Frequency channels are allocated to the access-points (APs) satisfying the co-channel interference in an IEEE 802.11 WLAN. Very few APs can be activated simultaneously with a conflict-free frequency assignment to them, due to limited number of frequencies. This may lead to a reduced aggregate throughput. We argue that aggregate throughput can significantly be improved by allowing some of the selected interfering APs to be activated with the same frequency but to operate in a fairly time-scheduled manner to satisfy the co-channel interference. We introduce the notion of class and cluster and based on it propose a combined frequency assignment, AP scheduling and association algorithm with the objective of maximizing the aggregate throughput. Simulation results show that the proposed algorithm is superior than both the algorithms that ignores the co-channel interference altogether by assuming proper frequency planning and that allows to activate only those APs for which a conflict-free frequency assignment exists.
{"title":"A Combined Frequency Assignment and AP Scheduling for Throughput Maximization in IEEE 802.11 WLAN","authors":"Babul P. Tewari, Sasthi C. Ghosh","doi":"10.1145/2536853.2536890","DOIUrl":"https://doi.org/10.1145/2536853.2536890","url":null,"abstract":"Frequency channels are allocated to the access-points (APs) satisfying the co-channel interference in an IEEE 802.11 WLAN. Very few APs can be activated simultaneously with a conflict-free frequency assignment to them, due to limited number of frequencies. This may lead to a reduced aggregate throughput. We argue that aggregate throughput can significantly be improved by allowing some of the selected interfering APs to be activated with the same frequency but to operate in a fairly time-scheduled manner to satisfy the co-channel interference. We introduce the notion of class and cluster and based on it propose a combined frequency assignment, AP scheduling and association algorithm with the objective of maximizing the aggregate throughput. Simulation results show that the proposed algorithm is superior than both the algorithms that ignores the co-channel interference altogether by assuming proper frequency planning and that allows to activate only those APs for which a conflict-free frequency assignment exists.","PeriodicalId":135195,"journal":{"name":"Advances in Mobile Multimedia","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121959891","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}
Michael Leichtfried, Christoph Kaltenriner, Annette Mossel, H. Kaufmann
In this paper, we present a low-weight and low-cost Unmanned Aerial Vehicle (UAV) for autonomous flight and navigation in GPS-denied environments using an off-the-shelf smartphone as its core on-board processing unit. Thereby, our approach is independent from additional ground hardware and the UAV core unit can be easily replaced with more powerful hardware that simplifies setup updates as well as maintenance. The UAV is able to map, locate and navigate in an unknown indoor environment fusing vision based tracking with inertial and attitude measurements. We choose an algorithmic approach for mapping and localization that does not require GPS coverage of the target area, therefore autonomous indoor navigation is made possible. We demonstrate the UAVs capabilities of mapping, localization and navigation in an unknown 2D marker environment. Our promising results enable future research on 3D self-localization and dense mapping using mobile hardware as the only on-board processing unit.
{"title":"Autonomous Flight using a Smartphone as On-Board Processing Unit in GPS-Denied Environments","authors":"Michael Leichtfried, Christoph Kaltenriner, Annette Mossel, H. Kaufmann","doi":"10.1145/2536853.2536898","DOIUrl":"https://doi.org/10.1145/2536853.2536898","url":null,"abstract":"In this paper, we present a low-weight and low-cost Unmanned Aerial Vehicle (UAV) for autonomous flight and navigation in GPS-denied environments using an off-the-shelf smartphone as its core on-board processing unit. Thereby, our approach is independent from additional ground hardware and the UAV core unit can be easily replaced with more powerful hardware that simplifies setup updates as well as maintenance. The UAV is able to map, locate and navigate in an unknown indoor environment fusing vision based tracking with inertial and attitude measurements. We choose an algorithmic approach for mapping and localization that does not require GPS coverage of the target area, therefore autonomous indoor navigation is made possible. We demonstrate the UAVs capabilities of mapping, localization and navigation in an unknown 2D marker environment. Our promising results enable future research on 3D self-localization and dense mapping using mobile hardware as the only on-board processing unit.","PeriodicalId":135195,"journal":{"name":"Advances in Mobile Multimedia","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122123174","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}
T. Kiriyama, Tomohiro Akagawa, Taichi Inoue, Ayaka Yamamoto
This study aims at designing implicit interaction between human and robots. We try to make mobile robots reactive to humans, while not trying to force humans perform active actions. We experiment such interaction in a museum setting with an ongoing exhibit.
