R. Crepaldi, Ryan Beavers, Braden Ehrat, M. Jaeger, S. Biersteker, R. Kravets
Internet connectivity is nowadays an ubiquitous service. However, on the road we obtain access using costly and limited data cellular network subscriptions. This, along with significant network congestion, severely limits network use. Opportunistic access to indoor APs is limited by three factors. First, establishing a link to an AP requires a significant amount of time, and, second, links on the street usually have poor quality. Third, the lifetime of this link is very short in a moving car, due to indoor APs generally covering small areas of the street. Combined, these factors thwart opportunistic use of APs for Internet access. In this paper, we propose a novel approach that leverages the large number of parked cars to separate these three factors and tackle them independently: a parked car can connect to an AP with a link that, despite its poor quality, has a long lifetime. A moving vehicle can instead benefit from the better link with a parked car and use it as a relay. As our experiments show, our approach enables the use of this free, high throughput channel for a number of non time-sensitive applications, thus reducing cost and the load on the cellular network.
{"title":"LoadingZones: leveraging street parking to enable vehicular internet access","authors":"R. Crepaldi, Ryan Beavers, Braden Ehrat, M. Jaeger, S. Biersteker, R. Kravets","doi":"10.1145/2348616.2348622","DOIUrl":"https://doi.org/10.1145/2348616.2348622","url":null,"abstract":"Internet connectivity is nowadays an ubiquitous service. However, on the road we obtain access using costly and limited data cellular network subscriptions. This, along with significant network congestion, severely limits network use. Opportunistic access to indoor APs is limited by three factors. First, establishing a link to an AP requires a significant amount of time, and, second, links on the street usually have poor quality. Third, the lifetime of this link is very short in a moving car, due to indoor APs generally covering small areas of the street. Combined, these factors thwart opportunistic use of APs for Internet access. In this paper, we propose a novel approach that leverages the large number of parked cars to separate these three factors and tackle them independently: a parked car can connect to an AP with a link that, despite its poor quality, has a long lifetime. A moving vehicle can instead benefit from the better link with a parked car and use it as a relay. As our experiments show, our approach enables the use of this free, high throughput channel for a number of non time-sensitive applications, thus reducing cost and the load on the cellular network.","PeriodicalId":211112,"journal":{"name":"CHANTS '12","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126756378","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}
Worldwide, mobile data connectivity is now widespread, but not yet ubiquitous due to coverage limits and cost concerns. Mobile data offloading to WiFi---where available---could greatly decrease the usage of cellular data networks. In delay-tolerant applications, one could delay network communication in order to exploit free WiFi connections expected to appear soon. However, WiFi connectivity is limited, and even delay-tolerant applications must meet quality-of-service deadlines. To explore such bandwidth scheduling issues, we develop an optimal MILP-based scheduling framework. Our framework schedules multiple application data streams with varying size and delay tolerance, onto networks with varying coverage and bandwidth, in order to minimize cellular data usage. The ability to subdivide data streams into scheduling units is important, because it allows applications to exploit brief windows of WiFi coverage and it allows tradeoffs between solution quality and solver runtime.
{"title":"Adaptive usage of cellular and WiFi bandwidth: an optimal scheduling formulation","authors":"Ozlem Bilgir, M. Martonosi","doi":"10.1145/2348616.2348631","DOIUrl":"https://doi.org/10.1145/2348616.2348631","url":null,"abstract":"Worldwide, mobile data connectivity is now widespread, but not yet ubiquitous due to coverage limits and cost concerns. Mobile data offloading to WiFi---where available---could greatly decrease the usage of cellular data networks. In delay-tolerant applications, one could delay network communication in order to exploit free WiFi connections expected to appear soon. However, WiFi connectivity is limited, and even delay-tolerant applications must meet quality-of-service deadlines. To explore such bandwidth scheduling issues, we develop an optimal MILP-based scheduling framework. Our framework schedules multiple application data streams with varying size and delay tolerance, onto networks with varying coverage and bandwidth, in order to minimize cellular data usage. The ability to subdivide data streams into scheduling units is important, because it allows applications to exploit brief windows of WiFi coverage and it allows tradeoffs between solution quality and solver runtime.","PeriodicalId":211112,"journal":{"name":"CHANTS '12","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131950934","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}
Current mobile opportunistic networks often use social routing protocols to transfer messages among users and to the services. In the face of changing underlying topology, mobility patterns and density of users and their queries, fixed algorithms for user anonymisation cannot provide sufficient level of user anonymity, and adaptive mechanisms for achieving user anonymity are needed. This paper describes a novel flexible and adaptive approach, AdaptAnon that is suitable for dynamic and heterogeneous mobile opportunistic networks. Our approach is multidimensional and combines multiple heuristics based on user profiles, analysis of user connectivity and history of anonymisation in order to predict and decide on the best set of nodes that can help anonymise the sending node. In our demonstration, we show that AdaptAnon achieves high quality of anonymisation in terms of both the number of nodes and the diversity of nodes in the anonymisation layer for varying query intensity and over live San Francisco cab mobility traces while neither decreasing success ratios nor increasing latency. We also compare AdaptAnon to other state of the art single dimensional anonymisation approaches and do real time visualization of performance parameters.
