Reliable Message Research Articles

An aspect-oriented framework for specification and enforcement of non-functional concerns in WS-BPEL

Web Service processes in WS-BPEL have several non-functional requirements such as security and reliable messaging. Although there are many WS-* specifications that address these concerns, their integration with WSBPEL is still open. In this paper, we discuss these non-functional requirements and present a survey on the current support for their specification and enforcement in WS-BPEL engines. Moreover, we introduce an aspect-oriented container framework that uses a declarative deployment descriptor to specify the non-functional requirements. For the enforcement, aspects in AO4BPEL 2.0 are generated, which intercept the process execution and call dedicated middleware Web Services.

MRFR - Multipath-based Routing Protocol with Fast-Recovery of Failures on MANETs

We propose a new multipath-based reliable routing protocol on MANETs, Multipath-based Reliable routing protocol with Fast-Recovery of failures (MRFR). For reliable message transmission, MRFR tries to find the most reliable path between a source and a destination considering the end-to-end packet reception reliability of the routes. The established path consists of a primary path that is used to transmit messages, and the secondary paths that are used to recover the path when detecting failures on the primary path. After establishing the path, the source transmits messages through the primary path. If a node detects a link failure during message transmission, it can recover the path locally by switching from the primary to the secondary path. By allowing the intermediate nodes to locally recover the route failure, the proposed protocol can handle the dynamic topological change of the MANETs efficiently. The simulation result using the QualNet simulator shows that the MRFR protocol performs better than other protocols in terms of the end-to-end message delivery ratio and fault-tolerance capability.

A scheme for reliable real‐time messaging with bounded delays

SUMMARYNetwork‐based real‐time computing applications that require tightly bounded end‐to‐end delays have been increasing at a steady rate in recent years. A messaging layer that yields tight bounds on the latencies in detecting message losses and enables the application layer to initiate a timely recovery action has thus become highly desirable. In this paper, we present a new reliable real‐time messaging scheme called the Delay‐Bounded Reliable Messaging Scheme (DB‐RMS) that is aimed at meeting such requirements. It is built on top of the User Datagram Protocol sub‐layer. DB‐RMS provides multiple service options, each with different fault detection/recovery capabilities and different costs in terms of the execution overhead. This feature makes DB‐RMS suitable for a variety of applications. In this paper, the DB‐RMS service options and the corresponding support protocols are presented first followed by a formal analysis on the detection and reaction latency bounds under various service options. A messaging layer prototype using DB‐RMS has been implemented. To demonstrate the practice of the DB‐RMS, we implemented a clock synchronization algorithm for 802.11 wireless local area networks on top of the DB‐RMS messaging layer. Performance measurements of the prototype implementation have been taken, and the positive results obtained are also presented. Copyright © 2011 John Wiley & Sons, Ltd.

A Physical and Logical Security Framework for Multilevel AFCI Systems in Smart Grid

The arc fault circuit interrupter (AFCI) is expected to be one of the most essential components in smart grid systems for providing physical security and safety against electrical fire hazards caused by arc faults. As AFCIs are widely deployed as a part of mandatory installation requirements, a hierarchy consisting of multilevel AFCIs has been established, where a portable AFCI is connected serially to an outlet box AFCI. However, this multilevel AFCI structure causes serious problems when the AFCI detects arc faults in the surveillance area of its descendant AFCIs. This can cause de-energizing of the entire area covered by the upper-level AFCI, which may lead to blackouts over large areas. This paper proposes an integrated security framework comprised of physical and logical security measures as a solution for this problem. Firstly, the problem is tackled through communication between the hierarchy levels. Since the proposed system deals with physical security and safety, the communication must guarantee reliable message delivery within the specified deadlines. A controller area network (CAN) is chosen as the communication technology because it provides deterministic message delivery that meets the system requirements. Moreover, CAN has the advantages of verified performance and cost competitiveness through accelerated industrial adoption. Along with the physical security framework, a logical security framework is also proposed with group key management that prevents unauthorized access. Finally, this paper reports an integrated methodology for optimizing the design parameters satisfying the bandwidth and security demands of physical and logical measures because both demands competitively share a common communication resource.

