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Abstract The purpose of this paper is to solve the problem of low recognition accuracy of three-degree-of-freedom myoelectric prosthesis and long training time.According to the nonstationarity of the EMG signal, the wavelet packet is used to decompose the EMG signal and the energy and variance of the wavelet packet coefficients of the four-channel EMG signal are extracted as feature vectors.Then Particle Swarm Optimization(PSO) was combined with improved support vector machine(ISVM) to construct a new model(PSO-ISVM). Under the premise of ensuring the sparseness of the SVM, the slack variables and the decision function was improved to reduce the constraint conditions for solving the optimal face in the quadratic programming. SVM is optimized by the PSO in order to improve the accuracy of the model.The experimental results show that the improved algorithm can effectively identify six kinds of commonly used upper limb movements compared with the traditional SVM. The average recognition rate reaches 90.66% and training time can be shortened 0.042 s. [ABSTRACT FROM AUTHOR]

In this paper, the problem of finite-time state estimation for delayed periodic neural networks over multiple-packet transmission is addressed. The components of measurement output are separately transmitted by multiple-packet transmission, and the randomly occurring packet dropouts of different channels are described by mutually independent Bernoulli processes. In order to improve the robustness of the estimator, a non-fragile estimator is designed. In addition, some sufficient criteria are given to ensure that the estimation error system is stochastically finite-time stable and stochastically finite-time bounded, and the gains of non-fragile estimator are then derived based on these results. Finally, simulation results are provided to illustrate the effectiveness of the proposed estimator design approach. [ABSTRACT FROM AUTHOR]

We consider networked control systems (NCSs) composed of a linear plant and a linear controller interconnected by packet-based communication channels with communication constraints. We are interested in the setup where direct-feedthrough terms are present in the plant and/or in the controller, a case that is largely ignored in the literature due to its inherent complexity and counterintuitive results in the analysis despite its relevance for important classes of controllers including Proportional–Integral (PI) regulators. This setup calls for a novel stability analysis, for which we take a renewed look at the concept of uniformly globally exponentially stable (UGES) scheduling protocols that turned out to be instrumental in earlier approaches. We provide a generalization of the UGES property, called ( D P , D C ) -UGES with D P ∕ D C being the direct-feedthrough matrices of the plant/controller, respectively, and we present generic conditions on these direct-feedthrough terms D P ∕ D C such that the classical UGES property of scheduling protocols implies ( D P , D C ) -UGES. This allows us to derive conditions leading to a maximally allowable transmission interval (MATI) such that stability of the overall NCS is guaranteed. In addition, it is shown that it is possible to get more tailored results for the well-known sampled-data (SD), round-robin (RR), and try-once-discard (TOD) protocols leading to less conservative conditions on the direct-feedthrough terms than the generic ones. We also introduce new ( D P , D C ) -UGES scheduling protocols, designed to handle the direct-feedthrough terms in a more effective way than existing protocols. Our results are illustrated using the example of a batch reactor. [ABSTRACT FROM AUTHOR]

This paper studies the problem of determining sensor locations in a large sensor network using only relative distance (range) measurement. Based on the barycentric coordinate representation, we propose a totally asynchronous distributed algorithm under DILOC framework due to independence of sensor update instants and unreliable networks with communication delays and packet losses. Through modeling the asynchronous algorithm as a linear difference equation with time-varying delays, we prove that the location estimates of sensors are globally convergent to the true coordinates if: (1) time interval between any two consecutive update instants is bounded from below and above, (2) communication delays and successive packet losses between sensors are finite. Simulation examples are provided to demonstrate the effectiveness of the theoretical result. [ABSTRACT FROM AUTHOR]

Wireless Sensor Networks nowadays find wide variety of applications especially in real time. Innovative methods of energy efficient protocols and transmission reduction techniques keep improving to enhance the lifetime of the sensor nodes as they are powered by non-rechargeable batteries. Multi hop transmission and data aggregation are major techniques to reduce the power spent by the sensor node. In this paper, we propose a new ribbon structure for the existing multi hop WSN topologies with modified media access control mechanism called co-operative MAC. The ribbon structure is proposed to reap benefits of PEGASIS and APTEEN protocols. The low power consumption as in PEGASIS is maintained but the number of data packets transmitted is reduced by half. In the proposed scheme, only one of the two nodes along the parallel path involves in data transmission alternating roles in every cycle of aggregation. However, for values sensed above threshold, the inactive node interferes with normal cycle and gets its data transmitted to the sink node. This algorithm is compared with cluster based and chain based protocols and the simulation results show significant energy savings. [ABSTRACT FROM AUTHOR]

There are two major issues in spatial crowdsourcing: travel route optimization and control policies. To address the two issues above, we introduce the concept of Pocket switch network (PSN) into the CD-system. First, we formulate a generalized optimization problem into three aspects of connectivity, profit and risk, motivated by the concepts in PSN. Afterward, these three aspects are mathematically described and optimized by a routing algorithm based on dynamic mobility and social graph. This algorithm consists of two parts: social graph extraction and social mobility based routing. Social graph learns the social knowledge of each patrician while social mobility based routing decides the leaving nodes of the passages according to their social graph. Finally, we evaluated the effectiveness and robustness of the proposed method on the realistic traces. The results demonstrated its superior performance in connectivity, profit, and risk. [ABSTRACT FROM AUTHOR]

