8487669
An SMR based advance resource reservation scheme for combined mobility and QoS Provisioning
One of the major problems of deploying RSVP in the mobile environment is called the advance resource reservation problem. If an RSVP reservation path is reserved in advance in the subnet that a mobile node will visit, the mobile node can continue its QoS session smoothly when it hands over to that subnet. However, if too many network resources are used for advance reservation, new QoS sessions originating from that subnet will experience a higher probability of being blocked needlessly. In this paper, we propose a new advance resource reservation scheme that properly constrains the amount of advance reservations in a subnet and only allows the mobile nodes with large value of session-to-mobility ratio (SMR) to make advance reservation. We evaluate the proposed scheme and the results show that our scheme can effectively reduce both active and passive reservation blocking probabilities and achieves a better utilisation of the network resources, especially when the traffic intensity is high.
6690308
PEPA Analysis of MAP Effects in Hierarchical Mobile IPv6
To overcome the drawbacks of the mobile IPv6 protocol on handling local mobility management, IETF proposed the HMIPv6 protocol which introduces an intermediate mobility anchor point (MAP) to hide the movement of a mobile node within a local area. However, the MAP forms a bottleneck in the network since all the traffic destined for its served nodes has to go through it. Most research on HMIPv6 focuses on protocol optimisation, and performance analysis of HMIPv6 is usually simulation-based. In this paper, we employ a performance evaluation formalism named PEPA to investigate the performance tradeoffs of MAPs in HMIPv6. Performance measures such as response time and MAP utilisation are presented.
804068
Evaluation of RSVP and Mobility-Aware RSVP Using Performance Evaluation Process Algebra
As a resource reservation mechanism, the Resource ReSerVation Protocol (RSVP) faces a lot of challenges when applying it to the wireless and mobile networks. The interworking problems of RSVP and mobility management protocols have been extensively discussed over the last decade. As the solutions of this problem, mobility-aware RSVP schemes that integrate RSVP and micro-mobility management are becoming more and more popular. Therefore, the investigation on how much they improve the performance of the basic RSVP is necessary and useful. Instead of the traditional simulation based approaches, in this paper we introduce a formal performance evaluation formalism, named Performance Evaluation Process Algebra (PEPA), and employ it to investigate the performance of the basic RSVP and mobility-aware RSVP. Important performance metrics such as handover blocking probability and signalling cost are presented.
21956342
Architectural design and implementation of highly available and scalable medical system with IBM Websphere middleware
Medical systems require the end-to-end high availability and scalability. There are many components in a medical system, and each individual component contributes to the overall system availability and scalability. We present the formulas to assess the overall system availability and capacity planning, and we architect approaches and technologies to make all components highly available in all tiers by clustering, workload management, and replication. We discuss how to unify all medical systems and design the uniform framework for different kinds of medical systems to hook up with this framework so that we can maintain a highly available and highly scalable system with ease. We use the n-tier distributed component based architecture and J2EE technologies as well as Web services to interact with .NET and others. We discuss how to program in the framework for high availability and scalability and how to upgrade application software without service interruption to achieve continuous availability. We show how to add or reduce hardware capacity in each tier and how to maintain hardware and software without service interruption as well as how to balance the capacity and availability among tiers.
16457860
A New Secure Authentication Scheme Based Threshold ECDSA For Wireless Sensor Network
Security is an important issue for Wireless Sensor Network (WSN), especially for security-sensitive application. In this paper, we address secure authentication problems in WSN. First, we propose distributed authentication model for WSN, and secondly, advance the threshold ECDSA authentication scheme in this model, finally construct a new way to choose distributed CA severs of threshold authentication scheme. Our simulation results and analysis show that our scheme can reduce effectively bandwidth and computation resources while providing a robust, highly secure and highly available authentication service.
17568245
Security metrics for software systems
Security metrics for software products provide quantitative measurement for the degree of trustworthiness for software systems. This paper proposes a new approach to define software security metrics based on vulnerabilities included in the software systems and their impacts on software quality. We use the Common Vulnerabilities and Exposures (CVE), an industry standard for vulnerability and exposure names, and the Common Vulnerability Scoring System (CVSS), a vulnerability scoring system designed to provide an open and standardized method for rating software vulnerabilities, in our metric definition and calculation. Examples are provided in the paper, which show that our definition of security metrics is consistent with the common practice and real-world experience about software quality in trustworthiness.
1622406
Structure Analysis and SNR-Variance Evolution for Parallel Concatenated Coded IDMA Systems
This paper is concerned with parallel concatenated coded interleave-division multiple-access (IDMA) systems. We briefly present the transmitter/receiver structure of these systems and propose an efficient SNR-variance evolution scheme for bit-error-rate (BER) performance evaluation. The proposed evolution scheme is also useful for system performance optimization. Numerical results show that the BER performance curves obtained by simulation and evolution are quite close when the data length is long enough.
10887794
Packet doppler: network monitoring using packet shift detection
Due to recent large-scale deployments of delay and loss-sensitive applications, there are increasingly stringent demands on the monitoring of service level agreement metrics. Although many end-to-end monitoring methods have been proposed, they are mainly based on active probing and thus inject measurement traffic into the network. In this paper, we propose a new scheme for monitoring service level agreement metrics, in particular, delay distribution. Our scheme is passive and therefore will not cause perturbation to real traffic. Using realistic delay and traffic demands, we show that our scheme achieves high accuracy and can detect burst events that will be missed by probing based methods.