Consumers’ Value, Environmental Consciousness, and Willingness to Pay more toward Green-Apparel Products

Consumer awareness of and concerns for the environment have increased significantly and environmental concerns now represent one of the major factors in consumer decision making. While there have been many studies regarding green marketing, limited research has been conducted concerning the consumers’ view on ethical issues in the fashion industry and its influence on their purchase behavior (Laroche, et al., 2001; Dickson, 2000; Butler & Francis, 1997). This study looks at the relationships among environmental consciousness, willingness to pay more toward environmentally friendly apparel products and buying behavior among college students. It also examines the effects of fashion involvement, which is considered one of the important values in apparel purchasing behavior. Laroch, et al.’s (2001) conceptual framework serves as a basis for the present research. In this framework, they consider factors that may influence consumers’ willingness to pay more for environmentally friendly products using five categories: demographics, knowledge, values, attitudes and behavior. Among these five categories, four of them (knowledge, values, attitudes and behavior) were adopted and knowledge, attitudes and behavior were considered as an environmental consciousness and those were included as predictors of willingness to pay more for green apparel in this research. In addition, since many studies examined the hierarchical relationship between values, knowledge, attitudes, and behaviors, it was hypothesized that value (fashion involvement) will influence environmental consciousness (knowledge, attitudes, and behavior) and environmental consciousness will have direct effect on willingness to pay more for eco-friendly apparel products following reviews of literature. Based on the previous discussion, six hypotheses were developed: H1. Consumers who have higher fashion involvement value will have less environmental knowledge than those who have lower fashion involvement value. H2. Consumers who have higher fashion involvement value will have lower environmental concern than those who have lower fashion involvement value. H3. Consumers who have higher fashion involvement value will demonstrate fewer environmentally sensitive behaviors than consumers who have lower fashion involvement value. H4. Consumers who have more environmental knowledge will demonstrate a greater willingness to pay more for environmentally friendly apparel products than consumers who have less environmental knowledge. H5. Consumers who have higher environmental concerns will show higher willingness to pay more for environmentally friendly apparel products than consumers who have lower environmental concerns. H6. Consumers who are more involved in environmentally sensitive behaviors will have higher willingness to pay more for environmentally friendly apparel products than consumers who are less engaged in general environmental behaviors. The questionnaire was developed from existing measures of the variables and from the author. The participants were 150 undergraduate students attending a Midwestern university. To test the hypothesized model, linear structural equation modeling (LISREL 8) was performed. The findings of this study provide that university students who had more interest in fashion tended to know less about environmental issues, to show less concern about the environment, and to be involved less in the environmentally sensitive behaviors. According to the results, there was no relationship between environmental knowledge and willingness to pay more for eco-friendly apparel. This indicates that people who have more knowledge about the environment are not necessarily the consumers of eco-friendly apparel. The findings also show that college students who were more concerned about the environment tended to be willing to pay more for green apparel. College students who made more effort to conserve energy and natural resources also tended to be willing to spend more for green apparel. This research provides valuable insights for eco-friendly apparel product retailers and manufacturers by indicating that two dimensions of environmental consciousness (attitude and behavior) were good predictors of college students’ willingness to spend more for green apparel. Environmentally sensitive behavior like conserving natural resources is a good indicator to intention to purchase environmentally friendly apparel products. Retailers and marketers might need to encourage students to be aware the importance of environmentally sensitive behaviors and to involve in those behaviors. Marketers in the fashion industry need to consider college students’ environmental concerns and conserving natural resources behaviors when they make marketing decisions for environmentally-friendly apparel products. The apparel marketers also need to develop creative marketing strategies for the eco-friendly apparel products to persuade the fashion-conscious consumers. Although environmental knowledge was not related to intention to pay more for green apparel, it might be related to environmental concern or other environmental behavior. It is also suggested that apparel retailers and marketers should use a consistent and reliable message about their practice of green marketing in order not to confuse consumers.

Design of a Real-Time Wireless Network for the Northern Pierre Auger Observatory

The Pierre Auger Cosmic Ray Observatory employs a large array of Surface Detector (SD) stations to detect the secondary particle showers generated by Ultra High Energy Cosmic Rays. The operational Auger South site uses a tower-based wireless network for communication between SD stations and the observatory campus. Plans for a larger Auger North array call for a similar system. However, a variety of factors render direct station-to-tower routing infeasible in Auger North. Thus, we have adopted a new peer-to-peer paradigm, the Wireless Architecture for Hard Real-Time Embedded Networks (WAHREN), designed specifically for highly reliable message delivery over fixed networks, under hard real-time deadlines. This paper introduces the topologies, protocols, performance, formal verification, and reliability modeling of WAHREN. It also presents the adaptation of WAHREN to Auger North, including its embedding in the SD array, hardware development, and plans for an in-situ Research and Development Array.

