Integrated Survivability Strategies of IP／GMPLS／Opticai Multi——layer Network

In last decade,due to that the popularity of the internet, data--central traffic kept growing, some emerging networking requirements have been posed on the today‘s telecommunication networks,especially in the area of network survivability. Obviously, as a key networking problem, network reliability will be more and more important. The integration of different technologies such as ATM, SDH, and WDM in multilayer transport networks raises many questions regarding the coordination of the individual network layers.This problem is referred as multilayer network survivability. The integrated multilayer network survivability is investingated as well as the representation of an interworking strategy between different single layer survivability schemes in IP via generalized multiprotocol label switching over ootical netwnrk     

Integrated Survivability Strategies of IP/GMPLS/Optical Multi-layer Network

In last decade,due to that the popularity of the internet, data-central traffic kept growing,some emerging networking requirements have been posed on the todays telecommunication networks,especially in the area of network survivability.Obviously,as a key networking problem,network reliability will be more and more important.The integration of different technologies such as ATM,SDH,and WDM in multilayer transport networks raises many questions regarding the coordination of the individual network layers.This problem is referred as multilayer network survivability.The integrated multilayer network survivability is investingated as well as the representation of an interworking strategy between different single layer survivability schemes in IP via generalized multi-protocol label switching over optical network.     

ISM:漂移意图可感知的IP网络生存性服务提供模型

由于传统的服务漂移方法存在一定不足,致使服务器集群的负担较重,且服务漂移的时间开销过大,严重影响服务连续性.为了改善这种情况,本文提出了一种漂移意图可感知的IP网络生存性服务提供模型(Intent-perceived Service Migration,ISM).在ISM模型中,我们设计了一种独特的服务漂移触发机制和目...     

采用多向散射通信进行可变中心组网研究

无线通信中的可变中心组网研究是一个具有创新性和需求迫切性的研究课题。可变中心组网是指在通信时,通信中心可根据具体情况进行变换,这样比固定通信中心的通信网络具有更大的灵活性和抗毁性。就采用多向散射通信方式进行可变中心组网的网络结构及特点进行了探讨和研究,提出了几种可行的无线、超视距及可变中心组网方案。     

Impact of the energy-based and location-based LEACH secondary cluster aggregation on WSN lifetime

The improvement of sensor networks’ lifetime has been a major research challenge in recent years. This is because sensor nodes are battery powered and may be difficult to replace when deployed. Low energy adaptive clustering hierarchical (LEACH) routing protocol was proposed to prolong sensor nodes lifetime by dividing the network into clusters. In each cluster, a cluster head (CH) node receives and aggregates data from other nodes. However, CH nodes in LEACH are randomly elected which leads to a rapid loss of network energy. This energy loss occurs when the CH has a low energy level or when it is far from the BS. LEACH with two level cluster head (LEACH-TLCH) protocol deploys a secondary cluster head (2CH) to relieve the cluster head burden in these circumstances. However, in LEACH-TLCH the optimal distance of CH to base station (BS), and the choicest CH energy level for the 2CH to be deployed for achieving an optimal network lifetime was not considered. After a survey of related literature, we improved on LEACH-TLCH by investigating the conditions set to deploy the 2CH for an optimal network lifetime. Experiments were conducted to indicate how the 2CH impacts on the network at different CH energy levels and (or) CH distance to BS. This, is referred to as factor-based LEACH (FLEACH). Investigations in FLEACH show that as CHs gets farther from the BS, the use of a 2CH extends the network lifetime. Similarly, an increased lifetime also results as the CH energy decreases when the 2CH is deployed. We further propose FLEACH-E which uses a deterministic CH selection with the deployment of 2CH from the outset of network operation. Results show an improved performance over existing state-of-the-art homogeneous routing protocols.     

对MANET AODV路由协议攻击效果分析

移动无线自组织网络(Mobile Ad Hoc Network,MANET)具有抗毁性强、组网灵活的特点,战场通信环境是其很重要的应用背景,基于距离向量的按需路由协议(Ad-hoc On-demand Vector Routing,AODV)在移动无线自组织网络中具有广泛的应用。针对移动无线自组网AODV路由协议,在分析其工作原理的基础上,建立网络流量的分析模型。从网络发起泛搜索路由引起网络流量变化的角度,分析不同的协议攻击方法对网络的影响。     

