In a challenged network environment, where end-to-end connectivity may be a rare occurrence, delay-tolerant routing protocols must strike a balance between the increased robustness and reliability that comes with message replication and the resulting high bandwidth and storage overhead. Network coded routing, in which a node combines messages from different sources, has been shown to increase reliability in the presence of link failures with small additional overhead. A drawback of network coded routing is the lack of a natural stopping condition to control the dissemination of data. We describe an enhanced coding router that uses the mathematical structure of the orthogonal complement, or nullspace, as an improved stopping condition to eliminate redundant transmissions, and an additional technique to balance multiple coded data flows. These changes are incorporated into the DTN2 Reference Implementation and evaluated in two types of experiments. In a simple data-mule scenario, our EBR router comes very close to perfect efficiency. In a more complicated scenario with segmented communities and occasional nodes moving between them, our solutions show a drastic improvement in delivery rates.
{"title":"Nullspace-based stopping conditions for network-coded transmissions in DTNs","authors":"Angela Hennessy, Alec Gladd, B. Walker","doi":"10.1145/2348616.2348627","DOIUrl":"https://doi.org/10.1145/2348616.2348627","url":null,"abstract":"In a challenged network environment, where end-to-end connectivity may be a rare occurrence, delay-tolerant routing protocols must strike a balance between the increased robustness and reliability that comes with message replication and the resulting high bandwidth and storage overhead. Network coded routing, in which a node combines messages from different sources, has been shown to increase reliability in the presence of link failures with small additional overhead. A drawback of network coded routing is the lack of a natural stopping condition to control the dissemination of data. We describe an enhanced coding router that uses the mathematical structure of the orthogonal complement, or nullspace, as an improved stopping condition to eliminate redundant transmissions, and an additional technique to balance multiple coded data flows. These changes are incorporated into the DTN2 Reference Implementation and evaluated in two types of experiments. In a simple data-mule scenario, our EBR router comes very close to perfect efficiency. In a more complicated scenario with segmented communities and occasional nodes moving between them, our solutions show a drastic improvement in delivery rates.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75698351","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 present procedures that exploit mobility prediction and prefetching to enhance offloading of traffic from mobile networks to WiFi hotspots, for both delay tolerant and delay sensitive traffic. We evaluate the procedures in terms of the percentage of offloaded traffic, the data transfer delay, and the cache size used for prefetching. The evaluation considers empirical measurements and shows how various parameters influence the performance of the procedures, and their robustness to time and throughput estimation errors.
{"title":"Enhancing mobile data offloading with mobility prediction and prefetching","authors":"V. Siris, Dimitrios Kalyvas","doi":"10.1145/2348676.2348682","DOIUrl":"https://doi.org/10.1145/2348676.2348682","url":null,"abstract":"We present procedures that exploit mobility prediction and prefetching to enhance offloading of traffic from mobile networks to WiFi hotspots, for both delay tolerant and delay sensitive traffic. We evaluate the procedures in terms of the percentage of offloaded traffic, the data transfer delay, and the cache size used for prefetching. The evaluation considers empirical measurements and shows how various parameters influence the performance of the procedures, and their robustness to time and throughput estimation errors.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79649047","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}
Recently, there has been a tremendous increase in mobile data usage with the wide-spread proliferation of smartphone like devices. However, this increased demand from users has caused severe traffic overloading in cellular networks. Offloading the traffic through several other devices (femtocells, WiFi access points) have been considered to be immediate remedy for such a problem. Thus, in this paper, we study the deployment of WiFi access points (AP) in a metropolitan area for efficient offloading of mobile data traffic. We analyze a large scale real user mobility traces and propose a deployment algorithm based on the density of user data request frequency. In simulations, we present offloading ratio that our algorithm can accomplish with different number of APs. The results demonstrate that our algorithm can achieve close to optimal offloading ratio that is higher than offloading ratios that existing algorithms can achieve with the same number of APs.
{"title":"WiFi access point deployment for efficient mobile data offloading","authors":"E. Bulut, B. Szymanski","doi":"10.1145/2502935.2502948","DOIUrl":"https://doi.org/10.1145/2502935.2502948","url":null,"abstract":"Recently, there has been a tremendous increase in mobile data usage with the wide-spread proliferation of smartphone like devices. However, this increased demand from users has caused severe traffic overloading in cellular networks. Offloading the traffic through several other devices (femtocells, WiFi access points) have been considered to be immediate remedy for such a problem. Thus, in this paper, we study the deployment of WiFi access points (AP) in a metropolitan area for efficient offloading of mobile data traffic. We analyze a large scale real user mobility traces and propose a deployment algorithm based on the density of user data request frequency. In simulations, we present offloading ratio that our algorithm can accomplish with different number of APs. The results demonstrate that our algorithm can achieve close to optimal offloading ratio that is higher than offloading ratios that existing algorithms can achieve with the same number of APs.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76722807","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}
A. N. Plymoth, P. Johansson, R. Cruz, O. Chipara, W. Griswold
This paper present Grapevine, a wireless networking protocol designed to be used in challenged environments such an emergency response network. These environments typically experience a lot of noise, interference, disconnections and high mobility resulting in high packet loss rates. As often critical data needs to be disseminated to other nodes it is important to have a protocol that efficiently delivers data under these conditions, but which is also efficient under good conditions. Grapevine uses to fountain coding to opportunistically and cooperatively to efficiently delivers data in high throughput wireless multi hop networks, as well as lossy and delay tolerant networks. Results show that our flooding based protocol is more efficient than traditional protocols in lossy networks both in terms of lower delay and lower overhead.