{"title":"Adaptive user anonymity for mobile opportunistic networks","authors":"M. Radenkovic, I. Vaghi","doi":"10.1145/2348616.2348635","DOIUrl":"https://doi.org/10.1145/2348616.2348635","url":null,"abstract":"Current mobile opportunistic networks often use social routing protocols to transfer messages among users and to the services. In the face of changing underlying topology, mobility patterns and density of users and their queries, fixed algorithms for user anonymisation cannot provide sufficient level of user anonymity, and adaptive mechanisms for achieving user anonymity are needed. This paper describes a novel flexible and adaptive approach, AdaptAnon that is suitable for dynamic and heterogeneous mobile opportunistic networks. Our approach is multidimensional and combines multiple heuristics based on user profiles, analysis of user connectivity and history of anonymisation in order to predict and decide on the best set of nodes that can help anonymise the sending node. In our demonstration, we show that AdaptAnon achieves high quality of anonymisation in terms of both the number of nodes and the diversity of nodes in the anonymisation layer for varying query intensity and over live San Francisco cab mobility traces while neither decreasing success ratios nor increasing latency. We also compare AdaptAnon to other state of the art single dimensional anonymisation approaches and do real time visualization of performance parameters.","PeriodicalId":211112,"journal":{"name":"CHANTS '12","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131158810","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 delay tolerant network (DTN) deals with the issue of frequently interrupted connections and relaxes the need for a continuous end-to-end relation between nodes. The Bundle Protocol is the typical way to set-up a DTN, but requires a common time in the whole network. Further, globally synchronized timestamps are required by many mechanisms like cryptography protocols or global event ordering. Since standard time synchronization approaches from classical networking do not work in DTNs, we introduce a novel algorithm to distribute a time reference in such networks. Our approach rates the quality of the local time with respect to the accuracy of the local clock. We show that this simple and self-aligning algorithm can provide an adequate accuracy depending on the inter-contact times between the nodes.
{"title":"Time-reference distribution in delay tolerant networks","authors":"J. Morgenroth, L. Wolf","doi":"10.1145/2348616.2348618","DOIUrl":"https://doi.org/10.1145/2348616.2348618","url":null,"abstract":"A delay tolerant network (DTN) deals with the issue of frequently interrupted connections and relaxes the need for a continuous end-to-end relation between nodes. The Bundle Protocol is the typical way to set-up a DTN, but requires a common time in the whole network. Further, globally synchronized timestamps are required by many mechanisms like cryptography protocols or global event ordering.\u0000 Since standard time synchronization approaches from classical networking do not work in DTNs, we introduce a novel algorithm to distribute a time reference in such networks. Our approach rates the quality of the local time with respect to the accuracy of the local clock. We show that this simple and self-aligning algorithm can provide an adequate accuracy depending on the inter-contact times between the nodes.","PeriodicalId":211112,"journal":{"name":"CHANTS '12","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128862394","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}
Teemu Kärkkäinen, M. Pitkänen, P. Houghton, J. Ott
In this paper we demonstrate an application platform architecture and implementation that allows developers to easily target opportunistic networks. The platform includes an opportunistic router, HTML5 application development framework, and an opportunistic application market for distributing applications. We demonstrate the platform and multiple HTML5 applications -- including chat, music and social networking applications -- running on Android devices.
