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Data Loss (data + loss)
Selected AbstractsWavelength retuning without service interruption in an all-optical survivable networkINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6 2009Rose Qingyang Hu Abstract This paper proposes a new wavelength retuning (WRT) scheme in an all-optical WDM network. Compared with the existing WRT schemes developed for all-optical networks, which can alleviate the wavelength-continuity constraint but cannot avoid service interruption or data loss, the proposed scheme is able to alleviate the wavelength-continuity constraint and reduce the connection blocking probability with no service interruption to the on-going traffic. This is achieved by allocating two routes, one for active path and one for backup path, to each incoming connection request and conducting WRT only on the backup path. The backup path provides an alternate path in case of a failure, while the active path carries traffic under normal conditions. Thus, WRT on the backup path will not cause any impact on data transmission. An optimal backup path WRT scheme and a heuristic algorithm are developed and the performance evaluation on the proposed schemes is presented. The simulation results show that the proposed optimal scheme reduces the connection blocking probability by 46.8% on average, while the proposed heuristic scheme reduces the blocking probability by 28.3% on average, all compared with the scheme without WRT. Copyright © 2009 John Wiley & Sons, Ltd. [source] Reliable and efficient multicast protocol for mobile IP networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 7 2008Sang-Jo Yoo Abstract To provide a multicasting service, several multicast protocols for mobile hosts (MHs) have been proposed. However, all of these protocols have faults, such as non-optimal delivery routes and data loss when hosts move to another network, resulting in insecure multicast data transmissions. Thus, this paper presents a new reliable and efficient multicast routing protocol for mobile IP networks. The proposed protocol provides a reliable multicast transmission by compensating the data loss from the previous mobile agent when a MH moves to another network. In addition, an additional function allows for direct connection to the multicast tree according to the status of agents, thereby providing a more efficient and optimal multicast path. The performance of the proposed protocol is confirmed based on simulations under various conditions. Copyright © 2008 John Wiley & Sons, Ltd. [source] Managing QoS requirements for video streaming: from intra-node to inter-nodeINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2006Y. Bai Abstract Streaming video over IP networks has become increasingly popular; however, compared to traditional data traffic, video streaming places different demands on quality of service (QoS) in a network, particularly in terms of delay, delay variation, and data loss. In response to the QoS demands of video applications, network techniques have been proposed to provide QoS within a network. Unfortunately, while efficient from a network perspective, most existing solutions have not provided end-to-end QoS that is satisfactory to users. In this paper, packet scheduling and end-to-end QoS distribution schemes are proposed to address this issue. The design and implementation of the two schemes are based on the active networking paradigm. In active networks, routers can perform user-driven computation when forwarding packets, rather than just simple storing and forwarding packets, as in traditional networks. Both schemes thus take advantage of the capability of active networks enabling routers to adapt to the content of transmitted data and the QoS requirements of video users. In other words, packet scheduling at routers considers the correlation between video characteristics, available local resources and the resulting visual quality. The proposed QoS distribution scheme performs inter-node adaptation, dynamically adjusting local loss constraints in response to network conditions in order to satisfy the end-to-end loss requirements. An active network-based simulation shows that using QoS distribution and packet scheduling together increases the probability of meeting end-to-end QoS requirements of networked video. Copyright © 2005 John Wiley & Sons, Ltd. [source] Linear quadratic optimal sliding mode flow control for connection-oriented communication networksINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 4 2009Przemys, aw Ignaciuk Abstract In this paper, a new sliding mode flow controller for multi-source connection-oriented communication networks is proposed. The networks are modelled as discrete time, nth-order systems. On the basis of the system state space description, novel sliding mode controllers with linear quadratic (LQ) optimal and sub-optimal switching planes are designed. The control law derivation focuses on the minimization of the LQ cost functional and solving the resultant matrix Riccati equation. Closed-loop system stability is demonstrated, and conditions for no data loss and full bottleneck link bandwidth utilization in the network are presented and strictly proved. To the best of our knowledge, this paper presents the first attempt to design a discrete time sliding mode flow control algorithm for connection-oriented communication networks. Copyright © 2008 John Wiley & Sons, Ltd. [source] Improving the Quality of Information Flows in the Backend of a Product Development Process: a Case StudyQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 2 2005Jaring Boersma Abstract Considerable research has gone into designing effective product development processes. This, coupled with the increasing need for products that are able to deliver reliable, complex functionality with a high degree of innovation, presents a major challenge to modern day industries in the business of developing products. In order to incorporate relevant field experience in the design and manufacturing of new products, increasingly detailed information needs to be retrieved from the market in a very short amount of time. In one particular consumer electronics industry, business process models describing the information flow in the backend of the product development process indicated massive data loss and also serious data quality degradation. This paper attempts to show how such losses can be mitigated and also proposes a business model that can adequately capture information of a higher quality and in a more structured manner. The end result will be a product development process that provides better feedback on current product performance and is more responsive to future market needs. Copyright © 2005 John Wiley & Sons, Ltd. [source] Quality of Information Flow in the Backend of a Product Development Process: a Case StudyQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 4 2004Jaring Boersma Abstract The increasing need for products that are able to reliably deliver complex functionality with a high degree of innovation presents a major challenge to the modern day product creation processes. In order to be able to use information on the field behaviour of previous products in the design of new products, increasingly detailed information needs to be retrieved from the market in an increasingly shorter time. The purpose of this study is to analyse, in a typical case in the consumer electronics industry, whether the underlying business process is able to generate this information with adequate quality sufficiently quickly. Information models of the company's service centre and call centre were developed using the concepts of maturity index on reliability. The results showed that the structure of the information handling process resulted in a massive data loss (up to 60% of the data gathered by the service centres) and also in serious data quality degradation. Would this information have not been lost, it could have been used by development teams for preventive and corrective actions. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||