Automated Deception Detection (ADD) is a challenging task and still under study as a visual analysis task. Based on the idea that human micro-expressions and body movements could be used as clues for ADD, many works have proposed some action recognition models for extracting face and body spatiotemporal features. However, these features are not sufficient evidence for deception; moreover, micro-expressions are difficult to detect and real-life deception samples are hard to collect, thus ADD still has many challenges. In this paper, we present a global two-stream network (GTSN), which not only extracts face and body features, but also utilizes the correlation between the deceptions. GTSN can improve the accuracy of deception detection by adding historical information based on the correlation between the deceptions. We build a dataset named Deception-Truthful (DT) for evaluating the performance of our proposed model. Experimental results demonstrate that our GTSN model outperforms other action recognition models used for ADD. Further, the proposed GTSN model also performs well on the real trial videos widely used in ADD.
Human action recognition in videos is a challenging task in the field of computer vision. Based on the idea of integrating temporal and spatial feature, many works have proposed a variety of methods for extracting spatiotemporal features, such as two-stream network and 3D convolution neural network (3D-CNN). However, due to the huge computational cost of optical flow for two-stream network and the huge number of parameters of 3D-CNN, the computational time required for action recognition is very long, therefore it is difficult to meet the requirements of real-time recognition. This paper aims to explore an efficient architecture of 3D-CNN for action recognition. On the premise of guaranteeing the recognition accuracy, we aim to greatly reduce the computational cost. In order to ensure good performance while reducing the amount of input data, we present Global Evaluate-and-Rescale (GER) Network, which is able to automatically extract the key frames of input data. We have evaluated the performance of our proposed model on two challenging human action recognition datasets UCF101 and HMDB51. The experimental results show that GER Network can reduce up to 50% of the computation time for recognition while achieving approximate accuracy with state-of-the-art 3D-CNN models.
Recently, superpixel-based methods have shown promising performance for synthetic aperture radar (SAR) image interpretation. In these methods, the statistical model-based local iterative clustering represents the mainstream of superpixel generation for SAR images. However, errors in the model parameter estimation degrade the accuracy of the model-based distance measure between a pixel and a cluster, which directly affects the performance of superpixel segmentation results. Further, the relative weight between statistical similarity and spatial proximity should be carefully selected to control the balance between boundary adherence and regularity of superpixels. An edge-dominated local clustering method is proposed to overcome these limitations. Edge information is introduced not only to define the dissimilarity of a pixel and a cluster but also to provide an adaptive grid with multiple layers for the initialization of cluster centers. Experiments on simulated and real datasets show that, compared with the previous algorithms using the statistical model-based dissimilarity, the proposed method produces superpixels, which have better edge adherence and stable performance.
Optical circuit-switched networks can offer end-to-end dedicated connection with high-capacity bandwidth for largescale
applications, but end-systems' performance in these applications often becomes the bottleneck of bulk data transfer
in ultra-high-speed network. We propose a bandwidth scheduler based on the end-systems' effective transfer rate and
study its performance through experiment.
A very important issue in executing a scientific workflow in optical grid is how to map the workflow tasks onto multiple
distributed resources. In this paper, we propose a new cost-based workflow scheduling algorithm (MCBS) which tries to
minimize the cost of the workflow execution while meeting the deadline defined by users. The simulation results prove
the efficiency of the MCBS algorithm.
An enhanced dynamic wavelength and bandwidth allocation (DWBA) algorithm in hybrid WDM/TDM PON is proposed
and experimentally demonstrated. In addition to the fairness of bandwidth allocation, this algorithm also considers the
varying propagation delays between ONUs and OLT. The simulation based on MATLAB indicates that the improved
algorithm has a better performance compared with some other algorithms.
Reliable service delivery becomes more significant due to increased dependency on electronic services all over society
and the growing importance of reliable service delivery. As the capability of PON increasing, both residential and
business customers may be included in a PON. Meanwhile, OPEX have been proven to be a very important factor of the
total cost for a telecommunication operator. Thus, in this paper, we present the partial protection PON architecture and
compare the operational expenditures (OPEX) of fully duplicated protection and partly duplicated protection for ONUs
with different distributed fiber length, reliability requirement and penalty cost per hour. At last, we propose a
differentiated protection method to minimize OPEX.
