Pub Date : 2014-12-01DOI: 10.1109/GLOCOMW.2014.7063413
Xiao Zhang, Wan Guo, Zhanhuai Li, Xiaonan Zhao, X. Qin
Cloud computing systems offer computing and storage resources at a low price. The users only pay for it when the VM(short for Virtual Machine) is running. While after VMs shut down, the vendors also need disk space to store multi-gigabyte VM images. Past studies use deduplication to reduce the space requirements, but it needs to calculate hash values of each block and store them. It also causes performance overhead costs to find identical content. In this paper, We propose a multiple layers file sharing system(MLFS) designed for cloud computing. It stores OS data, Application data, and user data in different layers. Multiple users share OS data layers. Application data are constructed according to users' selection, and they are deleted after VM shut down. We compare our solution with ordinary storage systems, storage systems with deduplication, the results show that MLFS can save more space than others, while achieving reasonable performance in file system I/O operating.
{"title":"MLFS: A multiple layers share file system for cloud computing","authors":"Xiao Zhang, Wan Guo, Zhanhuai Li, Xiaonan Zhao, X. Qin","doi":"10.1109/GLOCOMW.2014.7063413","DOIUrl":"https://doi.org/10.1109/GLOCOMW.2014.7063413","url":null,"abstract":"Cloud computing systems offer computing and storage resources at a low price. The users only pay for it when the VM(short for Virtual Machine) is running. While after VMs shut down, the vendors also need disk space to store multi-gigabyte VM images. Past studies use deduplication to reduce the space requirements, but it needs to calculate hash values of each block and store them. It also causes performance overhead costs to find identical content. In this paper, We propose a multiple layers file sharing system(MLFS) designed for cloud computing. It stores OS data, Application data, and user data in different layers. Multiple users share OS data layers. Application data are constructed according to users' selection, and they are deleted after VM shut down. We compare our solution with ordinary storage systems, storage systems with deduplication, the results show that MLFS can save more space than others, while achieving reasonable performance in file system I/O operating.","PeriodicalId":354340,"journal":{"name":"2014 IEEE Globecom Workshops (GC Wkshps)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122480598","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}
Pub Date : 2014-12-01DOI: 10.1109/GLOCOMW.2014.7063565
Omar Alhussein, S. Muhaidat, Jie Liang, Paul Yoo
We present a unified framework to evaluate the error rate performance of wireless networks over generalized fading channels. In particular, we propose a new approach to represent different fading distributions by mixture of Gamma distributions. The new approach relies on the expectation-maximization (EM) algorithm in conjunction with the so-called Newton-Raphson maximization algorithm. We show that our model provides similar performance to other existing state-of-art models in both accuracy and simplicity, where accuracy is analyzed by means of mean square error (MSE). In addition, we demonstrate that this algorithm may potentially approximate any fading channel, and thus we utilize it to model both composite and non-composite fading models. We derive novel closed form expression of the raw moments of a dual-hop fixed-gain cooperative network. We also study the effective capacity of the end-to-end SNR in such networks. Numerical simulation results are provided to corroborate the analytical findings.
