This document summarizes a research paper that proposes techniques for fast recovery from dual-link failures in mobile ad hoc networks (MANETs). It discusses link protection and path protection schemes, and proposes two approaches for dual-link failure recovery: failure dependent link protection (FDLP) and failure independent link protection (FILP). The paper develops an integer linear program and heuristic algorithm based on minimum cost path routing to solve the backup link mutual exclusion problem for dual-link failures. It evaluates the performance of the proposed approaches through simulations, finding that FDLP achieves a higher packet delivery ratio than FILP.
This document summarizes research on simulating and comparing the performance of different expansions of star network topologies using Opnet network simulator. It begins by introducing network topologies and classification based on parameters like topology, protocols, and architecture. It then describes common topologies like bus, ring, star, and tree. The research designs an original star network and three expansions including double star, tri-star, and tri-star with mesh topologies in Opnet. It simulates each network and compares performance metrics like delay across nodes to analyze the impact of topology on network performance.
This document summarizes a study that compares the performance of the MAC layer in flat and hierarchical mobile ad hoc networks (MANETs). The study uses simulation to analyze throughput and packet drops. It finds that throughput is the same for both network structures, but that hierarchical networks have fewer packet drops at the MAC layer. Specifically, packet drops only occurred at 3 nodes in the hierarchical network, whereas 14 nodes experienced drops in the flat network structure. Therefore, the hierarchical approach improves MAC layer performance by reducing packet drops.
Survivability Issues in Optical Wavalength Division Multiplexing (WDM) NetworkIOSR Journals
This document provides a survey of survivability issues in optical wavelength division multiplexing (WDM) networks. It discusses various protection techniques used in single and multi-domain WDM networks including link-based, path-based, and p-cycle protection. It reviews existing algorithms for survivability against multi-link failures such as LBSR, ESPP, and LSPP. It then proposes a new algorithm that combines p-cycle protection and wavelength assignment with Dijkstra's algorithm to reduce blocking probability. The document concludes that p-cycle protection is an effective technique and the proposed algorithm aims to find the shortest lightpath and optimize resource usage.
The document discusses different types of computer network topologies including bus, ring, star, mesh, tree, and hybrid topologies. It describes the key features, advantages, and disadvantages of each topology. It also covers transmission modes, common network types like LANs, MANs, and WANs, and defines what constitutes an internetwork and the Internet.
Achieving Transmission Fairness in Distributed Medium Access Wireless Mesh Ne...ijwmn
Wireless mesh networking gained an international interest over the years as a result to high recognition in
the wireless industry as a cost effective, scalable, wider coverage and capacity capable wireless technology.
The contention based distributed medium access in wireless networks has advanced not only in supporting
the quality of multimedia but also achieving high throughput and to minimize packet delay overheads in
legacy systems. Unfortunately, the impact of such enhancement has not been fully justified with mesh
network environments yet. The medium access frames are required to be contended over multi-hops to
overcome the challenges of improving overall system performance through concurrent transmissions. The
goal of this paper is to discuss the issues and challenges of transmission fairness and the effect of
concurrent transmission on system performance. To mitigate transmission fairness issues, we review
existing open literature on mesh networking and provide guidelines for better system design and
deployment. Finally, we conclude the paper with future research directions. This study may help network
designer and planner to overcome the remaining challenging issues in the design and deployment of WMNs
worldwide.
The document discusses the different types of network topologies, including bus, ring, star, mesh, tree, and hybrid topologies. It provides details on the key features, advantages, and disadvantages of each topology type. Star topology uses a central hub that all nodes connect to. Tree topology has a hierarchical structure with a root node. Hybrid topology combines two or more standard topologies to inherit benefits while addressing individual limitations.
Design and Implementation of Multistage Interconnection Networks for SoC Netw...IJCSEIT Journal
In this paper the focus is on a family of Interconnection Networks (INs) known as Multistage
Interconnection Networks (MINs). When it is exploited in Network-on-Chip (NoC) architecture designs,
smaller circuit area, lower power consumption, less junctions and broader bandwidth can be achieved.
Each MIN can be considered as an alternative for an NoC architecture design for its simple topology and
easy scalability with low degree. This paper includes two major contributions. First, it compares the
performance of seven prominent MINs (i.e. Omega, Butterfly, Flattened Butterfly, Flattened Baseline,
Generalized Cube, Beneš and Clos networks) based on 45nm-CMOS technology and under different types
of Synthetic and Trace-driven workloads. Second, a network called Meta-Flattened Network (MFN), was
introduced that can decrease the blocking probability by means of reduction the number of hops and
increase the intermediate paths between stages. This is also led into significant decrease in power
consumption.
The document discusses physical network topologies. There are two types of topologies: physical and logical. Physical topologies refer to the actual physical layout of cables and devices. The main physical topologies discussed are bus, star, ring, tree/hybrid, and mesh. For each topology, the document explains how it works, its advantages, and disadvantages.
This document summarizes research on simulating and comparing the performance of different expansions of star network topologies using Opnet network simulator. It begins by introducing network topologies and classification based on parameters like topology, protocols, and architecture. It then describes common topologies like bus, ring, star, and tree. The research designs an original star network and three expansions including double star, tri-star, and tri-star with mesh topologies in Opnet. It simulates each network and compares performance metrics like delay across nodes to analyze the impact of topology on network performance.
This document summarizes a study that compares the performance of the MAC layer in flat and hierarchical mobile ad hoc networks (MANETs). The study uses simulation to analyze throughput and packet drops. It finds that throughput is the same for both network structures, but that hierarchical networks have fewer packet drops at the MAC layer. Specifically, packet drops only occurred at 3 nodes in the hierarchical network, whereas 14 nodes experienced drops in the flat network structure. Therefore, the hierarchical approach improves MAC layer performance by reducing packet drops.
Survivability Issues in Optical Wavalength Division Multiplexing (WDM) NetworkIOSR Journals
This document provides a survey of survivability issues in optical wavelength division multiplexing (WDM) networks. It discusses various protection techniques used in single and multi-domain WDM networks including link-based, path-based, and p-cycle protection. It reviews existing algorithms for survivability against multi-link failures such as LBSR, ESPP, and LSPP. It then proposes a new algorithm that combines p-cycle protection and wavelength assignment with Dijkstra's algorithm to reduce blocking probability. The document concludes that p-cycle protection is an effective technique and the proposed algorithm aims to find the shortest lightpath and optimize resource usage.
The document discusses different types of computer network topologies including bus, ring, star, mesh, tree, and hybrid topologies. It describes the key features, advantages, and disadvantages of each topology. It also covers transmission modes, common network types like LANs, MANs, and WANs, and defines what constitutes an internetwork and the Internet.
Achieving Transmission Fairness in Distributed Medium Access Wireless Mesh Ne...ijwmn
Wireless mesh networking gained an international interest over the years as a result to high recognition in
the wireless industry as a cost effective, scalable, wider coverage and capacity capable wireless technology.
