The Experts below are selected from a list of 5946 Experts worldwide ranked by ideXlab platform
Max Ott - One of the best experts on this subject based on the ideXlab platform.
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predicting Network Availability using user context
International Conference on Mobile and Ubiquitous Systems: Networking and Services, 2008Co-Authors: Upendra Rathnayake, Max OttAbstract:Most mobile devices nowadays can simultaneously connect to different access Networks with different characteristics at different times. Most solutions proposed for such an environment are reactive in nature. For example, when Networks are encountered, the device performs a vertical handover to the Network that offers the highest bandwidth. But the cost of handover may not be justified if that Network is only available for a short time. Knowledge of future Network Availability and its capabilities would help to proactively handle the handover process more intelligently. Network Availability prediction is often addressed as user path predictions with Network coverage maps. In contrast, we model it as a more robust context prediction problem that can use any of the available context variables like GSM cell ID, WLAN AP, whether the power cable plugged, number of people around etc. Specifically, we propose a Semi-Markovian context prediction model to predict WLAN Availability. As collecting and processing context consumes power, we propose a method to rank each context variable according to their contributions to prediction accuracy. We also employ the same method for optimizing model parameters. Real user data collected in our experiments show that when WLAN status is static, prediction errors are nearly zero and even in changing environments, error is less than 26% on average and the obtained context variable ranking is realistic.
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MobiQuitous - Predicting Network Availability using user context
Proceedings of the 5th International ICST Conference on Mobile and Ubiquitous Systems: Computing Networking and Services, 2008Co-Authors: Upendra Rathnayake, Max OttAbstract:Most mobile devices nowadays can simultaneously connect to different access Networks with different characteristics at different times. Most solutions proposed for such an environment are reactive in nature. For example, when Networks are encountered, the device performs a vertical handover to the Network that offers the highest bandwidth. But the cost of handover may not be justified if that Network is only available for a short time. Knowledge of future Network Availability and its capabilities would help to proactively handle the handover process more intelligently. Network Availability prediction is often addressed as user path predictions with Network coverage maps. In contrast, we model it as a more robust context prediction problem that can use any of the available context variables like GSM cell ID, WLAN AP, whether the power cable plugged, number of people around etc. Specifically, we propose a Semi-Markovian context prediction model to predict WLAN Availability. As collecting and processing context consumes power, we propose a method to rank each context variable according to their contributions to prediction accuracy. We also employ the same method for optimizing model parameters. Real user data collected in our experiments show that when WLAN status is static, prediction errors are nearly zero and even in changing environments, error is less than 26% on average and the obtained context variable ranking is realistic.
Upendra Rathnayake - One of the best experts on this subject based on the ideXlab platform.
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EMUNE: Architecture for Mobile Data Transfer Scheduling with Network Availability Predictions
Mobile Networks and Applications, 2012Co-Authors: Upendra Rathnayake, Henrik Petander, Aruna SeneviratneAbstract:With the mobile communication market increasingly moving towards value-added services, the Network cost will need to be included in the service offering itself. This will lead service providers to optimize Network usage based on real cost rather than simplified Network plans sold to consumers traditionally. Meanwhile, today’s mobile devices are increasingly containing multiple radios, enabling users on the move to take advantage of the heterogeneous wireless Network environment. In addition, we observe that many bandwidth intensive services such as video on demand and software updates are essentially non real-time and buffers in mobile devices are effectively unlimited. We therefore propose EMUNE, a new transfer service which leverages these aspects. It supports opportunistic bulk transfers in high bandwidth Networks while adapting to device power concerns, application requirements and user preferences of cost and quality. Our proposed architecture consists of an API, a transport service and two main functional units. The well defined API hides all internal complexities from a programmer and provides easy access to the functionalities. The prediction engine infers future Network and bandwidth Availability. The scheduling engine takes the output of the prediction engine as well as the power and monetary costs, application requirements and user preferences into account and determines which interface to use, when and for how long for all outstanding data transfer requests. The transport service accordingly executes the inferred data transfer schedule. The results from the implementation of EMUNE’s and of the prediction and scheduling engines evaluated against real user data show the effectiveness of the proposed architecture for better utilization of multiple Network interfaces in mobile devices.
