, called MobTorrent. Currently MobTorrent supports only content downloading (implementation of upload functionality is ongoing). The target platform of MobTorrent is the S40 platform, which is based on the Java Micro Edition technology. This paper contains a brief overview of the BitTorrent protocol, introduces the applications and outlines the demonstration.","PeriodicalId":183858,"journal":{"name":"2008 5th IEEE Consumer Communications and Networking Conference","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126271255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many traffic engineering and network design tasks require a network-wide description as an input for their performance evaluation. Therefore, a traffic matrix represents the demands for these tasks and is applicable to them. Traffic matrix can be measured directly or estimated from an indirect data. Generating synthetic traffic matrix method, is a better way to achieve traffic matrix indirectly. We have previously proposed the conqueror traffic based synthetic traffic matrix and we have indicated that our conqueror traffic based matrix performed better in all cases where conqueror traffic existed. In this paper by measuring the maximum link-utilization, we consider how well the conqueror traffic based synthetic matrix optimizes the specific traffic engineering task; that is optimizing network routing to minimize congestion. First, we optimize the routing with the conqueror traffic based synthetic matrix to minimize congestion. Then, we test the performance of the resulting routing on the real traffic matrix. Simulation results indicate that OSPF optimization which we use in this paper to optimize the weights based on the conqueror traffic based synthetic matrix, optimize the routing better and result in a better performance on real traffic matrix.
{"title":"Optimizing Network Routing to Minimize Congestion, Using the Conqueror Traffic Based Synthetically Generated Traffic Matrices","authors":"S. Zargar, M. Moghaddam","doi":"10.1109/CCNC08.2007.133","DOIUrl":"https://doi.org/10.1109/CCNC08.2007.133","url":null,"abstract":"Many traffic engineering and network design tasks require a network-wide description as an input for their performance evaluation. Therefore, a traffic matrix represents the demands for these tasks and is applicable to them. Traffic matrix can be measured directly or estimated from an indirect data. Generating synthetic traffic matrix method, is a better way to achieve traffic matrix indirectly. We have previously proposed the conqueror traffic based synthetic traffic matrix and we have indicated that our conqueror traffic based matrix performed better in all cases where conqueror traffic existed. In this paper by measuring the maximum link-utilization, we consider how well the conqueror traffic based synthetic matrix optimizes the specific traffic engineering task; that is optimizing network routing to minimize congestion. First, we optimize the routing with the conqueror traffic based synthetic matrix to minimize congestion. Then, we test the performance of the resulting routing on the real traffic matrix. Simulation results indicate that OSPF optimization which we use in this paper to optimize the weights based on the conqueror traffic based synthetic matrix, optimize the routing better and result in a better performance on real traffic matrix.","PeriodicalId":183858,"journal":{"name":"2008 5th IEEE Consumer Communications and Networking Conference","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134605092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We study in this paper the scheduling problem in P2P file distribution. Our aim is to reduce the average distribution time. We present two distribution mechanisms: distributing the rarest pieces first and distributing to the least demanding nodes first. The new algorithm, rarest-piece-first and most-demanding-node-last-piece-oriented, is developed and we demonstrate by simulation its effectiveness over some related algorithms.
{"title":"Scheduling in P2P File Distribution - On Reducing the Average Distribution Time","authors":"Lingjun Ma, K. Lui","doi":"10.1109/CCNC08.2007.121","DOIUrl":"https://doi.org/10.1109/CCNC08.2007.121","url":null,"abstract":"We study in this paper the scheduling problem in P2P file distribution. Our aim is to reduce the average distribution time. We present two distribution mechanisms: distributing the rarest pieces first and distributing to the least demanding nodes first. The new algorithm, rarest-piece-first and most-demanding-node-last-piece-oriented, is developed and we demonstrate by simulation its effectiveness over some related algorithms.","PeriodicalId":183858,"journal":{"name":"2008 5th IEEE Consumer Communications and Networking Conference","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131797924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper proposes an Identity Federation-based Mobile Messaging Framework. It leverages the existing Identity Federation concepts, with enhancements for adapting them to a Mobile Messaging scenario. We further present how the framework, can enable User Control and Privacy, with regards to their Mobile Messaging-based service invocations. Application providers can be issued dynamic transaction-based transient authorizations, which can be delegated to further Application providers for service composition-based use-cases. At the same time, the Mobile Service Provider, by virtue of having an authentication and billing-based relationship with the User, is guaranteed a place in the MM-based services value chain. We also present a set of exemplary, yet novel use-cases, enabled by the framework.