The contention based distributed medium access in wireless networks has advanced not only in supporting
the quality of multimedia but also achieving high throughput and to minimize packet delay overheads in
legacy systems. Unfortunately, the impact of such enhancement has not been fully justified with mesh
network environments yet. The medium access frames are required to be contended over multi-hops to
overcome the challenges of improving overall system performance through concurrent transmissions. The
goal of this paper is to discuss the issues and challenges of transmission fairness and the effect of
concurrent transmission on system performance. To mitigate transmission fairness issues, we review
existing open literature on mesh networking and provide guidelines for better system design and
deployment. Finally, we conclude the paper with future research directions. This study may help network
designer and planner to overcome the remaining challenging issues in the design and deployment of WMNs
worldwide.
The document discusses the different types of network topologies, including bus, ring, star, mesh, tree, and hybrid topologies. It provides details on the key features, advantages, and disadvantages of each topology type. Star topology uses a central hub that all nodes connect to. Tree topology has a hierarchical structure with a root node. Hybrid topology combines two or more standard topologies to inherit benefits while addressing individual limitations.
Design and Implementation of Multistage Interconnection Networks for SoC Netw...IJCSEIT Journal
In this paper the focus is on a family of Interconnection Networks (INs) known as Multistage
Interconnection Networks (MINs). When it is exploited in Network-on-Chip (NoC) architecture designs,
smaller circuit area, lower power consumption, less junctions and broader bandwidth can be achieved.
Each MIN can be considered as an alternative for an NoC architecture design for its simple topology and
easy scalability with low degree. This paper includes two major contributions. First, it compares the
performance of seven prominent MINs (i.e. Omega, Butterfly, Flattened Butterfly, Flattened Baseline,
Generalized Cube, Beneš and Clos networks) based on 45nm-CMOS technology and under different types
of Synthetic and Trace-driven workloads. Second, a network called Meta-Flattened Network (MFN), was
introduced that can decrease the blocking probability by means of reduction the number of hops and
increase the intermediate paths between stages. This is also led into significant decrease in power
consumption.
The document discusses physical network topologies. There are two types of topologies: physical and logical. Physical topologies refer to the actual physical layout of cables and devices. The main physical topologies discussed are bus, star, ring, tree/hybrid, and mesh. For each topology, the document explains how it works, its advantages, and disadvantages.
This document discusses different network topologies including bus, star, ring, mesh, tree, and hybrid topologies. It provides details on how each topology connects devices, how data is transferred, advantages and disadvantages of each. Bus topology uses a central backbone cable to connect all devices but if it fails the whole network fails. Star topology uses a central hub to connect devices in a point-to-point fashion, avoiding single point of failure issues but the hub remains a bottleneck. Ring topology connects devices in a continuous ring path allowing data to travel in one direction, but a single break disconnects the whole network. Hybrid topologies combine two or more standard topologies to utilize their advantages while reducing weaknesses.
DSSS with ISAKMP Key Management Protocol to Secure Physical Layer for Mobile ...IJNSA Journal
The wireless and dynamic nature of mobile ad hoc networks (MANETs) leaves them more vulnerable to security attacks than their wired counterparts. The nodes act both as routers and as communication end points. This makes the physical layer more prone to security attacks. The MANET physical layer is challenging to DoS attack and also some passive attacks. The physical layer protocol in MANETs is responsible for bit-level transmission between network nodes. The proposed model combines spread spectrum technology Direct Sequence Spread Spectrum (DSSS) with key management technique ISAKMP to defend against signal jamming denial-of-service attacks in physical layer of MANET.DSSS with ISAKMP is found to be a good security solution even with its known security problems. The simulation is done using network simulator qualnet 5.0 for different number of mobile nodes. The proposed model has shown improved results in terms of Average throughput, Average end to end delay, Average packet delivery ratio, and Average jitter.
The document discusses efficient transmission of data blocks over physical bursts in IEEE 802.16e/WiMAX networks. It addresses how to optimally divide protocol data units (PDUs) within bursts to maximize several performance criteria. Algorithms are presented to compute the best way to define PDUs in a burst to maximize burst goodput and data goodput, assuming either an infinite or limited number of data blocks. Guidelines are also given on selecting the optimal modulation and coding scheme based on channel signal-to-noise ratio.
This document is a study material for Class 12 Informatics Practices published by the Kendriya Vidyalaya Sangathan. It contains an index and four units on topics like networking, programming, relational database management systems, and IT applications. The networking unit discusses computer networks, communication media, network devices, topologies, protocols, and security concepts. It also covers open source concepts. The programming unit reviews concepts from Class 11 and discusses programming fundamentals. The database unit reviews RDBMS concepts and SQL commands. The IT applications unit discusses developing front-end interfaces, backend databases, and demonstrating applications in domains like e-governance, e-business and e-learning. Sample question papers are also included.
In network topology, i am explaining about how to set a network, how many types of network topology, explanation of each type and its advantages and disadvantages.
Linkedin - https://in.linkedin.com/in/prakharmaurya
A New Approach to Improve the Efficiency of Distributed Scheduling in IEEE 80...IDES Editor
The recent standard for broadband wireless
access networks, IEEE 802.16, which resulted in the
development of metropolitan area wireless networks,
includes two network organization modes: Point to Multi
Point and Mesh. The mesh mode provides distributed
channel access operations of peering nodes and uses TDMA
technique for channel access modulation. According to
IEEE 802.16 MAC protocol, there are two scheduling
algorithms for assigning TDMA slots to each network node:
centralized and distributed. In distributed scheduling
algorithm, network nodes have to transmit scheduling
message in order to inform other nodes about their transfer
schedule. In this paper a new approach is proposed to
improve distributed scheduling efficiency in IEEE 802.16
mesh mode, with respect to network condition in every
transferring opportunity. For evaluating the proposed
algorithm efficiency, several extensive simulations are
performed in various network configurations and the most
important system parameters which affect the network
performance are analyzed.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Networking tutorials introduction to networkingVinod Jadhav
This document provides an overview of networking concepts including different network topologies (physical layouts), classifications (LANs, WANs, PANs), and standards (IEEE 802). It discusses the characteristics of common topologies like bus, star, ring, and mesh. It also covers wired and wireless network models, comparing infrastructure wireless to ad-hoc wireless networks. Key networking standards like Ethernet (802.3), Token Ring (802.5), and wireless (802.11) are summarized.
A simulation model of ieee 802.15.4 gts mechanism and gtswissem hammouda
This document presents a simulation model of the IEEE 802.15.4 GTS mechanism and known GTS attacks developed in OMNeT++. The model includes a GTS management scheme model that implements beacon transmission, PAN association, GTS slot allocation and data transmission during GTS slots. It also includes a GTS attacks model that simulates five known GTS attack variants. The models were integrated to provide a comprehensive simulation of both normal GTS operation and attacks against the mechanism. The document describes the architecture, parameters and operation of the models in detail.
This document presents an analytical model to evaluate the performance of multithreaded multiprocessors with distributed shared memory. The model uses a multi-chain closed queuing network to model the processor, memory, and network subsystems in an integrated manner. This captures the strong coupling between subsystems. The model shows that high performance is achieved when the memory request rate matches the weighted sum of memory bandwidth and average remote memory access distance. The model is validated using a stochastic timed Petri net model.
Abstract
Routing in MANET is one of the most researched areas in the field of networking; moreover it is one of the most complex tasks.
