{"title":"A Cache Based Session Setup Mechanism for IMS","authors":"Yufei Cao, J. Liao, Q. Qi, Xiaomin Zhu","doi":"10.1109/ICCW.2008.55","DOIUrl":"https://doi.org/10.1109/ICCW.2008.55","url":null,"abstract":"This paper improves the IMS basic session setup mechanism, and proposes a novel session setup mechanism based on caching. An analytical model is established and the cost function and mean time delay function are presented based on the model. Moreover, the performance of this mechanism is evaluated over the basic session setup mechanism and the outcomes show that the novel mechanism gets the benefit in cost and time delay.","PeriodicalId":360127,"journal":{"name":"ICC Workshops - 2008 IEEE International Conference on Communications Workshops","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125586739","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}
{"title":"Exact Outage Probability of Cooperative Diversity with Opportunistic Spectrum Access","authors":"H. Suraweera, Peter J. Smith, N. A. Surobhi","doi":"10.1109/ICCW.2008.20","DOIUrl":"https://doi.org/10.1109/ICCW.2008.20","url":null,"abstract":"Opportunistic spectrum access, popularly known as cognitive radio technology is an innovative radio design philosophy which aims to increase spectrum utilization by exploiting unused spectrum in dynamic environments. In this paper, we present an exact outage performance analysis for the rates of a decode-and-forward cooperative network where a source communicates with its destination using the well- known repetition-based relaying scheme or using the single best relay, i.e, selection cooperation. Closed-form expressions are obtained for independent Rayleigh fading channels. Selection cooperation exhibits lower outage probabilities compared to the repetition-based scheme. However, the inability of relays to sense unoccupied spectrum can cause a larger drop in the outage performance of selection cooperation, especially in the high SNR regime. The analytical outage probability expressions have been validated through simulations.","PeriodicalId":360127,"journal":{"name":"ICC Workshops - 2008 IEEE International Conference on Communications Workshops","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121158363","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}
{"title":"Performance Improvement of the DSRC System Using a Novel S and PI-Decision Demapper","authors":"J. Mar, Chi-Cheng Kuo","doi":"10.4236/wsn.2009.14033","DOIUrl":"https://doi.org/10.4236/wsn.2009.14033","url":null,"abstract":"Based on the constellation diagram of the different modulations, a novel S and pi -decision rules are designed for the analog demapper of the OFDM systems. The DSRC system is chosen as an OFDM platform to compare the performance among the proposed S and pi -decision decoder, hard-decision and soft-decision decoders. Simulation results demonstrate that both the complexity and performance of S and pi -decision demapper used for M-ary QAM OFDM system can be greatly improved. The number of decisions between the received symbol and constellation points can be simplified to look up table log2 M times for M-ary QAM OFDM system.","PeriodicalId":360127,"journal":{"name":"ICC Workshops - 2008 IEEE International Conference on Communications Workshops","volume":"53 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117002315","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}
{"title":"OBS Simulation Tools: A Comparative Study","authors":"V. Soares, I. Veiga, J.J.P. Rodrigues","doi":"10.1109/ICCW.2008.54","DOIUrl":"https://doi.org/10.1109/ICCW.2008.54","url":null,"abstract":"Regarding network performance, simulators are the most frequently used instrument, in comparison with analytical tools and in situ measurements. Optical Burst Switching (OBS) is a new paradigm where the use of modeling and simulation tools is very important. This paper studies and compares the four most relevant simulators used in scientific and academic research to model OBS networks (Network Simulator 2 (ns-2), OBS-ns Simulator, NCTUns, and OBSsimulator). The study can be used either to assist choosing the most adequate simulator for a particular scenario or to help improving the existing ones (or even create a new simulator from scratch). It's important to identify the parameters and protocols not supported (or implemented) whose performance analysis on OBS networks is critical and needs to be studied. Available simulators have several limitations because either they are not appropriate because they are based on packet traffic instead of burst traffic, or make simplistic assumptions not taking into account all of the resource reservation protocols and parameters that can influence the overall OBS network performance. We conclude that, based on the objectives of a user, this paper furnish the guidelines helping to the best choice taking into account the available simulation tools for OBS networks.","PeriodicalId":360127,"journal":{"name":"ICC Workshops - 2008 IEEE International Conference on Communications Workshops","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117179175","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}
{"title":"User-Centric Utility-Based Data Replication in Heterogeneous Networks","authors":"Seung-Bum Lee, Gabriel-Miro Muntean, A. Smeaton","doi":"10.1109/ICCW.2008.61","DOIUrl":"https://doi.org/10.1109/ICCW.2008.61","url":null,"abstract":"Information overload and convergence of devices aggravate the difficulties of accessing data distributed among various user devices especially when this is performed by mobile users and over heterogeneous wireless networks. Existing data replication systems help increase the performance of the distributed data system, but they do not consider users' different levels of interest in various pieces of data and neither heterogeneous wireless connectivity issues. This paper presents the Smart Personal Information Network (Smart PIN), a performance and cost-aware personal information network which uses a novel user- centric utility-based data replication scheme to exchange content automatically, based on both network performance and user interests. The proposed user-centric data replication scheme's evaluation, through simulation, shows improved results in comparison with existing solutions.","PeriodicalId":360127,"journal":{"name":"ICC Workshops - 2008 IEEE International Conference on Communications Workshops","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128046551","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}
