In this paper, the queueing delay and packets loss performance of multiprotocol label switching (MPLS) systems is analyzed through the nonpreemptive M/M/m/K finite queueing model with bulk arrivals, where the traffic ...
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In this paper, the queueing delay and packets loss performance of multiprotocol label switching (MPLS) systems is analyzed through the nonpreemptive M/M/m/K finite queueing model with bulk arrivals, where the traffic burstiness characteristic is considered. The analytical results reveal the queueing time relation of different priority classes of data traffic due to the MPLS classification, queueing, and sch.duling (CQS) operations, which provide design guidelines for future label switching routers (LSRs). The objective of this paper is to provide an analysis of MPLS routers and network traffic streams for various system server topologies applying the nonpreemptive priority M/M/m/K queueing model.
Generalized multiprotocol label switching (GMPLS) promises a unified control plane for a variety of switching technologies by separating the control plane from the forwarding plane. In this paper a brief overview of t...
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Generalized multiprotocol label switching (GMPLS) promises a unified control plane for a variety of switching technologies by separating the control plane from the forwarding plane. In this paper a brief overview of the ongoing research on different aspects of GMPLS is first presented. Then a comparison is conducted between the network access layer (NAL) and the optical/physical layer in GMPLS based on the restoration capabilities and the performance analysis of channel connectivity and the traffic aggregation in the two layers. At last the logical channel connections of the IP/NAL layer are compared to the physical channel connections of the optical/physical layer where the probability of blocking (Pb) is calculated considering both wavelength conversion and non-wavelength conversion cases.
It is well known that traditional analytic methods of queueing systems are based on the distributions of inter-arrival time and service time. However, it is quite inconvenient to employ these methods directly to he an...
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It is well known that traditional analytic methods of queueing systems are based on the distributions of inter-arrival time and service time. However, it is quite inconvenient to employ these methods directly to he analysis of current self-similar traffic models. In this paper, we first derive, a novel analytic model based on the arrival rate and the service rate for single-class steady-state queueing systems. Then the derivations are extended to provide upper and lower boundary conditions for multi-priority queues in networks deploying differentiated services (DS). In addition, the analytical model is also applied to the analysis of DS effects on self-similar traffic. The results illustrate the performance gain in queue length of the priority classes that DS can provide compared to a network that does not deploy DS. Additionally, the upper lower boundary conditions of the queue lengths for each priority class also serves as a system design guideline.
To support the highly demanding quality of service (QoS) requirements of current and future communication networking services, network devices are required to support high-speed data transfer and also be very reliable...
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To support the highly demanding quality of service (QoS) requirements of current and future communication networking services, network devices are required to support high-speed data transfer and also be very reliable. To ensure uninterrupted services, the restoration time in case of fiber cut or node failure has to be extremely low as disruption in high-speed networks causes considerable loss even if it is an extremely small duration. Restoration strategies like line restoration and path restoration alone have a mixture of advantages and disadvantages. To address this problem, we propose a dual-stage hybrid restoration protocol (DHRP) for achieving enhanced survivability in optical networks. In the DHRP topology, the moment that the event of link failure is detected, the line and path restoration procedures are initiated. The DHRP algorithm first conducts line restoration to immediately to restore the problem link. Then as soon as the path restoration topology is prepared it will be activated to bring the overall network traffic balance back to it optimal status. The drawback of the DHRP topology is the amount of backup capacity that is required to enable rapid line restoration. Although by implementing differentiated services combined with the DHRP restoration topology it is expected that the amounts of backup capacity can be significantly reduced.
We propose a method for designing a filter to meet a set of specifications that is area-efficient. Our approach reduces the complexity of the realized digital FIR filter to give a good design with low round-off noise,...