RF based transmission techniques are widely used in wireless communication networks. Due to the availability of sophisticated
optical components, the networking domain could be merged with optical domain to have a higher capacity and better
transmission. So in order to overcome the disadvantages of RF domain, we can use light as a medium between nodes. i.e, FSOMANET.
This work is aimed at designing an efficient routing in FSO MANET. This paper proposes a method to find the stable
path as well as stable nodes between the source and destination. The steps are as follows. i) Topology Management ii) Trust Level
Calculation iii) Award and Reward ranking iv)Path Selection. The proposed technique will be implemented in the working
platform of MATLAB.
Keywords: Mobile Ad Hoc Network, Free Space Optics, Link Stability, Delay Tolerant Networking, Clustering
Technique, Award and Reward
The document discusses different network topologies including bus, star, ring, mesh, and tree. It defines network topology as the layout of how computers or workstations are connected in a network. The main types of network topologies are then described in detail, outlining their basic structures and advantages and disadvantages of each design.
Abstract—Geographic routing also called as Geo routing is a routing principle which relies on the Geographic position information. Geographic routing is the most commonly used routing for MANETs. In Geographic routing each node should be aware of its neighbor’s location to maintain the local topology accuracy. Hence, each node should update its location information through a message called beacon. Existing mechanisms invoke periodic beacon update scheme which consumes the network resources such as energy and bandwidth specifically when the network traffic is high, it creates packet loss in the network and it leads to retransmission of data packet causing additional delay and energy consumption. In this work, adaptive position update is proposed which dynamically adjusts the beacon updation frequency according to the varying network conditions.APU makes use of mobility prediction rule and on demand learning rule for beacon updation.
Strategies and Metric for Resilience in Computer Networksdmarinojr
The document discusses strategies and metrics for resilience in computer networks. It proposes a resilience factor to measure a network's ability to withstand targeted attacks. It also proposes two strategies, called PropAdd and PropRew, to improve network resilience by preferentially adding links or rewiring existing links based on centrality metrics. Experimental results on real network topologies confirm the effectiveness of the proposed approach.
Overview of Improving Robustness of MAODV Protocol by Combining Tree and Mesh...IOSR Journals
This document summarizes research on improving the robustness of the MAODV multicast routing protocol in mobile ad hoc networks. It discusses how MAODV uses a tree structure for routing but lacks redundancy, hurting performance in high load or dynamic networks. The document proposes a new MAODV-BB protocol that combines tree and mesh structures by using group messages to update shorter branches and construct a multicast tree with backup branches. This improves robustness without extra overhead.
ENERGY EFFICIENT MULTICAST ROUTING IN MANET ijac journal
In this paper, we have presented the Modified Multicasting through Time Reservation using Adaptive
Control for Excellent Energy efficiency (MMC-TRACE). It is a real time multicasting architecture for
Mobile Ad-Hoc networks to make their work an energy efficient one .MMC-TRACE is a cross layer design
where the network layer and medium access control layer functionality are done in a single integrated
layer design. The basic design of the architecture is to establish and maintain an active multicast tree
surrounded by a passive mesh within a mobile ad hoc network. Energy efficiency is maximized by enabling
the particular node from sleep to awake mode while the remaining nodes of the same path are maintained
at sleep mode. Energy efficiency too achieved by eliminating most of the redundant data receptions across
nodes. The performance of MMC-TRACE are evaluated with the help of ns-2 simulations and comparisons
are made with its predecessor such as MC-TRACE. The results show that the MMC-TRACE provides
superior energy efficiency, competitive QoS performance and bandwidth efficiency.
“Optimizing the data transmission between multiple nodes during link failure ...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document discusses different network topologies including bus, star, ring, and mesh. It describes the key characteristics of each topology such as their physical layout, how data is transmitted, advantages and disadvantages. Hybrid topologies that combine two or more standard topologies are also discussed. The document emphasizes understanding network topologies is essential for designing efficient computer networks and choosing the best option for different network requirements.
The document summarizes an algorithmic approach for detecting selfish and malicious nodes in cluster-based ad hoc wireless networks. It discusses:
1) Mobile ad hoc networks can have nodes that are selfish and refuse to forward packets to save energy or disrupt the network. Clustering is proposed to detect misbehavior within each cluster.
2) The algorithm classifies nodes into clusters, allowing each cluster head to detect false accusations within the cluster. It also describes how clusters are constructed.
3) A 2ACK scheme is proposed where the source node sends a packet to the first node, which forwards it to the next node. Each node then sends an ACK to the previous node. This detects misbehaving nodes that drop
The document discusses network topologies and is intended to teach students about different network structures. It defines network topology and describes three main types: bus, ring, and star. For each topology, it provides the definition, advantages, and disadvantages. The objectives are for students to explain and differentiate the three network topologies. It includes content sections defining the topologies and exercises for students to test their understanding.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document presents research on developing real-time adaptive feedforward control for an XY table system. The researchers identified mathematical models of the XY table plant using system identification techniques. They obtained both minimum phase and non-minimum phase models by varying the sampling time during data collection. They then developed and tested two types of feedforward zero phase error tracking controllers on the system models. Experimental results showed that the modified controller improved tracking performance for both minimum and non-minimum phase systems.
This document discusses different network topologies including bus, star, ring, mesh, tree, and hybrid topologies. It provides details on how each topology connects devices, how data is transferred, advantages and disadvantages of each. Bus topology uses a central backbone cable to connect all devices but if it fails the whole network fails. Star topology uses a central hub to connect devices in a point-to-point fashion, avoiding single point of failure issues but the hub remains a bottleneck. Ring topology connects devices in a continuous ring path allowing data to travel in one direction, but a single break disconnects the whole network. Hybrid topologies combine two or more standard topologies to utilize their advantages while reducing weaknesses.
DSSS with ISAKMP Key Management Protocol to Secure Physical Layer for Mobile ...IJNSA Journal
The wireless and dynamic nature of mobile ad hoc networks (MANETs) leaves them more vulnerable to security attacks than their wired counterparts. The nodes act both as routers and as communication end points. This makes the physical layer more prone to security attacks. The MANET physical layer is challenging to DoS attack and also some passive attacks. The physical layer protocol in MANETs is responsible for bit-level transmission between network nodes. The proposed model combines spread spectrum technology Direct Sequence Spread Spectrum (DSSS) with key management technique ISAKMP to defend against signal jamming denial-of-service attacks in physical layer of MANET.DSSS with ISAKMP is found to be a good security solution even with its known security problems. The simulation is done using network simulator qualnet 5.0 for different number of mobile nodes. The proposed model has shown improved results in terms of Average throughput, Average end to end delay, Average packet delivery ratio, and Average jitter.
The document discusses efficient transmission of data blocks over physical bursts in IEEE 802.16e/WiMAX networks. It addresses how to optimally divide protocol data units (PDUs) within bursts to maximize several performance criteria. Algorithms are presented to compute the best way to define PDUs in a burst to maximize burst goodput and data goodput, assuming either an infinite or limited number of data blocks. Guidelines are also given on selecting the optimal modulation and coding scheme based on channel signal-to-noise ratio.