With rapid growth of Internet applications, supporting differentiated service and enlarging system capacity have been
new tasks for next generation access system. In recent years, research in OFDMA Passive Optical Networks (PON) has
experienced extraordinary development as for its large capacity and flexibility in scheduling. Although much work has
been done to solve hardware layer obstacles for OFDMA PON, scheduling algorithm on OFDMA PON system is still
under primary discussion. In order to support QoS service on OFDMA PON system, a novel dynamic wavelength
bandwidth allocation (DWBA) algorithm is proposed in this paper. Per-stream QoS service is supported in this algorithm.
Through simulation, we proved our bandwidth allocation algorithm performs better in bandwidth utilization and
differentiate service support.
A cost-effective and service-differentiated provisioning strategy is very desirable to service providers so that they can
offer users satisfactory services, while optimizing network resource allocation. Providing differentiated protection
services to connections for surviving link failure has been extensively studied in recent years. However, the
differentiated protection services for workflow-based applications, which consist of many interdependent tasks, have
scarcely been studied. This paper investigates the problem of providing differentiated services for workflow-based
applications in optical grid. In this paper, we develop three differentiated protection services provisioning strategies
which can provide security level guarantee and network-resource optimization for workflow-based applications. The
simulation demonstrates that these heuristic algorithms provide protection cost-effectively while satisfying the
applications' failure probability requirements.
We propose a simple configuration of wavelength-tunable self-seeding Fabry-Perot fiber laser at ONUs for upstream
transmission in hybrid WDM/TDM PON. The performances of the side-mode suppression ratio (SMSR), tuning range,
wavelength and power stability for the proposed laser module are experimentally investigated. The performance benefits
from the upstream wavelengths sharing are showed via simulations.
Fault-tolerant scheduling is an important issue for optical gird applications because of a wide range of grid resource
failures. To improve the availability of the DAGs (directed acyclic graphs), a primary-backup approach is considered
when making DAG scheduling decision. Experiments demonstrate the effectiveness and the practicability of the
proposed scheme.
We propose a novel scheme to overlay multicast service over a wavelength-division-multiplexed (WDM) passive optical
network (PON) based on dynamic wavelength reflection scheme. At the optical line terminal (OLT), for each WDM
channel, a dynamic wavelength reflector is used to selectively bypass the corresponding optical carrier to avoid multicast
data superimposition, while the remaining optical carriers go through the dynamic wavelength reflector and
simultaneously carry the multicast data. The proposed scheme is experimentally demonstrated with 5-Gb/s downstream
unicast, multicast data and 625-Mb/s upstream re-modulated data.
Effective management of large amount of heterogeneous resources in multi-domain optical grid
networks is critical to the performance of the grid application. This article proposes the design of a
distributed system for an integrated management of both application and network resources in
Distributed Hash Table (DHT) mode, called Distributed Resource Manager (DRM), and the core
component Quord in DRM is also implemented and evaluated.
These days while the traditional Internet cannot meet the requirement of data-intensive communications in large scale escience
grid applications, Optical network which is also referred to as Lambda Grid provide a simple means of achieving
guaranteed high bandwidth, guaranteed latency and deterministic connection. Lots of e-science applications like e-VLBI
and GTL require aggregating several hundred GB data files from distributed databases to super-computers frequently at
real time. Thus minimizing the aggregation time can improve the overall system performance. We consider the problem
of aggregating large data files from distributed databases to distributed computational resources on lambda grid. We
modify the model of Time-Path Scheduling Problem (TPSP) which has been proposed and propose a new N-destination
TPSP (NDTPSP) model. We present the proof of NDTPSP's NP-completeness. We also propose a list scheduling
algorithm and a modified list scheduling algorithm for our problem. The performance of different algorithms will be
compared and analyzed by simulations.