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We propose a method for designing a filter to meet a set of specifications that is area-efficient. Our approach reduces the complexity of the realized digital FIR filter to give a good design with low round-off noise, low coefficient sensitivity and small order. Unlike conventional approaches, our design is based on a variable precision method that reduces the word-length of the coefficients to reduce the complexity required to implement the FIR filter. In addition, we apply a low sensitivity structure with only a small number of taps so that the specification is satisfied while simultaneously reducing the resulting hardware area required by the implementation. Some examples are given to show the effectiveness of our design.
This paper focuses on providing technical solutions to the multiprotocol label switching (MPLS) label distribution protocol (LDP) signaling when interoperating with the asynchronous transfer mode (ATM) private network...
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This paper focuses on providing technical solutions to the multiprotocol label switching (MPLS) label distribution protocol (LDP) signaling when interoperating with the asynchronous transfer mode (ATM) private network-to-network interface (PNNI) and compares this with the interoperating procedures of the user network interfaces (UNI) topology. This paper proposes procedural operations that are necessary for interoperability of both of these networking architectures. Interoperability enhancement options are focused on managing quality of service (QoS) and traffic management support for applying loosely explicitly routed LDP and strictly explicitly routed LDP. The paper also investigates procedure for assigning the proper class to the supported differentiated services (Diff-Serv) for MPLS label switching routers (LSRs).
This paper proposes an optimal routing sch.me for routing Label Switched Path (LSP) setup in the MultiProtocol Label Switching (MPLS) [1] domain. Resource Reservation Protocol - Traffic engineering (RSVP-TE) [2] and L...
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This paper proposes an optimal routing sch.me for routing Label Switched Path (LSP) setup in the MultiProtocol Label Switching (MPLS) [1] domain. Resource Reservation Protocol - Traffic engineering (RSVP-TE) [2] and Label Distribution Protocol (LDP) [3] used for LSP setup usually use constraint based or source based routing in the MPLS domain to provide Quality of Service (QoS). In this paper we investigate the use of Rate Controlled Service (RCS) disciplines in Integrated Service networks which have been used for providing end to end delay and delay jitter bounds [6] [10]. We have incorporated this property of RCS disciplines in MPLS Label Switching Routers (LSR) and also proposed a routing algorithm for providing Guaranteed QoS in MPLS networks.
This paper addresses the required extensions to the MultiProtocol Label Switching (MPLS) signaling protocols, Resource Reservation Protocol with Traffic engineering extensions (RSVP-TE) and Label Distribution Protocol...
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This paper addresses the required extensions to the MultiProtocol Label Switching (MPLS) signaling protocols, Resource Reservation Protocol with Traffic engineering extensions (RSVP-TE) and Label Distribution Protocol (LDP), to support MPLS network multicasting functionalities. These extensions to the signaling protocols will enable MPLS networking to conduct all required multicasting features that IP multicasting protocols are capable of, while adding on the feature benefits of MPLS traffic engineering.
The X pinch is a very small size radiation source in the 3-10 keV x-ray band. As such, it has been used successfully to obtain high resolution images of &le 2 mm thick biological samples ranging from small bugs (f...
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The X pinch is a very small size radiation source in the 3-10 keV x-ray band. As such, it has been used successfully to obtain high resolution images of &le 2 mm thick biological samples ranging from small bugs (flies, beetles, etc.) to a small piece of mouse intestine. The X pinch source size as a function of the x-ray energy is important because it directly determines the spatial resolution of the imaging system. Furthermore, a small source size can provide high spatial coherence of the imaging x-rays, enabling their use for imaging low absorption, low contrast objects with excellent spatial resolution by a method called phase-contrast imaging. In order to determine the source size, several structures have been micro-fabricated that involve gold on a membrane that is transparent to the x-rays. If these structures are imaged in point projection radiography, a finite source size will cause penumbral blurring. Therefore, the shape of the shadow image pattern depends on the source size of the x-rays, the energy band of the x-rays, the shape and material used for the structures, and the geometry of the experiment. The experimental results must be compared with wave-optics calculations for the expected image pattern as a function of all of the above parameters, but especially the source size. The several conditions for phase-contrast imaging are discussed. Examples of high-resolution images of biological objects are presented.
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