Reduce Bandwidth Usage Research Articles

Bilinear Parings in Property-based attestation

One of the objectives of trusted computing is to provide remote attestation method that is able to confirm the status of remote platform or application. Existing property-based attestation is based on the strong-RSA assumption and the required key length is too long. What’s more, a considerable number of RSA-length operations having to be performed which lead to low computational efficiency. Bilinear parings-Based Attestation model, which based on elliptic curve discrete logarithm bilinear paring, can shorten the required key length and reduce bandwidth usage at the same premise of safety performance requirements, as well as ensure platform configurations not to be exposed to the platform while improving operating efficiency. On the other hand, the model includes many trusted computing platform parameters in order to resist replay attacks, and take use of information hiding technology to hide certificates and effectively preventing anyone with a source of certificate misuse of the certificate.

A Cluster Based Replication Architecture for Load Balancing in Peer-to-Peer Content Distribution

In P2P systems, large volumes of data are declustered naturally across a large number of peers. But it is very difficult to control the initial data distribution because every user has the freedom to share any data with other users. The system scalability can be improved by distributing the load across multiple servers which is proposed by replication. The large scale content distribution systems were improved broadly using the replication techniques. The demanded contents can be brought closer to the clients by multiplying the source of information geographically, which in turn reduce both the access latency and the network traffic. In addition to this, due to the intrinsic dynamism of the P2P environment, static data distribution cannot be expected to guarantee good load balancing. If the hot peers become bottleneck, it leads to increased user response time and significant performance degradation of the system. Hence an effective load balancing mechanism is necessary in such cases and it can be attained efficiently by intelligent data replication. In this paper, we propose a cluster based replication architecture for load-balancing in peer-to-peer content distribution systems. In addition to an intelligent replica placement technique, it also consists of an effective load balancing technique. In the intelligent replica placement technique, peers are grouped into strong and weak clusters based on their weight vector which comprises available capacity, CPU speed, access latency and memory size. In order to achieve complete load balancing across the system, an intracluster and inter-cluster load balancing algorithms are proposed. We are able to show that our proposed architecture attains less latency and better throughput with reduced bandwidth usage, through the simulation results.

Service Placement in Ad Hoc Networks

Service placement optimizes the number of instances of a service and their location within an ad hoc network in light of changes in service demand and network topology. The goal is to reduce bandwidth usage and latencies between clients and servers, while improving scalability and availability of the service.

Efficient wireless reprogramming through reduced bandwidth usage and opportunistic sleeping

Wireless reprogramming of a sensor network is useful for uploading new code or for changing the functionality of existing code. Reprogramming may be done multiple times during a node’s lifetime and therefore a node has to remain receptive to future code updates. Existing reprogramming protocols, including Deluge, achieve this by bundling the reprogramming protocol and the application as one code image which is transferred through the network. The reprogramming protocol being complex, the overall size of the program image that needs to be transferred over the wireless medium increases, thereby increasing the time and energy required for reprogramming a network. We present a protocol called Stream that significantly reduces this bloat by using the facility of having multiple code images on the node. It pre-installs the reprogramming protocol as one image and equips the application program with the ability to listen to new code updates and switch to this image. For a sample application, the increase in size of the application image is 1 page (48 packets of 36 bytes each) for Stream and 11 pages for Deluge. Additionally, we design an opportunistic sleeping scheme whereby nodes can sleep during the period when reprogramming has been initiated but has not yet reached the neighborhood of the node. The savings become significant for large networks and for frequent reprogramming. We implement Stream on Mica2 motes and conduct testbed and simulation experiments to compare delay and energy consumption for different network sizes with respect to the state-of-the-art Deluge protocol.

Stochastic analysis of the interplay between object maintenance and churn

Due to the prevalence of peer dynamics (i.e., churn), object maintenance becomes a fundamental issue in peer-to-peer storage systems. Although quite a few prototypes have been designed and implemented, they lack theoretical analysis to shed light on how the system evolves under churn and how to configure the system properly. The performance of peer-to-peer storage systems under churn (e.g., storage capacity, bandwidth usage, bandwidth spike, etc.) also become unclear. In this paper, we develop a simple model based on stochastic differential equations, with which we can analytically study the time-evolution of peer-to-peer storage systems under churn, and the interplay between object maintenance and churn. Different from previous Markovian analysis, we provide closed-form terms to capture the time-evolution of the storage system, and formally derive its related performance metrics under different maintenance strategies. Our analytical results provide valuable directions on the optimization of peer-to-peer storage systems, e.g., reducing bandwidth usage, provisioning for bandwidth spike, improving system capacity. Besides analytical studies, our theoretical results are also validated by extensive simulations.