In today's distributed computing systems, a large amount files contain huge data need to be transferred to their
destination as soon as possible or else the quality of these systems will be seriously affected, and these transfer requests
arrived dynamically. We propose some effective heuristic algorithm to this problem with the purposes of minimizing the
maximal file transmitting time, and we can get some primal results from the algorithm. However, as we known, the
problem of routing and scheduling for the dynamic arriving files in the optical network has a large number of constrains
and the exact solution is computationally expensive, so it is hard to get the optimal result about this problem and we can
not know whether the heuristic results is good or how closed it closed to its optimal result. In order to get some more
detail results, we apply the approach called Lagrangian relaxation combined with subgradient-based method and utility
the heuristic result to compute the lower bound of the optimal solution, and we consider the optimal target of minimizing
the maximal file transmitting complete time for it's an important aspect with the file transmitting problem.
We mainly use Lagrangian relaxation (LR) to research the dynamical lager file transmitting problem. Firstly, in order to
apply the LR method we formulation our dynamic file routing scheduling and distributing problem in WDM optical
network into mathematic model with some corresponding constraints. Secondly, change the formulation with some
added variables to let it more suitable for LR and then introduce the Lagrangian multipliers into the model to obtain the
Lagrangian function. With this function we can divided it into some small independent problems that could let it be
solved more easily and at last we utilize the result received from the heuristic algorithm to solve the Lagrangian
multiplier problem with subgradient-based method in order to getting the sharpest possible lower bound.
With the comparison of our simulation results, we can prove that the Subgradient algorithm based on LR can get better
results of the file transmitting time than the heuristic algorithm, and with the theorem of Lagrangian Bounding Principle
we can know that value of LR method is a lower bound on the optimal value.
Optical grid, the integrated computing environment based on optical network, is expected to be an efficient
infrastructure to support advanced data-intensive grid applications. In optical grid, the faults of both computational and
network resources are inevitable due to the large scale and high complexity of the system. With the optical network
based distributed computing systems extensive applied in the processing of data, the requirement of the application
failure probability have been an important indicator of the quality of application and an important aspect the operators
consider. This paper will present a task-based analysis method of the application failure probability in optical grid. Then
the failure probability of the entire application can be quantified, and the performance of reducing application failure
probability in different backup strategies can be compared, so that the different requirements of different clients can be
satisfied according to the application failure probability respectively. In optical grid, when the application based DAG
(directed acyclic graph) is executed in different backup strategies, the application failure probability and the application
complete time is different. This paper will propose new multi-objective differentiated services algorithm (MDSA). New
application scheduling algorithm can guarantee the requirement of the failure probability and improve the network
resource utilization, realize a compromise between the network operator and the application submission. Then
differentiated services can be achieved in optical grid.
Optical grids can integrate geographically distributed resources more efficiently to support applications because of characteristics of optical networks. The essential aspect of optical grid applications is scheduling. By scheduling, multiple optical grid applications from different users can be executed on one optical grid. This means multiple users can use one optical grid simultaneously. In this paper, we propose three new algorithms for the scheduling of multiple optical grid applications onto one optical grid, and one algorithm among these three can make the scheduling order dynamic. In these algorithms, communication contention has been incorporated into scheduling, and arrival time of multiple optical grid applications is assumed to abide by Poisson distribution to simulate multiple users. Our objects of scheduling are not only to make scheduling span short, but also to achieve low unfairness. Impacts of different algorithms are comparatively investigated by simulations.
This paper studies the problem of the implementation of distributed computing applications in local area networks. We
propose a novel Dynamical Wavelength Scheduled Wavelength Division Multiplexing Passive Optical Network (WDMPON)
architecture, in which the number of the available upstream wavelength channels is greatly less than that of optical
network units (ONU). And we experimentally demonstrate the feasibility of the proposed WDM-PON, which enables
dynamically scheduling upstream data in the time division multiplexing (TDM) and WDM scheme from ONU to
optical line terminal (OLT). The Time-Wavelength Co-Allocation (TWCA) Problem is defined in the proposed WDMPON
architecture to aggregate large files for distributed computing applications and three scheduling algorithms are
presented to solve this problem. The significant improvement compared with the conventional TDM-over-WDM PON is
illustrated through simulations.