Spatial Reuse Time-Division Multiple Access for Broadcast Ad Hoc Underwater Acoustic Communication Networks

Underwater acoustic communication (UWAC) is often the only viable solution to establish an ad hoc underwater communication network. The specific features of UWAC, arising from the physics of underwater acoustics, make the design of resource-efficient media access control (MAC) protocols important as well as challenging. In this paper, we tackle this task considering ad hoc UWAC networks that support high-traffic broadcast communication. To this end, we propose the application of the spatial reuse concept and the exploitation of direct sequence spread spectrum used at the UWAC physical layer to obtain a new hybrid spatial reuse time-division multiple-access (HSR-TDMA) protocol. By tracking the time-varying network topology, our protocol adaptively optimizes the set of active communication nodes and overcomes problems of UWAC networks such as the near-far problem, flickering, and formation of islands. Pertinent performance parameters, namely network availability, message reliability, and transmission rate, are analyzed for the proposed protocol. Evaluation of these analytical performance expressions demonstrates the significant advantages of HSR-TDMA over commonly used conventional TDMA for broadcast UWAC networks. We also report performance results for both the HSR-TDMA and the conventional TDMA protocol from a sea trial at the Haifa harbor, which corroborate the results obtained from the analysis.

Loupe: Verifying Publish-Subscribe Architectures with a Magnifying Lens

The Publish-Subscribe (P/S) communication paradigm fosters high decoupling among distributed components. This facilitates the design of dynamic applications, but also impacts negatively on their verification, making it difficult to reason on the overall federation of components. In addition, existing P/S infrastructures offer radically different features to the applications, e.g., in terms of message reliability. This further complicates the verification as its outcome depends on the specific guarantees provided by the underlying P/S system. Although model checking has been proposed as a tool for the verification of P/S architectures, existing solutions overlook many characteristics of the underlying communication infrastructure to avoid state explosion problems. To overcome these limitations, the Loupe domain-specific model checker adopts a different approach. The P/S infrastructure is not modeled on top of a general-purpose model checker. Instead, it is embedded within the checking engine, and the traditional P/S operations become part of the modeling language. In this paper, we describe Loupe's design and the dedicated state abstractions that enable accurate verification without incurring state explosion problems. We also illustrate our use of state-of-the-art software verification tools to assess some key functionality in Loupe's current implementation. A complete case study shows how Loupe eases the verification of P/S architectures. Finally, we quantitatively compare Loupe's performance against alternative approaches. The results indicate that Loupe is effective and efficient in enabling accurate verification of P/S architectures.

무선센서 네트워크에서 주기적 메시지에 대해 신뢰성 있는 메시지 전송을 위한 라우팅 프로토콜

In industrial distributed control systems, sensors collect data from the physical environment periodically and transmit them to the actuators, which process the control operations based on the received data. For the effective operation of the control systems, the data transmitted by the sensors has to be delivered to the actuators reliably within the deadline, and if the message reception rate of the actuators becomes lower than a threshold, then the performance of the control systems drops greatly. This paper suggests a message routing protocol to transmit periodic messages reliably in a distributed control system based on wireless sensor networks. For reliable message transmission, the proposed protocol selects a routing path whose end-to-end message reception rate is the highest before transmitting data messages. The proposed protocol has the capability of maintaining a target message reception rate for each flow. To maintain the required target reception rate, each destination monitors the actual message reception rate periodically and transmits a feedback message to the source if it drops below the target reception rate. On receiving the feedback message, the source tries to find a new path which can satisfy the target rate. The performance of the proposed protocol has been evaluated using simulation and compared with other protocols in terms of the message reception rate, the message delay and delay jitter, and so on. The simulation results show that the proposed protocol has a higher message reception rate and comparable message delay and delay jitter to other protocols. The simulation results also show that the proposed protocol has an ability to adapt well to the dynamic network traffic change.

Multi-state reliability and message time delay in wireless sensor networks

Reliability is an important parameter to measure the function of a wireless sensor network (WSN). In this paper, we consider a multi-state reliability model and message time delay problems in WSNs. The message time delay between target nodes and the sink node is an important factor to measure the reliability of WSNs. By defining the expected time delay for the message transmission, we further consider the multi-state reliability as the probability that there is at least one message which can be received by the sink node within the time period ?. Furthermore, an integer programming method is used to compute the multi-state reliability. Finally, examples are used to show the effectiveness of the proposed method.

