This document summarizes a research paper about admission control and routing algorithms for multi-hop wireless networks that provide quality of service guarantees for flows requesting a pre-specified bandwidth. The paper develops an optimal admission control and routing algorithm that has performance close to an offline algorithm with complete future knowledge. The algorithm makes no assumptions about flow arrival patterns and can be implemented in a distributed manner. It also proves this algorithm is asymptotically optimal with respect to competitive ratio, a metric that measures performance compared to an offline algorithm. Finally, the paper discusses how the algorithm can be modified to allow use of standard shortest-path algorithms for distributed implementation.
ANALYSIS AND STUDY OF MATHEMATICAL MODELS FOR RWA PROBLEM IN OPTICAL NETWORKSIJEEE
Blocking probability has been one of the key performance to solve Routing and Wavelength Assignment problem (RWA) indexes in the design of wavelength-routed all-optical WDM networks. To evaluate blocking probability different analytical model are introduced.
This document summarizes a research paper that compares the performance of three routing protocols (DSDV, DSR, and AODV) in a mobile ad hoc network using the NS-2 simulator. The paper analyzes key performance metrics like packet delivery ratio and end-to-end delay under different numbers of nodes. Simulation results show that the reactive DSR protocol generates and receives more packets than the proactive DSDV protocol. DSR also has better packet delivery ratio and lower end-to-end delay compared to DSDV and AODV as the number of nodes increases. The paper concludes that DSR performs best in the simulated chain topology network.
Performance Evaluation of ad-hoc Network Routing Protocols using ns2 SimulationIDES Editor
Ad-hoc networks are basically peer to peer multihop
mobile wireless networks in which the information packets
are transmitted in a ‘store and forward’ manner from a source
to an arbitrary destination via intermediate nodes. The main
objective of this paper is to evaluate the performance of various
ad-hoc networks routing protocols viz. DSDV (Destination
Sequence Distance Vector), DSR (Dynamic Source Routing)
and AODV (Ad-hoc On Demand Distance Vector). The
comparison of these protocols is based on different
performance metrics, which are throughput, packet delivery
ratio, routing overheads, packet drop and average end to end
delay. The performance evaluation has been done by using
simulation tool NS2 (Network Simulator) which is the main
simulator.
Mobility and Propagation Models in Multi-hop Cognitive Radio Networksszhb
This document discusses how mobility affects the performance of multi-hop cognitive radio networks under different propagation models. It summarizes the results of simulations run with the Network Simulator 2 (NS2) that tested free space, two-ray ground, and shadowing propagation models carrying MPEG4 video traffic over a cognitive radio network with mobile nodes. The key findings are: 1) Free space propagation provided the best throughput and lowest loss ratio compared to two-ray ground and shadowing models; 2) All propagation models performed significantly worse with mobile nodes compared to stationary nodes; 3) Mobility reduced average performance by disrupting signal strength and increasing noise as nodes moved.
This document presents a QoS-based packet scheduling algorithm for hybrid wireless networks. It proposes using the Earliest Deadline First (EDF) algorithm to schedule packets for online conference applications and the Least Slack Time First algorithm to schedule packets for online video applications. The goal is to reduce transmission delay and improve QoS. It implements this scheduling approach using the NS2 network simulator. The scheduling algorithm classifies packets by application type and places them in queues. EDF and Least Slack Time are then used to schedule packets from each queue to minimize delay for multimedia applications over hybrid wireless networks.
Modified PREQ in HWMP for Congestion Avoidance in Wireless Mesh NetworkIRJET Journal
This document summarizes a proposed technique called Modified PREQ in HWMP for Congestion Avoidance in Wireless Mesh Networks. The technique aims to determine congested paths using CCNF frames and provide rerouting to less congested paths before congestion occurs to reduce burden on congested nodes. It allows continued packet transmission on congested paths until a rerouting path is found during congestion scenarios. When a packet is transmitted on the new path, the previous path is deleted to avoid further delay. Sequence numbers are used to avoid flooding the network. The paper compares this Modified PREQ technique to other congestion avoidance techniques to improve throughput and average delay using an NS-3 simulator.
Performance Analysis of AODV and DSDV - FINAL YEAR PROJECTRavi Teja P
This document is a project report submitted by three students for their Bachelor of Technology degree. It analyzes the performance of the AODV and DSDV routing protocols for mobile ad hoc networks (MANETs) using the NS-2 network simulator. The report includes an introduction to MANETs, a literature review of routing protocols for MANETs including AODV and DSDV, a description of the simulation setup and design using NS-2, results of the simulations comparing the performance of AODV and DSDV under different metrics, and conclusions.
ANALYSIS AND STUDY OF MATHEMATICAL MODELS FOR RWA PROBLEM IN OPTICAL NETWORKSIJEEE
Blocking probability has been one of the key performance to solve Routing and Wavelength Assignment problem (RWA) indexes in the design of wavelength-routed all-optical WDM networks. To evaluate blocking probability different analytical model are introduced.
This document summarizes a research paper that compares the performance of three routing protocols (DSDV, DSR, and AODV) in a mobile ad hoc network using the NS-2 simulator. The paper analyzes key performance metrics like packet delivery ratio and end-to-end delay under different numbers of nodes. Simulation results show that the reactive DSR protocol generates and receives more packets than the proactive DSDV protocol. DSR also has better packet delivery ratio and lower end-to-end delay compared to DSDV and AODV as the number of nodes increases. The paper concludes that DSR performs best in the simulated chain topology network.
Performance Evaluation of ad-hoc Network Routing Protocols using ns2 SimulationIDES Editor
Ad-hoc networks are basically peer to peer multihop
mobile wireless networks in which the information packets
are transmitted in a ‘store and forward’ manner from a source
to an arbitrary destination via intermediate nodes. The main
objective of this paper is to evaluate the performance of various
ad-hoc networks routing protocols viz. DSDV (Destination
Sequence Distance Vector), DSR (Dynamic Source Routing)
and AODV (Ad-hoc On Demand Distance Vector). The
comparison of these protocols is based on different
performance metrics, which are throughput, packet delivery
ratio, routing overheads, packet drop and average end to end
delay. The performance evaluation has been done by using
simulation tool NS2 (Network Simulator) which is the main
simulator.
Mobility and Propagation Models in Multi-hop Cognitive Radio Networksszhb
This document discusses how mobility affects the performance of multi-hop cognitive radio networks under different propagation models. It summarizes the results of simulations run with the Network Simulator 2 (NS2) that tested free space, two-ray ground, and shadowing propagation models carrying MPEG4 video traffic over a cognitive radio network with mobile nodes. The key findings are: 1) Free space propagation provided the best throughput and lowest loss ratio compared to two-ray ground and shadowing models; 2) All propagation models performed significantly worse with mobile nodes compared to stationary nodes; 3) Mobility reduced average performance by disrupting signal strength and increasing noise as nodes moved.
This document presents a QoS-based packet scheduling algorithm for hybrid wireless networks. It proposes using the Earliest Deadline First (EDF) algorithm to schedule packets for online conference applications and the Least Slack Time First algorithm to schedule packets for online video applications. The goal is to reduce transmission delay and improve QoS. It implements this scheduling approach using the NS2 network simulator. The scheduling algorithm classifies packets by application type and places them in queues. EDF and Least Slack Time are then used to schedule packets from each queue to minimize delay for multimedia applications over hybrid wireless networks.
Modified PREQ in HWMP for Congestion Avoidance in Wireless Mesh NetworkIRJET Journal
This document summarizes a proposed technique called Modified PREQ in HWMP for Congestion Avoidance in Wireless Mesh Networks. The technique aims to determine congested paths using CCNF frames and provide rerouting to less congested paths before congestion occurs to reduce burden on congested nodes. It allows continued packet transmission on congested paths until a rerouting path is found during congestion scenarios. When a packet is transmitted on the new path, the previous path is deleted to avoid further delay. Sequence numbers are used to avoid flooding the network. The paper compares this Modified PREQ technique to other congestion avoidance techniques to improve throughput and average delay using an NS-3 simulator.