{"title":"SCAMPI application platform","authors":"Teemu Kärkkäinen, M. Pitkänen, P. Houghton, J. Ott","doi":"10.1145/2348616.2348636","DOIUrl":"https://doi.org/10.1145/2348616.2348636","url":null,"abstract":"In this paper we demonstrate an application platform architecture and implementation that allows developers to easily target opportunistic networks. The platform includes an opportunistic router, HTML5 application development framework, and an opportunistic application market for distributing applications. We demonstrate the platform and multiple HTML5 applications -- including chat, music and social networking applications -- running on Android devices.","PeriodicalId":211112,"journal":{"name":"CHANTS '12","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122365382","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}
Wireless Sensor Networks are networks formed by wireless sensor nodes that generally feature a low-power microcontroller and an IEEE 802.15.4 radio. Most Delay Tolerant Wireless Sensor Networks in literature use proprietary protocols that are specifically designed for a single purpose. In this paper we explore, how the Bundle Protocol can be used on top of the IEEE 802.15.4 PHY and MAC layers, while avoiding overhead for additional layers in between. To pursue this, a Convergence Layer has to realize certain tasks that usually are dealt with in layers 3 and 4 of the OSI 7-layer protocol stack. We argue that flow control has to be an integral ingredient of the Convergence Layer and compare the performance of four different mechanisms using our Bundle Protocol implementation for Contiki.
{"title":"Flow control mechanisms for the bundle protocol in IEEE 802.15.4 low-power networks","authors":"Wolf-Bastian Pöttner, L. Wolf","doi":"10.1145/2348616.2348630","DOIUrl":"https://doi.org/10.1145/2348616.2348630","url":null,"abstract":"Wireless Sensor Networks are networks formed by wireless sensor nodes that generally feature a low-power microcontroller and an IEEE 802.15.4 radio. Most Delay Tolerant Wireless Sensor Networks in literature use proprietary protocols that are specifically designed for a single purpose. In this paper we explore, how the Bundle Protocol can be used on top of the IEEE 802.15.4 PHY and MAC layers, while avoiding overhead for additional layers in between. To pursue this, a Convergence Layer has to realize certain tasks that usually are dealt with in layers 3 and 4 of the OSI 7-layer protocol stack. We argue that flow control has to be an integral ingredient of the Convergence Layer and compare the performance of four different mechanisms using our Bundle Protocol implementation for Contiki.","PeriodicalId":211112,"journal":{"name":"CHANTS '12","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130201672","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 variety of personal backup services now allow users to synchronise their files across multiple devices such as laptops and smartphones. These applications typically operate by synchronising each device with a centralised storage service across the Internet. However, access to the Internet may occasionally not be available, leaving any unsynchronised content in a vulnerable state. To address this, we introduce a cooperative backup storage system that could alternatively make use of storage capacity provided by other devices within close proximity, using ad-hoc or local network connectivity. Such devices can provide a secondary storage tier in case of Internet connectivity issues, and could also be used to forward files to central storage at a later time.
{"title":"Pocket backup storage system with cloud integration","authors":"Karthik Nilakant, Eiko Yoneki","doi":"10.1145/2348616.2348633","DOIUrl":"https://doi.org/10.1145/2348616.2348633","url":null,"abstract":"A variety of personal backup services now allow users to synchronise their files across multiple devices such as laptops and smartphones. These applications typically operate by synchronising each device with a centralised storage service across the Internet. However, access to the Internet may occasionally not be available, leaving any unsynchronised content in a vulnerable state. To address this, we introduce a cooperative backup storage system that could alternatively make use of storage capacity provided by other devices within close proximity, using ad-hoc or local network connectivity. Such devices can provide a secondary storage tier in case of Internet connectivity issues, and could also be used to forward files to central storage at a later time.","PeriodicalId":211112,"journal":{"name":"CHANTS '12","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116532859","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}
S. Schildt, Till Lorentzen, J. Morgenroth, Wolf-Bastian Pöttner, L. Wolf
Until now there exists no standardized or widely-used name resolution mechanism for Bundle Protocol based DTNs. In local IP based networks the IP Neighbor Discovery (IPND) protocol provides link-local discovery of DTN neighbors, however in the Internet there is no mechanism that maps Bundle Protocol addresses (EIDs) to Convergence Layer addresses. This seriously hampers connectivity in the DTNBone. In this paper we argue, that a DHT-based naming mechanism is a good fit for DTN networks. We show the advantages of using the existing DHT infrastructure from the BitTorrent file sharing network as a basis instead of rolling out a custom solution. We will present experiences and performance measures with a lightweight implementation of the proposed system that we began to distribute as integrated component of the IBR-DTN Bundle Protocol implementation.