Smart Message Service Platform for Mobile Environment

With increasing use of smartphone, users require a new message service to prevent security attack and provide integrated messages. Since smartphone uses data services such as 3G cell network and WiFi, it can provide reliable message transfer through various security policies. In addition, it can transfer various data collected using built-in camera and GPS. This paper proposes a smart message service platform which can provide security services such as authentication, confidentiality and integrity as well as transfer the integrated message including location, picture and text. To verity the functionality of the platform, this paper implements an iPhone app and message transfer server, and then shows the implementation results.

An Effective Route Selection Scheme with Considering Traffic Density in VANET

A geographical routing protocol is typically utilized for a route selection of VANET. Even if it is conceptually well adapted into VANET, message delivery tends to be unreliable with frequent network partitions, which mainly come from the inherent characteristics such as high mobility and irregular traffic density. In this paper, we deal with a method to enable reliable message delivery with reflecting the traffic density on routing decision. By concatenating the message delivery cost of each of inbetween junction section, <TEX>$1^{st}$</TEX> and <TEX>$2^{nd}$</TEX> shortest paths are initially determined. When it is not possible to deliver the message on a junction on the 1st path, we utilize two novel ideas, that is, letting the message stay on the junction to find out a new relay node, and putting a replicated copy to reach via a detour path. By using the NS-2 network simulator, our method has been examined in terms of message delivery rate and delay. It shows that our method is much efficient than the other method in the low density environment, while it brings similar results in the high density environment.

Error Performance of Channel Coding in Random-Access Communication

A new channel coding approach was proposed in [1] for random multiple access communication over the discrete-time memoryless channel. The coding approach allows users to choose their communication rates independently without sharing the rate information among each other or with the receiver. The receiver will either decode the message or report a collision depending on whether reliable message recovery is possible. It was shown that, asymptotically as the codeword length goes to infinity, the set of communication rates supporting reliable message recovery can be characterized by an achievable region which equals Shannon's information rate region possibly without a convex hull operation. In this paper, we derive achievable bounds on error probabilities, including the decoding error probability and the collision miss detection probability, of random multiple access systems with a finite codeword length. Achievable error exponents are obtained by taking the codeword length to infinity.

A Reliable and Energy Efficient Transport Protocol for Wireless Sensor Networks

In wireless sensor networks (WSN), an ideal transport layer needs to support reliable message delivery and provide congestion control in an efficient manner in order to extend the lifetime of a WSN. The main use of transport protocol in WSN is to overcome the congestion and the reliability with energy efficiency. In this paper, we develop a reliable and energy efficient transport protocol (REETP), which mainly focuses on the reliability and energy efficiency. Our proposed protocol consist of an Efficient Node Selection Algorithm to determine a set of efficient nodes called E-Nodes which form a near optimal coverage set with largest area and highest residual energy level. The key idea of REETP is to transfer encoded packets using LT codes from the source to the sink block by block and each block is forwarded to an E-node. After receiving encoded packets, the E-node tries to reconstruct the original data packets and it encodes the original data packets again and relays them to the next E-node until it reaches the sink. By simulation results, we show that our proposed protocol has more packet delivery ratio with reduced packet loss and energy consumption.

EOMP: an exactly once multicast protocol for distributed mobile systems

Reliable multicast provides an elegant mechanism for structuring communication among closely cooperating entities. In a distributed mobile computing environment, disconnections and physical mobility of the mobile hosts (MHs) may result in the loss of messages. This makes the problem of ensuring reliable multicast difficult for MHs. Apart from ensuring reliable message delivery, guaranteeing exactly once message delivery greatly helps in conserving the battery power. Moreover, for transaction-based applications, total ordering of messages are semantically essential. In this report, an exactly once multicast protocol (called EOMP) with totally ordered message delivery is proposed. An unreliable wireless MAC level multicast is used for delivering the messages to the MHs and a novel mechanism for multicasting messages in the cellular network is proposed. An EOMP tolerates mobile support station (MSS) failure by making the MSS stateless. Dynamic host group membership is also supported by an EOMP. The performance of EOMP has been evaluated and compared with an existing an EOMP by simulation. The results of the simulation show that an EOMP has lower delay, lesser handoff, reduced buffer space overhead, and are more scalable. To establish the effectiveness of a reliable multicast protocol with totally ordered message delivery for mobile systems, two different applications viz., a real-time distributed collaborative text editor and a distributed image rendering application, were developed as case studies. The applications were easy to develop as mobility and disconnection were hidden from the application by an EOMP. The applications are also efficient as they use a powerful reliable multicast primitive for communication.