Performance Analysis of AODV and DSDV - FINAL YEAR PROJECTRavi Teja P
This document is a project report submitted by three students for their Bachelor of Technology degree. It analyzes the performance of the AODV and DSDV routing protocols for mobile ad hoc networks (MANETs) using the NS-2 network simulator. The report includes an introduction to MANETs, a literature review of routing protocols for MANETs including AODV and DSDV, a description of the simulation setup and design using NS-2, results of the simulations comparing the performance of AODV and DSDV under different metrics, and conclusions.
The document proposes a new distributed joint queueing (DQ-J) protocol to improve the scalability of LoRa networks. DQ-J aims to reduce the contention overhead of the distributed queueing protocol and achieve balanced traffic loads across multiple channels in LoRa. It introduces an adaptive contention resolution scheme that controls the number of contention slots based on competition. It also presents a load balancing method to distribute data traffic evenly among channels. Analysis shows DQ-J can reduce contention overhead by up to 70% compared to the original DQ protocol and improve throughput by 23% for small payloads. It achieves near-optimal performance irrespective of arrival rates for payloads above 40 bytes in multi-channel LoRa networks.
This document summarizes a research paper that proposes a new cooperative channel load aware VoIP routing topology for 802.11 WLAN networks. It introduces the concept of cooperative channel transmitting technology for 802.11 WLAN networks and discusses some of the challenges in providing quality of service guarantees. It then presents a linear programming model and scheduling algorithm to implement cooperative channel transmissions while considering queue status and transitive node relationships to maximize throughput. Simulation results show that the proposed scheduling algorithm improves throughput and fairness compared to alternatives.
Intelligent Approach for Seamless Mobility in Multi Network EnvironmentIDES Editor
Seamless interoperability between two dissimilar
networks requires handoff from one network to the other.
Such handoffs are known as vertical handoffs. Vertical handoff
introduces a shift in the approach to handoffs. It deals with
handoffs between dissimilar networks, such as from an access
point to a base station or vice versa. The integration of diverse
but complementary cellular and wireless technologies in the
next generation of wireless communication systems requires
the design of intelligent vertical handoff decision algorithms
to enable mobile users to seamlessly switch network access
and experience uninterrupted service continuity anywhere
and anytime. This paper provides a vertical handoff decision
algorithm that enables wireless access network selection at a
mobile terminal. Example shows that our proposed vertical
handover algorithm is able to determine the best access
network.
Interference Aware Multi-path Routing in Wireless Sensor NetworksRakesh Behera
Routing in wireless sensor networks has been considered an important field of research over the past decade. Wireless sensor network essentially consists of data Sensor Nodes and Video Sensor Nodes, which senses both sound and motion of events. Single path routing protocol has been used for route discovery. Though this protocol reduces computation complexity and resource utilization, there are some disadvantages like reduced network throughput, network performance, increased traffic load and delay in data delivery. To overcome these drawbacks a new protocol called Interference Aware Multi-path Routing(IAMR) is proposed to improve the reliability of data transmission, fault-tolerance, Quality of Service. Here, the traffic intersection spread out among the multiple paths. This technique is applied between the sources and sink to reduce routing overhead and energy consumption. The proposed protocol is simulated using NS2
Typical Soft Technologies is one of the leading Software Company located in Chennai that offers best Quality projects and training to all customers.
We also deliver all the finest Projects at many Students, Companies. Our Computer Courses Provides best future for the Students. If you want any of our projects & Courses, then contact us.
Admin@typical.in
044-43555140, 093443 99926.
Comparative Analysis of Green Algorithm within Active Queue Management for Mo...ijtsrd
The Queue Management Techniques play an important role in improving the Quality of Service in Mobile Ad hoc Networks. The need of congestion control and Queue management is inevitable in Mobile Ad hoc Network. Understanding and analyzing the latest AQM Techniques give an insight to improving throughput, packet loss rate, average end to end delay and other parameters that severely affect the performance. The performance of mobile ad hoc networks is evaluated by varying the Channel Error Rate, Bandwidth and Delay at different fragment sizes of different traffic flows. The proposed method performs the network analysis of new Routing protocols. The work proposes to evaluate various Active Queue Management Techniques in a multi traffic environment i.e., sources generating both TCP and UDP traffic classes. The UDP is propagated via CBR and TCP is propagated via FTP. The implementation of the proposed queue management technique has been done in NS 2. In the proposed work we have make NS 2 compatible with GREEN by integrating source code into the ns 2 installation files and using various AQMs in comparison with GREEN to calculate the throughput at various Bandwidths across network. Using various AQMs in comparison with GREEN we have calculated the throughput at various Delays across the network and we have also calculated the throughput at various channels Error Rate across the network. The proposed method has been compared with other primitive AQM techniques so that a repository of best available results can be obtained for design and research purposes. The proposed method has outperformed the existing queue management techniques in number of scenarios. Zulai Khan | Rashmi Raj ""Comparative Analysis of Green Algorithm within Active Queue Management for Mobile Ad Hoc Network"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23950.pdf
Paper URL: https://www.ijtsrd.com/engineering/electronics-and-communication-engineering/23950/comparative-analysis-of-green-algorithm-within-active-queue-management-for-mobile-ad-hoc-network/zulai-khan
Investigation of Clock Synchronization Techniques and its Performance Impact ...ijctet
This document summarizes research on clock synchronization techniques in mobile ad hoc networks (MANETs). It begins by defining MANETs and explaining why time synchronization is important. It then discusses challenges in time synchronization due to clock imperfections and variable network delays. The document reviews existing clock synchronization methods like burst transmission and clock sampling. It also covers characteristics of MANETs like dynamic topology. Finally, it surveys previous research on time synchronization algorithms for MANETs, including a decentralized algorithm that achieves fast convergence times and high accuracy.
A Bandwidth Efficient Scheduling Framework for Non Real Time Applications in ...ijdpsjournal
The key concern on the bandwidth allocation and scheduling for non real time traffic are the fulfillment of its minimum throughput requirement and improvement of bandwidth utilization with acceptable delay. This paper proposes a simple and efficient scheduling framework for allocating bandwidth to non real time
polling service (nrtPS) users in IEEE 802.16 networks. In this framework, jointly selective repeat ARQ at the MAC layer and adaptive modulation and coding techniques at the physical are considered. Numerical simulations demonstrate that the proposed scheduling approach provides a graceful compromise between bandwidth utilization and packet delivery delay while maintaining the minimum throughput requirements of nrtPS applications. Thus proves the efficiency of the proposed framework. The simulation is done for unicast scenario.
Q-LEARNING BASED ROUTING PROTOCOL TO ENHANCE NETWORK LIFETIME IN WSNSIJCNCJournal
In resource constraint Wireless Sensor Networks (WSNs), enhancement of network lifetime has been one of the significantly challenging issues for the researchers. Researchers have been exploiting machine learning techniques, in particular reinforcement learning, to achieve efficient solutions in the domain of WSN. The objective of this paper is to apply Q-learning, a reinforcement learning technique, to enhance the lifetime of the network, by developing distributed routing protocols. Q-learning is an attractive choice for routing due to its low computational requirements and additional memory demands. To facilitate an agent running at each node to take an optimal action, the approach considers node’s residual energy, hop length to sink and transmission power. The parameters, residual energy and hop length, are used to calculate the Q-value, which in turn is used to decide the optimal next-hop for routing. The proposed protocols’ performance is evaluated through NS3 simulations, and compared with AODV protocol in terms of network lifetime, throughput and end-to-end delay.
we find out various power aware and data packet rate control with-collision-avoidance (CSMA/CA)-based ad hoc wireless network communication. And identifies that CSMA
This document summarizes a research paper on QoS routing protocols for mobile ad hoc networks (MANETs). It describes a QoS routing protocol called QOSRGA that uses a genetic algorithm to find high-quality routes between nodes that meet multiple QoS constraints like bandwidth, delay, and connectivity. The protocol relies on cooperation between sub-protocols to discover multiple paths, monitor node states, and measure bandwidth. It also introduces a new metric called node connectivity index to evaluate path quality. Simulation results show that QOSRGA performs well in finding routes that meet constraints, even as node mobility increases.