The paper presents a study of key aspects in the design of a flexible unified data plane capable of integrating both fronthaul and backhaul transport in future 5G systems. In this study, we first review candidate access and multiplexing technologies from the state of the art and assess their capability to support legacy and new fronthaul and backhaul traffic. We then propose a new design framework for the targeted flexible unified data plane, featuring a primary packet-switching path supported by an auxiliary circuit-switching for extreme low latency scenarios. This comprises a summary of the first results achieved in the 5G-Crosshaul EU project since its kick-off in July 2015. [ABSTRACT FROM AUTHOR]

This paper addresses the distributed fusion filtering problem for discrete-time random signals from measured outputs perturbed by random parameter matrices and correlated additive noises. These measurements are obtained by a sensor network with a given topology, where random packet dropouts occur during the data transmission through the different network communication channels. The distributed fusion estimation is accomplished in two phases. Firstly, by an innovation approach and using the last observation that successfully arrived if a packet is lost, a preliminary distributed least-squares estimator is designed at each sensor node using its own measurements and those from its neighbors. Secondly, every sensor collects the preliminary filters that are successfully received from its neighbors and fuses this information with its own one to generate the least-squares linear matrix-weighted distributed fusion estimator. The accuracy of the proposed estimators, which is measured by the estimation error covariances, is examined by a numerical simulation example. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the performance of transmit antenna selection in multiple-input multiple-output (MIMO) systems with N Stop and Wait (N-SAW) at the data link layer. The impact of packet size, number of SAW processes and the stalling of packets inside the receiver reordering buffer, due to N-SAW, on transmit antenna selection is investigated. Antenna selection is implemented as a signal processing technique that enhances the performance of the MIMO system; two schemes, throughput and capacity based transmit antenna selection are considered. Results show that under similar conditions, throughput maximization outperforms capacity maximization in terms of throughput, transmission latency and dropped packets when stall avoidance is implemented. The results further show that throughput and dropped packets increase with increase in SAW processes and decrease with increase in packet size. Transmission latency increases with increase in packet size and remains unchanged with increase in number of SAW processes. [ABSTRACT FROM AUTHOR]

In the present paper, we discuss the stabilization and controllability issues of the hybrid switching and impulsive higher order Boolean networks. First, the hybrid switching and impulsive controller is introduced. Second, the algebraic form of the system is given. Third, sufficient and necessary conditions for the stabilization and controllability of the system are presented, respectively. At last, an illustrative example shows the effectiveness of the main results. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new method for multi-damage extraction and classification of gear system is proposed. [•] Using PCA and KPCA to extracte the signal feature of gear system. [•] Five kinds of fault signal are analyzed under 300rpm, 900rpm, 1200rpm and 1500rpm. [•] Proposed method can be used to identify various faults (multi-fault) and damage level. [Copyright &y& Elsevier]

Abstract: Optical packet switch with multicast capability can inspire a broad range of multipoint to multipoint applications in future optical networks. An optical multicast packet switching architecture, equipped with feedback shared small number of limited-range multi-wavelength converters (LMWCs) and output shared some full-range wavelength converters (FRWCs), is proposed for a wavelength-division multiplexed optical multicast network to improve multicast performance in the paper. The FRWCs are used to overcome the performance degradation in terms of packet loss probability due to only use LMWCs. In the architecture, the two converters are shared by all the multicast packets importing to the optical multicast switch node. A maximum bipartite matching with minimum edges weights strategy was designed to employ fewer wavelength converters and avoid useless degradation of optical signal quality for the architecture to improve the node performance. The simulation results show that the proposed architecture and its wavelength converter scheduling algorithm can reduce the multicast packet loss probability with relatively lesser wavelength conversion cost. [Copyright &y& Elsevier]

Abstract: In many-core architectures different distributed applications are executed in parallel. The applications may need hard guarantees for communication with respect to latency and throughput to cope with their constraints. Networks on Chip (NoC) are the most promising approach to handle these requirements in architectures with a large number of cores. Dynamic reservation of communication resources in virtual channel NoCs is used to enable quality of service for concurrent communication. This paper presents a router design supporting best effort and connection-oriented guaranteed service communication. The communication resources are shared dynamically between the two communication schemes. The key contribution is a concept for virtual channel reservation supporting different bandwidth and latency guarantees for simultaneous guaranteed service communication flows. Different to state-of-the-art, the used scheduling approach allows to give hard guarantees regarding throughput and latency. The concept enables to adjust the bandwidth and latency requirements of connections at run-time to cope with dynamically changing application requirements. Due to its distributed reservation process and resource allocation it offers good scalability for many-core architectures. The implementation of a router and the required extension of a network interface to support the proposed concept are presented. The software perspective is discussed. An algorithm is presented that is used to establish guaranteed service connections according to the applications bandwidth requirements. Simulation results are compared to state-of-the-art arbitration schemes and show significant improvements of latency and throughput, e.g. for an MPEG4 application. Synthesis results expose the low area overhead and impact on energy consumption which makes the concepts highly attractive for QoS-constraint many-core architectures. [Copyright &y& Elsevier]

