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94
RxW: A Scheduling Approach for Large-Scale On-Demand Data Broadcast
, 1999
"... Broadcast is becoming an increasingly attractive data dissemination method for large client populations. In order to effectively utilize a broadcast medium for sucha service, it is necessary to have efficient, on-line scheduling algorithms that can balance individual and overall performance, and ca ..."
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Cited by 116 (2 self)
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Broadcast is becoming an increasingly attractive data dissemination method for large client populations. In order to effectively utilize a broadcast medium for sucha service, it is necessary to have efficient, on-line scheduling algorithms that can balance individual and overall performance, and can scale in terms of data set sizes, client populations, and broadcast bandwidth. We propose an algorithm, called RxW, that provides good performance across all of these criteria and that can be tuned to trade o# average and worst case waiting time. Unlike previous work on lowoverhead scheduling, the algorithm does not use estimates of the access probabilities of items, but rather, it makes scheduling decisions based on the current queue state, allowing it to easily adapt to changes in the intensity and distribution of the workload. We demonstrate the performance advantages of the algorithm under a range of scenarios using a simulation model and present analytical results that describe the intrinsic behavior of the algorithm.
Multi-Level Multi-Channel Air Cache Designs for Broadcasting in a Mobile Environment
, 2000
"... In this paper, we investigate efficient ways of broadcasting data to mobile users over multiple physical channels, which cannot be coalesced into a lesser number of high-bandwidth channels. We propose the use of MLMC (Multi-Level Multi-Channel ) Air-Cache which can provide mobile users with data bas ..."
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Cited by 40 (0 self)
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In this paper, we investigate efficient ways of broadcasting data to mobile users over multiple physical channels, which cannot be coalesced into a lesser number of high-bandwidth channels. We propose the use of MLMC (Multi-Level Multi-Channel ) Air-Cache which can provide mobile users with data based on their popularity factor. We provide a wide range of design considerations for the server which broadcasts over the MLMC cache. We also investigate some novel techniques for the mobile user to access data from the MLMC cache and show the advantages of designing the broadcast strategy in tandem with the access behavior of the mobile users . Finally, we provide experimental results to compare the techniques we introduce.
Performance evaluation of a wireless hierarchical data dissemination system
- in Proc. MobiCom
, 1999
"... Various techniques have been developed to improve the performance of wireless information services. Techniques such as information broadcasting, caching of frequently accessed data, and point-to-point channels for pull-based data requests are often used to reduce data access time. To efficiently uti ..."
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Cited by 35 (11 self)
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Various techniques have been developed to improve the performance of wireless information services. Techniques such as information broadcasting, caching of frequently accessed data, and point-to-point channels for pull-based data requests are often used to reduce data access time. To efficiently utilize information broadcast, indexing and scheduling schemes are employed for the organization of data broadcast. Most of the studies in the literature focused either on individual technique or a combination of them with some restrictive assumptions. There is no study considering these techniques working together in an integrated manner. In this paper, we propose a dynamic data delivery model for wireless communication environments. An important feature of our model is that data are disseminated through various storage mediums according to the dynamically collected data access patterns. Various results are presented in a set of simulation studies, which give some of the intuitions behind the design of a wireless data delivery system. 1
Optimal index and data allocation in multiple broadcast channels
- In Proceeding of the 16th International Conference on Data Engineering
, 2000
"... The issue of data broadcast has received much attention in mobile computing. A periodic broadcast of frequently requested data can reduce the workload of the up-link channel and facilitate data access for the mobile user. Since the mobile units usually have limited battery capacity, the minimization ..."
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Cited by 33 (6 self)
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The issue of data broadcast has received much attention in mobile computing. A periodic broadcast of frequently requested data can reduce the workload of the up-link channel and facilitate data access for the mobile user. Since the mobile units usually have limited battery capacity, the minimization of the access latency for the broadcast data is an important problem. The indexing and scheduling techniques on the broadcast data should be considered. In this paper we propose a solution to find the optimal index and data allocation, which minimizes the access latency for any number of broadcast channels. We represent all the possible allocations as a tree in which the optimal one is searched, and propose a pruning strategy based on some properties to greatly reduce the search space. Experiments are performed to show the effectiveness of the pruning strategy. Moreover, we propose two heuristics to solve the same problem when the size of the broadcast data is large. 1.