This document is a study material for Class 12 Informatics Practices published by the Kendriya Vidyalaya Sangathan. It contains an index and four units on topics like networking, programming, relational database management systems, and IT applications. The networking unit discusses computer networks, communication media, network devices, topologies, protocols, and security concepts. It also covers open source concepts. The programming unit reviews concepts from Class 11 and discusses programming fundamentals. The database unit reviews RDBMS concepts and SQL commands. The IT applications unit discusses developing front-end interfaces, backend databases, and demonstrating applications in domains like e-governance, e-business and e-learning. Sample question papers are also included.
In network topology, i am explaining about how to set a network, how many types of network topology, explanation of each type and its advantages and disadvantages.
Linkedin - https://in.linkedin.com/in/prakharmaurya
A New Approach to Improve the Efficiency of Distributed Scheduling in IEEE 80...IDES Editor
The recent standard for broadband wireless
access networks, IEEE 802.16, which resulted in the
development of metropolitan area wireless networks,
includes two network organization modes: Point to Multi
Point and Mesh. The mesh mode provides distributed
channel access operations of peering nodes and uses TDMA
technique for channel access modulation. According to
IEEE 802.16 MAC protocol, there are two scheduling
algorithms for assigning TDMA slots to each network node:
centralized and distributed. In distributed scheduling
algorithm, network nodes have to transmit scheduling
message in order to inform other nodes about their transfer
schedule. In this paper a new approach is proposed to
improve distributed scheduling efficiency in IEEE 802.16
mesh mode, with respect to network condition in every
transferring opportunity. For evaluating the proposed
algorithm efficiency, several extensive simulations are
performed in various network configurations and the most
important system parameters which affect the network
performance are analyzed.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Networking tutorials introduction to networkingVinod Jadhav
This document provides an overview of networking concepts including different network topologies (physical layouts), classifications (LANs, WANs, PANs), and standards (IEEE 802). It discusses the characteristics of common topologies like bus, star, ring, and mesh. It also covers wired and wireless network models, comparing infrastructure wireless to ad-hoc wireless networks. Key networking standards like Ethernet (802.3), Token Ring (802.5), and wireless (802.11) are summarized.
A simulation model of ieee 802.15.4 gts mechanism and gtswissem hammouda
This document presents a simulation model of the IEEE 802.15.4 GTS mechanism and known GTS attacks developed in OMNeT++. The model includes a GTS management scheme model that implements beacon transmission, PAN association, GTS slot allocation and data transmission during GTS slots. It also includes a GTS attacks model that simulates five known GTS attack variants. The models were integrated to provide a comprehensive simulation of both normal GTS operation and attacks against the mechanism. The document describes the architecture, parameters and operation of the models in detail.
This document presents an analytical model to evaluate the performance of multithreaded multiprocessors with distributed shared memory. The model uses a multi-chain closed queuing network to model the processor, memory, and network subsystems in an integrated manner. This captures the strong coupling between subsystems. The model shows that high performance is achieved when the memory request rate matches the weighted sum of memory bandwidth and average remote memory access distance. The model is validated using a stochastic timed Petri net model.
Abstract
Routing in MANET is one of the most researched areas in the field of networking; moreover it is one of the most complex tasks.
RF based transmission techniques are widely used in wireless communication networks. Due to the availability of sophisticated
optical components, the networking domain could be merged with optical domain to have a higher capacity and better
transmission. So in order to overcome the disadvantages of RF domain, we can use light as a medium between nodes. i.e, FSOMANET.
This work is aimed at designing an efficient routing in FSO MANET. This paper proposes a method to find the stable
path as well as stable nodes between the source and destination. The steps are as follows. i) Topology Management ii) Trust Level
Calculation iii) Award and Reward ranking iv)Path Selection. The proposed technique will be implemented in the working
platform of MATLAB.
Keywords: Mobile Ad Hoc Network, Free Space Optics, Link Stability, Delay Tolerant Networking, Clustering
Technique, Award and Reward
The document discusses different network topologies including bus, star, ring, mesh, and tree. It defines network topology as the layout of how computers or workstations are connected in a network. The main types of network topologies are then described in detail, outlining their basic structures and advantages and disadvantages of each design.
Abstract—Geographic routing also called as Geo routing is a routing principle which relies on the Geographic position information. Geographic routing is the most commonly used routing for MANETs. In Geographic routing each node should be aware of its neighbor’s location to maintain the local topology accuracy. Hence, each node should update its location information through a message called beacon. Existing mechanisms invoke periodic beacon update scheme which consumes the network resources such as energy and bandwidth specifically when the network traffic is high, it creates packet loss in the network and it leads to retransmission of data packet causing additional delay and energy consumption. In this work, adaptive position update is proposed which dynamically adjusts the beacon updation frequency according to the varying network conditions.APU makes use of mobility prediction rule and on demand learning rule for beacon updation.
Strategies and Metric for Resilience in Computer Networksdmarinojr
The document discusses strategies and metrics for resilience in computer networks. It proposes a resilience factor to measure a network's ability to withstand targeted attacks. It also proposes two strategies, called PropAdd and PropRew, to improve network resilience by preferentially adding links or rewiring existing links based on centrality metrics. Experimental results on real network topologies confirm the effectiveness of the proposed approach.
Overview of Improving Robustness of MAODV Protocol by Combining Tree and Mesh...IOSR Journals
This document summarizes research on improving the robustness of the MAODV multicast routing protocol in mobile ad hoc networks. It discusses how MAODV uses a tree structure for routing but lacks redundancy, hurting performance in high load or dynamic networks. The document proposes a new MAODV-BB protocol that combines tree and mesh structures by using group messages to update shorter branches and construct a multicast tree with backup branches. This improves robustness without extra overhead.
ENERGY EFFICIENT MULTICAST ROUTING IN MANET ijac journal
In this paper, we have presented the Modified Multicasting through Time Reservation using Adaptive
Control for Excellent Energy efficiency (MMC-TRACE). It is a real time multicasting architecture for
Mobile Ad-Hoc networks to make their work an energy efficient one .MMC-TRACE is a cross layer design
where the network layer and medium access control layer functionality are done in a single integrated
layer design. The basic design of the architecture is to establish and maintain an active multicast tree
surrounded by a passive mesh within a mobile ad hoc network. Energy efficiency is maximized by enabling
the particular node from sleep to awake mode while the remaining nodes of the same path are maintained
at sleep mode. Energy efficiency too achieved by eliminating most of the redundant data receptions across
nodes. The performance of MMC-TRACE are evaluated with the help of ns-2 simulations and comparisons
are made with its predecessor such as MC-TRACE. The results show that the MMC-TRACE provides
superior energy efficiency, competitive QoS performance and bandwidth efficiency.
“Optimizing the data transmission between multiple nodes during link failure ...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document discusses different network topologies including bus, star, ring, and mesh. It describes the key characteristics of each topology such as their physical layout, how data is transmitted, advantages and disadvantages. Hybrid topologies that combine two or more standard topologies are also discussed. The document emphasizes understanding network topologies is essential for designing efficient computer networks and choosing the best option for different network requirements.