This paper extends RBAC sessions with shareability, reusability and switchability properties. We define the Smatch (Secure MAnagement of swiTCH) model in which authorized users can join, leave, reopen and reuse dynamic sessions. In Smatch, subjects can also share sessions and dynamically switch their role or function with other subjects from the same or different organizations. Subjects can authenticate using their function which will automatically activate the set of roles associated with this function. The Smatch model is based on the situation calculus which extends first order logic with actions. It provides means to specify contextual access control and authentication policies which apply to control functional behavior of dynamic sessions. We formally analyze decidability and complexity of several problems like decision, planning and proof of properties in the Smatch model. We also suggest an implementation of Smatch using Eyeos, an open-source web based Operating System. [ABSTRACT FROM AUTHOR]

Abstract: We proposed and investigated superimposing intensity-modulated labels onto high-speed carrier-suppressed return-to-zero frequency shift keying-modulated payloads in optical label-switching packet networks. The transmission performances of 2.5Gb/s ASK label on 40Gb/s CSRZFSK payload is studied for the first time. [Copyright &y& Elsevier]

Abstract: Self-triggered sampling is an attractive paradigm for closed-loop control over energy-constrained wireless sensor networks (WSNs) because it may give substantial communication savings. The understanding of the performance of self-triggered control systems when the feedback loops are closed over IEEE 802.15.4 WSNs is of major interest, since the communication standard IEEE 802.15.4 is the de-facto reference protocol for energy-efficient WSNs. In this paper, a new approach to control several processes over a shared IEEE 802.15.4 network by self-triggered sampling is proposed. It is shown that the sampling time of the processes, the protocol parameters, and the scheduling of the transmissions must be jointly selected to achieve a good performance of the closed-loop system and an energy-efficient utilization of the network. The challenging part of the proposed analysis is ensuring globally uniformly ultimately boundedness of the controlled processes while providing efficient scheduling of the process state transmissions. Such a scheduling is difficult when asynchronous multiple control loops share the network, because transmissions over IEEE 802.15.4 are allowed only at certain time slots. The proposed approach establishes that the joint design of self-triggered samplers and the network protocol (1) ensures globally uniformly ultimately boundedness of each control loop, (2) reduces the number of sensor transmissions, and (3) increases the sleep time of the transmitting nodes. A new dynamic scheduling problem is proposed for the joint control of each process and network protocol adaptation. An algorithm is derived, which adapts the network parameters according to the self-triggered sampler of every control loop. Numerical examples illustrate the analysis and show the benefits of the approach. It is concluded that self-triggered control strategies over WSNs ensure desired control performance, reduce the network utilization, and reduce energy consumption only if the protocol parameters are appropriately regulated. [Copyright &y& Elsevier]

Abstract: Variable-Bit-Rate (VBR) video transmission over UMTS networks is assuming an ever growing importance, then scheduling VBR data over wireless channels attracts great interest today. This paper proposes an on-line PI control algorithm for easily and suitably scheduling interactive multimedia transmission of VBR video streams. It dynamically adapts the transmitted bit rate to the user''s actions that can suddenly and highly modify the client buffer level. The Real-time Transport Control Protocol (RTCP) packets periodically feed back the buffer level to the server for keeping the free buffer space at 50% of its capacity, so as to prevent both buffer overflow and underflow. Numerical results of different simulated scenarios show the effectiveness of the proposed controller in comparison with two well-established algorithms, enhanced with RTCP information. [Copyright &y& Elsevier]

Abstract: The exponential increase in the data center network traffic has posed new challenges for achieving high throughput, low latency and energy consumption. To address these challenges, this paper presents a novel scheme that combines optical circuit and packet switching technologies together in a single optical cross-connect for data center networks. By utilizing fast tunable linecards and parallel array waveguide grating routers, the optical cross-connect can offer low latency, large scalability and high throughput in datacenter networks. A scheduling technique is designed to simultaneously accommodate circuit switching and packet switching in the optical cross-connect. The physical performance of this optical cross-connect in circuit and packet switching modes is investigated by experiments. In addition, the network performance of the optical cross-connect is evaluated through simulations under a mixed circuit/packet-switched traffic pattern. Results show that the network performance of the optical cross-connect does not degrade significantly with an increase in the number of racks, but it is affected by the circuit-switched traffic proportion. [Copyright &y& Elsevier]

