{"title":"Maximum Likelihood trajectory estimation of a mobile node from RSS measurements","authors":"A. Coluccia, F. Ricciato","doi":"10.1109/WONS.2012.6152222","DOIUrl":"https://doi.org/10.1109/WONS.2012.6152222","url":null,"abstract":"In this paper we present a Maximum Likelihood (ML) trajectory estimation of a mobile node from Received Signal Strength (RSS) measurements. The reference scenario includes a number of nodes in fixed and known positions (anchors) and a target node (blind) in motion whose instantaneous position is unknown. We first consider the dynamic estimation of the channel parameters from anchor-to-anchor measurements, statistically modeled according to the well-known Path-Loss propagation model. Then, we address the ML estimation problem for the position and velocity of the blind node based on a set of blind-to-anchor RSS measurements. We compare also the algorithm with a ML-based single-point localization algorithm, and discuss the applicability of both methods for slowly moving nodes. We present simulation results to assess the accuracy of the proposed solution in terms of localization error and velocity estimation (modulus and angle). The distribution of the localization error on the initial and final point is analyzed and closed-form expressions are derived.","PeriodicalId":309036,"journal":{"name":"2012 9th Annual Conference on Wireless On-Demand Network Systems and Services (WONS)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131486003","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}
Sanpetch Chupisanyarote, S. T. Kouyoumdjieva, Ó. Helgason, G. Karlsson
{"title":"Caching in opportunistic networks with churn","authors":"Sanpetch Chupisanyarote, S. T. Kouyoumdjieva, Ó. Helgason, G. Karlsson","doi":"10.1109/WONS.2012.6152233","DOIUrl":"https://doi.org/10.1109/WONS.2012.6152233","url":null,"abstract":"In this paper we examine opportunistic content distribution. We design and evaluate a caching strategy where a node will fetch and share contents on behalf of other nodes, although the contents are not of its own interest. We propose three caching options for improving the use of network resources: relay request on demand, hop-limit, and greedy relay request. The proposed strategies are implemented in the OMNeT++ simulator and evaluated on mobility traces from Legion Studio that have churn. We also compare our strategies with a strategy from the literature. The results are analyzed and they show that the use of opportunistic caching for a community of nodes may enhance the performance marginally while overhead increases significantly.","PeriodicalId":309036,"journal":{"name":"2012 9th Annual Conference on Wireless On-Demand Network Systems and Services (WONS)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124635938","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":"Simulation of 802.11 PHY/MAC: The quest for accuracy and efficiency","authors":"Michele Segata, R. Cigno","doi":"10.1109/WONS.2012.6152246","DOIUrl":"https://doi.org/10.1109/WONS.2012.6152246","url":null,"abstract":"The goal of this work is to highlight and explain the limitations of traditional physical channel models used in network simulators for wireless LANs, with particular reference to VANETs, where these limitations may jeopardize the validity of results, specially for safety applications. The fundamental tradeoff is between simulation time and realism. Indeed, a simulator should provide realistic results as fast as possible, even if several nodes (i.e., hundreds) are considered. Our final goal, beyond this initial contribution, is the development of a stochastic channel model which improves reliability of simulations while increasing computational complexity only marginally. The design of our model is based on the representation of the packet decoding procedure as a Markov Decision (Stochastic) Process (MDP), thus avoiding the computational complexity of the simulation of the entire transmission - propagation - decoding chain bit-by-bit, which can surely provide enough accuracy, but at the price of unacceptable computational (and model) complexity. The paper identifies the key phenomena such as preamble detection, central-frequency misalignment, channel captures, vehicles relative speed, that represent the `state' of the MDP modeling the transmission chain, and propose an MDP structure to exploit it. The focus is on 802.11p and OFDM-based PHY layers, but the model is extensible to other transmission techniques easily. The design is tailored for implementation in ns-3, albeit the modeling principle is general and suitable for every event-driven simulator.","PeriodicalId":309036,"journal":{"name":"2012 9th Annual Conference on Wireless On-Demand Network Systems and Services (WONS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122877186","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":"A Risk-Aware Workload scheduler to support secure and efficient collaborative data transfer in mobile communities","authors":"S. Saleem, Ning Zhang","doi":"10.1109/WONS.2012.6152231","DOIUrl":"https://doi.org/10.1109/WONS.2012.6152231","url":null,"abstract":"Limited availability of computing devices and broadband access are among the biggest hurdles in bringing many data rich applications, to the masses in developing countries. Ad-hoc Mobile Collaborative Community (MCC) has been proposed as a solution to address these hurdles. MCC enables two or more persons to aggregate their mobile phone/PDA network channels for collaborative data transfer across the Internet. These channels may be heterogeneous and are characterized with frequent Quality of Service (QoS) fluctuations. Further, data to be transferred may contain multiple streams each having distinct, possibly conflicting security and QoS requirements. These factors make scheduling of data over multiple channels, a challenging task. In addition, battery and processing power limitations of mobile nodes imply that scheduler should be energy and processing cost efficient. This paper proposes a novel lightweight scheduler, a Risk-Aware Workload (RAW) scheduler, to support secure and efficient collaborative data transfer in MCC.","PeriodicalId":309036,"journal":{"name":"2012 9th Annual Conference on Wireless On-Demand Network Systems and Services (WONS)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130536593","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}