11-07-2012, 02:55 PM
CACHING STRATEGIES BASED ON INFORMATION DENSITY ESTIMATION IN WIRELESS AD HOC NETWORKS
[attachment=27451]
ABSTRACT:
Data caching strategy for ad hoc networks whose nodes exchange information items in a peer-to-peer fashion. Data caching is a fully distributed scheme where each node, upon receiving requested information, determines the cache drop time of the information or which content to replace to make room for the newly arrived information. These decisions are made depending on the perceived “presence” of the content in the nodes proximity, whose estimation does not cause any additional overhead to the information sharing system.
We devise a strategy where nodes, independent of each other, decide whether to cache some content and for how long. In the case of small-sized caches, we aim to design a content replacement strategy that allows nodes to successfully store newly received information while maintaining the good performance of the content distribution system. Under both conditions, each node takes decisions according to its perception of what nearby users may store in their caches and with the aim of differentiating its own cache content from the other nodes’.
The result is the creation of content diversity within the nodes neighborhood so that a requesting user likely finds the desired information nearby. We simulate our caching algorithms in different ad hoc network scenarios and compare them with other caching schemes, showing that our solution succeeds in creating the desired content diversity, thus leading to a resource-efficient information access.
PROJECT PURPOSE:
Peer-to-peer system could come in handy, if used in conjunction with cellular networks, to promote content sharing using ad hoc networking among mobile users. For highly popular content, peer-to-peer distribution can, indeed, remove bottlenecks by pushing the distribution from the core to the edge of the network.
However, a cache-all-you-see approach is unfeasible, because it would swamp node storage capacity with needless data that were picked up on the go several techniques of efficiently caching information in wireless ad hoc networks.
PROJECT SCOPE:
However, the solution that was proposed is based on the formation of an overlay network composed of “mediator” nodes, and it is only fitted to static connected networks with stable links among nodes. These assumptions, along with the significant communication overhead needed to elect “mediator” nodes, make this scheme unsuitable for the mobile environments that we address. A complete framework for information retrieval and caching in mobile ad hoc networks, and it is built on an underlying routing protocol and requires the manual setting of a network wide “cooperation zone” parameter. Note that assuming the presence of a routing protocol can prevent the adoption of the scheme in in highly mobile networks.
PRODUCT FEATURES:
However, our simulations over a wide range of network and application parameters show that the performance of the caching algorithms.
Presents a distributed implementation based on an approximation algorithm for the problem of cache placement of multiple data items under memory constraint.
The result is the creation of content diversity within the nodes neighborhood so that a requesting user likely finds the desired information nearby.
We simulate our caching algorithms in different ad hoc network scenarios and compare them with other caching schemes, showing that our solution succeeds in creating the desired content diversity, thus leading to a resource-efficient information access.
INTRODUCTION:
Ad hoc networks are multi hop wireless networks of small computing devices with wireless interfaces. The computing devices could be conventional computers (for example, PDA, laptop, or PC) or backbone routing platforms or even embedded processors such as sensor nodes. The problem of optimal placement of caches to reduce overall cost of accessing data is motivated by the following two defining characteristics of ad hoc networks. First, the ad hoc networks are multi hop networks without a central base station. Thus, remote access of information typically occurs via multi hop routing, which can greatly benefit from caching to reduce access latency. Second, the network is generally resource constrained in terms of channel bandwidth or battery power in the nodes. Caching helps in reducing communication, this results in savings in bandwidth, as well as battery energy. The problem of cache placement is particularly challenging when each network node has a limited memory to cache data items.
In this paper, our focus is on developing efficient caching techniques in ad hoc networks with memory limitations. Research into data storage, access, and dissemination techniques in ad hoc networks is not new. In particular, these mechanisms have been investigated in connection with sensor networking peer-to-peer networks mesh networks world wide Web and even more general ad hoc networks. However, the presented approaches have so far been somewhat “ad hoc” and empirically based, without any strong analytical foundation. In contrast, the theory literature abounds in analytical studies into the optimality properties of caching and replica allocation problems. However, distributed implementations of these techniques and their performances in complex network settings have not been investigated. It is even unclear whether these techniques are amenable to efficient distributed implementations.