Abstract: The basic standard protocol for supporting network mobility (NEMO) (i.e., NEMO-BSP specified by IETF) introduces several performance problems, such as multiple tunneling overhead and packet delivery latency, because it exploits mobile IPv6 (MIPv6), which was proposed for host mobility. To improve the basic NEMO solution, two network-based NEMO approaches, rNEMO and N-PMIPv6, have been proposed. The rNEMO is able to reduce significant packet tunneling overhead. The N-PMIPv6, on the other hand, reduces location update cost, but it leads to packet tunneling overhead. Thus, they commonly waste network resources in both wired and especially wireless network. No efficient and practical solutions for minimizing both the location update overhead and packet tunneling overhead have been presented until now. This situation motivated us to propose a resource-efficient network mobility scheme (RENEMO), reducing resource utilization required for network mobility support. We show that the proposed RENEMO outperforms both rNEMO and N-PMIPv6 in terms of network resource. [Copyright &y& Elsevier]

Abstract: Due to the rapid development of network applications, today the Internet plays an important role in our everyday life. Users hope that the network is always speedy enough to help them access the Internet without any delay. But the real situation is far from the ideal case. In the future, network researchers will continuously improve the network speed, and try to develop networks that are robust, without any crashes or packet loss. In this paper, we propose an aggressive path switching scheme for SCTP. Before data transmission, the scheme selects the fastest path as the primary path to transmit packets. When the path fails or transmission quality is poor, this scheme evaluates alternate paths, and selects the one with the best quality as the new primary path to substitute for the original one. After that, packets are delivered through the new path. Several factors are considered in the evaluation, including bandwidth, encryption/decryption, size of the congestion window, retransmission policy, routing policy, etc. [Copyright &y& Elsevier]

Abstract: In the problem of buffer management with bounded delay, packets with weights and deadlines arrive at a network switch over time, and the goal is to send those packets on the outgoing link while maximizing the total weight of the packets that are sent before their deadlines. We present a study of randomized algorithms that are competitive against an adaptive adversary. Previous studies considered only the oblivious adversary model that does not capture dependency of network traffic on the packet scheduling algorithm. We give a new analysis of a previously known algorithm, which shows that it remains -competitive even against an adaptive adversary. We complement this with a 4/3 lower bound on the competitive ratio on 2-bounded instances, in which each packet has a lifespan of one or two steps. We also study more restricted 2-uniform instances, in which every packet has a lifespan of exactly two steps. For such instances we give a 1.2 lower bound on the competitive ratio of arbitrary algorithms and 4/3 lower bound on the competitive ratio of memoryless scale-invariant algorithms. Finally, we devise a 4/3-competitive memoryless scale-invariant algorithm for 2-bounded instances, matching two of these lower bounds. [Copyright &y& Elsevier]

Abstract: Localization protocol is important for estimating node positions in a wireless multi-hop network. Routing protocol is also important for controlling paths. In previous research, localization and routing protocols have been discussed and evaluated separately. In this paper, we propose an integrated protocol for optimized link state routing (OLSR) and OLSR based localization (ROULA). Our protocol enables simultaneous localization and routing. ROULA’s localization is performed using OLSR overhead such as hello packets and routing tables. The routing overheads and the processing procedures can be efficiently integrated. We demonstrate that the integrated protocol for ROULA and OLSR enables simultaneous localization and routing. [Copyright &y& Elsevier]

Abstract: In the Optical Burst Switching (OBS) Network, the burst assembly technique is one of the challenging issues in the implementation of the system. It has the influence on the burst characteristic, which gives an impact on the network performance. Burst assembly is the process of assembling incoming data from the higher layer into bursts at the ingress edge node of the OBS network. The burst assembly mechanism must then place these packets into bursts based on some assembly policy. In this paper, the OBS system performance has been observed in simulated 12-node network based on Just-Enough-Time (JET) reservation protocol with various burst assembly techniques under the standard drop policy (DP) and the segmentation policy for contention resolution. The simulation results show that the performance of the proposed Adaptive-Threshold with Fixed Maximum Time Limitation (ATH-FMTL) burst assembly scheme is better than conventional burst assembly schemes in terms of loss probability and average assembly delay. Also, the proposed scheme avoids a sudden increase in the burst size and makes the burst sent out smoother as compared to conventional schemes. [Copyright &y& Elsevier]

Abstract: TCP (Transmission Control Protocol) is one of the protocols which are widely used in Internet environments. This paper presents an analytical model developed using the stochastic reward net (SRN) modeling technique for the TCP flow behavior in WLANs. The purpose of developing an analytical model is the evaluation of stationary TCP flow behavior. In this paper, we focus the attention on the TCP variant called TCP Reno which is implemented by most operating systems. The performance of TCP Reno is investigated through the SRN model. The model captures aspects such as congestion window (cwd) evolution, slow start and congestion avoidance phases, TCP packet transmissions, management of packet losses due to time-out, and due to generation of triple duplicate acknowledgements. The performance metrics such as throughput and delay of the TCP traffic are obtained using the SRN model. On the basis of these performance measures, the existing unfairness between the downstream and upstream flow at the AP in WLANs is also shown. The proposed analytical model is validated via simulation. [ABSTRACT FROM AUTHOR]