An investigation-on-efficient-spreading-codes-for-transmitter-based-technique...Cemal Ardil
This document summarizes research on efficient spreading codes for transmitter-based techniques to mitigate interference in time division duplex code division multiple access (TDD/CDMA) downlink systems. It investigates bitwise and blockwise multiuser transmission schemes that transfer complexity to the transmitter. Different spreading codes are evaluated based on correlation properties to determine suitability for techniques like precoding, pre-rake, and rake diversity. Performance is measured by bit error rate with varying numbers of users to identify the most efficient codes for interference mitigation.
ADAPTIVE RANDOM SPATIAL BASED CHANNEL ESTIMATION (ARSCE) FOR MILLIMETER WAVE ...IJCNCJournal
Millimeter-wave and mMIMO communications are the most essential success systems for next-generation wireless sensor networks to have enormous amounts of accessible throughput and spectrum. Through installing huge antenna arrays at the base station and performing coherent transceiver processing, mMIMO is a potential technology for enhancing the bandwidth efficiency of wireless sensor networks. The use of mmWave frequencies for mMIMO systems solves the problem of high path-loss through offering greater antenna gains. In this work, we provide a design with a random spatial sample structure that incorporates a totally random step before the analogue is received. It contains a totally random step before the analogue received signals are sent into the digital component of the HBF receiver. Adaptive random spatial based channel estimation (ARSCE) is proposed for channel session measurement collection, and an analogue combiner with valves has been used to estimate the signals at each receiving antenna. The proposed optimization problem formulation attempts to discover the orientations and gains of wideband channel routes. In addition, our proposed model has compared to various state-of-art techniques while considering error minimization.
This document reviews cross-layer attack aware routing in cognitive radio networks with multihop routing. It discusses how cognitive radio networks are vulnerable to denial of service (DDoS) attacks due to their characteristics. Most existing work uses AODV routing but it proposes using RPL, designed for low power and lossy networks. It aims to develop a network layer that can provide efficient routing even under DDoS attacks. By adding a layer for attack removal in cross-layer networks, the system could route effectively even if attacks occur, improving efficiency and throughput. The methodology section outlines comparing the proposed technique to existing work to analyze performance improvements for energy-efficient multihop routing in cognitive radio networks under attacks.
A novel low computational complexity robust adaptive blind multiuser detector, based on the minimum output energy (MOE) detector with multiple constraints and a quadratic inequality (QI) constraint is developed in this paper. Quadratic constraint has been a widespread approach to improve robustness against mismatch errors, uncertainties in estimating the data covariance matrix, and random perturbations in detector parameters. A diagonal loading technique is compulsory to achieve the quadratic constraint where the diagonal loading level is adjusted to satisfy the constrained value. Integrating the quadratic constraint into recursive algorithms seems to be a moot point since there is no closed-form solution for the diagonal loading term. In this paper, the MOE detector of DS/CDMA system is implemented using a fast recursive steepest descent adaptive algorithm anchored in the generalized sidelobe canceller (GSC) structure with multiple constraints and a QI constraint on the adaptive portion of the GSC structure. The Lagrange multiplier method is exploited to solve the QI constraint. An optimal variable loading technique, which is capable of providing robustness against uncertainties and mismatch errors with low computational complexity is adopted. Simulations for several mismatch and random perturbations scenarios are conducted in a rich multipath environment with near–far effect to explore the robustness of the proposed detector.
Analysis of Latency and Throughput of 2D Torus Topology using Modified XY Rou...IDES Editor
Network-on-Chip (NoC) is a packet switched onchip
communication network designed using a layered
methodology i.e. “routes packets, not wires”. It is an efficient
on chip communication architecture for System on Chip (SoC)
architectures. NoCs solved the disadvantages of SoCs and are
scalable. Each route in NoC includes some routers and it takes
a few clock periods by passing a router.
When the network is in congestion, the package transmission
will produce much more time delay. So adopting an appropriate
routing algorithm to get the balance between the time delay
and throughput rate becomes the key problem. In this paper
we tried to solve that problem using torus topology with our
modified XY routing algorithm.
We used NIRGAM simulator for analysis of latency and
throughput of modified XY routing algorithm for 2D torus
topology. 3x3 network size used for analyze the performance.
We consider all tiles as source, all tiles as destination and
vary the packet size & traffic used is Constant Bit Rate (CBR)
random traffic. It is found that packet size increases then
latency/packet increases and throughput (in Gbps) also
increases but latency/flit decreases.
Energy efficient cluster-based service discovery in wireless sensor networksambitlick
1) The document proposes an energy-efficient service discovery protocol for wireless sensor networks that exploits a cluster-based network overlay.
2) Clusterhead nodes form a distributed service registry to minimize communication costs during service discovery and maintenance.
3) The performance of the proposed integrated clustering and service discovery solution is evaluated through simulations under different network conditions.
Onder het mom van COREPER worden door de Europese Unie diverse snoepreisjes georganiseerd. OPvallend is dat de leden van COREPER hun partner kunnen meenemen op een dergelijke snoepreis.
The document proposes a new distributed joint queueing (DQ-J) protocol to improve the scalability of LoRa networks. DQ-J aims to reduce the contention overhead of the distributed queueing protocol and achieve balanced traffic loads across multiple channels in LoRa. It introduces an adaptive contention resolution scheme that controls the number of contention slots based on competition. It also presents a load balancing method to distribute data traffic evenly among channels. Analysis shows DQ-J can reduce contention overhead by up to 70% compared to the original DQ protocol and improve throughput by 23% for small payloads. It achieves near-optimal performance irrespective of arrival rates for payloads above 40 bytes in multi-channel LoRa networks.
This document summarizes a research paper that proposes a new cooperative channel load aware VoIP routing topology for 802.11 WLAN networks. It introduces the concept of cooperative channel transmitting technology for 802.11 WLAN networks and discusses some of the challenges in providing quality of service guarantees. It then presents a linear programming model and scheduling algorithm to implement cooperative channel transmissions while considering queue status and transitive node relationships to maximize throughput. Simulation results show that the proposed scheduling algorithm improves throughput and fairness compared to alternatives.
Intelligent Approach for Seamless Mobility in Multi Network EnvironmentIDES Editor
Seamless interoperability between two dissimilar
networks requires handoff from one network to the other.
Such handoffs are known as vertical handoffs. Vertical handoff
introduces a shift in the approach to handoffs. It deals with
handoffs between dissimilar networks, such as from an access
point to a base station or vice versa. The integration of diverse
but complementary cellular and wireless technologies in the
next generation of wireless communication systems requires
the design of intelligent vertical handoff decision algorithms
to enable mobile users to seamlessly switch network access
and experience uninterrupted service continuity anywhere
and anytime. This paper provides a vertical handoff decision
algorithm that enables wireless access network selection at a
mobile terminal. Example shows that our proposed vertical
handover algorithm is able to determine the best access
network.
Interference Aware Multi-path Routing in Wireless Sensor NetworksRakesh Behera
Routing in wireless sensor networks has been considered an important field of research over the past decade. Wireless sensor network essentially consists of data Sensor Nodes and Video Sensor Nodes, which senses both sound and motion of events. Single path routing protocol has been used for route discovery. Though this protocol reduces computation complexity and resource utilization, there are some disadvantages like reduced network throughput, network performance, increased traffic load and delay in data delivery. To overcome these drawbacks a new protocol called Interference Aware Multi-path Routing(IAMR) is proposed to improve the reliability of data transmission, fault-tolerance, Quality of Service. Here, the traffic intersection spread out among the multiple paths. This technique is applied between the sources and sink to reduce routing overhead and energy consumption. The proposed protocol is simulated using NS2
Typical Soft Technologies is one of the leading Software Company located in Chennai that offers best Quality projects and training to all customers.
We also deliver all the finest Projects at many Students, Companies. Our Computer Courses Provides best future for the Students. If you want any of our projects & Courses, then contact us.
Admin@typical.in
044-43555140, 093443 99926.