{"title":"Identity Federation-Based Mobile Messaging","authors":"S. Saklikar, Subir Saha","doi":"10.1109/CCNC08.2007.34","DOIUrl":"https://doi.org/10.1109/CCNC08.2007.34","url":null,"abstract":"This paper proposes an Identity Federation-based Mobile Messaging Framework. It leverages the existing Identity Federation concepts, with enhancements for adapting them to a Mobile Messaging scenario. We further present how the framework, can enable User Control and Privacy, with regards to their Mobile Messaging-based service invocations. Application providers can be issued dynamic transaction-based transient authorizations, which can be delegated to further Application providers for service composition-based use-cases. At the same time, the Mobile Service Provider, by virtue of having an authentication and billing-based relationship with the User, is guaranteed a place in the MM-based services value chain. We also present a set of exemplary, yet novel use-cases, enabled by the framework.","PeriodicalId":183858,"journal":{"name":"2008 5th IEEE Consumer Communications and Networking Conference","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126592825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
IP multicast technology enables simultaneous delivery of multimedia content to numerous users. However, the quality of experience (QoE) is subject to degradation due to packet loss because quality of service (QoS) is not guaranteed in best-effort IP networks. To maintain good QoE, streaming applications typically use an application-layer FEC (forward error correction) technique. Conventional FEC techniques always transfer redundant packets, but these redundant packets are only used when packet loss has occurred. This causes inefficiency in networks where packets are not often lost. To avoid filling network paths with unnecessary redundant packets, we developed a new application-layer packet loss recovery mechanism based on layered multicast using FEC and ARQ. This mechanism divides redundant packets into fundamental and supplementary redundant packet groups and sends them in separate multicast sessions. The supplementary redundant packets are received only by receivers participating in the multicast session of them or requesting retransmission. This mechanism realizes efficient reliable multicast for HDTV IP broadcasting by reducing unnecessary redundant packets and preventing an explosion of requests. We tested the effectiveness of our mechanism in streaming HDTV experiments over a commercial best-effort IP network. The results of experiment show that the proposed mechanism avoids transferring wasteful, redundant packets and efficiently maintains reliability with preventing an explosion of requests.
{"title":"Efficient Reliable Multicast Using FEC and Limited Retransmission for HDTV IP Broadcasting","authors":"S. Aoki, Takeharu Shimizu, S. Nishimura, K. Aoki","doi":"10.1109/CCNC08.2007.190","DOIUrl":"https://doi.org/10.1109/CCNC08.2007.190","url":null,"abstract":"IP multicast technology enables simultaneous delivery of multimedia content to numerous users. However, the quality of experience (QoE) is subject to degradation due to packet loss because quality of service (QoS) is not guaranteed in best-effort IP networks. To maintain good QoE, streaming applications typically use an application-layer FEC (forward error correction) technique. Conventional FEC techniques always transfer redundant packets, but these redundant packets are only used when packet loss has occurred. This causes inefficiency in networks where packets are not often lost. To avoid filling network paths with unnecessary redundant packets, we developed a new application-layer packet loss recovery mechanism based on layered multicast using FEC and ARQ. This mechanism divides redundant packets into fundamental and supplementary redundant packet groups and sends them in separate multicast sessions. The supplementary redundant packets are received only by receivers participating in the multicast session of them or requesting retransmission. This mechanism realizes efficient reliable multicast for HDTV IP broadcasting by reducing unnecessary redundant packets and preventing an explosion of requests. We tested the effectiveness of our mechanism in streaming HDTV experiments over a commercial best-effort IP network. The results of experiment show that the proposed mechanism avoids transferring wasteful, redundant packets and efficiently maintains reliability with preventing an explosion of requests.","PeriodicalId":183858,"journal":{"name":"2008 5th IEEE Consumer Communications and Networking Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131172774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In peer-to-peer streaming systems, a lower join latency is desirable. We propose a method to reduce the initial join latency by providing a list of preferred peers that have a high probability of being available to other peers. By collecting partial knowledge about the peer-to-peer overlay, the source peer maintains information about preferred peers. This information is supplied to new peers entering the streaming system. We develop lightweight cache algorithms and a P2P protocol. Analytical models are presented for the cache design and the probability distribution of join latency. The models and simulation results show that the PPL method can significantly reduce the initial join time compared to a prior art probe-based join scheme.