Abstract: With increasing number of cores, the communication latency of Network-on-Chip becomes a dominant problem due to complex operations per node. In this paper, we try to reduce communication latency by proposing single-cycle router architecture with wing channel, which forwards the incoming packets to free ports immediately with the inspection of switch allocation results. Also, the incoming packets granted with wing channel can fill in the time-slots of crossbar switch and reduce the contentions with subsequent ones, thereby pushing throughput effectively. We design the proposed router using 65nm CMOS process, and the results show that it supports different routing schemes and outperforms express virtual channel, prediction and Kumar’s single-cycle ones in terms of latency and throughput. When compared to the speculative router, it provides 45.7% latency reduction and 14.0% throughput improvement. Moreover, we show that the proposed design incurs a modest area overhead of 8.1% but the power consumption is saved by 7.8% due to less arbitration activities. [Copyright &y& Elsevier]

Abstract: The input buffers of the current packet-switched Network-on-Chip (NoC) architectures consume a significant portion of the total power of the interconnection network. Reducing the size of input buffers would result in degraded performance, while eliminating all buffers would result in increased power at high network load. In this article, we propose DXbar: an innovative dual-crossbar design. By combining the advantages of buffered and bufferless networks, we achieve at least 20% performance improvement in terms of throughput and latency, and at least 20% power saving over buffered networks with virtual channels. Furthermore, DXbar can outperform current bufferless networks with deflecting and dropping protocols while consuming at most half of the power. [Copyright &y& Elsevier]

Abstract: This paper presents a design methodology for IP networks under end-to-end Quality-of-Service (QoS) constraints. Particularly, we consider a more realistic problem formulation in which the link capacities of a general-topology packet network are discrete variables. This Discrete Capacity Assignment (DCA) problem can be classified as a constrained combinatorial optimization problem. A refined TCP/IP traffic modeling technique is also considered in order to estimate performance metrics for networks loaded by realistic traffic patterns. We propose a discrete variable Particle Swarm Optimization (PSO) procedure to find solutions for the problem. A simple approach called Bottleneck Link Heuristic (BLH) is also proposed to obtain admissible solutions in a fast way. The PSO performance, compared to that one of an exhaustive search (ES) procedure, suggests that the PSO algorithm provides a quite efficient approach to obtain (near) optimal solutions with small computational effort. [Copyright &y& Elsevier]

Abstract: Traditionally, congestion control in packet networks is performed by reducing the transmission rate when congestion is detected, in order to cut down the traffic that overwhelms the capacity of the network. However, if the bottleneck is a wireless link, congestion is often cumulated because of retransmissions derived from bit errors. In this case, it might be beneficial to allow delivery of partly corrupted packets up to the application layer instead of reducing the transmission rate. This would decrease the number of retransmissions in the link layer and therefore relieve congestion, but at the cost of bit errors appearing in the packet payload. In this paper, we study a congestion control mechanism for streaming applications that combines traditional congestion control with selective link layer partial checksumming allowing bit errors in the less sensitive parts of data. We have compared the performance of the proposed mechanism against traditional congestion control with a simulation study. The results show that the proposed approach can improve the overall performance both by increasing the throughput over the wireless and improving the video quality in terms of peak signal-to-noise ratio (PSNR) by up to 8dB, depending on the error conditions and the content. [Copyright &y& Elsevier]

Abstract: This paper proposes a novel Network-on-Chip architecture that not only enhances network transmission performance while maintaining a feasible implementation cost, but also provides a power-efficient solution for interconnection network scenarios. Diagonally-linked mesh NoC that uses wormhole packet switching technique implements a high-performance NoC platform to meet both cost and power consumption requirements. The proposed architecture uses an adaptive quasi-minimal routing algorithm so that it can improve average latency and saturation traffic load owing to its flexibility and adaptiveness. Based on these features, a congestion-aware routing algorithm is proposed to balance traffic load so as to alleviate congestion caused by high throughput network activities. Simulation results show that saturation load is improved dramatically for various traffic patterns. Implementation results also show that employing diagonal links is a more area-efficient method for improving network performance than using large buffers. It is shown that congestion-aware router requires negligible cost overhead but provides better throughput. Finally, simulation results also reveal that power consumption in the proposed architecture outperforms traditional mesh networks. [Copyright &y& Elsevier]

Abstract: This paper proposes multi-hop scheduling algorithms for the All-to-All Broadcast (AAB) problem in Wavelength Division Multiplexed (WDM) optical star networks. The multi-hop AAB problem can be split into two subproblems: Logical Topologies Construction (LTC) problem, and Transmission Scheduling (TS) problem. For improving the efficiency of multi-hop scheduling, we focus on a new multi-hop transmission model and transfer the LTC problem to a special case of the Round Robin Tournament (RRT) problem. In the proposed logical topologies, our multi-hop scheduling algorithms can easily overlap the tuning latency and reduce the number of tuning operations on each node. We compare our results with previous research in terms of schedule length. Overall results indicate that our multi-hop scheduling algorithms have better performance than previous algorithms. [ABSTRACT FROM AUTHOR]