The document summarizes an algorithmic approach for detecting selfish and malicious nodes in cluster-based ad hoc wireless networks. It discusses:
1) Mobile ad hoc networks can have nodes that are selfish and refuse to forward packets to save energy or disrupt the network. Clustering is proposed to detect misbehavior within each cluster.
2) The algorithm classifies nodes into clusters, allowing each cluster head to detect false accusations within the cluster. It also describes how clusters are constructed.
3) A 2ACK scheme is proposed where the source node sends a packet to the first node, which forwards it to the next node. Each node then sends an ACK to the previous node. This detects misbehaving nodes that drop
The document discusses network topologies and is intended to teach students about different network structures. It defines network topology and describes three main types: bus, ring, and star. For each topology, it provides the definition, advantages, and disadvantages. The objectives are for students to explain and differentiate the three network topologies. It includes content sections defining the topologies and exercises for students to test their understanding.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document presents research on developing real-time adaptive feedforward control for an XY table system. The researchers identified mathematical models of the XY table plant using system identification techniques. They obtained both minimum phase and non-minimum phase models by varying the sampling time during data collection. They then developed and tested two types of feedforward zero phase error tracking controllers on the system models. Experimental results showed that the modified controller improved tracking performance for both minimum and non-minimum phase systems.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document summarizes a study that examines heat and mass transfer over a vertical plate in a porous medium with Soret and Dufour effects, a convective surface boundary condition, chemical reaction, and magnetic field. The governing equations for the fluid flow, heat transfer, and mass transfer are presented. Similarity solutions are used to transform the governing partial differential equations into ordinary differential equations, which are then solved numerically. The results are presented graphically to show the influence of various parameters on velocity, temperature, concentration, skin friction, Nusselt number, and Sherwood number.
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This document provides an overview of wireless sensor networks, including their architecture, requirements, and differences from conventional networks. Wireless sensor networks consist of dense deployments of sensor nodes that self-organize into a collaborative network. The nodes have stringent limitations on energy, computing power, and bandwidth. They monitor physical conditions and transmit aggregated sensor data in a multi-hop fashion to sink nodes for collection and analysis. Routing protocols are critical given the constraints of wireless sensor networks.
This document discusses the optimization and simulation of Josephson junctions as switching elements. It begins with an introduction stating the need to optimize Josephson junction parameters and characteristics to increase switching speed. It then provides a brief review of the Josephson effect and properties of Josephson junctions. The rest of the document details a theoretical approach to estimating junction parameters, characteristics, and optimization methods, and using computer simulation to model the dynamic response of Josephson junctions to better understand their switching performance and speed.
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This document summarizes a study on the effect of process parameters on the strength of resistance spot welded aluminum alloy A5052 sheets with cover plates. The researchers welded 1mm thick aluminum alloy sheets using resistance spot welding with cold-rolled steel cover plates. They investigated the effect of welding current, time, and electrode force on nugget diameter, tensile-shear strength, and failure mode. Increasing welding current and time increased nugget diameter and strength, while increasing electrode force decreased nugget diameter and strength. Hardness was lowest in the nugget region compared to the base metal. Interfacial failure occurred for smaller nuggets and nugget pullout failure for larger nuggets
The document discusses a study on using melt-densified post-consumer recycled plastic bags as lightweight aggregate in concrete. Melt-densified aggregates (MDA) were prepared by melting plastic bags in a furnace at 160°C. Concrete mixtures with 0-20% replacement of conventional aggregates with MDA were tested. Test results showed that as MDA replacement increased, compressive strength and density decreased. With 20% replacement, compressive strength dropped 44% and density dropped 3.2%. The study concludes that MDA can partially replace conventional aggregates to reduce concrete weight while providing a way to dispose of plastic waste.
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This document analyzes the performance of energy detection algorithms for spectrum sensing in cognitive radio systems. It discusses how energy detection works by formulating the spectrum sensing problem as a binary hypothesis test to determine if a primary user is present or absent. It finds that increasing the signal-to-noise ratio, sample size, or dynamic detection threshold can improve detection performance. However, it also notes that energy detection is very sensitive to noise uncertainty, which can seriously degrade performance, especially in low signal-to-noise environments. A dynamic thresholding approach is proposed to improve robustness to noise uncertainty.
This document summarizes a research paper that proposes a new routing protocol called Vector-Based Forwarding (VBF) for underwater sensor networks. VBF is a location-based routing approach that uses the position of nodes to efficiently route data through a network of moving underwater sensors. It forms redundant forwarding paths between source and destination nodes to improve reliability. VBF also uses a self-adaptation algorithm to allow nodes to discard redundant packets to reduce energy consumption. The paper argues that VBF provides robust, scalable and energy efficient routing for underwater sensor networks.
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Este documento resume los diferentes tipos de comunicación, incluyendo la comunicación oral, escrita, gráfica, audiovisual, corporal y semiótica. La comunicación oral utiliza la palabra para transmitir el mensaje, mientras que la comunicación escrita no está limitada por el espacio y el tiempo. La comunicación gráfica transmite mensajes de manera visual, la comunicación audiovisual usa sistemas sonoros y visuales como la radio y la televisión, y la comunicación corporal transmite mensajes sin palabras a través de señales y gestos. Finalmente, la comunicación
A empresa de tecnologia anunciou um novo smartphone com câmera aprimorada, maior tela e bateria de longa duração. O dispositivo também possui processador mais rápido e armazenamento expansível. O novo modelo será lançado em outubro por um preço inicial de US$799.
The document discusses sequence points in C and C++ programming. It explains that sequence points govern the order of evaluation and side effects in a program. However, the order of evaluation between sequence points is unspecified, meaning compilers are free to rearrange operations as long as the observable behavior is consistent with the sequence points. This can lead to undefined behavior if a program relies on a specific evaluation order. Several examples are provided to illustrate this.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
O documento é um catálogo de produtos eletrônicos codificados pela sigla UETA, com descrições e especificações de cada produto. Está organizado por categorias como pisca-alerta, módulos, relés, conversores, entre outros. Fornece informações técnicas sobre centenas de itens eletrônicos para automotivos.
A Review on Network Survivability in Optical NetworksIJERA Editor
With the continuous advancement in technology data communication at higher data rates have become the need
for the present and future technology. The data can be highly sensitive and loss of such data can hamper the
communication which can cause huge loss to data, time and revenue. Thus survivability plays a very crucial role
in optical networks. It is the ability of the optical network to overcome failure by pre reservation of resources
(Proactive Approach) or by finding available resources after link failure (Reactive Approach) has occurred
.Thus restoration of the failed link plays a very important role and is a very important area of research and
efforts should be made to improve the survivability of optical networks. The objective of this paper is to analyze
the existing survivability techniques
This document summarizes a research paper that proposes a graph-based lightpath restoration method for detecting multiple failures in wavelength division multiplexed (WDM) optical networks. The method uses predefined cycles to restore backup paths when a link fails, in order to reduce time complexity. When the first link fails, its adjacent shorter cycle is used as the backup path. Then the cycles are updated using this restoration method to handle multiple link failures. The method aims to improve performance over existing restoration methods.