Comparative Analysis of Green Algorithm within Active Queue Management for Mo...ijtsrd
The Queue Management Techniques play an important role in improving the Quality of Service in Mobile Ad hoc Networks. The need of congestion control and Queue management is inevitable in Mobile Ad hoc Network. Understanding and analyzing the latest AQM Techniques give an insight to improving throughput, packet loss rate, average end to end delay and other parameters that severely affect the performance. The performance of mobile ad hoc networks is evaluated by varying the Channel Error Rate, Bandwidth and Delay at different fragment sizes of different traffic flows. The proposed method performs the network analysis of new Routing protocols. The work proposes to evaluate various Active Queue Management Techniques in a multi traffic environment i.e., sources generating both TCP and UDP traffic classes. The UDP is propagated via CBR and TCP is propagated via FTP. The implementation of the proposed queue management technique has been done in NS 2. In the proposed work we have make NS 2 compatible with GREEN by integrating source code into the ns 2 installation files and using various AQMs in comparison with GREEN to calculate the throughput at various Bandwidths across network. Using various AQMs in comparison with GREEN we have calculated the throughput at various Delays across the network and we have also calculated the throughput at various channels Error Rate across the network. The proposed method has been compared with other primitive AQM techniques so that a repository of best available results can be obtained for design and research purposes. The proposed method has outperformed the existing queue management techniques in number of scenarios. Zulai Khan | Rashmi Raj ""Comparative Analysis of Green Algorithm within Active Queue Management for Mobile Ad Hoc Network"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23950.pdf
Paper URL: https://www.ijtsrd.com/engineering/electronics-and-communication-engineering/23950/comparative-analysis-of-green-algorithm-within-active-queue-management-for-mobile-ad-hoc-network/zulai-khan
Investigation of Clock Synchronization Techniques and its Performance Impact ...ijctet
This document summarizes research on clock synchronization techniques in mobile ad hoc networks (MANETs). It begins by defining MANETs and explaining why time synchronization is important. It then discusses challenges in time synchronization due to clock imperfections and variable network delays. The document reviews existing clock synchronization methods like burst transmission and clock sampling. It also covers characteristics of MANETs like dynamic topology. Finally, it surveys previous research on time synchronization algorithms for MANETs, including a decentralized algorithm that achieves fast convergence times and high accuracy.
A Bandwidth Efficient Scheduling Framework for Non Real Time Applications in ...ijdpsjournal
The key concern on the bandwidth allocation and scheduling for non real time traffic are the fulfillment of its minimum throughput requirement and improvement of bandwidth utilization with acceptable delay. This paper proposes a simple and efficient scheduling framework for allocating bandwidth to non real time
polling service (nrtPS) users in IEEE 802.16 networks. In this framework, jointly selective repeat ARQ at the MAC layer and adaptive modulation and coding techniques at the physical are considered. Numerical simulations demonstrate that the proposed scheduling approach provides a graceful compromise between bandwidth utilization and packet delivery delay while maintaining the minimum throughput requirements of nrtPS applications. Thus proves the efficiency of the proposed framework. The simulation is done for unicast scenario.
Q-LEARNING BASED ROUTING PROTOCOL TO ENHANCE NETWORK LIFETIME IN WSNSIJCNCJournal
In resource constraint Wireless Sensor Networks (WSNs), enhancement of network lifetime has been one of the significantly challenging issues for the researchers. Researchers have been exploiting machine learning techniques, in particular reinforcement learning, to achieve efficient solutions in the domain of WSN. The objective of this paper is to apply Q-learning, a reinforcement learning technique, to enhance the lifetime of the network, by developing distributed routing protocols. Q-learning is an attractive choice for routing due to its low computational requirements and additional memory demands. To facilitate an agent running at each node to take an optimal action, the approach considers node’s residual energy, hop length to sink and transmission power. The parameters, residual energy and hop length, are used to calculate the Q-value, which in turn is used to decide the optimal next-hop for routing. The proposed protocols’ performance is evaluated through NS3 simulations, and compared with AODV protocol in terms of network lifetime, throughput and end-to-end delay.
we find out various power aware and data packet rate control with-collision-avoidance (CSMA/CA)-based ad hoc wireless network communication. And identifies that CSMA
This document summarizes a research paper on QoS routing protocols for mobile ad hoc networks (MANETs). It describes a QoS routing protocol called QOSRGA that uses a genetic algorithm to find high-quality routes between nodes that meet multiple QoS constraints like bandwidth, delay, and connectivity. The protocol relies on cooperation between sub-protocols to discover multiple paths, monitor node states, and measure bandwidth. It also introduces a new metric called node connectivity index to evaluate path quality. Simulation results show that QOSRGA performs well in finding routes that meet constraints, even as node mobility increases.
An investigation-on-efficient-spreading-codes-for-transmitter-based-technique...Cemal Ardil
This document summarizes research on efficient spreading codes for transmitter-based techniques to mitigate interference in time division duplex code division multiple access (TDD/CDMA) downlink systems. It investigates bitwise and blockwise multiuser transmission schemes that transfer complexity to the transmitter. Different spreading codes are evaluated based on correlation properties to determine suitability for techniques like precoding, pre-rake, and rake diversity. Performance is measured by bit error rate with varying numbers of users to identify the most efficient codes for interference mitigation.
ADAPTIVE RANDOM SPATIAL BASED CHANNEL ESTIMATION (ARSCE) FOR MILLIMETER WAVE ...IJCNCJournal
Millimeter-wave and mMIMO communications are the most essential success systems for next-generation wireless sensor networks to have enormous amounts of accessible throughput and spectrum. Through installing huge antenna arrays at the base station and performing coherent transceiver processing, mMIMO is a potential technology for enhancing the bandwidth efficiency of wireless sensor networks. The use of mmWave frequencies for mMIMO systems solves the problem of high path-loss through offering greater antenna gains. In this work, we provide a design with a random spatial sample structure that incorporates a totally random step before the analogue is received. It contains a totally random step before the analogue received signals are sent into the digital component of the HBF receiver. Adaptive random spatial based channel estimation (ARSCE) is proposed for channel session measurement collection, and an analogue combiner with valves has been used to estimate the signals at each receiving antenna. The proposed optimization problem formulation attempts to discover the orientations and gains of wideband channel routes. In addition, our proposed model has compared to various state-of-art techniques while considering error minimization.
This document reviews cross-layer attack aware routing in cognitive radio networks with multihop routing. It discusses how cognitive radio networks are vulnerable to denial of service (DDoS) attacks due to their characteristics. Most existing work uses AODV routing but it proposes using RPL, designed for low power and lossy networks. It aims to develop a network layer that can provide efficient routing even under DDoS attacks. By adding a layer for attack removal in cross-layer networks, the system could route effectively even if attacks occur, improving efficiency and throughput. The methodology section outlines comparing the proposed technique to existing work to analyze performance improvements for energy-efficient multihop routing in cognitive radio networks under attacks.
A novel low computational complexity robust adaptive blind multiuser detector, based on the minimum output energy (MOE) detector with multiple constraints and a quadratic inequality (QI) constraint is developed in this paper. Quadratic constraint has been a widespread approach to improve robustness against mismatch errors, uncertainties in estimating the data covariance matrix, and random perturbations in detector parameters. A diagonal loading technique is compulsory to achieve the quadratic constraint where the diagonal loading level is adjusted to satisfy the constrained value. Integrating the quadratic constraint into recursive algorithms seems to be a moot point since there is no closed-form solution for the diagonal loading term. In this paper, the MOE detector of DS/CDMA system is implemented using a fast recursive steepest descent adaptive algorithm anchored in the generalized sidelobe canceller (GSC) structure with multiple constraints and a QI constraint on the adaptive portion of the GSC structure. The Lagrange multiplier method is exploited to solve the QI constraint. An optimal variable loading technique, which is capable of providing robustness against uncertainties and mismatch errors with low computational complexity is adopted. Simulations for several mismatch and random perturbations scenarios are conducted in a rich multipath environment with near–far effect to explore the robustness of the proposed detector.
Analysis of Latency and Throughput of 2D Torus Topology using Modified XY Rou...IDES Editor
Network-on-Chip (NoC) is a packet switched onchip
communication network designed using a layered
methodology i.e. “routes packets, not wires”. It is an efficient
on chip communication architecture for System on Chip (SoC)
architectures. NoCs solved the disadvantages of SoCs and are
scalable. Each route in NoC includes some routers and it takes
a few clock periods by passing a router.