{"title":"Reactive Behaviors of Mobile Robots in a Museum Exhibit","authors":"T. Kiriyama, Tomohiro Akagawa, Taichi Inoue, Ayaka Yamamoto","doi":"10.1145/2536853.2536950","DOIUrl":"https://doi.org/10.1145/2536853.2536950","url":null,"abstract":"This study aims at designing implicit interaction between human and robots. We try to make mobile robots reactive to humans, while not trying to force humans perform active actions. We experiment such interaction in a museum setting with an ongoing exhibit.","PeriodicalId":135195,"journal":{"name":"Advances in Mobile Multimedia","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125165751","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}
Peter Riedl, Phillip Koller, R. Mayrhofer, Andreas Möller, Marion Koelle, M. Kranz
The ongoing evolution of mobile phones to "pocket computers" generated a demand for more and more applications to be ported to the mobile phone. Because a full security assessment for a whole mobile operating system would be prohibitively costly, currently security critical applications can not be implemented. We address this challenge by introducing security zones to enable applications with high security demands like driving licenses, health insurance cards, or passports on mobile phones. This zone concept creates the need for visualization of the current zone and a way to switch between zones. In this paper we discuss several possible ways of achieving this.
{"title":"Visualizations and Switching Mechanisms for Security Zones","authors":"Peter Riedl, Phillip Koller, R. Mayrhofer, Andreas Möller, Marion Koelle, M. Kranz","doi":"10.1145/2536853.2536948","DOIUrl":"https://doi.org/10.1145/2536853.2536948","url":null,"abstract":"The ongoing evolution of mobile phones to \"pocket computers\" generated a demand for more and more applications to be ported to the mobile phone. Because a full security assessment for a whole mobile operating system would be prohibitively costly, currently security critical applications can not be implemented. We address this challenge by introducing security zones to enable applications with high security demands like driving licenses, health insurance cards, or passports on mobile phones. This zone concept creates the need for visualization of the current zone and a way to switch between zones. In this paper we discuss several possible ways of achieving this.","PeriodicalId":135195,"journal":{"name":"Advances in Mobile Multimedia","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128070512","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}
W. Kurschl, Mirjam Augstein, Holger Stitz, Peter Heumader, Claudia Pointner
Since a couple of years tablets are gaining ever increasing markets share, so that desktop PCs are slowly losing their dominant role. People with disabilities are also attracted by tablets but they are sometimes challenged by the multi-touch technology itself and the natural interfaces of the provided applications. This paper presents an approach, where a novel user modelling wizard for people with motor impairments is used to gain a deeper understanding of very specific interaction patterns leading to a user model, which allows us to automatically derive an application- and user-specific configuration. An evaluation showed promising results because the configuration resulting from the user model is comparable to the configuration proposed by consultants. The result can either be used by the consultants to configure applications accordingly, or by the application itself, to provide an adaptive user interface suited to the individual capabilities.
{"title":"A User Modelling Wizard for People with Motor Impairments","authors":"W. Kurschl, Mirjam Augstein, Holger Stitz, Peter Heumader, Claudia Pointner","doi":"10.1145/2536853.2536860","DOIUrl":"https://doi.org/10.1145/2536853.2536860","url":null,"abstract":"Since a couple of years tablets are gaining ever increasing markets share, so that desktop PCs are slowly losing their dominant role. People with disabilities are also attracted by tablets but they are sometimes challenged by the multi-touch technology itself and the natural interfaces of the provided applications.\u0000 This paper presents an approach, where a novel user modelling wizard for people with motor impairments is used to gain a deeper understanding of very specific interaction patterns leading to a user model, which allows us to automatically derive an application- and user-specific configuration. An evaluation showed promising results because the configuration resulting from the user model is comparable to the configuration proposed by consultants. The result can either be used by the consultants to configure applications accordingly, or by the application itself, to provide an adaptive user interface suited to the individual capabilities.","PeriodicalId":135195,"journal":{"name":"Advances in Mobile Multimedia","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130114714","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 technologies have been facilitating potential digital inclusion opportunities and a wide range of community partnership platforms. Wireless Mesh Networking (WMN) plays a key role in the next generation wireless and mobile networks. Supporting QoS-aware communications to enable a rich portfolio of real-time and QoS sensitive applications is foreseen to be vital for the success of the next generation WMNs. Unfortunately, existing standards supporting instant group communications in WMNs are not perfectly equipped to cater to this task as these standards come with an inherent complexity and suffer from innate problems with respect to QoS provisioning. Thus, in this study, we propose a new multicast algorithm, namely, Multicast Gateway Centralized Multi-hop Routing algorithm (MGCMR) to facilitate the instant/real time communication applications. The MGCMR is the first that considers both the requirements of instant applications and the capability of gateway based management in WMNs. Our experiments confirm the superiority of our proposed MGCMR against its counterparts.