Abstract: Circumventing the speed bottleneck of electronic switching, novel switching approaches like optical burst switching (OBS) and optical packet switching (OPS) handle the switching of bursts (or packets) in backbone nodes optically, and include a set of fiber delay lines (FDLs) for optical buffering. While previous work acknowledges the performance difference between optical FDL buffers and electronic RAM buffers, the important role of synchronization herein has received little attention to date. Addressing this, we developed a single-wavelength FDL model that allows to capture the interplay between FDL buffer performance, burst size distribution and synchronization. Relying on generating functions, we constructed a discrete-time queueing model with batch arrivals that is valid for general burst and batch size distribution, and allows to quantify how synchronization impacts performance. This paper presents our model and compares its output for different synchronization levels. Whether or not buffer performance benefits from synchronization, turns out to depend strongly on the burst size distribution. [ABSTRACT FROM AUTHOR]

Abstract: We propose a new system of a packet of quantum bits generation using a soliton pulse within a microring resonator. A quantum gate can be formed by using a polarization control unit incorporating into the system. The random signal and idler pairs can be formed within the photon correlation bandwidth, which can be generated, and randomly form the packet quantum bits, i.e. quantum packet switching. Each random code (logic) can be performed by combining the signal and idler of each entangled photon pair via the quantum gate. Results obtained have shown that the packet of quantum logic bits can be generated using the entangled photon pairs generated by the proposed system. [ABSTRACT FROM AUTHOR]

Abstract: We propose a new design of the secure packet switching device using the nonlinear behaviors of soliton in a micro ring resonator, where the nonlinear penalty of light traveling in the device becomes beneficial. The chaotic signals are generated by a Kerr effects nonlinear type of the input soliton pulse in a micro ring resonator, where the control input power can be used to specify the output filtering signals. Some device parameters are chosen and simulated using the proposed model. The potential of using such a device for communication security is performed and discussed. For instance, the packet switching of the chaotic encoding data increases from the chaotic signal encoding of 100bits−1. Results obtained have shown the potential of using such a proposed device for the tunable bandpass and band-stop filters, in which packet switching data can be performed and secured. [Copyright &y& Elsevier]

Abstract: In this paper, we investigate the performance of optical burst switched networks for erbium-doped fiber amplifiers (EDFAs) and semiconductor optical amplifiers (SOAs). We show that EDFAs are more suitable for burst switching as compared to SOAs. We further investigate the burst length for 18, 24.6 and 55km optical switched network. It is observed that burst length should neither be very small nor very large. If the burst length is small, throughput will be less, and if the burst length is very large, delay will be very large. This is due to higher wait times incurred when packets are formed into larger bursts causing additional overall delay. It is observed that performance decreases up to a small burst length of 1500μs, which is the minimum burst length required for the creation of the burst. Once this burst is created, there is significant improvement in the quality factor up to 3000μs. After this burst length, the performance again degrades. Hence the burst length can be optimized for the best quality factor in optical burst switched networks. We further show that by increasing EDFA gain, the quality deteriorates as increasing the EDFA gain results in increased levels of additive phase noise, which can further induce nonlinearities. [Copyright &y& Elsevier]

Abstract: We propose a new design of secured packet switching generated by using nonlinear behaviors of light in a micro ring resonator. The use of chaotic signals generated by the micro ring resonator to form the filtering and packet switching characteristics is described, where the high-capacity and security switching using such form is presented. The key advantage is that the high capacity of communication data can be secured in the transmission link, where the nonlinear penalty of light traveling in the device is beneficial. For instance, the required information can be transmitted and retrieved by using the proposed packet switching scheme. In principle, the chaotic signals are generated by a Kerr effects nonlinear type of light in a micro ring resonator, where the control input power can be specified by the required output filtering signals. The ring radii used range between 10 and 20μm, κ=0.0225, α=0.5dB and n 2=2.2×10−15 m2/W. Simulation results obtained have been described based on the practical device parameters. Three forms of the applications have been simulated, the potential of using for the tunable band pass and band stop filters, in which high-capacity packet switching data can be performed, and the fs switching time is plausible. [Copyright &y& Elsevier]

Abstract: The burstiness of video traffic in future wired and wireless networks makes dynamic management of network resources more critical. This helps to meet stringent delay and loss requirements of video traffic and improves its Quality of Service (QoS). Since buffer management in queueing system plays an important role towards effective control of QoS for various types of applications, we have focused on its dynamic management. In this paper, we have proposed ADPBS scheme for priority queueing system. The performance of this scheme is analyzed with MPEG-4 encoded video sequence as input to the ADPBS queue. The simulation is carried out in MATLAB for various combinations of threshold control parameters, different traffic load and input traffic mix variations. The results of simulations indicate that dynamically controlled threshold in ADPBS contributes to significant reduction of packet loss of different priority classes as compared with static partial buffer sharing queue and first in first out queue based on threshold control parameters and the traffic type. [Copyright &y& Elsevier]