Cache access and replacement for future wireless Internet

In the last two decades we have witnessed the tremendous success of the Internet and its technologies. Wireless Internet access becomes important to continue this success. However, wireless Internet access suffers from limited battery power, limited bandwidth, high mobility, and an increasing degree of heterogeneity. Cache mechanisms have been proposed to improve access latency, reduce battery power consumption, and reduce bandwidth usage in the wireless Internet. In this article we discuss issues in wireless Internet caching. In particular, we classify and survey cache access mechanisms and replacement algorithms, which should be designed considering both the limitations of wireless networks/devices and heterogeneity of the future wireless Internet.

An optimal trade-off between content freshness and refresh cost

Caching is an effective mechanism for reducing bandwidth usage and alleviating server load. However, the use of caching entails a compromise between content freshness and refresh cost. Constant refreshing allows a high degree of content freshness at a greater cost of system resource. Conversely, too little refreshing reduces content freshness but saves the cost of resource usage. To address the freshness-cost problem, we formulate the refresh scheduling problem with a generic cost model and use this cost model to determine an optimal refresh frequency that gives the best trade-off between refresh cost and content freshness. We prove the existence and uniqueness of an optimal refresh frequency under the assumptions that the arrival of updated content is Poisson and the age-related cost monotonically increases with decreasing freshness. In addition, we provide an analytic comparison of system performance under fixed refresh scheduling and random refresh scheduling, showing that two refresh schedulings with the same average refresh frequency are mathematically equivalent in terms of the long-run average cost.

An optimal trade-off between content freshness and refresh cost

Caching is an effective mechanism for reducing bandwidth usage and alleviating server load. However, the use of caching entails a compromise between content freshness and refresh cost. Constant refreshing allows a high degree of content freshness at a greater cost of system resource. Conversely, too little refreshing reduces content freshness but saves the cost of resource usage. To address the freshness-cost problem, we formulate the refresh scheduling problem with a generic cost model and use this cost model to determine an optimal refresh frequency that gives the best trade-off between refresh cost and content freshness. We prove the existence and uniqueness of an optimal refresh frequency under the assumptions that the arrival of updated content is Poisson and the age-related cost monotonically increases with decreasing freshness. In addition, we provide an analytic comparison of system performance under fixed refresh scheduling and random refresh scheduling, showing that two refresh schedulings with the same average refresh frequency are mathematically equivalent in terms of the long-run average cost.

Topics in internet technology

he Internet Technology series is published in May and October every year. The issue deals with survey and tutorial articles on current research issues relating to Internet Technology. Over the years, there has been a steady and increasing number of submissions to this series, indicating a strong interest in its topics among our readers. This time, nine articles were submitted for possible publication in this issue. After a rigorous review process, we accepted only three articles for publication in this issue. The future Internet will consist of an interconnection of heterogeneous networks consisting of wireless, wired, and optical networks. Wireless Internet access is challenging in terms of minimizing requirements for battery power and bandwidth, and interworking with heterogeneous networks. Caching can improve access latency, reduce battery power consumption, and reduce bandwidth usage in the wireless Internet. Chen and Xiao provide a classification and detailed survey of cache access mechanisms and replacement algorithms. They suggest that wireless networks should be designed keeping in consideration the limitations posed by wireless networks/devices and the future heterogeneous wireless Internet. Heterogeneous networks also give rise to the problem of different networking protocols and packet formats. Tunneling, which consists of encapsulating a packet or frame within another packet of the same or a different network layer, is a commonly used technique to solve the issue of internetworking heterogeneous networks. Tunneling has also been used to provide end-to-end secure communications. The article by Saad, Alawieh, Gulder, and Mouftah discussed various tunneling techniques and looks at the interations between them to provide end-to-end connectivity. The article by McGregor Kaczmarek, Mosley, Dease, and Adams discusses the requirements of the next-generation Internet for national security and emergency preparedness. Such users must be assured of effective and priority service even under catastrophic conditions such as natural disasters and terrorist attacks, similar to what is now-a-days offered by telecommunication providers. The authors present test results of voice over IP for such priority users. The quality of this series depends on the quality of articles and the stringent refereeing carried out by a large number of volunteers. We would like to thank the authors and reviewers for their time and dedication to this series. We also invite potential authors to continue submitting high-quality articles. We would like to acknowledge the help of the Editor in Chief, Tom Chen, and Joe Milizzo and Sue Lange of the ComSoc publications staff for helping with the production of this series. We welcome any comments you may have to further improve the quality of this series.

A Web caching primer

The article provides a primer on Web resource caching, one technology used to make the Web scalable. Web caching can reduce bandwidth usage, decrease user-perceived latencies, and reduce Web server loads transparently. As a result, caching has become a significant part of the Web's infrastructure. Caching has even spawned a new industry: content delivery networks, which are also growing at a fantastic rate. Readers familiar with relatively advanced Web caching topics such as the Internet Cache Protocol (ICP), invalidation, and interception proxies are not likely to learn much here. Instead, the article is designed for the general audience of Web users. Rather than a how-to guide to caching technology deployment, it is a high-level argument for the value of Web caching to content consumers and producers. The article defines caching, explains how it applies to the Web, and describes when and why it is useful.