{"title":"A unified approach for representing wireless channels using EM-based finite mixture of gamma distributions","authors":"Omar Alhussein, S. Muhaidat, Jie Liang, Paul Yoo","doi":"10.1109/GLOCOMW.2014.7063565","DOIUrl":"https://doi.org/10.1109/GLOCOMW.2014.7063565","url":null,"abstract":"We present a unified framework to evaluate the error rate performance of wireless networks over generalized fading channels. In particular, we propose a new approach to represent different fading distributions by mixture of Gamma distributions. The new approach relies on the expectation-maximization (EM) algorithm in conjunction with the so-called Newton-Raphson maximization algorithm. We show that our model provides similar performance to other existing state-of-art models in both accuracy and simplicity, where accuracy is analyzed by means of mean square error (MSE). In addition, we demonstrate that this algorithm may potentially approximate any fading channel, and thus we utilize it to model both composite and non-composite fading models. We derive novel closed form expression of the raw moments of a dual-hop fixed-gain cooperative network. We also study the effective capacity of the end-to-end SNR in such networks. Numerical simulation results are provided to corroborate the analytical findings.","PeriodicalId":354340,"journal":{"name":"2014 IEEE Globecom Workshops (GC Wkshps)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122735542","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}
Pub Date : 2014-12-01DOI: 10.1109/GLOCOMW.2014.7063421
Yongyi Ran, Youkang Shi, E. Yang, Shuangwu Chen, Jian Yang
Due to diverse network conditions and heterogeneous devices, there may be various video demands with different video qualities and formats from the client side. Compared to keeping all necessary copies for the same video, video transcoding in real-time should be an essential solution. The complex nature of video transcoding enables cloud computing to be uniquely suitable for dynamically providing transcoding resource. However, due to the fluctuation and uncertainty of the future transcoding demand, it is still a challenge to dynamically determine the optimal resource allocation to save cost while guaranteeing the Quality of Service (QoS). Overload may result in the transcoding jitter and increase the lateness which directly affects video freezes while over-provisioning naturally increases the cost. To address this problem, in this paper, by defining the transcoding jitter probability as a metric of QoS, we proposed a dynamic resource allocation algorithm based on the large deviation principle, which is capable of proactive calculating the optimal number of transcoding nodes for the upcoming transcoding demand subject to the transcoding jitter probability below a desired threshold. Finally, the experiments are performed on a cloud-based prototype system to show the attainable performance of the proposed resource allocation algorithm and verify that the proposed algorithm can make a good tradeoff between cost saving and QoS guaranteeing.
{"title":"Dynamic resource allocation for video transcoding with QoS guaranteeing in cloud-based DASH system","authors":"Yongyi Ran, Youkang Shi, E. Yang, Shuangwu Chen, Jian Yang","doi":"10.1109/GLOCOMW.2014.7063421","DOIUrl":"https://doi.org/10.1109/GLOCOMW.2014.7063421","url":null,"abstract":"Due to diverse network conditions and heterogeneous devices, there may be various video demands with different video qualities and formats from the client side. Compared to keeping all necessary copies for the same video, video transcoding in real-time should be an essential solution. The complex nature of video transcoding enables cloud computing to be uniquely suitable for dynamically providing transcoding resource. However, due to the fluctuation and uncertainty of the future transcoding demand, it is still a challenge to dynamically determine the optimal resource allocation to save cost while guaranteeing the Quality of Service (QoS). Overload may result in the transcoding jitter and increase the lateness which directly affects video freezes while over-provisioning naturally increases the cost. To address this problem, in this paper, by defining the transcoding jitter probability as a metric of QoS, we proposed a dynamic resource allocation algorithm based on the large deviation principle, which is capable of proactive calculating the optimal number of transcoding nodes for the upcoming transcoding demand subject to the transcoding jitter probability below a desired threshold. Finally, the experiments are performed on a cloud-based prototype system to show the attainable performance of the proposed resource allocation algorithm and verify that the proposed algorithm can make a good tradeoff between cost saving and QoS guaranteeing.","PeriodicalId":354340,"journal":{"name":"2014 IEEE Globecom Workshops (GC Wkshps)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127798437","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}
Pub Date : 2014-12-01DOI: 10.1109/GLOCOMW.2014.7063627
C. Thai, Jemin Lee, Chi Cheng, Tony Q. S. Quek
In this paper, we propose a physical-layer secret key generation scheme for multi-antenna legitimate nodes with the help from multiple untrusted relays with single antenna. The relays' actions conform to the rules but they passively eavesdrop the information. Different from most previous key generation schemes, where a key is generated based on a channel coefficient, in the proposed scheme, we use the linear combination of channel coefficients to generate a key. Simulation results show that the rate leaked to the untrusted relays is low and the secret key rate is therefore high. We also point out that the relay communication can achieve higher secret key rate than the direct communication in several distance ranges.