Optical Grid has been thought as a promising technology to support large-scale data-intensive distributed applications. For such a system with so many heterogeneous resources involved, faults seem to be inevitable. A fault in Optical Grid may lead to the failure of the application. Therefore, fault-tolerant policies are necessary to improve the performance of Optical Grid and satisfy the SLA requirements of the applications. In this paper, we propose several fault-tolerant policies for Optical Grid. The performances of different polices are compared by simulation.
In this paper we proposed a Max-Flow Oriented Algorithm (MFOA) to achieve the shortest finish time in Time-Path
Scheduling Problem (TPSP). The signification of our algorithm is that it combines both benefits of the Max-Flow
algorithm and heuristic algorithms, so we can achieve a better result with lower time cost. Another feature of our
algorithm is that all the data on the same node in the network can be considered as a single merged data, so the time cost
is mainly depended on the network topology and the task numbers will not affect the time cost much. This feature makes
our algorithm suitable for large scale applications. In this paper we figured out the relationship of Max-Flow routing and
our objective: shortest finish time, and how the Max-Flow theoretic helps to achieve it. We also build the mathematical
model of our MFOA with Max-Flow Oriented Scheduling (MFOS) rerouting strategy. To investigate the performance of
our algorithm, we compare it with existing optimization algorithm and algorithms with 4 other heuristic rerouting
strategies. Based on the results of simulations on different topologies, our algorithm is best in most of the situations.
Besides the method used in this paper also helps to develop more efficient algorithms.
This paper describes the Task Scheduling problem over Ethernet Virtual Connections which provides multiple-granularity
and the problem of scheduling tasks over two user network interfaces is considered. Three approximate
models, 2SP, 2LSP and BWS are proposed with algorithms respectively. Numerical simulation results and comparisons
are also presented.
In the IPTV systems, multicasting will play a crucial role in the delivery of high-quality video services,
which can significantly improve bandwidth efficiency. However, the scalability and the signal quality
of current IPTV can barely compete with the existing broadcast digital TV systems since it is difficult
to implement large-scale multicasting with end-to-end guaranteed quality of service (QoS) in
packet-switched IP network. China 3TNet project aimed to build a high performance broadband trial
network to support large-scale concurrent streaming media and interactive multimedia services. The
innovative idea of 3TNet is that an automatic switched optical networks (ASON) with the capability of
dynamic point-to-multipoint (P2MP) connections replaces the conventional IP multicasting network in
the transport core, while the edge remains an IP multicasting network. In this paper, we will introduce
the network architecture and discuss challenges in such IP over Optical multicasting for video delivery.
Network traffic grows in an unpredictable way, which forces network operators to over-provision their backbone
network in order to meet the increasing demands. In the consideration of new users, applications and unexpected failures,
the utilization is typically below 30% [1]. There are two methods aimed to solve this problem. The first one is to adjust
link capacity with the variation of traffic. However in optical network, rapid signaling scheme and large buffer is
required. The second method is to use the statistical multiplexing function of IP routers connected point-to-point by
optical links to counteract the effect brought by traffic's variation [2]. But the routing mechanism would be much more
complex, and introduce more overheads into backbone network. To exert the potential of network and reduce its
overhead, the use of Valiant Load-balancing for backbone network has been proposed in order to enhance the utilization
of the network and to simplify the routing process. Raising the network utilization and improving throughput would
inevitably influence the end-to-end delay. However, the study on delays of Load-balancing is lack. In the work presented
in this paper, we study the delay performance in Valiant Load-balancing network, and isolate the queuing delay for
modeling and detail analysis. We design the architecture of a switch with the ability of load-balancing for our simulation
and experiment, and analyze the relationship between switch architecture and delay performance.