{"title":"A Method for P2P Streaming System Join Latency Reduction Using Preferred Peer List","authors":"Jeonghun Noh, S. Deshpande","doi":"10.1109/CCNC08.2007.73","DOIUrl":"https://doi.org/10.1109/CCNC08.2007.73","url":null,"abstract":"In peer-to-peer streaming systems, a lower join latency is desirable. We propose a method to reduce the initial join latency by providing a list of preferred peers that have a high probability of being available to other peers. By collecting partial knowledge about the peer-to-peer overlay, the source peer maintains information about preferred peers. This information is supplied to new peers entering the streaming system. We develop lightweight cache algorithms and a P2P protocol. Analytical models are presented for the cache design and the probability distribution of join latency. The models and simulation results show that the PPL method can significantly reduce the initial join time compared to a prior art probe-based join scheme.","PeriodicalId":183858,"journal":{"name":"2008 5th IEEE Consumer Communications and Networking Conference","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131212170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. W. Tantra, Mai Ngoc Son, Dang Duc Nguyen, T. Lim, C. Yeo, Bu-Sung Lee
In recent years, wireless communication technologies have been pervasive. We have many wireless options to connect to the Internet: IEEE 802.11 WLANs, GPRS, UMTS and many other competing technologies. These wireless standards were designed independently of each other. Hence, these standards do not specify a common solution to perform connection handover between two different standards. Given that each of these standards has its own advantages and disadvantages, users may want to use the best available connection for their needs. In this paper, we propose a scheme that enables seamless transitions between different wireless standards through SIP protocol. With our scheme, IP mobility across both vertical and horizontal handovers is possible without any modification to the existing applications. We define a guideline for handovers between networks, and then perform experiments with our scheme implementation to confirm the feasibility of our proposed scheme. Our results show that with our scheme, connection disruption is minimized.
{"title":"Seamless Mobility Across Heterogeneous Wireless Domains","authors":"J. W. Tantra, Mai Ngoc Son, Dang Duc Nguyen, T. Lim, C. Yeo, Bu-Sung Lee","doi":"10.1109/CCNC08.2007.25","DOIUrl":"https://doi.org/10.1109/CCNC08.2007.25","url":null,"abstract":"In recent years, wireless communication technologies have been pervasive. We have many wireless options to connect to the Internet: IEEE 802.11 WLANs, GPRS, UMTS and many other competing technologies. These wireless standards were designed independently of each other. Hence, these standards do not specify a common solution to perform connection handover between two different standards. Given that each of these standards has its own advantages and disadvantages, users may want to use the best available connection for their needs. In this paper, we propose a scheme that enables seamless transitions between different wireless standards through SIP protocol. With our scheme, IP mobility across both vertical and horizontal handovers is possible without any modification to the existing applications. We define a guideline for handovers between networks, and then perform experiments with our scheme implementation to confirm the feasibility of our proposed scheme. Our results show that with our scheme, connection disruption is minimized.","PeriodicalId":183858,"journal":{"name":"2008 5th IEEE Consumer Communications and Networking Conference","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133388564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
State management is a basic requirement for multiuser virtual environments (VEs) such as massively multiplayer online games (MMOGs). Current MMOGs rely on centralized server-clusters that possess inherent scalability bottlenecks and are expensive to adopt and deploy. In this paper, we propose Voronoi state management (VSM) to maintain object states for peer-to-peer-based virtual worlds. By dynamically partitioning the VE with Voronoi diagrams and aggregating game states of overloaded nodes onto superpeers, VSM supports existing consistency control to enable scalable, load balanced, and fault tolerant VE state management. As both client and server-side resources are utilized collaboratively, VSM also integrates both client-server and peer-to-peer VE designs in a unified approach.
{"title":"Voronoi State Management for Peer-to-Peer Massively Multiplayer Online Games","authors":"Shun-Yun Hu, Shao-Chen Chang, Jehn-Ruey Jiang","doi":"10.1109/CCNC08.2007.255","DOIUrl":"https://doi.org/10.1109/CCNC08.2007.255","url":null,"abstract":"State management is a basic requirement for multiuser virtual environments (VEs) such as massively multiplayer online games (MMOGs). Current MMOGs rely on centralized server-clusters that possess inherent scalability bottlenecks and are expensive to adopt and deploy. In this paper, we propose Voronoi state management (VSM) to maintain object states for peer-to-peer-based virtual worlds. By dynamically partitioning the VE with Voronoi diagrams and aggregating game states of overloaded nodes onto superpeers, VSM supports existing consistency control to enable scalable, load balanced, and fault tolerant VE state management. As both client and server-side resources are utilized collaboratively, VSM also integrates both client-server and peer-to-peer VE designs in a unified approach.","PeriodicalId":183858,"journal":{"name":"2008 5th IEEE Consumer Communications and Networking Conference","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132162809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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