{"title":"V2V Wireless Communication Protocol for Rear-End Collision Avoidance on Highways","authors":"Fei Ye, Matthew Adams, Sumit Roy","doi":"10.1109/ICCW.2008.77","DOIUrl":"https://doi.org/10.1109/ICCW.2008.77","url":null,"abstract":"More than 23% of annual vehicle accidents are rear-end collisions, which provides an important test-case for enhanced collision avoidance approaches based on v2v wireless communications. In this work, we propose and study the impact of a 802.11 based multi-hop MAC protocol that propagates an emergency warning message (EWM) down a platoon of cars on a highway. The design objective is to ensure reception of this message with stringent (low) delay constraints so as to provide drivers with requisite available maneuver time (AMT) to avoid rear-end collision. We provide realistic simulation studies of protocol performance within ns-2 environment for various topology (1 lane and 3 lanes) and background traffic scenarios, as well as different protocol parameter settings, to highlight the potential of this approach for effective collision avoidance or mitigation.","PeriodicalId":360127,"journal":{"name":"ICC Workshops - 2008 IEEE International Conference on Communications Workshops","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128299323","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}
{"title":"Performance Analysis of IEEE 802.11-Based Ad Hoc Networks Using Game Theory","authors":"Chunfeng Liu, Y. Shu, Wucheng Yang, O. Yang","doi":"10.1109/ICCW.2008.52","DOIUrl":"https://doi.org/10.1109/ICCW.2008.52","url":null,"abstract":"This paper describes a type of selfish node behavior in the MAC layer and studies its effects on the performance of ad hoc networks. We use a game-theoretic approach to investigate the selfish behavior problem by focusing on the strategy that a node can adopt during wireless channel access. Based on this investigation, we obtained the guidelines to design a mechanism that can force the selfish node to obey the IEEE 802.11 protocol, and therefore improve the performance of wireless ad hoc networks. The algorithm consists of two parts. The first part detects selfish behavior based on the throughput, and the second part prevents the selfish behavior. The algorithm has been validated by extensive simulation. Simulation results show that our algorithm are effective in detecting the selfish nodes and eliminate their selfish behavior. As a result, every node can obtain a relatively fair throughput when following the guideline of our algorithm.","PeriodicalId":360127,"journal":{"name":"ICC Workshops - 2008 IEEE International Conference on Communications Workshops","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124403635","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}
{"title":"On Per-Flow Fairness and Scheduling in Wireless Multihop Networks","authors":"Aggeliki Sgora, D. J. Vergados, D. Vergados","doi":"10.1109/ICCW.2008.46","DOIUrl":"https://doi.org/10.1109/ICCW.2008.46","url":null,"abstract":"In wireless multihop networks communication between two-end nodes is carried out by hopping over multiple short wireless links. Traditional CSMA/CA based media access control does not work well in a multihop scenario, since transmitters are often out of reach of other users' sensing range. Therefore TDMA seems to be a more promising solution. Several algorithms may be found in the literature for scheduling TDMA transmissions for these networks. These algorithms try to determine the optimal scheduling, in order to increase the capacity and reduce the delay for a given network topology. In our previous work, a TDMA scheduling algorithm has been proposed that schedules the transmissions in a fair manner and takes into account the communication requirements of the active flows of the network. In this research effort, we compare the performance of the proposed algorithm with several TDMA scheduling algorithms, in terms of frame length, throughput and fairness. Simulation results showed that the proposed algorithm exhibits improved performance compared to the other solutions, not only in terms of fairness, but also in terms of throughput.","PeriodicalId":360127,"journal":{"name":"ICC Workshops - 2008 IEEE International Conference on Communications Workshops","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114367256","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}
{"title":"On Scheduling of Data Dissemination in Vehicular Networks with Mesh Backhaul","authors":"Liu Zhong-Yi, Liu Bin, Zhao Tong, Yan Wei","doi":"10.1109/ICCW.2008.79","DOIUrl":"https://doi.org/10.1109/ICCW.2008.79","url":null,"abstract":"Vehicular networks have become increasingly popular in the research community. Messages in vehicular networks are usually subject to both time and space constraints, and therefore should be disseminated during a specified duration and within a specific coverage. Since vehicles are constantly moving in and out of a region, dissemination of a message should be repeated to achieve reliability. However, the reliable dissemination for some messages might be at the cost of unreliable or even no chance of dissemination for other messages, which raises tradeoffs between reliability and fairness. In this paper, we study the scheduling of data dissemination in vehicular networks with mesh infrastructure. Performance metrics for reliability and fairness are proposed first. Our metric for reliability covers factors in both time and space dimensions and the metric for fairness incorporates fairness in both the network-wise sense and the mesh roadside unit-wise (MRU-wise) sense. Several scheduling algorithms are developed: one reliability-oriented algorithm, one fairness- oriented algorithm and three hybrid schemes. Extensive evaluation work is performed to quantitively analyze different scheduling algorithms. Our evaluation results show that (1) hybrid schemes outperform reliability-oriented and fairness-oriented algorithms in the sense of overall efficiency and (2) different algorithms have quite different characteristics on reliability and fairness.","PeriodicalId":360127,"journal":{"name":"ICC Workshops - 2008 IEEE International Conference on Communications Workshops","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114780778","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}
{"title":"Performance Analysis of Discrete-Time Autoregressive Queueing Systems","authors":"D. Fiems, D. Claeys, H. Bruneel","doi":"10.1109/ICCW.2008.49","DOIUrl":"https://doi.org/10.1109/ICCW.2008.49","url":null,"abstract":"We consider a discrete-time single server queueing system with an autoregressive arrival process. Arrivals stem from two discrete autoregressive arrival processes of order 1. This aggregated arrival process combines analytical tractability with the ability to capture both short- and long-term correlation. Closed-form expressions for the mean and variance of the queue content and packet delay are obtained. We illustrate our approach by means of some numerical examples.","PeriodicalId":360127,"journal":{"name":"ICC Workshops - 2008 IEEE International Conference on Communications Workshops","volume":"s3-32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130135910","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}