Abstract: This paper proposes a novel method to study the modelling problem of a networked control system. We first identify the minimum packet drop sequences for a given plant or controller using the dynamics of the plant or controller. Then we represent these minimum packet drop sequences as states of a Markov chain. The state transition of the Markov chain is triggered at each packet transmission. Finally, this new modelling technique is demonstrated using the most commonly employed PID controller. [Copyright &y& Elsevier]

Abstract: A novel scheme of time-stacked optical code label based on optical code division multiple (OCDM) technique for optical packet switching network is proposed, in which two-dimensional wavelength–time OCDM code is used as the optical label. Packet loss rate and system characteristic based on the proposed scheme are studied. Results show that less packet loss rate of proposed scheme can be achieved as compared with that of one-dimension time-stacked optical code label system. [Copyright &y& Elsevier]

Abstract: This paper considers a batch arrival retrial queue with general retrial times under a modified vacation policy. Any arriving batch finding the server busy or on vacation enters an orbit. Otherwise, one customer from the arriving batch obtains the service immediately while the rest join the orbit. If the orbit is empty, the server takes at most vacations repeatedly until at least one customer appears in the orbit upon returning from a vacation. If the orbit is nonempty when the server returns from a vacation, the server waits idly for customers from the orbit or new arrivals. On the other hand, if no customers are recorded in the orbit at the end of the th vacation, the server waits for new customers to arrive. This retrial system has potential applications in packet-switched networks. By applying the supplementary variable technique, some important system characteristics are derived. The results presented in the paper may be useful for network system designers and software system engineers. [Copyright &y& Elsevier]

Abstract: In this paper, an optically controlled loop buffer is proposed and experimentally demonstrated. It utilizes a semiconductor optical amplifier (SOA) based loop mirror as a fast switch to realize the writing and reading of packets within this buffer and a circulator based optical reflector to achieve internal re-circulations. By adding fibers with different lengths between the loop mirror and the circulator, variable delay time per circulations can be obtained. We also demonstrate the performance of the 2.5 and 10Gb/s data packets in this buffer structure, as well as the influence of the two different control signal formats on the packet signal degradation during buffering. This loop buffer has the merits of low cost and improved performance compared to other similar loop buffer structures. According to the obtained results, the achieved number of circulations is greatly increased. [Copyright &y& Elsevier]

Abstract: non-preemptive priority queue with bulk arrivals has already been analysed in many papers. Two problems are known in this area: first, when the number of priorities is greater than 2, the analysis for priority processes is obviously very difficult to handle. Therefore, the earlier work on the subject was restricted mostly to two priority classes; and second, although analytically explicit results are available, they require sophisticated closed-form expressions of the mean queue length. One particular bulk size distribution – the GE distribution – is motivated by an ME (Maximum Entropy) formulation for the behavior of a G/G/1 queue. The choice of a GE distribution is motivated by the fact that measurements of actual inter-arrival traffic or service times may be generally limited and so only few parameters, such as mean and variance, can be computed reliably. Thus this paper we can obtain very simple and analytic closed-form expression for the mean queue length of a GE/G/1 priority queue and a significant increase in performance evaluation has been achieved. We present the four-class priority queues, performance analysis and simulation of the LER (Label Edge Router) system in the ATM-based MPLS (Multiprotocol Label Switching) network. We wish to obtain the boundary conditions of the mean queue lengths and the mean queueing delays for each priority class, since this metric is one of the most important in performance evaluation parameters for improving QoS and system performance of the LER system in ATM-based MPLS network. A significant numerical example is presented and discussed as well. In order to obtain optimizing the performance analysis for EF flow, AF 1 flow, AF 2 flow and BE flow, the optimum ratios of COV (Coefficient of Variation) can be found via many numerical experiments carried out by the authors for queueing network model with HOL (Head of Line) priority rules. However, the ratios of COV value constraints exist. Furthermore, we find that each service class gradually begins to deteriorate when SQVs (Squared Coefficient of Variations), , and traffic intensity is greater than 0.95. We also find the values of maximum allowed burst size for EF flow and AF 1 flow and perform necessary policing actions on EF flow and AF 1 flow at the boundary node of the network. Finally, the four-class GE/G/1 priority queues and performance analysis of the LER system are shown accurate and robust after the comparison between theoretical evaluates and computer simulation results. [Copyright &y& Elsevier]

Abstract: In active networks, the Execution Environment in an active node executes user codes to tailor the processing of packets to application needs. However, the existing implementation of a software-based active node has a dilemma of only using the user mode Execution Environment or, alternatively, only using the kernel mode Execution Environment because neither mode of the Execution Environments meets application needs. The dilemma stems from the choice between high overheads of a user mode Execution Environment and poor services of a kernel mode Execution Environment in executing user codes. In this paper, we propose the Dual-Mode Execution Environment to overcome this dilemma, i.e. arguing for the necessity of an Execution Environment that supports dual modes. Currently, we develop and make the Lifetime-Sensitive Quantity-based Policy the workload adjustment policy in the Dual-Mode Execution Environment. We implement the prototype in Windows 2000. We conduct experiments to compare the prototype with active nodes that uses either the user mode Execution Environment or the kernel mode Execution Environment. We prove that the prototype meets application needs and outperforms the compared active nodes. [Copyright &y& Elsevier]