[attachment=27451]
ABSTRACT:
Data caching strategy for ad hoc networks whose nodes exchange information items in a peer-to-peer fashion. Data caching is a fully distributed scheme where each node, upon receiving requested information, determines the cache drop time of the information or which content to replace to make room for the newly arrived information. These decisions are made depending on the perceived “presence” of the content in the nodes proximity, whose estimation does not cause any additional overhead to the information sharing system.
We devise a strategy where nodes, independent of each other, decide whether to cache some content and for how long. In the case of small-sized caches, we aim to design a content replacement strategy that allows nodes to successfully store newly received information while maintaining the good performance of the content distribution system. Under both conditions, each node takes decisions according to its perception of what nearby users may store in their caches and with the aim of differentiating its own cache content from the other nodes’.
The result is the creation of content diversity within the nodes neighborhood so that a requesting user likely finds the desired information nearby. We simulate our caching algorithms in different ad hoc network scenarios and compare them with other caching schemes, showing that our solution succeeds in creating the desired content diversity, thus leading to a resource-efficient information access.
PROJECT PURPOSE:
Peer-to-peer system could come in handy, if used in conjunction with cellular networks, to promote content sharing using ad hoc networking among mobile users. For highly popular content, peer-to-peer distribution can, indeed, remove bottlenecks by pushing the distribution from the core to the edge of the network.
However, a cache-all-you-see approach is unfeasible, because it would swamp node storage capacity with needless data that were picked up on the go several techniques of efficiently caching information in wireless ad hoc networks.
PROJECT SCOPE:
However, the solution that was proposed is based on the formation of an overlay network composed of “mediator” nodes, and it is only fitted to static connected networks with stable links among nodes. These assumptions, along with the significant communication overhead needed to elect “mediator” nodes, make this scheme unsuitable for the mobile environments that we address. A complete framework for information retrieval and caching in mobile ad hoc networks, and it is built on an underlying routing protocol and requires the manual setting of a network wide “cooperation zone” parameter. Note that assuming the presence of a routing protocol can prevent the adoption of the scheme in in highly mobile networks.
PRODUCT FEATURES:
However, our simulations over a wide range of network and application parameters show that the performance of the caching algorithms.
Presents a distributed implementation based on an approximation algorithm for the problem of cache placement of multiple data items under memory constraint.
The result is the creation of content diversity within the nodes neighborhood so that a requesting user likely finds the desired information nearby.
We simulate our caching algorithms in different ad hoc network scenarios and compare them with other caching schemes, showing that our solution succeeds in creating the desired content diversity, thus leading to a resource-efficient information access.
INTRODUCTION:
Ad hoc networks are multi hop wireless networks of small computing devices with wireless interfaces. The computing devices could be conventional computers (for example, PDA, laptop, or PC) or backbone routing platforms or even embedded processors such as sensor nodes. The problem of optimal placement of caches to reduce overall cost of accessing data is motivated by the following two defining characteristics of ad hoc networks. First, the ad hoc networks are multi hop networks without a central base station. Thus, remote access of information typically occurs via multi hop routing, which can greatly benefit from caching to reduce access latency. Second, the network is generally resource constrained in terms of channel bandwidth or battery power in the nodes. Caching helps in reducing communication, this results in savings in bandwidth, as well as battery energy. The problem of cache placement is particularly challenging when each network node has a limited memory to cache data items.
In this paper, our focus is on developing efficient caching techniques in ad hoc networks with memory limitations. Research into data storage, access, and dissemination techniques in ad hoc networks is not new. In particular, these mechanisms have been investigated in connection with sensor networking peer-to-peer networks mesh networks world wide Web and even more general ad hoc networks. However, the presented approaches have so far been somewhat “ad hoc” and empirically based, without any strong analytical foundation. In contrast, the theory literature abounds in analytical studies into the optimality properties of caching and replica allocation problems. However, distributed implementations of these techniques and their performances in complex network settings have not been investigated. It is even unclear whether these techniques are amenable to efficient distributed implementations.