Facing the evolvement of the Optical Grid technology, dynamic task scheduling can largely improve the efficiency of
the Grid environment under the real circumstances. We propose a Serve On Time (SOT) algorithm - based on the idea
of combining all the dynamic multi tasks so that all the tasks will obtain the rights to be served as soon as possible. We
then introduce the basic First Come First Serve (FCFS) algorithm. A simulation will show the advantage of SOT.
With the increasing number of internet users, more and more real-time services are added into the network, such as IPTV,
online-video, Voice over IP, etc. As we know, throughput is a highly important performance criterion for scheduling
algorithms of networks. Besides throughput, these growing real-time services are very sensitive to delay variance termed
as jitter. Therefore, high performance scheduling algorithm should achieve good performance in terms of throughput,
delay, jitter and fairness together. Scheduling algorithm with deadline-awareness employed in packet switching plays a
key role in QoS guarantees.
Although traditional hard-deadline can provide guarantee on in-node delay-deadline criteria, the end-to-end
delay-deadline criteria cannot be guaranteed due to the characteristic of hard-deadline, while the delay-deadline
guaranteed throughput is low. Thus, soft-deadline scheduling algorithm has been proposed. In this paper, we investigate
and compare the classical hard-deadline and soft-deadline switching algorithm. A new scheme "Bonus System" is
proposed in order to realize the idea of soft-deadline switching algorithm. Bonus System based on soft-deadline is
compared with classical Early-Deadline First scheme based on hard-deadline, which shows that Bonus System has better
performance in End-to-End deadline guarantee.
Many distributed computing applications need transfer large files between distributed locations as fast as possible. A
dynamic routing algorithm for optical network is designed to modify existing transfers and spare network resources for
new request to satisfy both old and new transfers' requirements. In data intensive application on circuit-switch optical
network, light-path resources are scarce and there should be concurrent file transfers competing for the same fibers. In
static routing optical network, if new coming file transfer cannot acquire light-path with enough bandwidth, it could only
wait for the releasing of current used resources. Due to the waiting, the delay time will be large. So we use our dynamic
routing algorithm to schedule and modify existing light-paths, to spare a light-path with enough bandwidth for new
coming file. Our optimized target is to make every file finish transferring in less time, so we propose two objectives
defined in the paper: one is to make maximal delay time of all tasks less and the other is to make average delay time less.
The algorithm proposed has two mainly steps: 1) Routing process; 2) Dynamic routing process. In routing step, when
task of file arrives we firstly get k random paths, then use Least Congestion Algorithm (LCA) (or Shortest Path
Algorithm (SPA)) to get the primary path P1 of maximal residual bandwidth (RB) from k paths and the alternate path P2
of the second maximal RB. If the bandwidth of P1 is enough for this task, transfer the file in P1 path. If not, we go to the
dynamic routing process. In the second process, get all the links of P1 then we change the existing light paths of tasks in
the P1 path one by one to their alternative paths until we can get enough bandwidth of P1. In the dynamic routing
process, we design two different queuing strategies. The first strategy is First Arrive First Modified (FAFM) strategy,
namely we schedule the first arrival task firstly. The other is Larger Bandwidth First Modified (LBFM) and the file with
larger bandwidth is scheduled firstly.
By comparison of simulation results, we can prove that our two kinds of dynamic routing algorithms can get better
results for both decreasing maximal delay time and average delay time than LCA and SPA routing algorithms. In the two
queuing strategies, LBFM can get better results than FAFM strategy. The receivers in the destinations can get better
results by using our dynamic routing algorithm.
In switch scheduling, jitter becomes an important performance criterion for increasing real-time applications. Low Jitter
Decomposition (LJS) was proposed in the frame-based scheduling switches [9]. However, we notice that in LJS, the
bandwidth requirement of schedule tables is greater than the actual amount of traffic. The redundant bandwidth
requirement not only wastes the resource of switch, but also introduces an extra jitter.