When the network is in congestion, the package transmission
will produce much more time delay. So adopting an appropriate
routing algorithm to get the balance between the time delay
and throughput rate becomes the key problem. In this paper
we tried to solve that problem using torus topology with our
modified XY routing algorithm.
We used NIRGAM simulator for analysis of latency and
throughput of modified XY routing algorithm for 2D torus
topology. 3x3 network size used for analyze the performance.
We consider all tiles as source, all tiles as destination and
vary the packet size & traffic used is Constant Bit Rate (CBR)
random traffic. It is found that packet size increases then
latency/packet increases and throughput (in Gbps) also
increases but latency/flit decreases.
Energy efficient cluster-based service discovery in wireless sensor networksambitlick
1) The document proposes an energy-efficient service discovery protocol for wireless sensor networks that exploits a cluster-based network overlay.
2) Clusterhead nodes form a distributed service registry to minimize communication costs during service discovery and maintenance.
3) The performance of the proposed integrated clustering and service discovery solution is evaluated through simulations under different network conditions.
Onder het mom van COREPER worden door de Europese Unie diverse snoepreisjes georganiseerd. OPvallend is dat de leden van COREPER hun partner kunnen meenemen op een dergelijke snoepreis.
Hoe rijk is eurocommissaris Marianne Thyssen?Thierry Debels
Nieuwbakken eurocommissaris Marianne Thyssen moet een verklaring afleggen over haar vermogen. Uit dat document blijkt dat ze een aanzienlijk roerend en onroerend vermogen heeft.
The document proposes an energy-efficient service discovery protocol for wireless sensor networks. It uses a lightweight clustering algorithm to build a distributed directory of service registrations. Each cluster head maintains information about services in its cluster. The protocol aims to minimize communication costs during service discovery and maintenance of the distributed directory. It constructs disjoint tree clusters where high-capability nodes become cluster heads and advertise their roles, while other nodes select parents based on capability grades.
On Multihop Distances in Wireless Sensor Networks with Random Node Locationsambitlick
The document analyzes the distribution of maximum multihop distances in wireless sensor networks with random node locations. It proposes a greedy method to maximize the multihop distance in 2D networks by restricting propagation direction outward from the source in each hop and searching for the furthest neighbor. This differs from prior work modeling 1D networks that used a Gaussian distribution, which is shown to not accurately model 2D distances. The paper transforms the Gamma distribution to effectively approximate maximum distances in 2D and provides a more consistent representation of the multihop distance distribution compared to the Gaussian model. It derives the expected value and standard deviation of distances using the Gamma approximation and compares to simulation results.
Stichting van Jacques van Ypersele kreeg geld van rijke AmerikanenThierry Debels
Op 24 september 2013 richt Jacques van Ypersele de stichting Centres Ste-Thérèse op.
Uit een officieel document van de VS blijkt dat de stichting een geldsom kreeg van rijke Amerikaanse geldschieters.
Het gaat meer bepaald om The Stephen F & Camilla T Brauer Charitable Trust.
Hieruit blijkt dat Van Ypersele nog steeds erg goede relaties onderhoudt met onderdanen uit de Verenigde Staten.
An efficient hybrid peer to-peersystemfordistributeddatasharingambitlick
The document proposes a hybrid peer-to-peer system that combines the advantages of structured and unstructured networks. It consists of two parts: 1) a structured core network that forms the backbone and provides efficient data lookup; 2) multiple unstructured networks attached to each core node, allowing flexible peer joining/leaving. This two-tier design decouples efficiency and flexibility. Simulation results show the hybrid system balances these properties better than single-approach networks.
A novel pause count backoff algorithm for channel accessambitlick
The document summarizes a proposed novel backoff algorithm called Pause Count Backoff (PCB) for channel access in IEEE 802.11 wireless networks. PCB observes the number of pauses in a node's backoff procedure to estimate the number of active stations and set an appropriate contention window size. Simulation results show PCB outperforms other algorithms like DCF, EIED, and AEDCF in terms of goodput, fairness index, and end-to-end delay under different network conditions.
A collaborative wireless sensor network routingambitlick
This document proposes a new routing scheme called node reliance for wireless sensor networks. Node reliance rates how much each node is relied upon for routing data from sources to sinks. Sources will route through nodes with low reliance ratings to avoid overusing critical nodes and maximize network lifetime. The scheme is evaluated using an example network and compared to other routing methods. Node reliance aims to reduce energy waste from disconnected sources by encouraging collaboration between sources in path selection.
The document lists 23 networking and mobile computing projects implemented in NS2. It includes projects on topics like mobility in wireless networks, intrusion detection, neighbor discovery, energy renewal with wireless power transfer, load balancing, and spectrum access control. Contact information is provided for those interested in the project reports, presentations, source code, or implementing new projects.
TCP Fairness for Uplink and Downlink Flows in WLANsambitlick
The document discusses simulation parameters for a wireless network simulation in NS2 including the simulator used, simulation time, packet interval, background data traffic types, packet size, transmission range, routing protocol, and MAC protocol. It also briefly discusses queue management for wireless networks and how it differs from wired networks by not being visible. Client-server computing and networking is defined as well as packet scheduling policies and comparing FIFO to RENO scheduling. Bandwidth sharing approaches are examined for heterogeneous congestion control protocols. Finally, end-to-end throughput is defined and its decrease with more nodes in a chain topology is explained due to relaying overhead at intermediate nodes.
Architecture for reliable service discoveryambitlick
The authors provide an overview of standardized service discovery and delivery solutions for mobile ad hoc networks (MANETs). They propose a novel architecture that allows selecting a service provider based on metrics like the power supply of the provider and the path to the destination. This architecture is based on a decentralized approach using Service Location Protocol (SLP) extensions. It aims to provide reliable service discovery and delivery in MANETs by considering energy constraints affecting the network topology and connectivity.
1) This document proposes a new anomaly detection scheme for mobile ad hoc networks (MANETs) based on dynamic learning.
2) The scheme uses a statistical decision theory to calculate projection distances between the current and normal states of nodes using weighted coefficients and a forgetting curve.
3) Simulations evaluate the scheme's effectiveness in detecting five types of attacks on the ad hoc on-demand distance vector (AODV) routing protocol for MANETs of different sizes.
Waarom proces van Delphine wellicht met sisser aflooptThierry Debels
Op 23 september 2014 wordt het proces van Delphine Boël verdergezet. Hierop krijgt de rechtbank een maand de tijd om een uitspraak te doen. Tegen deze uitspraak kan vervolgens door alle partijen hoger beroep aangetekend worden.
De rechtszaak met dossiernummer 2013 / A / 9225 bevat enkele merkwaardige elementen.
Jean-Jacques De Gucht heeft een passie voor kunst. In interviews heeft hij al eens gezegd dat hij er stiekem van droomt om galeriehouder te worden.
Die droom heeft hij nu waargemaakt. In het voorjaar van 2014 heeft De Gucht met zijn echtgenote de bvba De filatuur opgericht, een kunstgalerie.
This document summarizes research on parameters for vertical handoff in heterogeneous wireless networks. It discusses several key parameters that influence vertical handoff decisions, including available bandwidth, received signal strength, cost, latency, and quality of service. The document reviews several existing approaches for vertical handoff that consider parameters like bandwidth, RSS, access fee, packet delay, available bandwidth, and network load. Overall, the document analyzes parameters that are important for designing efficient vertical handoff mechanisms in next-generation heterogeneous wireless networks.
IRJET- Aggregate Signature Scheme and Secured ID for Wireless Sensor Netw...IRJET Journal
This document proposes a cross-layer resource allocation scheme over wireless relay networks to guarantee quality of service (QoS) in terms of delay. The scheme aims to maximize network throughput subject to a given delay constraint, characterized by a QoS exponent θ. Dynamic resource allocation algorithms are developed for amplify-and-forward and decode-and-forward relay networks based on network channel state information and the QoS constraint. Simulations show the scheme efficiently supports diverse QoS requirements over wireless relay networks, and relay networks outperform direct transmissions under stringent delay constraints.