Abstract: Active queue management (AQM) is a key congestion control scheme for reducing packet loss and improving network utilization in TCP/IP networks. This paper proposes a proportional–integral-derivative (PID) controller as an active queue manager for Internet routers. Due to the limitations of packet-dropping probability and the effects of propagation delays in TCP networks, the TCP AQM network was modeled as a time-delayed system with a saturated input. An improved genetic algorithm is employed to derive optimal or near optimal PID controller gains such that a performance index of integrated-absolute error (IAE) is minimized, and thereby a stable queue length, low packet loss, and high link utilization for TCP networks are guaranteed. The performance of the proposed control scheme is evaluated in various network scenarios via a series of numerical simulations. [Copyright &y& Elsevier]

Abstract: In mobile ad hoc networks (MANETs), flooding is a required message dissemination technique for network-wide broadcast. The conventional blind flooding algorithm causes broadcast storm problem, a high number of unnecessary packet rebroadcasts thus resulting in high contention and packet collisions. This paper proposes a new probabilistic approach that dynamically fine-tunes the rebroadcasting probability of a node for routing request packets (RREQs) according to the number of neighbour nodes. We evaluate the performance of the proposed approach for the ad hoc on demand distance vector (AODV) routing protocol and compared against the blind flooding, fixed probabilistic and adjusted probabilistic flooding [L.M.M.M. Bani-Yassein, M. Ould-Khaoua et al., Performance analysis of adjusted probabilistic broadcasting in mobile ad hoc networks, International Journal of Wireless Information Networks 13(2) (2006) 127–140; M.B. Yassein, M.O. Khaoua et al., Improving route discovery in on-demand routing protocols using local topology information in MANETs, Proceedings of the ACM international workshop on Performance Monitoring, Measurement, and Evaluation of Heterogeneous Wireless and Wired Networks, Terromolinos, Spain, ACM Press, 2006, pp. 95–99.] approaches. The simulation results show that our proposed approach demonstrates better performance than blind flooding, fixed probabilistic and adjusted flooding approaches. [Copyright &y& Elsevier]

Abstract: This paper presents a study of feasibility of different existing methodologies linked to field’s data acquisition from remote meteorological stations. The data transmission serves to collect field’s meteorological information, such as temperature, humidity and radiation. In our study the experimental data is registered in a weather station located about 100km from the University of Almeria. Various existing techniques are studied, especially Radio, GSM (global system of mobile communication) and GPRS (general packet radio service). In the result of these studies has been designed a system of field’s data acquisition (herein referred as Meteologger) which we are going to present in this paper. The system is based on an ATmega 16 microcontroller, which scans 8 sensors together at any programmable intervals. This paper presents the study of the mentioned project, application and some main characteristics of the prototype system and its program. We attempt to implement the system, and subsequently present the performance of tests regarding the mentioned system. To verify its functioning some comparison of this measurement system with two others commercial data-acquisition system (Campbell and Hobo H8) has been carried out. [Copyright &y& Elsevier]

Abstract: An all-optical differential group delay (DGD) monitor for packet-switched networks is proposed. The monitoring approach consists of an integrated active Mach–Zehnder interferometer acting as a logic XOR gate. According to the estimated DGD value, a latching switch is employed to route the input packets “on-the-fly”. The simulation results show a successful operation which has been confirmed with the experimental validation of the XOR-based monitoring subsystem. [Copyright &y& Elsevier]

Abstract: Dynamic Resource Allocation (DRA) algorithms set up different connections over the same resources and perform a scheduling policy to distribute the resources usage. Recently, intelligent DRA techniques based on Hopfield Neural Networks computational methods have been proposed, showing their potential for solving this kind of complex optimization problems. However, the initial algorithms suffer from severe instability problems impacting performance. This paper addresses these specific limitations stressing the proper neuron dynamics and proposing an efficient energy formulation and an optimum calculation of the weighting coefficients. These changes result in a maximum resource utilization together with an optimized neural network convergence. [Copyright &y& Elsevier]

Abstract: We propose a novel 2×2 wavelength-convertible optical switch based on dual-pump fiber parametric devices: one is driven by linearly parallel pumps, and the other one by perpendicular pumps. Theoretical analysis is made on the polarization effects on the switching performance of the two devices. The result predicts that two incident signals which are positioned symmetrically with respect to one pump can be switched independently, with judicious combinations of the relative pump-signal polarization states. Simulations performed in OptiSystem show that the scheme can achieve crosstalk-free packet switching with acceptable extinction ratios for both signals. Besides, future applications of this novel scheme in high-speed switching nodes are discussed. [Copyright &y& Elsevier]