In this paper, we propose two algorithms to reduce the extra jitter caused by redundancy: Integer Average Redundancy
Control (IARC) and Dichotomy Sequence Redundancy Control (DSRC). We demonstrate that the jitter bound of the two
algorithms is lower than that of the scheme without redundancy control. Simulation experiments show that DSRC and
IARC can reduce nearly 50% jitter of the scheme without redundancy control at medium switch load. We also show that
DSRC has a low complexity (O(1) for each input-output pair) which is important for high-speed switches.
Because SONET/SDH technology which includes contiguous concatenation and virtual concatenation is used in
GMPLS-Controlled Multi-services Transport Platform (MSTP) Network, it is more complex when we consider the label
assignment when setting up a Label Switch Path (LSP). It is very imperative to use a method which could use the
limited labels effectively. In this paper, we study the structure of the label space and different label algorithm to allocate
SONET/SDH labels, which include virtual concatenation labels and contiguous concatenation labels in GMPLS-Controlled
MSTP Network. We proposed a minimum Contiguous Labels Algorithm (min-CLA) to solve the problem of
using the limited label space on each interface at the most degree. Different from the previous schemes worked on
Route Wavelength Assignment (RWA) in the Wavelength-Division-Multiplex (WDM) networks, our scheme finds out
the primary and easy method based on SONET/SDH label which has virtual concatenation labels and contiguous
concatenation labels used for different kinds of needs. Because of taking the multiple services requirements into
account, the proposed algorithm finds out more efficient feasible solution requiring less network resources and even find
a feasible solution which will enable some label assignment failed in other label assignment algorithm and we will
compare our scheme and the Fist Fit Scheme.
Optical grid is expected to be an efficient infrastructure to support advanced data-intensive grid applications. In
optical grid, the faults of both computational and network resources are inevitable due to the large scale and high
complexity of the system. Even though many researches have been published on fault-tolerance policy for either grid
system or optical network, but few works have been done to consider fault-tolerance when faults may happen in grid
system and optical networks. In this paper, we address to the fault-tolerance problem in optical grid system and
propose a rescheduling policy to handle both computational resources and network resources faults. Simulation
results prove that our policy achieves better performance.
As bandwidth-intensive and time-sensitive streams applications such as high-definition television (HDTV) get popular, there rises a demand of supporting multicast communication directly at optical layer on next-generation optical networks. The multicast-capable optical cross-connect (MC-OXCs) is the necessary device to implement multicasting at optical layer. The functional building blocks for MC-OXC are light splitters (space splitters) or multi-wavelength converters (frequency splitters). The space splitter has no wavelength conversion capability, whereas the frequency splitter has limited fanout, decreased optical signal-to-noise ratio and also is expensive. We therefore proposed a tradeoff architecture called joint multicasting capable optical cross-connect (jMC-OXC) integrating both space splitters and multi-wavelength converters. In this paper, we investigate the network performance and the physical transmission performance on the jMC-OXC architecture by dynamic simulation and experimental demonstration. Three simulation schemes are designed and the results show that the network performance of the jMC-OXCs with limited multi-wavelength converters can obtain a close performance to that with full multi-wavelength converters. A prototype of jMC-OXC is examined and its bit error rate (BER) performance is tested after passing the multi-wavelength converters.
Some grid applications need a reliable, real-time and large bandwidth network as infrastructure for mass data exchange between local and remote resources. Deploying grid applications on the optical network has a great significance. In this article, we propose the network architecture that integrates optical network with grid computing resources. Based on the network architecture, we present a model of service interface for grid over ASON.
We propose a more practical resource model for optical grid applications by extending the classic list scheduling algorithm to achieve communication contention aware scheduling of optical grid applications. An effective adaptive routing scheme is also proposed to improve the performance of the extended list scheduling. The impacts of different routing schemes on the extended list scheduling are comparatively investigated by simulations.