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Network Availability prediction with hidden context
Performance Evaluation, 2011Co-Authors: Upendra Rathnayake, Maximilian Ott, Aruna SeneviratneAbstract:Modern mobile devices are increasingly capable of simultaneously connecting to multiple access Networks with different characteristics. Restricted coverage combined with user mobility will vary the Availability of Networks for a mobile device. Most proposed solutions for such an environment are reactive in nature, such as performing a vertical handover to the Network that offers the highest bandwidth. But the cost of the handover may not be justified if that Network is only available for a short time. Knowledge of future Network Availability and their capabilities are the basis for proactive schemes which will improve Network selection and utilization. We have previously proposed a prediction model that can use any available context such as GSM Location Area, WLAN presence or even whether the power cable is plugged in, to predict Network Availability. As it may not be possible to sense all of the context variables that influence future Network Availability, in this paper we introduce a generic, new model incorporating a hidden variable to account for this. Specifically, we propose a Dynamic Bayesian Network based context prediction model to predict Network Availability. Predictions performed for WLAN Availability with the real user data collected in our experiments show 20% or more improvement compared to both of our earlier proposals of order 1 and 2 semi-Markov models.
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Network Availability prediction: Can it be done?
Global Information Infrastructure Symposium - GIIS 2011, 2011Co-Authors: Aruna Seneviratne, Jhoanna Rhodette Pedrasa, Upendra RathnayakeAbstract:With the Availability of more powerful mobile devices and a variety of access Networks, users are expecting more and more services whilst on the move. There have been many attempts develop methods of providing these types of services form a user as well as a service provider perspective. All of these methods are based on the ability to predict the future. In this paper, will first present an overview of the research on one aspect of this, namely Network Availability prediction. We first, summarise the work that has been done in Network Availability prediction and categorize them. Using the categorisation, we show that one of the existing mechanisms provide the necessary accuracy and robustness. Then we present a hybrid design which overcome the limitations of the current systems. We show the viability of the the proposed hybrid system by summarising a dynamic baysean Network and report exchange based predication mechanisms. We conclude the paper with a brief discussion on the open issues of developing such a hybrid scheme.
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MSWiM - A DBN approach for Network Availability prediction
Proceedings of the 12th ACM international conference on Modeling analysis and simulation of wireless and mobile systems - MSWiM '09, 2009Co-Authors: Upendra Rathnayake, Maximilian Ott, Aruna SeneviratneAbstract:Modern mobile devices are increasingly capable of simultaneously connecting to multiple access Networks with different characteristics. Restricted coverage combined with user mobility will vary the Availability of Networks for a mobile device. Most proposed solutions for such an environment are reactive in nature, such as performing a vertical handover to the Network that offers the highest bandwidth. But the cost of the handover may not be justified if that Network is only available for a short time. Knowledge of future Network Availability and their capabilities are the basis for proactive schemes which will improve Network selection and utilization. We have previously proposed a prediction model that can use any available context such as GSM Location Area, WLAN presence or even whether the power cable is plugged in, to predict Network Availability. As it may not be possible to sense all of the context variables that influence future Network Availability, in this paper we introduce a generic, new model incorporating a hidden variable to account for this. Specifically, we propose a Dynamic Bayesian Network based context prediction model to predict Network Availability. When the predictions were performed for WLAN Availability with the real user data collected in our experiments, this model shows 20% or more improvement than both of our earlier proposals of order 1 and 2 Semi-Markov models.
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predicting Network Availability using user context
International Conference on Mobile and Ubiquitous Systems: Networking and Services, 2008Co-Authors: Upendra Rathnayake, Max OttAbstract:Most mobile devices nowadays can simultaneously connect to different access Networks with different characteristics at different times. Most solutions proposed for such an environment are reactive in nature. For example, when Networks are encountered, the device performs a vertical handover to the Network that offers the highest bandwidth. But the cost of handover may not be justified if that Network is only available for a short time. Knowledge of future Network Availability and its capabilities would help to proactively handle the handover process more intelligently. Network Availability prediction is often addressed as user path predictions with Network coverage maps. In contrast, we model it as a more robust context prediction problem that can use any of the available context variables like GSM cell ID, WLAN AP, whether the power cable plugged, number of people around etc. Specifically, we propose a Semi-Markovian context prediction model to predict WLAN Availability. As collecting and processing context consumes power, we propose a method to rank each context variable according to their contributions to prediction accuracy. We also employ the same method for optimizing model parameters. Real user data collected in our experiments show that when WLAN status is static, prediction errors are nearly zero and even in changing environments, error is less than 26% on average and the obtained context variable ranking is realistic.
Won-sik Yoon - One of the best experts on this subject based on the ideXlab platform.