{"title":"Physical-layer secret key generation with untrusted relays","authors":"C. Thai, Jemin Lee, Chi Cheng, Tony Q. S. Quek","doi":"10.1109/GLOCOMW.2014.7063627","DOIUrl":"https://doi.org/10.1109/GLOCOMW.2014.7063627","url":null,"abstract":"In this paper, we propose a physical-layer secret key generation scheme for multi-antenna legitimate nodes with the help from multiple untrusted relays with single antenna. The relays' actions conform to the rules but they passively eavesdrop the information. Different from most previous key generation schemes, where a key is generated based on a channel coefficient, in the proposed scheme, we use the linear combination of channel coefficients to generate a key. Simulation results show that the rate leaked to the untrusted relays is low and the secret key rate is therefore high. We also point out that the relay communication can achieve higher secret key rate than the direct communication in several distance ranges.","PeriodicalId":354340,"journal":{"name":"2014 IEEE Globecom Workshops (GC Wkshps)","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133907385","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}
Pub Date : 2014-12-01DOI: 10.1109/GLOCOMW.2014.7063644
Jixin Feng, Xin Li, E. Pasiliao, J. Shea
Wireless communication systems are susceptible to jamming attacks, and the use of unmanned vehicles brings new opportunities for coordinated jamming attacks. At the same time, systems of autonomous vehicles that coordinate their movements over a wireless network may be particularly vulnerable to jamming attacks that disrupt the control information. Much research has been conducted on how to efficiently jam single communication links and how to protect such links from jamming. However, less research has focused on problems of jamming attacks on the overall network. In this paper, we consider the problem of determining how to efficiently position jammers so as to partition a wireless network. The communication network is represented as a graph with the vertices representing the radios, and the edges representing the communication links. Although there has been extensive research into the problem of efficiently partitioning a graph via edge separators, the action of a jammer in a wireless network is more closely analogous to blocking reception at one or more radios, which may be modeled as partitioning a graph via node separators. We formulate several optimization problems for jammer placement. Since the optimal solution to these problems are computationally complex, we develop suboptimal solutions using spectral partitioning followed by greedy jammer placement and also a harmony search. The results show that these algorithms offer a tradeoff between complexity and performance. In the scenarios where we were able to compare performance with the optimal solution, the harmony search algorithm offered performance close to that of the optimal solution while requiring a much lower complexity.
{"title":"Jammer placement to partition wireless network","authors":"Jixin Feng, Xin Li, E. Pasiliao, J. Shea","doi":"10.1109/GLOCOMW.2014.7063644","DOIUrl":"https://doi.org/10.1109/GLOCOMW.2014.7063644","url":null,"abstract":"Wireless communication systems are susceptible to jamming attacks, and the use of unmanned vehicles brings new opportunities for coordinated jamming attacks. At the same time, systems of autonomous vehicles that coordinate their movements over a wireless network may be particularly vulnerable to jamming attacks that disrupt the control information. Much research has been conducted on how to efficiently jam single communication links and how to protect such links from jamming. However, less research has focused on problems of jamming attacks on the overall network. In this paper, we consider the problem of determining how to efficiently position jammers so as to partition a wireless network. The communication network is represented as a graph with the vertices representing the radios, and the edges representing the communication links. Although there has been extensive research into the problem of efficiently partitioning a graph via edge separators, the action of a jammer in a wireless network is more closely analogous to blocking reception at one or more radios, which may be modeled as partitioning a graph via node separators. We formulate several optimization problems for jammer placement. Since the optimal solution to these problems are computationally complex, we develop suboptimal solutions using spectral partitioning followed by greedy jammer placement and also a harmony search. The results show that these algorithms offer a tradeoff between complexity and performance. In the scenarios where we were able to compare performance with the optimal solution, the harmony search algorithm offered performance close to that of the optimal solution while requiring a much lower complexity.","PeriodicalId":354340,"journal":{"name":"2014 IEEE Globecom Workshops (GC Wkshps)","volume":"227 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131787032","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}