Multipath Routing Protocol by Breadth First Search Algorithm in Wireless Mesh...IOSR Journals
This document proposes a multipath routing protocol for wireless mesh networks that uses a parallel layer-based approach and breadth-first search algorithm to discover multiple paths between a source and destination. It organizes nodes into layers based on distance from the destination and performs iterative breadth-first searches to find partial paths connecting nodes in lower layers, storing the partial paths. This process repeats until reaching the destination to find all possible paths. The primary path is then elected using an Expected Forwarding Counter metric to select the most reliable path. The protocol was evaluated in NS-2 and showed improved throughput, delivery ratio, and reduced delay compared to other protocols.
Call Admission Control (CAC) with Load Balancing Approach for the WLAN NetworksIJARIIT
The cell migrations take place between the different network operators, and require the significant information exchange between the operators to handle the migratory users. The new user registration requires the pre-shared information from the user’s equipment, which signifies the user recognition before registering the new user over the network. In this thesis, the proposed model has been aimed at the development of the new call admission control mechanism with the sub-channel assignment. The very basic utilization of the proposed model is to increase the number of the users over the given cell units, which is realized by using the sub-channel assignment to the users of the network. The proposed model is aimed at solving the issue by assigning the dual sub channels over the single communication channel. Also the proposed model is aimed at handling the minimum resource users by incorporating the load balancing approach over the given network segment. The load balancing approach shares the load of the overloaded cell with the cell with lowest resource utilization. The proposed model performance has been evaluated in the various scenarios and over all of the BTS nodes. The proposed model results have been obtained in the form of the resource utilization, network load, transmission delay, consumed bandwidth and data loss. The proposed model has shown the efficiency obtained by using the proposed call admission control (CAC) along with the new load balancing mechanism. The proposed model has shown the robustness of the proposed model in handling the cell overloading factors.
The document describes a proposed multi-hop clustering (MHC) approach for vehicular ad-hoc networks (VANETs). The MHC approach selects cluster heads based on the node's speed being closest to the average speed and having a high network life. It calculates distrust values to isolate malicious nodes and determines a QoS value considering bandwidth, number of neighbors, distance and velocity ratios. The approach aims to improve stability, reliability and security compared to previous work. It was simulated in NS2 and showed better results than existing techniques for parameters like overhead, throughput, delay, loss and delivery ratio. The key contribution is adding calculations for percentage of stability and path length.
Talhunt is a leader in assisting and executing IEEE Engineering projects to Engineering students - run by young and dynamic IT entrepreneurs. Our primary motto is to help Engineering graduates in IT and Computer science department to implement their final year project with first-class technical and academic assistance.
Project assistance is provided by 15+ years experienced IT Professionals. Over 100+ IEEE 2015 and 200+ yester year IEEE project titles are available with us. Projects are based on Software Development Life-Cycle (SDLC) model.
This document provides summaries of 15 networking projects from TTA including the project code, title, description, and reference. The projects cover topics like delay analysis of opportunistic spectrum access MAC protocols, load balancing for network traffic measurement, key exchange protocols for parallel network file systems, anomaly detection in intrusion detection systems, and energy efficient group key agreement for wireless networks. The document provides contact information at the end for obtaining full project papers.
The document discusses the network layer in computer networking. It describes how the network layer is responsible for routing packets from their source to destination. It covers different routing algorithms like distance vector routing and link state routing. It also compares connectionless and connection-oriented services, as well as datagram and virtual circuit subnets. Key aspects of routing algorithms like optimality, stability, and fairness are defined.
Practical active network services within content-aware gatewaysTal Lavian Ph.D.
The Internet has seen an increase in complexity due to the introduction of new types of networking devices and services, particularly at points of discontinuity known as network edges. As the networking industry continues to add revenue generating services at network edges, there is an increasing need to provide a systematic method for dynamically introducing and providing these new services in lieu of the ad-hoc approach that is in use today. To this end we support a phased approach to "activating" the Internet and suggest that there exists an immediate need for realizing Active Networks concepts at the network edges. In this context, we present our efforts towards the development of a Content-aware Active Gateway (CAG) architecture. With the help of two practical services running on our initial prototype, built from commercial networking devices, we give a qualitative and quantitative view of the CAG potential.
Multi-Criteria Handoff Decision Algorithms In Wireless Networksiosrjce
IOSR Journal of Mobile Computing & Application (IOSR-JMCA) aims to cover innovative topics to research findings to trends analysis on Mobile Computing and Application related theories, technologies, methods, applications, and services from all engineering, business and organizational perspectives
Dual-resource TCPAQM for Processing-constrained Networksambitlick
This document summarizes a research paper that examines congestion control issues for TCP flows that require in-network processing by network elements like routers. It proposes a new active queue management (AQM) scheme called Dual-Resource Queue (DRQ) that can approximate proportional fairness for bandwidth and CPU resources without changing TCP stacks. The study finds that current TCP/AQM schemes can lose throughput and cause unfairness in networks where CPU cycles are scarce. DRQ maintains separate queues for each resource and works with classes of flows based on their known processing requirements, making it scalable without per-flow state. Simulation results show DRQ achieves fair and efficient resource allocation with low implementation costs.
Wireless Sensor Network Using Six Sigma Multi Hop RoutingIOSR Journals
Abstract: The most significant problem in the design of wireless sensor networks is to coordinate the sensors with dynamism into a wireless communication network and route sensed data to the base station. The energy efficiency is the most important key point of the network routing designing. This paper presents the efficient multi hop routing algorithm to extend the lifetime of sensor networks and focuses by employing six sigma principles to obtain the Quality of Service. To attain QoS support, we have to find either a route to assure the application requirements or offering network response to the application when the requirements cannot be met. Keywords: Wireless Sensor Networks, Multi hop routing, six sigma, QoS
Wireless Sensor Network Using Six Sigma Multi Hop RoutingIOSR Journals
The most significant problem in the design of wireless sensor networks is to coordinate the sensors
with dynamism into a wireless communication network and route sensed data to the base station. The energy
efficiency is the most important key point of the network routing designing. This paper presents the efficient
multi hop routing algorithm to extend the lifetime of sensor networks and focuses by employing six sigma
principles to obtain the Quality of Service. To attain QoS support, we have to find either a route to assure the
application requirements or offering network response to the application when the requirements cannot be met.
Intelligent network selection using fuzzy logic for 4 g wireless networksIAEME Publication
This document presents an intelligent network selection algorithm using fuzzy logic for 4G wireless networks. It proposes a fuzzy logic-based vertical handoff scheme that uses linguistic variables to estimate when a handoff is needed and to select a new network attachment point. Separate fuzzy logic controllers are used for different traffic types like conversational and streaming to improve overall system performance. A fuzzy multi-attribute decision making function is used to select a suitable network based on factors like user speed, network characteristics, user preferences, cost and quality of service requirements of applications. The goal is to enhance service mobility and continuity by choosing the most appropriate network based on an application's quality of service demands and network properties.