{"title":"Multicast Multi-hop Routing for Wireless Mesh Networks","authors":"A. Al-Dubai, Liang Zhao","doi":"10.1145/2536853.2536889","DOIUrl":"https://doi.org/10.1145/2536853.2536889","url":null,"abstract":"Wireless technologies have been facilitating potential digital inclusion opportunities and a wide range of community partnership platforms. Wireless Mesh Networking (WMN) plays a key role in the next generation wireless and mobile networks. Supporting QoS-aware communications to enable a rich portfolio of real-time and QoS sensitive applications is foreseen to be vital for the success of the next generation WMNs. Unfortunately, existing standards supporting instant group communications in WMNs are not perfectly equipped to cater to this task as these standards come with an inherent complexity and suffer from innate problems with respect to QoS provisioning. Thus, in this study, we propose a new multicast algorithm, namely, Multicast Gateway Centralized Multi-hop Routing algorithm (MGCMR) to facilitate the instant/real time communication applications. The MGCMR is the first that considers both the requirements of instant applications and the capability of gateway based management in WMNs. Our experiments confirm the superiority of our proposed MGCMR against its counterparts.","PeriodicalId":135195,"journal":{"name":"Advances in Mobile Multimedia","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124544728","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 talk we will argue that developments in science will continue with increasing speed, opening completely new vistas. Why this is so is not just due to the usual trivial observations such as "developments are happening very fast and it seems even at accelerating speed". Rather, we will show a number of much deeper reasons, why nw developments will come at us as surprise, and to an extent hard to imagine. Some of the arguments are surprising in themselves and shed a light on how we think, and how we have to change our thinking to at least grasp a bit of what is going to happen. Surprisingly, it also turns out that some reasons show the weaknesses of our information age and how knowing this, we can become better in handling complicated situations and negotiations. If this sounds all a bit vague, it is, and it is vague on purpose: the speaker wants to surprise everyone in the audience a few times by presenting concrete samples and does not want to give away some of the highlights in this abstract.
{"title":"New Technologies: We have seen nothing yet","authors":"H. Maurer","doi":"10.1145/2536853.2536855","DOIUrl":"https://doi.org/10.1145/2536853.2536855","url":null,"abstract":"In this talk we will argue that developments in science will continue with increasing speed, opening completely new vistas. Why this is so is not just due to the usual trivial observations such as \"developments are happening very fast and it seems even at accelerating speed\". Rather, we will show a number of much deeper reasons, why nw developments will come at us as surprise, and to an extent hard to imagine. Some of the arguments are surprising in themselves and shed a light on how we think, and how we have to change our thinking to at least grasp a bit of what is going to happen. Surprisingly, it also turns out that some reasons show the weaknesses of our information age and how knowing this, we can become better in handling complicated situations and negotiations. If this sounds all a bit vague, it is, and it is vague on purpose: the speaker wants to surprise everyone in the audience a few times by presenting concrete samples and does not want to give away some of the highlights in this abstract.","PeriodicalId":135195,"journal":{"name":"Advances in Mobile Multimedia","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121286122","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}
Sports tracking applications are increasingly available on the market, and research has recently picked up this topic. Tracking a user's running track and providing feedback on the performance are among the key features of such applications. However, little attention has been paid to the accuracy of the applications' localization measurements. In evaluating the nine currently most popular running applications, we found tremendous differences in the GPS measurements. Besides this finding, our study contributes to the scientific knowledge base by qualifying the findings of previous studies concerning accuracy with smartphones' GPS components.