可生存网络系统的构建方法

在攻击、故障和意外事故存在的情况下，可生存的网络系统仍然具有提供连续、可靠的网络服务的能力．本文提出了构建可生存网络系统的方法，可以增强网络系统最重要的三个特性：抵御、识别和恢复，从而从整体上有效地增强了网络系统的可生存性．这种构建网络系统的方法使得网络系统的可生存性不再依赖于特定的系统组件，相应地保护了网络系统的应用．     

A hybrid,game theory based,and distributed clustering protocol for wireless sensor networks

Clustering has been well known as an effective way to reduce energy dissipation and prolong network lifetime in wireless sensor networks. Recently, game theory has been used to model clustering problem. Each node is modeled as a player which can selfishly choose its own strategies to be a cluster head (CH) or not. And by playing a localized clustering game, it gets an equilibrium probability to be a CH that makes its payoff keep equilibrium. In this paper, based on game theory, we present a clustering protocol named Hybrid, Game Theory based and Distributed clustering. In our protocol, we specifically define the payoff for each node when choosing different strategies, where both node degree and distance to base station are considered. Under this definition, each node gets its equilibrium probability by playing the game. And it decides whether to be a CH based on this equilibrium probability that can achieve a good trade-off between minimizing energy dissipation and providing the required services effectively. Moreover, an iterative algorithm is proposed to select the final CHs from the potential CHs according to a hybrid of residual energy and the number of neighboring potential CHs. Our iterative algorithm can balance the energy consumption among nodes and avoid the case that more than one CH occurs in a close proximity. And we prove it terminates in finite iterations. Simulation results show that our protocol outperforms LEACH, CROSS and LGCA in terms of network lifetime.     

Adaptive and Dynamic Mechanism for Round Length Determination in Cluster Based Wireless Sensor Networks

The resource-constrained nature of WSNs require efficient use of resources, especially energy, to prolong their lifetime. Clustering is one of the popular approaches to allocate the resources efficiently among the WSN nodes. In this work, we analyze the problem of round length determination in cluster based WSN which has severe impact on the energy efficiency. This problem is very important since round length determines how often the cluster head (CH) rotates or re-clustering process occurs. A longer round length will cause the CH nodes to operate for a long time and drain their energies faster than other nodes resulting in uneven energy consumption in the network, while a shorter round length results in considerable wastage of energy due to frequent running of the setup phase. Hence, we propose an adaptive and dynamic mechanism for round length determination in cluster based WSNs by adapting Behavior Curve Function modeled by quadratic Bezier curves, where we associate the remaining energy level of the cluster to its round operation length and to its assigned criticality which is defined based on network energy level. This helps to determine the number of frames in a round or how many times the data collection occurs in a cluster in a round and the criticality of the energy in the WSN. Simulation results reveal that the proposed mechanism has effectively reduced the energy consumption and improved the WSN lifetime in both homogeneous and heterogeneous network settings.

     

A Three Layered Peer-to-Peer Energy Efficient Protocol for Reliable and Secure Data Transmission in EAACK MANETs

The wireless body sensor network (WBSN) an extensive of WSN is in charge for the detection of patient’s health concerned data. This monitored health data are essential to be routed to the sink (base station) in an effective way by approaching the routing technique. Routing of tremendous sensed data to the base station minimizes the life time of the network due to heavy traffic occurrence. The major concern of this work is to increase the lifespan of the network which is considered as a serious problem in the wireless network functionalities. In order to recover this issue, we propose an optimal trust aware cluster based routing technique in WBSN. The human body enforced for the detection of health status is assembled with sensor nodes. In this paper, three novel schemes namely, improved evolutionary particle swarm optimization (IEPSO), fuzzy based trust inference model, and self-adaptive greedy buffer allocation and scheduling algorithm (SGBAS) are proposed for the secured transmission of data. The sensor nodes are gathered to form a cluster and from the cluster, it is necessary to select the cluster head (CH) for the effective transmission of data to nearby nodes without accumulation. The CH is chosen by considering IEPSO algorithm. For securable routing, we exhibit fuzzy based trust inference model to select the trusted path. Finally, to reduce traffic occurrence in the network, we introduce SGBAS algorithm. Experimental results demonstrate that our proposed method attains better results when compared with conventional clustering protocols and in terms of some distinctive QoS determinant parameters.     