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International Conference on Computational Science (2) - On the effect of heterogeneous traffic sources on the Network Availability for wireless sensor grids
Computational Science – ICCS 2006, 2006Co-Authors: Ali Hammad Akbar, Ki-hyung Kim, Won-sik YoonAbstract:Wireless sensor grids are poised for applications where pre-deployment information is highly available to optimize communication and computation costs. Using two widely known grid traversal schemes, we critique the effect of multiple services being rendered by a sensor Network onto its Availability. We derive an interesting result using Markovian model to appreciate the effect of load heterogeneity onto node and Network lifetimes. Our mathematical model also analyzes synchronous sleep for its effect on energy conservation. We also propose a epicenter regulated, asynchronous sleep scheme which allows nodes to conserve energy yet relay data towards the sink effectively. The performance results show that the proposed scheme prolongs Network Availability in sensor grids.
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Availability considerations for wireless sensor grids
Lecture Notes in Computer Science, 2006Co-Authors: Ali Hammad Akbar, Ki-hyung Kim, Seung-jin Bang, Waleed Mansoor, Won-sik YoonAbstract:In this paper, we derive and analyze Network Availability for sensor grids by considering an elaborate energy consumption model. Sensor grids that form chain topologies are compared for two widely known grid traversal models, namely staircase and Delannoy number. Based upon the mathematical model, we analyze two sleep modes, viz, synchronous and asynchronous for their effects on the Network Availability of sensor grids with regard to energy conservation and packet loss. We also propose a non-uniform, asynchronous sleep scheme in sensor grids which allows nodes to sleep in a manner such that nodes closer to the gateway sleep less than the nodes in the fringes. The performance results show that the proposed scheme prolongs Network Availability effectively in sensor grids.
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GPC - Availability considerations for wireless sensor grids
Advances in Grid and Pervasive Computing, 2006Co-Authors: Ali Hammad Akbar, Ki-hyung Kim, Seung-jin Bang, Waleed Mansoor, Won-sik YoonAbstract:In this paper, we derive and analyze Network Availability for sensor grids by considering an elaborate energy consumption model. Sensor grids that form chain topologies are compared for two widely known grid traversal models, namely staircase and Delannoy number. Based upon the mathematical model, we analyze two sleep modes, viz, synchronous and asynchronous for their effects on the Network Availability of sensor grids with regard to energy conservation and packet loss. We also propose a non-uniform, asynchronous sleep scheme in sensor grids which allows nodes to sleep in a manner such that nodes closer to the gateway sleep less than the nodes in the fringes. The performance results show that the proposed scheme prolongs Network Availability effectively in sensor grids.
Ali Hammad Akbar - One of the best experts on this subject based on the ideXlab platform.
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International Conference on Computational Science (2) - On the effect of heterogeneous traffic sources on the Network Availability for wireless sensor grids
Computational Science – ICCS 2006, 2006Co-Authors: Ali Hammad Akbar, Ki-hyung Kim, Won-sik YoonAbstract:Wireless sensor grids are poised for applications where pre-deployment information is highly available to optimize communication and computation costs. Using two widely known grid traversal schemes, we critique the effect of multiple services being rendered by a sensor Network onto its Availability. We derive an interesting result using Markovian model to appreciate the effect of load heterogeneity onto node and Network lifetimes. Our mathematical model also analyzes synchronous sleep for its effect on energy conservation. We also propose a epicenter regulated, asynchronous sleep scheme which allows nodes to conserve energy yet relay data towards the sink effectively. The performance results show that the proposed scheme prolongs Network Availability in sensor grids.
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Availability considerations for wireless sensor grids
Lecture Notes in Computer Science, 2006Co-Authors: Ali Hammad Akbar, Ki-hyung Kim, Seung-jin Bang, Waleed Mansoor, Won-sik YoonAbstract:In this paper, we derive and analyze Network Availability for sensor grids by considering an elaborate energy consumption model. Sensor grids that form chain topologies are compared for two widely known grid traversal models, namely staircase and Delannoy number. Based upon the mathematical model, we analyze two sleep modes, viz, synchronous and asynchronous for their effects on the Network Availability of sensor grids with regard to energy conservation and packet loss. We also propose a non-uniform, asynchronous sleep scheme in sensor grids which allows nodes to sleep in a manner such that nodes closer to the gateway sleep less than the nodes in the fringes. The performance results show that the proposed scheme prolongs Network Availability effectively in sensor grids.