A Cross-Layer Based Multipath Routing Protocol To Improve QoS In Mobile Adhoc...IDES Editor
In Mobile ad hoc networks, due to the high packet loss rates
and frequent topological changes, the unbalanced transport
layer and reserved amount of traffic is carried out by the
network. In a QoS based routing metric for MANETs, it is
necessary to combine the minimum available bandwidth and
end-to-end delay along with the congestion around a link. In
this paper, a cross layer based multipath routing (CBMR)
protocol to improve QoS in mobile ad hoc networks to allot
weights to individual links, depending on the metrics link
quality, channel quality and end-to-end delay is developed. In
order to validate load balancing and interference between the
links using the same channel, the individual link weights are
integrated into a routing metric. Therefore, the weight value
helps the routing protocol to avoid the routing traffic through
the congested area hence the traffic is balanced and the
network capacity is improved. Then the proportion of traffic
to be routed to each neighbor is selected to execute routing
such that the weight of the node is a minimum. We also
propose an enhanced TCP congestion control mechanism for
wireless networks, based on a cross-layer scheme. By our
simulation results, the robustness of our protocol achieves
increased packet delivery ratio with reduced latency was
demonstrated.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes security issues and quality of service (QoS) challenges in mobile ad-hoc networks (MANETs). It begins with an introduction to MANETs and discusses their key features. It then outlines some of the main QoS challenges in MANETs, including routing, limited resources, and supporting different service levels given a changing network topology. The document also discusses several security issues for MANETs, such as vulnerabilities to attacks from both internal and external entities. It proposes a methodology for QoS support in MANETs that allocates resources to individual flows and considers aspects like identifying flows and reserving/releasing resources. In closing, it notes that QoS support for MANETs
The rapid need of wireless demands a great deal of security and reliable routing in order to keep all the data sources and equipments secure. In order to develop efficient and robust protocols, it is essential to understand the inherent characteristics of wireless networks such as connectivity, coverage and varying channel conditions. Wireless LAN introduces the concept that use can connect to any one at any place at anytime by using various mobile appliances that can be carried at any place. Now Communication is no longer limited to a one place by holding wired phones. This is the big boom to the I.T industry but it also brings a lot of opportunities and challenges for the Network Administrator who is looking after the Wireless LANs (WLAN). WLAN traffic travels over radio waves that cannot be constrained by the walls or any Simranjeet Kaur"Reliable and Efficient Routing in WLAN" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-6 , October 2017, URL: http://www.ijtsrd.com/papers/ijtsrd3585.pdf http://www.ijtsrd.com/computer-science/computer-network/3585/reliable-and-efficient-routing-in-wlan/simranjeet-kaur
Comparative analysis of the performance of various active queue management te...IJECEIAES
This paper demonstrates the robustness of active queue management techniques to varying load, link capacity and propagation delay in a wireless environment. The performances of four standard controllers used in Transmission Control Protocol/Active Queue Management (TCP/AQM) systems were compared. The active queue management controllers were the Fixed-Parameter Proportional Integral (PI), Random Early Detection (RED), Self-Tuning Regulator (STR) and the Model Predictive Control (MPC). The robustness of the congestion control algorithm of each technique was documented by simulating the varying conditions using MATLAB® and Simulink® software. From the results obtained, the MPC controller gives the best result in terms of response time and controllability in a wireless network with varying link capacity and propagation delay. Thus, the MPC controller is the best bet when adaptive algorithms are to be employed in a wireless network environment. The MPC controller can also be recommended for heterogeneous networks where the network load cannot be estimated.
Improved qo s support for wimax networks a surveyAlexander Decker
This document summarizes three approaches for improving quality of service (QoS) support in WiMAX networks:
1) A hierarchical scheduling framework that divides scheduling into three tiers to provide QoS support in point-to-point WiMAX networks.
2) A cross-layer optimization framework for resource allocation that exchanges information across protocol layers to optimize performance and maintain end-to-end QoS for users.
3) An on-demand bandwidth allocation technique that allocates bandwidth based on service flow demands to efficiently manage bandwidth utilization.
An efficient vertical handoff mechanism for future mobile networkBasil John
This document proposes a novel fuzzy logic based vertical handoff decision algorithm for heterogeneous wireless networks. It introduces a speed-adaptive system discovery scheme to improve the update rate of candidate networks based on the mobile terminal's speed. It also includes a pre-handoff decision method to quickly filter candidate networks and reduce unnecessary handoffs. The key aspects of the proposed algorithm are: 1) It uses a speed-adaptive scheme to dynamically adjust the discovery of candidate networks. 2) It employs a pre-handoff decision method to filter networks and reduce ping-pong effects. 3) It applies fuzzy logic to evaluate multiple parameters like bandwidth, RSS, and cost to select the best network. Simulations show it outperforms traditional RSS-based
Similar to Admission control and routing in multi hop wireless networks (20)
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This document lists 15 potential 2013 IEEE NS2 project titles related to wireless networks and sensor networks. It includes projects on topics like capacity of hybrid wireless mesh networks, delay-optimal broadcast in multihop wireless networks, detection of spoofing attackers, and harvesting-aware energy management for wireless sensor networks. The document provides contact information for a company called Ambitlick Solutions that offers support and deliverables for IEEE projects, including project abstracts, papers, presentations, reports, and certification.
This document lists over 40 potential 2013 IEEE Java Dotnet project titles across various domains including wireless networks, mobile computing, network security, data mining, cloud computing, parallel and distributed computing, and multimedia/image processing. The projects focus on technical topics such as wireless sensor networks, wireless mesh networks, cognitive radio networks, mobile ad hoc networks, network coding, video streaming, machine learning, data warehousing, and more. Project deliverables include an abstract, IEEE paper, presentation, report, working prototype or proof of concept, and certification. Bulk older and new projects can be provided at a low cost.
Handling selfishness in replica allocationambitlick
The document discusses techniques for handling selfish nodes in replica allocation over mobile ad hoc networks. It aims to reduce traffic overhead while maintaining high data accessibility. The techniques include a selfish node detection algorithm that considers partial selfishness and novel replica allocation methods to address issues caused by selfish nodes hoarding replicas for their own benefit instead of sharing memory space. Simulations are used to evaluate the performance of these techniques in improving data delivery rates.
Mutual Distance Bounding Protocols enable entities to determine an upper bound on their physical distance and authenticate each other. They have been actively researched due to distance-based attacks on wireless systems like RFID. While most protocols provide unilateral authentication of a tag to a reader, one was proposed to provide mutual authentication with a lower false acceptance rate. However, this analysis is shown to overestimate security, as a new attack achieves a higher false acceptance rate. A method is also introduced to modify existing unilateral authentication protocols into mutual authentication protocols.
Moderated group authoring system for campus wide workgroupsambitlick
This paper describes a distributed authoring system for campus workgroups that allows group members to modify any document type using their own devices. Each member maintains an updatable copy of shared content, and read-only copies are distributed asynchronously based on wireless availability. Group members manually reconcile updates through moderation, merging changes from others into their copy. Over time, successive moderation converges all copies into a single version. An evaluation found the asynchronous update model effective and the moderation process intuitive for students.
Efficient spread spectrum communication without pre shared secretsambitlick
This document proposes a new mechanism called Time Reversed Message Extraction and Key Scheduling (TREKS) that allows for efficient spread spectrum communication without pre-shared secrets. TREKS is four orders of magnitude faster than previous solutions to this problem. It enables long-term spread spectrum communication with optimal energy costs, minimal storage overhead, and a computation cost at most twice traditional spread spectrum. The approach was evaluated through simulations and experiments sustaining 1Mbps communication spread over 100 Megachips per second using modest hardware.
Adaptive weight factor estimation from user review 1ambitlick
This document proposes a novel technique called Adjacent Pair Priorities (APP) to estimate weight factors for quality of service parameters in vertical handoff decision algorithms. The APP technique allows users to set relative priority levels for adjacent pairs of QoS parameters in descending order using an exponential mapping. This adaptive approach controls the width of the weight distribution to provide flexibility for users. The document outlines the system requirements, block diagram, modules and references several research papers on vertical handoff decision schemes and network selection algorithms.
The document proposes an Integrated Institutional Portal that allows all colleges and institutions within a university or district to share information. [1] The portal would allow students and staff from different colleges to discuss and request information from one another through blogs, forums and by publishing notices. [2] Currently, each college maintains separate portals without a common forum for communication. [3] The proposed centralized portal managed by a super administrator would make all college information like results, events and departments accessible to benefit students and staff across institutions.
This document describes an Embassy Administration portal that aims to centralize and automate manual processes at a college. [1] The portal allows separate login access for staff, parents, students and other members of the college. [2] It displays student results, attendance, and performance for parents to view as well as enables communication between parents and faculty. [3] The system conducts model and unit examinations.
The document proposes a customer relationship management system (CRMS) to help space marketing executives, managers, and management interact and share information online. The existing CRMS is manual and DOS-based, which has disadvantages like a distributed database, obsolete technology, and low efficiency. The proposed system is a web-based online CRMS designed for the space marketing department. It allows monitoring executive calls, tracking performance, and sharing information among departments to improve customer relationships and business operations. The system has modules for corporate administration, regional management, center management, and executives to organize work and monitor progress at different levels.