Generalized Sharing in Survivable Optical Networks

Shared path protection has been demonstrated to be a very efficient survivability scheme for optical networking. In this scheme, multiple backup paths can share a given optical channel if their corresponding primary routes are not expected to fail simultaneously. The focus in this area has been the optimization of the total channels (i.e., bandwidth) provisioned in the network through the intelligent routing of primary and backup routes. In this work, we extend the current path protection sharing scheme and introduce the Generalized Sharing Concept. In this concept, we allow for additional sharing of important node devices. These node devices (e.g., optical-electronic-optical regenerators (OEOs), pure all-optical converters, etc.) constitute the dominant cost factor in an optical backbone network and the reduction of their number is of paramount importance. For demonstration purposes, we extend the concept of 1:N shared path protection to allow for the sharing of electronic regenerators needed for coping with optical transmission impairments. Both design and control plane issues are discussed through numerical examples. Considerable cost reductions in electronic budget are demonstrated     

Management and control of transparent optical networks

Multiwavelength optical networking is expected to play a significant role in the next-generation transport networks providing capacity enhancements as well as built-in network survivability and reconfigurability. While advances have been made in the hardware technologies, considerable research effort is still required in the area of network management and control in order for optical networking to be proven commercially viable. This paper investigates key design issues concerning optical network management and control and examines how the networking architecture is influenced by the various management considerations     

Improved low energy adaptive clustering hierarchy and its optimum cluster head selection

ABSTRACT

Wireless sensor networks (WSNs) play a vital role in present-day world, which are being used in different types of applications and occupy an important part in networking domain. The main objective of WSNs is to sense and collect the information from a given area of interest and provide the gathered data to the sink. WSN comprises of number of sensor nodes with batteries of limited energy for communication and computational activities, which are not possible to recharge the batteries after their deployment in the region of interest. Therefore, saving battery energy and utilising the limited power to the optimum level for extending network lifetime became the main factor of WSN. Hence, optimum cluster head (CH) selection will make the network to support longer lifetime and balanced energy consumption during its lifetime. Our proposed protocol selects the optimum CH and found out to be more efficient than the existing low energy adaptive clustering hierarchy. The simulated output shows better network lifetime and in some other performance metric.     

基于APT潜伏攻击的网络可生存性模型与分析

基于传统网络攻击模式和高级持续性威胁（Advanced Persistent Threat,简称APT）攻击模式提出网络可生存性的评估模型。建立网络攻击场景,仿真验证提出的网络可生存性模型,并比较两种模式的性能。得到的结论：提出的评估模型合理刻画了网络可生存性的两个重要参数,网络攻击传播速率和网络修复速率;基于APT潜伏攻击模式下的网络可生存性性能低于传统攻击模式。     

End‐to‐end delay and packet drop rate performance for a wireless sensor network with a cluster‐tree topology

In this paper, we study the delay performance in a wireless sensor network (WSN) with a cluster‐tree topology. The end‐to‐end delay in such a network can be strongly dependent on the relative location between the sensors and the sink and the resource allocations of the cluster heads (CHs). For real‐time traffic, packets transmitted with excessive delay are dropped. Given the timeline allocations of each CH for local and inter‐cluster traffic transmissions, an analytical model is developed to find the distribution of the end‐to‐end transmission delay for packets originated from different clusters. Based on this result, the packet drop rate is derived. A heuristic scheme is then proposed to jointly find the timeline allocations of all the CHs in a WSN in order to achieve the minimum and balanced packet drop rate for traffic originated from different levels of the cluster tree. Simulation results are shown to verify the analysis and to demonstrate the effectiveness of the proposed CH timeline allocation scheme. Copyright © 2012 John Wiley & Sons, Ltd.     

Survivability and scalability of space networks: a survey

Survivability and scalability are key terms for any network. The challenge is greater in space networks than in terrestrial networks. Satellites have various uses, some notable uses are communication, observation, meteorology, navigation etc. In future satellites will aid terrestrial users by providing Internet connectivity. With proliferation of Internet users, demand for satellite services will increase and soon we will suffer from bandwidth limitation. Hence, the scalability and survivability of space networks are very important issues to ensure smooth connectivity to all the users both mobile and immobile. Since, most of the existing works on network survivability and scalability are focused on terrestrial networks. We have categorized the existing works on survivability and scalability of terrestrial networks. In addition, we have performed a comprehensive survey on the popular products available in the market for network survivability and scalability. Finally, we have listed the major issues and challenges of space networks that needs to be considered before applying network scalability and survivability solutions on them. This work can help network engineers to select suitable solutions for space networks considering the available choices and challenges listed in this paper.     