Pub Date : 2014-12-01DOI: 10.1109/GLOCOMW.2014.7063619
Pin-Hsun Lin, Frederic Gabry, R. Thobaben, Eduard Axel Jorswieck, M. Skoglund
In this paper we investigate the cooperative secure communication in a four-node cognitive channel where the secondary receiver is treated as a potential eavesdropper with respect to the primary transmission with variational distance constraint. And the primary user's secrecy rate is required to be unchanged. We propose the clean relaying with the cooperative jamming scheme to achieve this goal, where the secondary transmitter splits its transmitting phase into two non-overlapped intervals after successfully decoding the primary message. Due to the considered secrecy metric, we resort to the information spectrum method, to derive the achievable secrecy rates for the primary user. Then we formulate the secondary user's rate maximization problem over the power allocation and time splitting at the cognitive transmitter under the constraint that primary user's secrecy rate is unchanged. Numerical results show that the secondary transmitter can choose clean relaying or pure cooperative jamming according to the relative positions of the nodes to achieve better performance than the one without any clean phase.
{"title":"Clean relaying in cognitive radio networks with variational distance secrecy constraint","authors":"Pin-Hsun Lin, Frederic Gabry, R. Thobaben, Eduard Axel Jorswieck, M. Skoglund","doi":"10.1109/GLOCOMW.2014.7063619","DOIUrl":"https://doi.org/10.1109/GLOCOMW.2014.7063619","url":null,"abstract":"In this paper we investigate the cooperative secure communication in a four-node cognitive channel where the secondary receiver is treated as a potential eavesdropper with respect to the primary transmission with variational distance constraint. And the primary user's secrecy rate is required to be unchanged. We propose the clean relaying with the cooperative jamming scheme to achieve this goal, where the secondary transmitter splits its transmitting phase into two non-overlapped intervals after successfully decoding the primary message. Due to the considered secrecy metric, we resort to the information spectrum method, to derive the achievable secrecy rates for the primary user. Then we formulate the secondary user's rate maximization problem over the power allocation and time splitting at the cognitive transmitter under the constraint that primary user's secrecy rate is unchanged. Numerical results show that the secondary transmitter can choose clean relaying or pure cooperative jamming according to the relative positions of the nodes to achieve better performance than the one without any clean phase.","PeriodicalId":354340,"journal":{"name":"2014 IEEE Globecom Workshops (GC Wkshps)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123178515","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}
Pub Date : 2014-12-01DOI: 10.1109/GLOCOMW.2014.7063643
K. A. Hafeez, A. Anpalagan, Lian Zhao
The Dedicated Short Range Communication (DSRC) technology has been adopted by the IEEE community to enable safety and non-safety application for Vehicular Ad hoc Networks (VANETs). To better serve these two classes of applications, the DSRC standard divides the bandwidth into seven channels. One channel, called control channel (CCH) to serve safety applications and the other six channels, called service channels (SCHs) to serve non-safety applications. The DSRC standard specifies a channel switching scheme to allow vehicles to alternate between these two classes of application. The standard also recommends that vehicles should visit the CCH every 100ms, called Synchronization Interval (SI), to send and receive their status messages. It is highly desirable that these status messages be delivered to the neighbouring vehicles reliably and within an acceptable delay bound. It is obvious that increasing the time share of the CCH from the SI will increase the reliability of safety applications. In this paper, we will optimize the control channel access such that safety applications have a high successful transmission rate within their share of the SI interval. Moreover, a new algorithm, called Optimal Channel Access (OCA), will be introduced to enhance the performance of the DSRC while keeping the CCH I as small as possible. Hence non-safety applications will have a fair share of the DSRC bandwidth.