{"title":"GRAPEVINE: hybrid cooperative opportunistic routing for challenged wireless networks using fountain coding","authors":"A. N. Plymoth, P. Johansson, R. Cruz, O. Chipara, W. Griswold","doi":"10.1145/2502935.2502947","DOIUrl":"https://doi.org/10.1145/2502935.2502947","url":null,"abstract":"This paper present Grapevine, a wireless networking protocol designed to be used in challenged environments such an emergency response network. These environments typically experience a lot of noise, interference, disconnections and high mobility resulting in high packet loss rates. As often critical data needs to be disseminated to other nodes it is important to have a protocol that efficiently delivers data under these conditions, but which is also efficient under good conditions. Grapevine uses to fountain coding to opportunistically and cooperatively to efficiently delivers data in high throughput wireless multi hop networks, as well as lossy and delay tolerant networks. Results show that our flooding based protocol is more efficient than traditional protocols in lossy networks both in terms of lower delay and lower overhead.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81796089","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}
Opportunistic networking between mobile devices relies on the capabilities of those devices to establish ad-hoc communication among each other. While the two dominant wireless interface technologies, IEEE 802.11 wireless LAN and Bluetooth, offer such capabilities in theory, limitations of the protocol specification, chipsets, and operating systems in mobile devices render those features largely unusable in practice. Researchers have recognized these shortcomings and devised mechanisms in which mobile devices act as WLAN access points to simulate WLAN infrastructure-based operation. In this paper, we complement these approaches by instrumenting commercial WLAN APs that do not employ L2 security to serve as link layer packet relays without requiring the mobile nodes to authenticate with the WLAN hot-spot. We present different mechanisms for peer discovery, evaluate their feasibility for a set of commercial hot-spots, and discuss operational considerations for fair use of commercial access points.
{"title":"Enabling ad-hoc-style communication in public WLAN hot-spots","authors":"Teemu Kärkkäinen, M. Pitkänen, J. Ott","doi":"10.1145/2502935.2502937","DOIUrl":"https://doi.org/10.1145/2502935.2502937","url":null,"abstract":"Opportunistic networking between mobile devices relies on the capabilities of those devices to establish ad-hoc communication among each other. While the two dominant wireless interface technologies, IEEE 802.11 wireless LAN and Bluetooth, offer such capabilities in theory, limitations of the protocol specification, chipsets, and operating systems in mobile devices render those features largely unusable in practice. Researchers have recognized these shortcomings and devised mechanisms in which mobile devices act as WLAN access points to simulate WLAN infrastructure-based operation. In this paper, we complement these approaches by instrumenting commercial WLAN APs that do not employ L2 security to serve as link layer packet relays without requiring the mobile nodes to authenticate with the WLAN hot-spot. We present different mechanisms for peer discovery, evaluate their feasibility for a set of commercial hot-spots, and discuss operational considerations for fair use of commercial access points.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78387729","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 propose an execution model for web apps that eschews the current need for static partitioning of web apps into client-side JavaScript and server-side "data center" code, but rather enables dynamic partitioning by allowing the client and server to share code and migrate computation between each other. Our model abstracts and represents shared code and data as a graph of fixed-sized chunks; our runtime then manages and migrates the graph rather than managing the code and its dependencies directly. We demonstrate our model through PhotoBoss, a suite of web apps for editing high-resolution photos.
{"title":"Distributed web app execution with chunks","authors":"Justin Mazzola Paluska, H. Pham, Steve Ward","doi":"10.1145/2436196.2436202","DOIUrl":"https://doi.org/10.1145/2436196.2436202","url":null,"abstract":"We propose an execution model for web apps that eschews the current need for static partitioning of web apps into client-side JavaScript and server-side \"data center\" code, but rather enables dynamic partitioning by allowing the client and server to share code and migrate computation between each other. Our model abstracts and represents shared code and data as a graph of fixed-sized chunks; our runtime then manages and migrates the graph rather than managing the code and its dependencies directly. We demonstrate our model through PhotoBoss, a suite of web apps for editing high-resolution photos.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79181057","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}
Wolfgang Richter, Kiryong Ha, Alok Shankar, A. A. Sani, J. Harkes, Lin Zhong, M. Satyanarayanan
We present a cloud-based approach to opportunistic, near real-time search of untagged images on smartphones that is sensitive to bandwidth and energy constraints. Our approach is inspired by the long-established practice of photographers using contact sheets to rapidly visualize a new collection of photographs, and then selecting a subset on which to focus attention. On behalf of each smartphone, the cloud maintains a virtual contact sheet of images that have been captured but not yet uploaded. The virtual contact sheet consists of a set of low-fidelity images as well as full or partial meta-data associated with each image. If search processing on the cloud indicates that a particular low-fidelity object is relevant, then its full-fidelity image can be obtained just-in-time from the corresponding smartphone for further search processing or presentation to the user. Our approach is not limited to images, but they provide a convenient query space to test search optimizations.