{"title":"On the (In-)Accuracy of GPS Measures of Smartphones: A Study of Running Tracking Applications","authors":"Christine Bauer","doi":"10.1145/2536853.2536893","DOIUrl":"https://doi.org/10.1145/2536853.2536893","url":null,"abstract":"Sports tracking applications are increasingly available on the market, and research has recently picked up this topic. Tracking a user's running track and providing feedback on the performance are among the key features of such applications. However, little attention has been paid to the accuracy of the applications' localization measurements. In evaluating the nine currently most popular running applications, we found tremendous differences in the GPS measurements. Besides this finding, our study contributes to the scientific knowledge base by qualifying the findings of previous studies concerning accuracy with smartphones' GPS components.","PeriodicalId":135195,"journal":{"name":"Advances in Mobile Multimedia","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115243542","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}
Robert H Acker, Andreas Plies, M. Massoth, Ralf S. Mayer, Torsten Wiens
Many online services require an authentication of the user against the service provider. Most telephone services have insufficient security mechanisms. Even though, modern IP-based telephone networks are exposed to a larger range of security threats in camparison to classical circuit switched networks. In this paper, we present a concept and prototype, which uses smart cards for user authentication in Voice-over-IP (VoIP) calls. During an encrypted VoIP call the user is able to authenticate himself against the service provider, e.g. a company, using a smart card and an NFC-enabled smartphone. The papers describes the server infrastructure of the service provider, the implementation on the mobile device of the user and the integration of the smart card.
{"title":"Mobile Call Authentication using Near Field Communication-based Smart Cards for Proof of Identity towards a Company","authors":"Robert H Acker, Andreas Plies, M. Massoth, Ralf S. Mayer, Torsten Wiens","doi":"10.1145/2536853.2536929","DOIUrl":"https://doi.org/10.1145/2536853.2536929","url":null,"abstract":"Many online services require an authentication of the user against the service provider. Most telephone services have insufficient security mechanisms. Even though, modern IP-based telephone networks are exposed to a larger range of security threats in camparison to classical circuit switched networks. In this paper, we present a concept and prototype, which uses smart cards for user authentication in Voice-over-IP (VoIP) calls. During an encrypted VoIP call the user is able to authenticate himself against the service provider, e.g. a company, using a smart card and an NFC-enabled smartphone. The papers describes the server infrastructure of the service provider, the implementation on the mobile device of the user and the integration of the smart card.","PeriodicalId":135195,"journal":{"name":"Advances in Mobile Multimedia","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131553104","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}
The penetration rate of smart phones is increasing rapidly and therefore these mobile devices become more and more dominating in daily life. Within an extremely short period of time the way of communication, reading books, listening music, viewing images e.g. has changed dramatically. For elderly people definitively too little time to adapt to this new type of interaction paradigm accordingly. But the number of senior people is growing worldwide and therefore the user experience of these mobile devices has to be adapted to the needs of the elderly. In this paper we introduce a touch screen based UI concept for senior users. This concept is based on two different interface layers: the integrated scalable help system and the book-oriented application design which uses the metaphor of books for menu selection and a flat navigation tree for reducing short-term memory load.
{"title":"An Adaptive and Book-Oriented Mobile Touch Screen User Interface Concept for Novice Senior Users","authors":"M. Hölzl, C. Schaffer","doi":"10.1145/2536853.2536869","DOIUrl":"https://doi.org/10.1145/2536853.2536869","url":null,"abstract":"The penetration rate of smart phones is increasing rapidly and therefore these mobile devices become more and more dominating in daily life. Within an extremely short period of time the way of communication, reading books, listening music, viewing images e.g. has changed dramatically. For elderly people definitively too little time to adapt to this new type of interaction paradigm accordingly. But the number of senior people is growing worldwide and therefore the user experience of these mobile devices has to be adapted to the needs of the elderly. In this paper we introduce a touch screen based UI concept for senior users. This concept is based on two different interface layers: the integrated scalable help system and the book-oriented application design which uses the metaphor of books for menu selection and a flat navigation tree for reducing short-term memory load.","PeriodicalId":135195,"journal":{"name":"Advances in Mobile Multimedia","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130884022","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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