This document summarizes a research paper that proposes a graph-based light path restoration method for detecting multiple failures in wavelength division multiplexed (WDM) optical networks. The method uses predefined cycles to restore backup paths when a link fails, in order to reduce time complexity. When the first link fails, its adjacent shorter cycle is used as the backup path. Then the cycles are updated using this restoration method to handle multiple link failures. The method aims to improve performance over existing restoration methods.
Ad hoc networks are the special networks formed for specific applications. Operating in ad-hoc mode
allows all wireless devices within range of each other to discover and communicate in a peer-to-peer
fashion without involving central access points. Many routing protocols like AODV, DSR etc have been
proposed for these networks to find an end to end path between the nodes. These routing protocols are
prone to attacks by the malicious nodes. There is a need to detect and prevent these attacks in a timely
manner before destruction of network services.
Study of Various Schemes for Link Recovery in Wireless Mesh Networkpijans
As there is a growing need for the cost effective and highly dynamic large-bandwidth networks over large
coverage area , the Wireless Mesh Network provide first step towards effective communication. A Wireless
Mesh Network is one of the most advanced wireless network used for communication. During their
operating period , the wireless mesh network may suffer from frequent link failure which results in poor
performance of network. Link failure detection plays crucial role in performance of WMN. The proposed
paper presents the review of various techniques used for detection of link failure and the techniques used
for recovery of wireless mesh network.
A Framework for Routing Misbehavior Recognition in MANETSEECJOURNAL
Mobile Ad-hoc Networks (MANETs) operate on the basic underlying assumption that all participating nodes fully collaborate in self-organizing functions. However, performing network functions consumes energy and other resources. Therefore, some network nodes may decide against cooperating with others. These nodes are called selfish / misbehaving nodes. Misbehavior of suspicious nodes in MANETs is detected, and the information is propagated throughout the network, so that the misbehaving node will be cut off from the rest of the network. We propose a network-layer acknowledgment-based scheme, termed the 2ACK scheme, which can be simply added-on to any source routing protocol. The proposed scheme detects misbehaving nodes, and then seeks to alleviate the problem by notifying the routing protocol to avoid them in future routes. Our results show that proposed scheme reasonably improves the packet delivery ratio, with some additional routing overhead.
A Study on IP Network Recovery through Routing Protocolsijeei-iaes
Internet has taken major role in our communication infrastructure. Such that requirement of internet availability and reliability has increasing accordingly. The major network failure reasons are failure of node and failure of link among the nodes. This can reduce the performance of major applications in an IP networks. The network recovery should be fast enough so that service interruption of link or node failure. The new path taken by the diverted traffic can be computed either at the time of failures or before failures. These mechanisms are known as Reactive and Proactive protocols respectively. In this paper, we surveyed reactive and proactive protocols mechanisms for IP network recovery.
REAL TIME SECURING OF ALL-OPTICAL NETWORKS AGAINST SECURITY ATTACKS AT THE PH...IJNSA Journal
The document describes protocols for securing all-optical networks against physical layer security attacks. It proposes:
1. Calculating security indices for network components and storing them in databases at source nodes. This is used to establish secure lightpaths avoiding attacked components.
2. Establishing lightpaths using fiber diversity between nodes for redundancy against fiber attacks.
3. Monitoring components for attacks during data transfer. Attacked components are partially restored on-the-fly to minimize data loss instead of tearing down lightpaths.
REAL TIME SECURING OF ALL-OPTICAL NETWORKS AGAINST SECURITY ATTACKS AT THE PH...IJNSA Journal
This paper deals with protecting all-optical networks (AON) from security attacks at the physical level. It firstly presents an overall high level protocol for establishment, management and on-the-fly restoration of optimal secure lightpaths established by applying constraint-based open shortest path first (OSPF) source routing using proposed security databases of components. Secondly it presents a protocol for using fiber diversity between adjacent nodes to protect against attacks on fiber links. Thirdly it presents analytical models of propagation of security attacks on optical amplifiers and switches. These models are then used to develop security envelopes around these components, to calculate security indices and on-the-fly real-time restoration of components in case of an attack. Fourthly it presents simulation results for evaluation of the performance of these on-the-fly restoration schemes. These on-the-fly restoration schemes eliminate need for tearing down of attacked lightpaths and prevent consequent loss of large amount of data.
This document discusses collision avoidance mechanisms in wireless ad hoc networks using distributed medium access control (MAC) protocols. It analyzes two main approaches for collision avoidance - out-of-band signaling using a busy tone, and an in-band handshaking approach using request-to-send and clear-to-send messages. The hidden node problem is a major cause of collisions at intermediate nodes in ad hoc networks, so the goal is to reduce collisions and improve transmission reliability. Algorithms for collision avoidance at intermediate nodes are presented for both the out-of-band and in-band approaches.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document analyzes various approaches for making routing more energy efficient in mobile ad hoc networks (MANETs). It discusses the need for energy efficiency in MANETs due to nodes having limited battery power. Several energy efficient routing methods are described, including modifying existing protocols like AOMDV to select routes with higher remaining node energy. Other approaches discussed vary the transmission range, prioritize routes with nodes that have sent fewer messages, use multiple route replies like in reverse AODV, and base routing decisions on received signal strength and battery levels. The document evaluates these different energy efficient routing techniques and their ability to increase network lifetime in MANETs.
A network is nothing but multiple nodes are
connected with each other in some manner. The communication
between each node and the topology of the network are important
to make the environment more efficient. The communications
between systems are broadly categorized into two; that are wired
and wireless communication. In wired network, each node will be
connected through physical wires and follows a topology. But in
wireless network the communication between each node will be
happen a centralized node called Access Point. In wireless
environment a special wireless network is called MANET, in
which there will be no centralized Access Points. MANET is
nothing but Mobile Ad-hoc NETwork. In MANET each node acts
as a sender and receiver. And there is no fixed route between
nodes. Based on the nodes reachable, node will change the
routing table dynamically. So the mobility and scalability of the
nodes will not impact the MANET. The self-configuring ability of
the MANET made it popular in military applications and
emergency recovery. So the communication between each node
should be more secure and trustable. And it’s important to
identify the malicious nodes in MANET too. The malicious nodes
are nodes which are not able to sends packets further or the
nodes which are sends false report to the sender. To identify these
malicious nodes and sends the messages with more secure with
authorization need to implement new Intrusion Identification
System called Digital Signature with Acknowledgement name as
Enhanced Adaptive Acknowledgement. The objective of MANET
is fast communication. So its need to analyze the network
throughput also once the new Intrusion Identification System
introduced.
Shared bandwidth reservation of backup paths of multipleiaemedu
This document summarizes an article from the International Journal of Computer Engineering and Technology that discusses algorithms for shared bandwidth reservation of backup paths for multiple MPLS connections. The article reviews restoration models in MPLS networks including local and end-to-end restoration as well as bandwidth sharing among backup paths. It also discusses the types of routing information that can be used by restoration path selection algorithms, including no information, partial information, and complete network topology information. Finally, it evaluates existing fast restoration algorithms and their scalability based on the routing information model.