{"title":"A contact sheet approach to searching untagged images on smartphones","authors":"Wolfgang Richter, Kiryong Ha, Alok Shankar, A. A. Sani, J. Harkes, Lin Zhong, M. Satyanarayanan","doi":"10.1145/2436196.2436203","DOIUrl":"https://doi.org/10.1145/2436196.2436203","url":null,"abstract":"We present a cloud-based approach to opportunistic, near real-time search of untagged images on smartphones that is sensitive to bandwidth and energy constraints. Our approach is inspired by the long-established practice of photographers using contact sheets to rapidly visualize a new collection of photographs, and then selecting a subset on which to focus attention. On behalf of each smartphone, the cloud maintains a virtual contact sheet of images that have been captured but not yet uploaded. The virtual contact sheet consists of a set of low-fidelity images as well as full or partial meta-data associated with each image. If search processing on the cloud indicates that a particular low-fidelity object is relevant, then its full-fidelity image can be obtained just-in-time from the corresponding smartphone for further search processing or presentation to the user. Our approach is not limited to images, but they provide a convenient query space to test search optimizations.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85922528","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}
People-centric sensing is a novel approach that exploits the sensing capabilities offered by smartphones and the mobility of users to sense large scale areas without requiring the deployment of sensors in-situ. Given the ubiquitous nature of smartphones, people-centric sensing is a viable and efficient solution for crowdsourcing data. In this work, we propose a fully distributed, opportunistic sensing framework that involves two main components which both work in an ad hoc fashion: Recruitment and Data Collection. We analyzed the feasibility of our distributed approach for both components through preliminary simulations. The results show that our recruitment method is able to select 66% of the nodes that are appropriate for the sensing activity and 88% of the messages sent by these selected nodes reach the sink by using our data collection method.
{"title":"Autonomous and distributed recruitment and data collection framework for opportunistic sensing","authors":"Güliz Seray Tuncay, G. Benincasa, A. Helmy","doi":"10.1145/2436196.2436219","DOIUrl":"https://doi.org/10.1145/2436196.2436219","url":null,"abstract":"People-centric sensing is a novel approach that exploits the sensing capabilities offered by smartphones and the mobility of users to sense large scale areas without requiring the deployment of sensors in-situ. Given the ubiquitous nature of smartphones, people-centric sensing is a viable and efficient solution for crowdsourcing data. In this work, we propose a fully distributed, opportunistic sensing framework that involves two main components which both work in an ad hoc fashion: Recruitment and Data Collection. We analyzed the feasibility of our distributed approach for both components through preliminary simulations. The results show that our recruitment method is able to select 66% of the nodes that are appropriate for the sensing activity and 88% of the messages sent by these selected nodes reach the sink by using our data collection method.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86172187","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 this article, we introduce VIRMANEL a tool we developed to establish an environment for the study of multihop mobile networks. VIRMANEL is a tool that manages virtual machines corresponding to mobile nodes, emulates their movements and the resulting disconnections. It features a GUI to observe the behavior of mobile nodes. Nodes mobility is specified using SILUMOD, a domain-specific language that allows, through a set of dedicated.
{"title":"Using virtualization to study mobile multihop networks","authors":"Yacine Benchaïb, Claude Chaudet","doi":"10.1145/2436196.2436207","DOIUrl":"https://doi.org/10.1145/2436196.2436207","url":null,"abstract":"In this article, we introduce VIRMANEL a tool we developed to establish an environment for the study of multihop mobile networks. VIRMANEL is a tool that manages virtual machines corresponding to mobile nodes, emulates their movements and the resulting disconnections. It features a GUI to observe the behavior of mobile nodes. Nodes mobility is specified using SILUMOD, a domain-specific language that allows, through a set of dedicated.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85936530","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}
V. Manolopoulos, S. Tao, A. Rusu, Panos Papadimitratos
Traffic Information Systems (TISs) can play a significant role towards creating sustainable cities through improved traffic conditions. The collection of reliable and rich information with low cost is paramount. The use of smartphones carried by individuals for future implementations of TISs present several advantages compared to traditional solutions. This demo integrates our results from previous work addressing challenges on traffic estimation for urban road networks and on security and privacy protection for such TISs.
{"title":"Smartphone-based traffic information system for sustainable cities","authors":"V. Manolopoulos, S. Tao, A. Rusu, Panos Papadimitratos","doi":"10.1145/2436196.2436213","DOIUrl":"https://doi.org/10.1145/2436196.2436213","url":null,"abstract":"Traffic Information Systems (TISs) can play a significant role towards creating sustainable cities through improved traffic conditions. The collection of reliable and rich information with low cost is paramount. The use of smartphones carried by individuals for future implementations of TISs present several advantages compared to traditional solutions. This demo integrates our results from previous work addressing challenges on traffic estimation for urban road networks and on security and privacy protection for such TISs.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91373175","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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