A good dynamic routing scheme is very important to improve the provisioning efficiency of wavelength-routed optical networks. The existing dynamic routing algorithms are usually based on first-come-first-serve (FCFS) scheme to process the lightpath requests one by one. However, multiple lightpath requests may arrive simultaneously and burstly in data-intensive applications, and can not be treated efficiently by using the FCFS scheme. We will propose a new online dynamic routing scheme to process the lightpath requests in batch instead of one by one, which is termed batch-come-batch-serve (BCBS) scheme. A mathematic model and several adaptive routing algorithms are proposed and investigated comparatively. The simulation results suggest that the proposed scheme achieves better network blocking performances.
Existing multicast models have taken traffic concentration, source-end delay, delay jitter into consideration, while some
dynamic application like digital TV delivery poses a new challenge. Users can join/leave multicast group dynamically
and arbitrarily. When users have left the multicast group, multicast protocols will delete the corresponding delivery edge
in the multicast tree. This leads to great control overhead in delivery network. This overhead comes from several aspects,
like forwarding tree maintain, update, membership management. Even if the multicast tree is pre-calculated and cannot
delete edge in runtime, the users' leaving action can lead to resource utilization problem, especially when the delivery
network's bandwidth is expensive. In this paper we designed an algorithm to find the optimized multicast tree to ensure
stability of network under dynamic user behavior. With this algorithm, we can smooth out effect of users' random
behavior, thus increase performance of the delivery network.
The multicast capability of a multicast-capable optical add/drop multiplexer (MC-OADM) is analyzed and the dynamic network performance on the WDM ring employing such MC-OADMs is investigated. The MC-OADM multicast scheme can provide more multicast services while consume less resources in comparison with that of the normal OADM ring without multicast capability.
Optical Grid that provides a way to integrate the geographical distributed resources for large-scale grid applications. This
paper mainly focuses on the task scheduling issue in Optical Grid and proposes two task scheduling algorithms to minimize
the total time or scheduling length required for a given task. A simulated optical grid has been addressed to demonstrate
the effectiveness of the scheduling approach. The performance tests and analysis of the two algorithms are investigated
to show the effect of the routing policy on the scheduling length. A more flexible policy is able to further improve
scheduling length.
Because any link failure on the multicast session may disrupt the signal transmission to several downstream nodes, it is imperative to effectively protect the multicast sessions against link failure. In this paper, we study schemes for establishing primary and backup multicast trees for multicast sessions in a optical mesh network against link failure, e.g., fiber or conduit cut, with taking the different leaf availability requirement and availability guarantee into account. We propose an Mixed Integer Linear Program (MILP) approach to solve the problem of provisioning survivable multicast sessions with differentiated leaf availability guaranteed. Different from the previous schemes, our scheme finds out the complete (the tree spans the root and all the leaf nodes) primary and complete or incomplete (the tree spans the root and part of the leaf nodes) backup trees for multicast sessions guarantees the availability requirement. Because of taking the different leaf availability requirements into ccount, the proposed algorithm finds out more efficient feasible solution requiring less network resources, and even find a feasible solution where the previous algorithms fail.
We analyze the multicast capability of a multicast-capable optical add/drop multiplexer (MC-OADM) and investigate the dynamic network performance of the MC-OADM ring in comparison with that of the normal OADM ring without multicast capability. The simulation results show that the multicast scheme using MC-OADMs provides more multicast services and occupies fewer resources.
A kind of optical coarse packet switching based on optical label routing is intrduced. In the switching, the swapping granularity is coarse compared to common optical packet switching, and the header of optical packet is labeled by multi-wavelengths. Some realization techniques on core switching node and edge node with terminator are studied. A principle experiment system is established to perform the optical coarse packet transmitting, switching, and receiving, and verify the feasibility of such optical coarse packet switching.
We address the problem of routing and wavelength assignment (RWA) considering differentiated reliability (DiR) in WDM mesh networks. The backup resource can be shared by the primary lightpaths. However, both the primary-backup sharing and the different levels of fault tolerance requirement have never been considered together in the literature. In the paper, we consider the dynamic character of the link availability, which is caused by primary-backup sharing. Moreover, the priority of traffic is considered in the paper. The paper focuses on routing under dynamic availability of wavelength resource while the requested reliability of traffic has to be met, using the modified shortest path algorithm. A layered availability model is established based on wavelength layered graph model. Using this model, we propose a new algorithm called dynamic layered availability (DLA) algorithm. We evaluate the performance of the proposed algorithm on the NSFNET.