Shared bandwidth reservation of backup paths of multiple lsp against link and...IAEME Publication
This document summarizes an article from the International Journal of Computer Engineering and Technology that discusses algorithms for shared bandwidth reservation of backup paths for multiple MPLS Label Switched Paths (LSPs) against link and node failures. It begins with an introduction to MPLS fast reroute and the need for efficient restoration bandwidth management. It then provides an overview of restoration models, including local vs. end-to-end restoration and shared bandwidth reservation approaches. Finally, it reviews several fast restoration algorithms that aim to maximize backup path bandwidth sharing using different levels of routing information.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Design and development of anonymous location based routing for mobile ad-hoc...IJECEIAES
Mobile ad-hoc network (MANET) consists of wireless nodes interacting with each other impulsively over the air. MANET network is dynamic in nature because of which there is high risk in security. In MANET keeping node and routing secure is main task. Many proposed methods have tried to clear this issue but unable to fully resolve. The proposed method has strong secure anonymous location based routing (S2ALBR) method for MANET using optimal partitioning and trust inference model. Here initially partitions of network is done into sectors by using optimal tug of war (OTW) algorithm and compute the trustiness of every node by parameters received signal strength, mobility, path loss and co-operation rate. The process of trust computation is optimized by the optimal decided trust inference (ODTI) model, which provides the trustiness of each node, highest trust owned node is done in each sector and intermediate nodes used for transmission. The proposed method is focusing towards optimization with respect to parameter such as energy, delay, network lifetime, and throughput also above parameter is compared with the existing methods like anonymous location-based efficient routing protocol (ALERT), anonymous location-aided routing in suspicious MANET (ALARM) and authenticated anonymous secure routing (AASR).
A Multiparametric Reliable AODV Protocol using Alternate Routing in MANET’s u...Editor IJCATR
In this paper, we design and formulate a trust-based routing protocol for secure transactions, such as military and disaster
relief operations, banking in mobile ad hoc networks (MANETs). The proposed approach is showing the idea of a trust model in the
network layer of MANET.AODV is ad hoc on demand distance vector, this protocol starts the route specially when some node claims
to send data. In AODV whenever a link breaks an error message is sent indicating the link and packet sending is dropped. In our
proposed scheme a packet is sent through alternative path. In this approach a trust node is made with neighbors. Simulation results
shows that proposed scheme has less packet loss and packet ratio delivered is more.
The document discusses using Bayesian inference and Dempster-Shafer theory to establish trust relationships and achieve security in mobile ad hoc networks (MANETs). It proposes combining direct observation using Bayesian inference with indirect observation using Dempster-Shafer theory to calculate trust values for nodes. The approach is tested in simulations using the AODV routing protocol, showing improved packet delivery ratio, throughput, and end-to-end delay compared to existing systems.
This document discusses security issues in ad-hoc networks. It begins by outlining some key problems in ad-hoc network routing including lack of infrastructure, dynamic topology changes, wireless communication vulnerabilities, and implicit trust between nodes. It then analyzes specific attacks like modifying routing protocol messages. Several solutions are proposed, including concealing network topology using security agents or zone routing, and using watchdog and pathrater mechanisms to identify and isolate misbehaving nodes to improve throughput. The watchdog detects nodes that fail to forward packets by listening to transmissions, while pathrater avoids routing through misbehaving nodes to choose more reliable paths.
1. Ms.Ashwina .N. Patil , Prof. S.S. Kanade , Ms. S.S. Bhakare / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue4, July-August 2012, pp.1486-1489
Fast Recovery For Dual-Link Failure Through Backup Path
Ms.Ashwina .N. Patil* , Prof. S.S. Kanade** , Ms. S.S. Bhakare***
*
Department of CSE, College of Engineering. Osmanabad
**
Head of E&TC Dept, College of Engineering , Osmanabad
***
Department of CSE, Sinhgad College of Engineering. Pune.
ABSTRACT
The nodes in Mobile Ad Hoc Network [4], [5]. Although the WDM network and wireless
(MANET) are mobile resulting in dynamic ad-hoc settings are quite different in nature, they
topology with high rate of link breakage and share a number of problems and challenges. One of
network partitions leading to interruptions in the them is failures of network components. If a link
ongoing communication. Because of node mobility failure is detected on the primary path (through
and power limitations, the network topology which actual data transmission is taking place), the
changes frequently. Link failures or path failure source can switch to an alternate path instead of
are common in such type of network. Therefore initiating a route discovery/recovery process. A new
the networks employ path/link protection to discovery takes place only when all precomputed
achieve fast recovery from dual failures. While the paths break.
first link failure can be protected using link Since in a wireless ad-hoc network has no
protection, but if second link is failed then we fixed infrastructure and there is no centralized control
have the problem of recover that path so the over the nodes ; no designated routers. So nodes
purpose of our system is that recovery from serve as routers for each other, and data packets are
second failure. One of the strategies to recover forwarded from node to node in a multi-hop fashion.
from dual-link failures is to employ link Protecting the circuits or connections established in
protection for the two failed links independently, such networks against single-link failures may be
which requires that two links may not use each achieved in two ways: path protection or link
other in their backup paths if they may fail protection [6]. Main focus of this paper is to protect
simultaneously. Such a strategy is referred to as end-to-end connections from dual-link failures using
backup link mutual exclusion (BLME). This path protection and link protection.
paper develops a solution to the BLME problem
by using two approaches by: 1) integer linear 2. TAXONOMY OF PROTECTION SCHEMES
program; 2) developing a polynomial time Protection schemes proposed in the
heuristic based on minimum cost path routing. literature can be broadly classified as link protection
and path protection.
Keywords-MANET, BLME, FDLP, FILP.
2.1 Link protection
1. INTRODUCTION Link protection schemes route a connection
A Mobile Adhoc Network (MANET) is a around a failed link. Re-routing is performed by the
network composed of mobile nodes mainly node connected to the failed link to the neighboring
characterized by the absence of centralized node on the original path. Such a protection may be
coordination or fixed infrastructure, which makes any achieved in the network in a way that is transparent
node in the network act as potential router. MANETs to the source node, except in cases where a link
are also characterized by a dynamic, random and connected to the source or destination fails. Link
rapidly changing topology. In MANETs, protection, as shown in Fig. 1, reroutes all the
communication link between mobile nodes always connections on the failed link around it. When
require over multi-hop paths. Since no infrastructure accepting a call request, the link protection scheme
exists and node may cause frequent link failure. will reserve the network resource for the associated
In WDM network, the failure of a single protection path. The protection path connects the two
fiber link may lead to tremendous data loss since a nodes adjacent to the failed link. When a link failure
single fiber link can carry a huge amount of data (on occurs, the node adjacent to and upstream of the
the order of terabits per second).Therefore, network failed link immediately redirects the traffic along the
survivability is an important problem in network predetermined protection path to the node on the
design and its real-time operation. In order to reduce other end of the failed link to restores transmission.