{"title":"Enhancing the DSRC reliability to allow the coexistence of VANET's applications","authors":"K. A. Hafeez, A. Anpalagan, Lian Zhao","doi":"10.1109/GLOCOMW.2014.7063643","DOIUrl":"https://doi.org/10.1109/GLOCOMW.2014.7063643","url":null,"abstract":"The Dedicated Short Range Communication (DSRC) technology has been adopted by the IEEE community to enable safety and non-safety application for Vehicular Ad hoc Networks (VANETs). To better serve these two classes of applications, the DSRC standard divides the bandwidth into seven channels. One channel, called control channel (CCH) to serve safety applications and the other six channels, called service channels (SCHs) to serve non-safety applications. The DSRC standard specifies a channel switching scheme to allow vehicles to alternate between these two classes of application. The standard also recommends that vehicles should visit the CCH every 100ms, called Synchronization Interval (SI), to send and receive their status messages. It is highly desirable that these status messages be delivered to the neighbouring vehicles reliably and within an acceptable delay bound. It is obvious that increasing the time share of the CCH from the SI will increase the reliability of safety applications. In this paper, we will optimize the control channel access such that safety applications have a high successful transmission rate within their share of the SI interval. Moreover, a new algorithm, called Optimal Channel Access (OCA), will be introduced to enhance the performance of the DSRC while keeping the CCH I as small as possible. Hence non-safety applications will have a fair share of the DSRC bandwidth.","PeriodicalId":354340,"journal":{"name":"2014 IEEE Globecom Workshops (GC Wkshps)","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134560675","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}
Pub Date : 2014-12-01DOI: 10.1109/GLOCOMW.2014.7063548
Jian Li, M. Peng, Y. Yu, Aolin Cheng
The heterogeneous cloud radio access networks (H-CRANs) are presented in this paper as a promising new paradigm for future heterogeneous converged networks. To maintain low traffic queue congestion and make the sum utility of average throughput arbitrarily close to the optimum, the dynamic optimization problem of traffic admission control, heterogeneous processing node (HPN)/remote radio head (RRH) association, resource block (RB) and power allocation subject to the average power consumption constraints of RRHs is formulated using the general framework of Lyapunov optimization. The optimization problem can be decomposed into three subproblems. To solve the third mixed-integer subproblem, the continuity relaxation is utilized and the optimality can be still preserved. Finally, the simulation results validate the out-performances of the proposed solution with appropriate control parameter.
{"title":"Dynamic resource optimization with congestion control in heterogeneous cloud radio access networks","authors":"Jian Li, M. Peng, Y. Yu, Aolin Cheng","doi":"10.1109/GLOCOMW.2014.7063548","DOIUrl":"https://doi.org/10.1109/GLOCOMW.2014.7063548","url":null,"abstract":"The heterogeneous cloud radio access networks (H-CRANs) are presented in this paper as a promising new paradigm for future heterogeneous converged networks. To maintain low traffic queue congestion and make the sum utility of average throughput arbitrarily close to the optimum, the dynamic optimization problem of traffic admission control, heterogeneous processing node (HPN)/remote radio head (RRH) association, resource block (RB) and power allocation subject to the average power consumption constraints of RRHs is formulated using the general framework of Lyapunov optimization. The optimization problem can be decomposed into three subproblems. To solve the third mixed-integer subproblem, the continuity relaxation is utilized and the optimality can be still preserved. Finally, the simulation results validate the out-performances of the proposed solution with appropriate control parameter.","PeriodicalId":354340,"journal":{"name":"2014 IEEE Globecom Workshops (GC Wkshps)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134321483","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}
Pub Date : 2014-12-01DOI: 10.1109/GLOCOMW.2014.7063639
Torsten Andre, Daniel Neuhold, C. Bettstetter
We present and evaluate new ROS packages for coordinated multi-robot exploration, namely communication, global map construction, and exploration. The packages allow completely distributed control and do not rely on (but allow) central controllers. Their integration including application layer protocols allows out of the box installation and execution. The communication package enables reliable ad hoc communication allowing to exchange local maps between robots which are merged to a global map. Exploration uses the global map to spatially spread robots and decrease exploration time. The intention of the implementation is to offer basic functionality for coordinated multi-robot systems and to enable other research groups to experimentally work on multi-robot systems. The packages are tested in real-world experiments using Turtlebot and Pioneer robots. Further, we analyze their performance using simulations and verify their correct working.