{"title":"Free-riding the BitTorrent DHT to improve DTN connectivity","authors":"S. Schildt, Till Lorentzen, J. Morgenroth, Wolf-Bastian Pöttner, L. Wolf","doi":"10.1145/2348616.2348619","DOIUrl":"https://doi.org/10.1145/2348616.2348619","url":null,"abstract":"Until now there exists no standardized or widely-used name resolution mechanism for Bundle Protocol based DTNs. In local IP based networks the IP Neighbor Discovery (IPND) protocol provides link-local discovery of DTN neighbors, however in the Internet there is no mechanism that maps Bundle Protocol addresses (EIDs) to Convergence Layer addresses. This seriously hampers connectivity in the DTNBone.\u0000 In this paper we argue, that a DHT-based naming mechanism is a good fit for DTN networks. We show the advantages of using the existing DHT infrastructure from the BitTorrent file sharing network as a basis instead of rolling out a custom solution. We will present experiences and performance measures with a lightweight implementation of the proposed system that we began to distribute as integrated component of the IBR-DTN Bundle Protocol implementation.","PeriodicalId":211112,"journal":{"name":"CHANTS '12","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131838087","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}
Sujoy Saha, V. Shah, Rohit Verma, Ratna Mandal, S. Nandi
After any natural disaster the availability of existing conventional communication infrastructure almost gets ruled out. After the devastation, to restore the communication system in ad hoc basis; ensuring almost 100% packet delivery within acceptable latency with optimal utilization of resources are prime design motives. Our work proposes a four tier planned hybrid architecture, which conforms the aforesaid motives yielding a desired performance in terms of delivery probability within least latency, for a given disaster hit area map with a suitable heuristic algorithm. Our study also reveals that there exists no deterministic polynomial time solution that can implement the desired design motives as well as the feasibility of our planned methodology. Compared to any brute force strategy, as per the simulation results, our approach shows 42% higher delivery probability and 49% lower latency.
{"title":"Is it worth taking a planned approach to design ad hoc infrastructure for post disaster communication?","authors":"Sujoy Saha, V. Shah, Rohit Verma, Ratna Mandal, S. Nandi","doi":"10.1145/2348616.2348637","DOIUrl":"https://doi.org/10.1145/2348616.2348637","url":null,"abstract":"After any natural disaster the availability of existing conventional communication infrastructure almost gets ruled out. After the devastation, to restore the communication system in ad hoc basis; ensuring almost 100% packet delivery within acceptable latency with optimal utilization of resources are prime design motives. Our work proposes a four tier planned hybrid architecture, which conforms the aforesaid motives yielding a desired performance in terms of delivery probability within least latency, for a given disaster hit area map with a suitable heuristic algorithm. Our study also reveals that there exists no deterministic polynomial time solution that can implement the desired design motives as well as the feasibility of our planned methodology. Compared to any brute force strategy, as per the simulation results, our approach shows 42% higher delivery probability and 49% lower latency.","PeriodicalId":211112,"journal":{"name":"CHANTS '12","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126387780","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}
Gleneesha M. Johnson Williams, B. Walker, Angela Hennessy
As delay-tolerant networking (DTN) finds applications in a wider variety of environments, DTN implementations have been ported to a variety of devices. Performance testing of DTN implementations has typically been carried out on powerful hardware, but there have been few performance evaluations on resource-constrained devices. We present the results of experiments comparing two of the major open-source DTN implementations, DTN2 and IBR-DTN, on resource-constrained nodes. The comparison is in terms of storage and receive performance, as well as network throughput.
{"title":"A performance comparison of DTN bundle protocol implementations on resource constrained nodes","authors":"Gleneesha M. Johnson Williams, B. Walker, Angela Hennessy","doi":"10.1145/2348616.2348634","DOIUrl":"https://doi.org/10.1145/2348616.2348634","url":null,"abstract":"As delay-tolerant networking (DTN) finds applications in a wider variety of environments, DTN implementations have been ported to a variety of devices. Performance testing of DTN implementations has typically been carried out on powerful hardware, but there have been few performance evaluations on resource-constrained devices. We present the results of experiments comparing two of the major open-source DTN implementations, DTN2 and IBR-DTN, on resource-constrained nodes. The comparison is in terms of storage and receive performance, as well as network throughput.","PeriodicalId":211112,"journal":{"name":"CHANTS '12","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121067856","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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