the data loss, various protection and restoration
mechanisms have been proposed and studied in the
literature to recover traffic after a failure occurs and
before the failure is physically repaired [1], [2], [3],
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2. Ms.Ashwina .N. Patil , Prof. S.S. Kanade , Ms. S.S. Bhakare / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue4, July-August 2012, pp.1486-1489
5 6 7 8 9 1 ILP Backup
0 User Method Length
Or BLME
Node Problem Results
3 4
Heuristic
Time
Method
1 2 In Sec
Primary path
Backup
Fig 1: Link Protection path Fig 3 : System architecture
2.2 Path protection 4. INTEGER LINEAR PROGRAMMING
Path protection schemes recover from a Dual-link failure resiliency strategies are
failure by re-routing the connections at the source. classified based on the nature in which the
Path protection schemes may be classified into two connections are recovered from first and second
categories based on their knowledge of the failure failures. The recovery from the first link failure is
location. Assignment of a backup path that does not assumed to employ link protection strategy. Fig. 4
require precise knowledge of the link failure is shows an example network where link 1-2 is
referred to as failure-independent path protection protected by the backup path 1-3-4-2. The second
(FIPP). Alternatively, if a connection may be protection strategy will refer to the manner in which
assigned more than one backup path depending on the backup path of the first failed link is recovered.
the failure, then it is referred to as failure-dependent
path protection (FDPP).Path protection, as illustrated 5 6 7 8 9 10
in Fig. 2, reserves network resources for a single
protection path in addition to the primary path. Since
it is impossible to find which link on the primary path
will fail, the system allocates a protection path, which 3 4
is completely link-disjoint from the primary path.
The primary path therefore shares no common link
with its associated protection path. When a link fails, 2
1
the source and destination nodes of a call on the
failed link are informed of the failure, and the Fig 4: Back up link
communication is switched to the protection path.
5 6 7 8 9 1
4.1 Failure Dependent Link Protection (FDLP)
0
If the backup path is affected by the second
failure, a backup path under dual-link failure is
provided. This backup path is computed by
3 4 eliminating the two failed links from the network and
computing shortest path between the specific node
pairs. Fig.4 shows the backup path assigned for link
1 2 1-2 under dual-link failures. It may be observed that
the backup path assignment is different for different
Primary path failures that affect the path. When a second link
Backup
Fig 2: Path Protection failure occurs, a failure notification must be sent to
path
node 1, explicitly mentioning the failure location in
3. LINK FAILURE RECOVERY the path 1-3-4-2. Every link is assigned one backup
Path protection schemes recover from a path for single link failure and multiple backup paths
failure by re-routing the connections at the source. (depending on the number of links in the backup path
Path protection schemes may be classier into three for the single link failure) under dual-link failures. If
categories based on their knowledge of the failure the primary path and link 1-3 of backup path fails
location. Assignment of a backup path that does not down , then this dual failed link is recovered by the
require precise knowledge of the link failure is path 1-5-3-4-2,similarly for link 3-4 and 4-5 fails, the
referred to as failure independent path protection recovery will be 1-5-6-7-8-4-2 and 1-3-4-10-2.
(FIPP). Alternatively, if a connection may be
assigned more than one backup path depending on 4.2 Failure Independent Link Protection (FILP)
the failure, then it is referred to as failure-dependent One approach to dual-link failure resiliency
path protection (FDPP). Link protection schemes using link protection is to compute two link-disjoint
route a connection around a failed link. backup paths for every link. For any two adjacent
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3. Ms.Ashwina .N. Patil , Prof. S.S. Kanade , Ms. S.S. Bhakare / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue4, July-August 2012, pp.1486-1489
nodes, there exist two link-disjoint backup paths for the rectangular region according to the “random way-
the link connecting the two nodes. Let Bl and B'l point” mobility model. All data packets are 512 bytes
denote the two link-disjoint backups for link Bl. If long. All traffic sessions are established at random
any link in the backup path Bl fails, the backup path times near the beginning of the simulation run and
of will be reconfigured to B'l. Hence, the nodes the sessions stay active until the end. Each simulation
connected to link l must have the knowledge of the is run for 100 sec. We evaluate the performance by
failure in its backup paths (not necessarily the varying number of nodes for both the methods.
location).If the link 1-2 fails, then under dual-link
failure the backup path assigned by FILP will be 1-5- 6.2 Performance Metrics
6-7-8-9-10-2. The backup path is identical under any The performance of the ILP and heuristic
second failure that affects the path 1-3-4-2. When the algorithm developed in this paper are evaluated by
second failure occurs, a failure notification must be using the given performance metrics .
sent to nodes 1 and 2, although this notification need Packet delivery ratio (PDR):
not explicitly mention which link failed in path 1-3- Path length
4-2. Throughput
Packet delivery ratio is the ratio of the
5. HEURISTIC APPROACH number of data packets received at the destinations
The heuristic solution is based on iterative and the number of data packets actually sent to the
computation of minimum cost routing. The network network. This measures the quality of the
is treated as an undirected graph G. A set of auxiliary discovered path. The packet delivery ratio in IMCP
graphs corresponding to failure of a link l € G is and FDLP is shown in figure 5.As the number of
created: Xl = G ( N , L-{l } ). In each auxiliary graph nodes varies, the packet delivery ratio of both the
Xl the objective is to obtain a path between the nodes methods increases. The packet delivery ratio of
that were originally connected by link l . Let Pl FDLP is higher than that of IMCP.
denote the path selected in auxiliary graph Xl . If a
link l’ is a part of the path selected on graph Xl ,
then the path in graph Xl must avoid the use of link l
.This is accomplished by imposing a cost on the links
in the auxiliary graphs, and having the path selection
approach select the minimum cost path. Let Wl l’
denote the cost of link l’ on graph Xl such that it
indicates that graph Xl ‘ contains link l and the two
links l and l’ may be unavailable simultaneously.
Hence, the cost values are binary in nature. The cost
of a path in an auxiliary graph is the sum of the cost
of links in it. At any given instant during the
computation, the total cost of all the paths (T) is the
sum of the cost of the paths across all auxiliary
graphs. It may be observed that the total cost must be
Fig 5 :Packet Delivery Ratio for IMCP and FDLP
an even number, as every link l’ in a path Pl that has
The average hop length in IMCP and FDLP
a cost of 1 implies that link l in path Pl ‘ would also
is shown in figure 6. The path length is calculated
have a cost of 1. For a given network, the minimum
during the packet delivery. The alternative path may
value of the total cost would then be two times the
be longer than the main path.
number of dual-link failure scenarios that would have
the network disconnected. If τ denotes the number of
dual-link failure scenarios that would disconnect the
graph, then the termination condition for the heuristic
is given by T = 2τ .
6. PERFORMANCE EVALUATION
6.1 Simulation setup
The setup of the simulation depicts an ad
hoc network that consists of a varying number of
Mobile Hosts (MHs) that move randomly in a square
field free of obstacles. The setup is based on the
OMNeT++ discrete simulator. The implementation of
the proposed methods is based on the AODV routing
Fig 6 :Average hop length for IMCP and FDLP
protocol. We have fixed the area to a rectangular
Figure 7 shows the throughput comparison of IMCP
region of 350m x 350m. The transmission range of
and FDLP. The ratio of the total amount of data that
each node is fixed to 250 m. Nodes move around in
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4. Ms.Ashwina .N. Patil , Prof. S.S. Kanade , Ms. S.S. Bhakare / International Journal of
Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
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