Energy‐efficient cluster manager‐based cluster head selection technique for communication networks

The Mobile Adhoc Network (MANET) is a distributed network without any standard infrastructure. In MANETs, several nodes in the network are grouped by which they can communicate with each other. Clustering is a grouping of mobiles nodes performs the communication process by means of optimal usage of available bandwidth and high network throughput. Several clustering schemes exist, but they suffer from the consumption of energy because of the cluster head's workload and increase in the number of clusters. In this paper, we propose a cluster manager‐based cluster head selection (CMBCH) scheme to overcome the energy problems and leverage CH workload. CMBCH consists of two components, such as cluster manager (CM) and cluster head (CH). The CM takes the responsibility of controlling and monitoring of nodes activities. The CH leads and performing packet transfer among the nodes in the network. At this stage, when current CH energy level is drained, CM elects the corresponding node with high energy level and the new, as well as old CH activities, are simultaneously stored by CM. To prove the proposed scheme efficiency, a simulation experiment was conducted for 20 to 100 nodes under the AODV routing protocol. The network parameters packet delivery ratio and energy consumption are compared for the CMBCH,DLC and HCAL. The obtained results are compared to others; CMBCH conserves minimal energy and bandwidth and also achieves reliable throughput through stable routing.     

Weighted Graph Based Clustering and Local Mobility Management for Dense Small Cell Network with X2 Interface

Along with the surge in mobile data, dense small cell network has become an effective method to improve system capacity and spectrum efficiency. However, because more small cells are deployed, the interference among dense small cells exacerbates. It also makes frequent handover for mobile users (UEs), which brings a great deal of signaling overhead to the core network. In order to solve the problems of interference and frequent handover, a novel clustering scheme for dense small cell network is proposed in this paper. The scheme is based on the weighted graph. First, we present a dense small cell clustering model based on X2 interface to minimize core network signaling overhead. To improve the usability of the model, we model the system as an undirected weighted graph. Then we propose the maximum benefit merging algorithm to reduce the complexity. This method enables adjacent small cells to cooperate and form virtual cellular cluster according to handover statistics information. Then we select cluster head (CH) according to certain rule in each cluster. Cluster head acts as the mobility anchor, managing the handovers between cluster members. This can reduce core network signaling overhead and the interference among small cells effectively. Compared with the 3GPP handover algorithm, the proposed clustering model in this paper can reduce the signaling overhead more than 70%. The simulation results show that the proposed clustering model can effectively cluster the dense small cell.     

Optimized design of survivable MPLS over optical transport networks

In this paper we study different options for the survivability implementation in MPLS over Optical Transport Networks (OTNs) in terms of network resource usage and configuration cost. We investigate two approaches to the survivability deployment: single-layer survivability, where some recovery mechanism (e.g. protection or restoration) is implemented in a single network layer and multilayer survivability, where recovery is implemented in multiple network layers. The survivable MPLS over OTN design is implemented as a static network optimization problem and incorporates various methods for spare capacity allocation (SCA) to reroute disrupted traffic.The comparative analysis between the single layer and the multilayer survivability shows the influence of the traffic granularity on the survivability cost: for high-bandwidth LSPs, close to the optical channel capacity, the multilayer survivability outperforms the single layer one, whereas for low-bandwidth LSPs the single-layer survivability is more cost-efficient. For the multilayer survivability we demonstrate that by mapping efficiently the spare capacity of the MPLS layer onto the resources of the optical layer one can achieve up to 22% savings in the total configuration cost and up to 37% in the optical layer cost. Further savings (up to 9%) in the wavelength use can be obtained with the integrated approach to network configuration over the sequential one; however, this is at the increase in the optimization problem complexity. These results are based on a cost model with current technology pricing and were obtained for networks targeted to a nationwide coverage.     

Survivability in multi-domain optical networks using p-cycles

Survivability is becoming an important issue in optical networks due to the huge bandwidth offered by optical technology. Many works have studied network survivability. The majority of these works are destined for single-domain networks. In this work, we address the survivability of multi-domain optical networks. This paper provides a classification of the existing protection solutions proposed for multi-domain networks and analyses their advantages and limitations. We propose a new solution for multi-domain optical networks based on p-cycles (pre-configured cycles). For scalability and security reasons, we also propose a topology aggregation model adapted to p-cycle computations. This aggregation model allows our proposed solution to find a trade-off between two competing goals: efficient use of backup resources and short running time. Simulation results show that the proposed solution is a good trade-off between resource utilization and running time compared to existing solutions.