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GPC - Availability considerations for wireless sensor grids
Advances in Grid and Pervasive Computing, 2006Co-Authors: Ali Hammad Akbar, Ki-hyung Kim, Seung-jin Bang, Waleed Mansoor, Won-sik YoonAbstract:In this paper, we derive and analyze Network Availability for sensor grids by considering an elaborate energy consumption model. Sensor grids that form chain topologies are compared for two widely known grid traversal models, namely staircase and Delannoy number. Based upon the mathematical model, we analyze two sleep modes, viz, synchronous and asynchronous for their effects on the Network Availability of sensor grids with regard to energy conservation and packet loss. We also propose a non-uniform, asynchronous sleep scheme in sensor grids which allows nodes to sleep in a manner such that nodes closer to the gateway sleep less than the nodes in the fringes. The performance results show that the proposed scheme prolongs Network Availability effectively in sensor grids.
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Longevity Enhancing Measures for Sensor Grids
2006Co-Authors: Ali Hammad Akbar, Waleed Mansoor, Ahmad Ali Iqbal, Shafique Ahmad Chaudhry, Ki-hyung KimAbstract:In this paper, we have analyzed Network Availability of sensor grids in the context of criticality of individual nodes in ensuring Network connectivity that form such grids. By assuming staircase traversal to adjacent neighbors only, we consider the Network Availability of a two dimensional grid. We propose simple yet innovative schemes for such pla- nar arrangements of sensor nodes to improve their longevity. Through the interpretation of the stochastic model we have obtained, the usability of our schemes can be duly verified.
Ki-hyung Kim - One of the best experts on this subject based on the ideXlab platform.
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International Conference on Computational Science (2) - On the effect of heterogeneous traffic sources on the Network Availability for wireless sensor grids
Computational Science – ICCS 2006, 2006Co-Authors: Ali Hammad Akbar, Ki-hyung Kim, Won-sik YoonAbstract:Wireless sensor grids are poised for applications where pre-deployment information is highly available to optimize communication and computation costs. Using two widely known grid traversal schemes, we critique the effect of multiple services being rendered by a sensor Network onto its Availability. We derive an interesting result using Markovian model to appreciate the effect of load heterogeneity onto node and Network lifetimes. Our mathematical model also analyzes synchronous sleep for its effect on energy conservation. We also propose a epicenter regulated, asynchronous sleep scheme which allows nodes to conserve energy yet relay data towards the sink effectively. The performance results show that the proposed scheme prolongs Network Availability in sensor grids.
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Availability considerations for wireless sensor grids
Lecture Notes in Computer Science, 2006Co-Authors: Ali Hammad Akbar, Ki-hyung Kim, Seung-jin Bang, Waleed Mansoor, Won-sik YoonAbstract:In this paper, we derive and analyze Network Availability for sensor grids by considering an elaborate energy consumption model. Sensor grids that form chain topologies are compared for two widely known grid traversal models, namely staircase and Delannoy number. Based upon the mathematical model, we analyze two sleep modes, viz, synchronous and asynchronous for their effects on the Network Availability of sensor grids with regard to energy conservation and packet loss. We also propose a non-uniform, asynchronous sleep scheme in sensor grids which allows nodes to sleep in a manner such that nodes closer to the gateway sleep less than the nodes in the fringes. The performance results show that the proposed scheme prolongs Network Availability effectively in sensor grids.
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GPC - Availability considerations for wireless sensor grids
Advances in Grid and Pervasive Computing, 2006Co-Authors: Ali Hammad Akbar, Ki-hyung Kim, Seung-jin Bang, Waleed Mansoor, Won-sik YoonAbstract:In this paper, we derive and analyze Network Availability for sensor grids by considering an elaborate energy consumption model. Sensor grids that form chain topologies are compared for two widely known grid traversal models, namely staircase and Delannoy number. Based upon the mathematical model, we analyze two sleep modes, viz, synchronous and asynchronous for their effects on the Network Availability of sensor grids with regard to energy conservation and packet loss. We also propose a non-uniform, asynchronous sleep scheme in sensor grids which allows nodes to sleep in a manner such that nodes closer to the gateway sleep less than the nodes in the fringes. The performance results show that the proposed scheme prolongs Network Availability effectively in sensor grids.
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Longevity Enhancing Measures for Sensor Grids
2006Co-Authors: Ali Hammad Akbar, Waleed Mansoor, Ahmad Ali Iqbal, Shafique Ahmad Chaudhry, Ki-hyung KimAbstract:In this paper, we have analyzed Network Availability of sensor grids in the context of criticality of individual nodes in ensuring Network connectivity that form such grids. By assuming staircase traversal to adjacent neighbors only, we consider the Network Availability of a two dimensional grid. We propose simple yet innovative schemes for such pla- nar arrangements of sensor nodes to improve their longevity. Through the interpretation of the stochastic model we have obtained, the usability of our schemes can be duly verified.