Design issues and experimental studies of wireless LAN Mesh

Wireless mesh networking, as a low-cost and reliable technology for rapid network deployment, has attracted considerable attention from academia and standardization in the industry. The IEEE 802.11s standard defines a wireless LAN mesh using the IEEE 802.11 medium access control and physical layers, and is one of the most active standards with increasing commercial opportunities. This study presents the design and development of a WLAN mesh system conforming to the latest IEEE 802.11s draft amendment. Without costly hardware modifications, the proposed solution is a pure software extension for commercial off-the-shelf WLAN chipsets. This study constructs an experimental testbed, and evaluates issues such as the transmission reliability of mesh broadcast-type control messages and multichannel transmissions. Experimental results demonstrate that the delivery of mesh broadcast-type control messages, such as routing construction frames, using the multiple acknowledged unicast scheme improves mesh stability from an 86 to a 98 percent success ratio in a 16-node grid. Transmitting packets using a single radio interface switching between multiple channels reduces inter-flow interference and doubles the throughput in our testbed.

Non-functional properties in the model-driven development of service-oriented systems

Systems based on the service-oriented architecture (SOA) principles have become an important cornerstone of the development of enterprise-scale software applications. They are characterized by separating functions into distinct software units, called services, which can be published, requested and dynamically combined in the production of business applications. Service-oriented systems (SOSs) promise high flexibility, improved maintainability, and simple re-use of functionality. Achieving these properties requires an understanding not only of the individual artifacts of the system but also their integration. In this context, non-functional aspects play an important role and should be analyzed and modeled as early as possible in the development cycle. In this paper, we discuss modeling of non-functional aspects of service-oriented systems, and the use of these models for analysis and deployment. Our contribution in this paper is threefold. First, we show how services and service compositions may be modeled in UML by using a profile for SOA (UML4SOA) and how non-functional properties of service-oriented systems can be represented using the non-functional extension of UML4SOA (UML4SOA-NFP) and the MARTE profile. This enables modeling of performance, security and reliable messaging. Second, we discuss formal analysis of models which respect this design, in particular we consider performance estimates and reliability analysis using the stochastically timed process algebra PEPA as the underlying analytical engine. Last but not least, our models are the source for the application of deployment mechanisms which comprise model-to-model and model-to-text transformations implemented in the framework VIATRA. All techniques presented in this work are illustrated by a running example from an eUniversity case study.

PercolationNET: A multi-tree P2P overlay network supporting high coverage search

Flooding with a time-to-live constraint is a popular algorithm in unstructured peer-to-peer (P2P) networks. However, blind flooding may cause a large amount of network traffic. Moreover, it cannot guarantee acquiring all required data objects, especially for rare ones. To mitigate these problems, this paper proposes PercolationNET, a multi-tree sub-overlay, which is built on top of an existing P2P overlay (named original overlay). PercolationNET organises peers in a tree-based structure which facilitates reliable and efficient message dissemination for search. The search process is divided into two stages. A query message is first propagated on the original overlay, and then broadcast along the sub-overlay PercolationNET. PercolationNET combines the advantages of fast coverage speed in flooding-based scheme and low traffic cost in tree-based scheme. The experimental results of PercolationNET compared with FloodNet confirm the superiority of PercolationNET in achieving faster coverage speed and lower message cost.

Diffusion-based approach to deploying wireless sensor networks

An important objective of Wireless Sensor Networks (WSNs) is to reliably sense data about the environment in which they are deployed. Reliability in WSNs has been widely studied in terms of providing reliable routing protocols for message dissemination and reliability of communication from sink to sensors. In this work, we define a reliability metric by the amount of data sensed by the network. In order to satisfy this reliability constraint, we propose a diffusion-based approach for a deployment pattern for the sensor nodes. We show that this deployment pattern achieves sufficient coverage and connectivity and requires lesser number of sensors than popular regular deployment patterns. We further obtain the bounds on establishing connectivity between nodes in the WSN and extend this analysis for heterogeneous WSNs.

Unconditionally reliable and secure message transmission in undirected synchronous networks: possibility, feasibility and optimality

We study the interplay of network connectivity and the issues related to the 'possibility', 'feasibility' and 'optimality' for unconditionally reliable message transmission (URMT) and unconditionally secure message transmission (USMT) in an undirected synchronous network, under the influence of an adaptive mixed adversary having unbounded computing power, who can corrupt some of the nodes in the network in Byzantine, omission, fail-stop and passive fashion respectively. We consider two types of adversary, namely threshold and non-threshold. One of the important conclusions we arrive at from our study is that allowing a negligible error probability significantly helps in the 'possibility', 'feasibility' and 'optimality' of both reliable and secure message transmission protocols. To design our protocols, we propose several new techniques which are of independent interest.