A Hybrid Index Technique for Power Efficient Data Broadcast
- J. Distributed and Parallel Databases (DPDB
"... The intention of power conservative indexing techniques for wireless data broadcast is to reduce mobile client tune-in time while maintaining an acceptable data access time. In this paper, we investigate indexing techniques based on index trees and signatures for data disseminated on a broadcast cha ..."
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Cited by 27 (11 self)
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The intention of power conservative indexing techniques for wireless data broadcast is to reduce mobile client tune-in time while maintaining an acceptable data access time. In this paper, we investigate indexing techniques based on index trees and signatures for data disseminated on a broadcast channel. Moreover, a hybrid indexing method combining strengths of the signature and the index tree techniques is proposed. Different from previous studies, our research takes into consideration of two important data organization factors, namely, clustering and scheduling. Cost models for the three indexing methods are derived for various data organization accommodating these two factors. Based on our analytical comparisons, the signature and the hybrid indexing techniques are the best choices for power conservative indexing of various data organization on wireless broadcast channels. 1 Introduction Due to resource limitations in a mobile environment, it is important to efficiently utilize w...
Dynamic generation of data broadcasting programs for a broadcast disk array in a mobile computing environment
- In Proceedings of the 9th ACM International Conference on Information and Knowledge Management (CIKM’2000
, 2000
"... We explore in this paper the problem of generating hierarchical broadcast programs with the data access frequencies and the number of broadcast disks in a broadcast disk array given. Specifically, we first transform the problem of generating hierarchical broadcast programs into the one of constructi ..."
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Cited by 26 (6 self)
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We explore in this paper the problem of generating hierarchical broadcast programs with the data access frequencies and the number of broadcast disks in a broadcast disk array given. Specifically, we first transform the problem of generating hierarchical broadcast programs into the one of constructing a channel allocation tree with variant-fanout. By exploiting the feature of tree generation with variantfanout, we develop a heuristic algorithm VF K to minimize the expected delay of data items in the broadcast program. Performance of these algorithms is analyzed. It is shown by our simulation results that by exploiting the feature of variant-fanout in constructing the channel allocation tree, the solution obtained by algorithm VF K is of very high quality and is in fact very close to the optimal one.
Indexing techniques for wireless data broadcast under data clustering and scheduling
- In Proc. of the 8th International Conference on Information and Knowledge Management
, 1999
"... This paper investigates power conserving indexing techniques for data disseminated on a broadcast channel. A hybrid indexing method combining strengths of the signature and the index tree techniques is presented. Different from previous studies, our research takes into consideration two important da ..."
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Cited by 26 (6 self)
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This paper investigates power conserving indexing techniques for data disseminated on a broadcast channel. A hybrid indexing method combining strengths of the signature and the index tree techniques is presented. Different from previous studies, our research takes into consideration two important data organization factors, namely, clustering and scheduling. Cost models for index, signature and hybrid methods are derived by taking into account various data organizations accommodating these two factors. Based on our analytical comparisons, the signature and the hybrid indexing techniques are the best choices for power conserving indexing of various data organizations on wireless broadcast channels. 1
Adaptive Data Delivery in Wireless Communication Environments
- In Workshop on Mobile Data Access
, 2000
"... The combination of broadcast and on-demand data delivery services is an economic way to build a highly scalable wireless information system with limited bandwidth. The use of data broadcasting should be adaptive so that the system response time can always be minimised. A traditional approach require ..."
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Cited by 22 (7 self)
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The combination of broadcast and on-demand data delivery services is an economic way to build a highly scalable wireless information system with limited bandwidth. The use of data broadcasting should be adaptive so that the system response time can always be minimised. A traditional approach requires the development of a system response time equation in order to nd the optimal solution. However, obtaining such an equation is not always possible. We observe that by maintaining a certain level of on-demand request arrival rate, a close approximation to the optimal solution can be obtained. Using this approach, a real-time adaptive data delivery algorithm is developed. Our algorithm does not require the access information of the data items to be known exactly, which is needed normally for this kind of optimization problems. A simple and low overhead bit vector mechanism is able to capture the relative popularities of the data items. With this information, our algorithm can give a perform...
A study on channel allocation for data dissemination in mobile computing environments
, 1999
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