{"title":"Coordinated multi-robot exploration: Out of the box packages for ROS","authors":"Torsten Andre, Daniel Neuhold, C. Bettstetter","doi":"10.1109/GLOCOMW.2014.7063639","DOIUrl":"https://doi.org/10.1109/GLOCOMW.2014.7063639","url":null,"abstract":"We present and evaluate new ROS packages for coordinated multi-robot exploration, namely communication, global map construction, and exploration. The packages allow completely distributed control and do not rely on (but allow) central controllers. Their integration including application layer protocols allows out of the box installation and execution. The communication package enables reliable ad hoc communication allowing to exchange local maps between robots which are merged to a global map. Exploration uses the global map to spatially spread robots and decrease exploration time. The intention of the implementation is to offer basic functionality for coordinated multi-robot systems and to enable other research groups to experimentally work on multi-robot systems. The packages are tested in real-world experiments using Turtlebot and Pioneer robots. Further, we analyze their performance using simulations and verify their correct working.","PeriodicalId":354340,"journal":{"name":"2014 IEEE Globecom Workshops (GC Wkshps)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132692521","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}
Pub Date : 2014-12-01DOI: 10.1109/GLOCOMW.2014.7063480
P. Lopresti, N. Hutchins, Steven Kohrmann, M. F. Babelli, H. Refai
A transmitter and receiver design based on the use of fiber optic bundles have been proposed and studied both experimentally in the laboratory and theoretically through simulation, and have shown promise for providing enhanced functionality in mitigating the effects of turbulence and weather on the pointing, acquisition and tracking problem. In this paper, the operation of an FSO link constructed from these designs is analyzed under similar environmental conditions but transmitting at two different wavelengths. A transmitter with a linear fiber array transmitted over a brick surface at either 1310 nm or 1550 nm wavelength to a receiver constructed using a hexagonal array of 19 fibers located 15 feet away. Data at 100 kb/s was transmitted across the link and the collected signal was recorded for off-line statistical analysis, including achieved bit-error rate. The investigation finds that, when eliminating effects due to artifacts in source operation, dependence of link operation on wavelength is minimal, even though the optical alignment was optimized for only 1550 nm.
{"title":"Wavelength dependence of a fiber-bundle based FSO link","authors":"P. Lopresti, N. Hutchins, Steven Kohrmann, M. F. Babelli, H. Refai","doi":"10.1109/GLOCOMW.2014.7063480","DOIUrl":"https://doi.org/10.1109/GLOCOMW.2014.7063480","url":null,"abstract":"A transmitter and receiver design based on the use of fiber optic bundles have been proposed and studied both experimentally in the laboratory and theoretically through simulation, and have shown promise for providing enhanced functionality in mitigating the effects of turbulence and weather on the pointing, acquisition and tracking problem. In this paper, the operation of an FSO link constructed from these designs is analyzed under similar environmental conditions but transmitting at two different wavelengths. A transmitter with a linear fiber array transmitted over a brick surface at either 1310 nm or 1550 nm wavelength to a receiver constructed using a hexagonal array of 19 fibers located 15 feet away. Data at 100 kb/s was transmitted across the link and the collected signal was recorded for off-line statistical analysis, including achieved bit-error rate. The investigation finds that, when eliminating effects due to artifacts in source operation, dependence of link operation on wavelength is minimal, even though the optical alignment was optimized for only 1550 nm.","PeriodicalId":354340,"journal":{"name":"2014 IEEE Globecom Workshops (GC Wkshps)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117155348","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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