Automatic Switched Optical Networks, or ASON, is regarded as one promising networking technology for future optical networks. From network operators' perspective, it is well agreed that ASON should provide the following features: fast provisioning, easier network operation, higher network reliability, scalability, simpler planning and design, and multi-vendor inter-operability. Fast provisioning enables ASON to meet the requirements of more dynamic applications such as bandwidth on demand and content distribution. Protection and restoration is crucial because of the extremely high data-rate the network will carry. Mesh type network and fast provisioning capability leave more space for a more reliable and flexible network.
Unlike traditional transport networks that are constructed purely for point-to-point connectivity, ASON deployed in regional or metro-area networks needs to provide high connectivity to its clients. And, as a result, the planning and designing problem becomes very complex due to the large number of devices, the variety of interface types and network protocols. It is also important that the network will be able to inter-connect devices from different vendors and provide support to different client signals such as SONET/SDH, Ethernet, IP, ATM and Frame Relay.
A kind of optical multi-wavelength label switching adopting Gigabit Ethernet technology is introduced. In this switching, optical header is labeled by several optical pulses at different wavelengths in the same optical communication channel band as optical payload, and a specific Gigabit Ethernet adapter is used as the optical payload sender and receiver. The principle of optical switching is explained, and a demonstration experiment is described.
The ASON is a typical client-server network model. Via explicit interfaces between client network and server network, the client users, including UNI-C and NMS, can create an Optical Layer Connection with three schemes. This may arise the problems such as concurrency due to simultaneously accessing the same resources from UNI and NMI. This paper proposes an approach of a middleware component using CORBA-based product. The middleware component performs to define the ownership and access rules for network resources and prove global network topology and status of the network resources to the client users. It screens the difference between NMI-T, NMI-A and UNI and shields the detail of the ASON network protocols. The standardized IDL interfaces ensure that ASON products from different vendors or employing different technologies can interoperate at the common intermediate plane level and make the implementation of the management functions more simply and efficiently.
This paper provides an overview of prototyping research activities of automatically switched optical networks and transport networks (ASONs/ASTNs) in China. In recent years, China has recognized the importance and benefits of the emerging ASON/ASTN techniques. During the period of 2001 and 2002, the national 863 Program of China started the preliminary ASON research projects with the main objectives to build preliminary ASON testbeds, develop control plane protocols and test their performance in the testbeds. During the period of 2003 and 2004, the 863 program started ASTN prototyping equipment projects for more practical applications. Totally 12 ASTN equipments are being developed by three groups led by Chinese venders: ZTE with Beijing University of Posts and Telecommunications (BUPT), Wuhan Research Institute of Posts and Telecommunication (WRI) with Shanghai Jiao Tong University (SJTU), and Huawei Inc. Meanwhile, as the ASTN is maturing, some of the China’s carries are participating in the OIF’s World Interoperability Demonstration, carrying out ASTN test, or deploying ASTN backbone networks. Finally, several ASTN backbone networks being tested or deployed now will be operated by the carries in 2005. The 863 Program will carry out an ASTN field trail in Yangtse River Delta, and finally deploy the 3TNET. 3TNET stands for Tbps transmission, Tbps switching, and Tbps routing, as well as a network integrating the above techniques. A task force under the “863” program is responsible for ASTN equipment specifications and interoperation agreements, technical coordination among all the participants, schedule of the whole project during the project undergoing, and organization of internetworking of all the equipments in the laboratories and field trials.
A novel method called data plane shared ring scheme (DPSRS) is proposed in IP over automatic switched transport networks (ASTN) overlay network. Based on the novel scheme, explicit analysis on related network architecture, edge node structure and operation process are made. For decision of bandwidth restriction parameters two algorithms are also proposed.
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