Mutual Distance Bounding Protocols enable entities to determine an upper bound on their physical distance and authenticate each other. They have been actively researched due to distance-based attacks on wireless systems like RFID. While most protocols provide unilateral authentication of a tag to a reader, one was proposed to provide mutual authentication with a lower false acceptance rate. However, this analysis is shown to overestimate security, as a new attack achieves a higher false acceptance rate. A method is also introduced to modify existing unilateral authentication protocols into mutual authentication protocols.
Moderated group authoring system for campus wide workgroupsambitlick
This paper describes a distributed authoring system for campus workgroups that allows group members to modify any document type using their own devices. Each member maintains an updatable copy of shared content, and read-only copies are distributed based on wireless availability. Group members manually reconcile updates through moderation, merging changes from others into their copy. Over time, successive moderations converge the multiple versions into a single version. An evaluation found the asynchronous update propagation and moderation process intuitive for students.
Efficient spread spectrum communication without pre shared secretsambitlick
This document proposes a new mechanism called Time Reversed Message Extraction and Key Scheduling (TREKS) that allows for efficient spread spectrum communication without pre-shared secrets. TREKS is four orders of magnitude faster than previous solutions to this problem and enables long-term spread spectrum communication without establishing keys. It was evaluated through simulation and on a testbed and can sustain 1Mbps communication spread over a 100 Megachips bandwidth in real-time, with provably optimal energy cost and minimal storage overhead.
Comments on “mabs multicast authentication based on batch signature”ambitlick
This document summarizes and critiques the MABS-DSA protocol proposed by Zhou et al. for multicast authentication using batch verification. While MABS-DSA was intended to increase efficiency and security over other implementations, the author finds through reexamination of the arithmetic that the algorithm is actually incorrect and batch signature verification would fail almost always, even when individual packets were properly signed by an honest sender. The key issue is a flaw in protocol correctness rather than the intended security improvements.
Energy-Efficient Protocol for Deterministic and Probabilistic Coverage In Sen...ambitlick
The document proposes a new probabilistic coverage protocol (PCP) for sensor networks that can employ different sensing models. PCP aims to address the costly task of designing and testing different coverage protocols for each sensing model. It works with common disk sensing models as well as probabilistic sensing models with minimal changes. Simulation results show that PCP outperforms other deterministic and probabilistic protocols in terms of number of activated sensors, total energy consumed, and network lifetime while being robust against failures and inaccuracies.
Energy efficient protocol for deterministicambitlick
The document describes a new probabilistic coverage protocol (PCP) for sensor networks that can employ both deterministic and probabilistic sensing models. PCP works by activating sensors to construct an approximate triangular lattice over the monitored area. It is more energy efficient than previous protocols by reducing the number of activated sensors needed for coverage. Simulation results show PCP outperforms other protocols in terms of energy consumption and network lifetime while maintaining coverage under various conditions.
Estimating Parameters of Multiple Heterogeneous Target Objects Using Composit...ambitlick
This article proposes a method for estimating parameters of multiple heterogeneous target objects (objects with different sizes and shapes) using networked binary sensors. The sensors are simple and only report detections, but no individual sensor location is known. The method introduces "composite sensor nodes" containing multiple sensors in a fixed arrangement. This provides relative location information to help distinguish individual target objects. As an example, the article considers a composite node with two sensors on a line segment. Measures from these nodes can identify target shapes and estimate object parameters like radius and side lengths. Numerical tests demonstrate networked composite sensors can estimate parameters of multiple target objects.
A Privacy-Preserving Location Monitoring System for Wireless Sensor Networksambitlick
This document proposes a privacy-preserving location monitoring system for wireless sensor networks. The system uses two in-network location anonymization algorithms:
1) A resource-aware algorithm that aims to minimize communication and computational costs by having each sensor node find a cloaked area containing at least k persons and report only aggregate location information.
2) A quality-aware algorithm that aims to maximize accuracy by iteratively refining cloaked areas reported by the resource-aware algorithm to minimize their size, while still maintaining k-anonymity.
The system collects anonymous aggregate location information to build a spatial histogram for estimating person distributions and answering queries about aggregate locations, while preserving individuals' location privacy against potential attacks from untrusted
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...EduSkills OECD
Andreas Schleicher, Director of Education and Skills at the OECD presents at the launch of PISA 2022 Volume III - Creative Minds, Creative Schools on 18 June 2024.
How to Manage Reception Report in Odoo 17Celine George
A business may deal with both sales and purchases occasionally. They buy things from vendors and then sell them to their customers. Such dealings can be confusing at times. Because multiple clients may inquire about the same product at the same time, after purchasing those products, customers must be assigned to them. Odoo has a tool called Reception Report that can be used to complete this assignment. By enabling this, a reception report comes automatically after confirming a receipt, from which we can assign products to orders.
A Visual Guide to 1 Samuel | A Tale of Two HeartsSteve Thomason
These slides walk through the story of 1 Samuel. Samuel is the last judge of Israel. The people reject God and want a king. Saul is anointed as the first king, but he is not a good king. David, the shepherd boy is anointed and Saul is envious of him. David shows honor while Saul continues to self destruct.
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐍𝐚𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐒𝐜𝐨𝐩𝐞 𝐨𝐟 𝐚𝐧 𝐄𝐧𝐭𝐫𝐞𝐩𝐫𝐞𝐧𝐞𝐮𝐫:
-Define entrepreneurship, distinguishing it from general business activities by emphasizing its focus on innovation, risk-taking, and value creation. Students will describe the characteristics and traits of successful entrepreneurs, including their roles and responsibilities, and discuss the broader economic and social impacts of entrepreneurial activities on both local and global scales.
CapTechTalks Webinar Slides June 2024 Donovan Wright.pptxCapitolTechU
Slides from a Capitol Technology University webinar held June 20, 2024. The webinar featured Dr. Donovan Wright, presenting on the Department of Defense Digital Transformation.
Temple of Asclepius in Thrace. Excavation resultsKrassimira Luka
The temple and the sanctuary around were dedicated to Asklepios Zmidrenus. This name has been known since 1875 when an inscription dedicated to him was discovered in Rome. The inscription is dated in 227 AD and was left by soldiers originating from the city of Philippopolis (modern Plovdiv).
2. 47th IEEE CDC, Cancun, Mexico, Dec. 9-11, 2008 WeA14.6
in [14] takes into account contention under the implicit mance of the best possible off-line algorithm for any request
assumption that the interference range of a node is equal sequence, and for a given performance measure.
to its transmission range.
IV. N ETWORK M ODEL
In [15] the use of packet scheduling to guarantee QoS
in multi-hop networks is studied. Some proposals rely on a The network is composed of a set N of N nodes, where
central algorithm to do admission control [16], [17], while node n ∈ N has capacity u(n). Without loss of generality,
others have proposed strategies assuming a TDMA [18]– in the rest of the paper we will assume that
[20] or CDMA over TDMA [21], [22] layer. The work in u(n) = 1 f or all n ∈ N . (1)
[23] explores how to provide implicit synchronization in
CSMA/CA networks to achieve TDM-like performance. The input to the algorithm is a set of flow requests F =
A solution for multichannel multi-hop networks has been {f1 , f2 , . . . , fk }, where flow j is specified by
proposed in [3] under the assumption that requests can be fj = sj , dj , rj (t), tS , tF , ρj .
j j
split; if requests are non-splittable a heuristic is introduced
where requests are routed in the least-congested, minimum- Nodes sj and dj are the source and destination respec-
hop path. To the best of our knowledge, our algorithm is tively of an unidirectional flow.1 Flow j requests a bandwidth
the first provably optimal for general networks that allows a rj (t) at time t, where we define rj (t) = 0 for t ∈ [ tS , tF ).
/ j j
distributed implementation. Thus, tS and tF are the start and finish times of flow j.
j j
For simplicity, and without loss of generality, we assume
III. C OMPETITIVE A NALYSIS that these times are integers. A profit of ρj is accrued if
The concept of competitive ratio was first introduced by the flow is admitted into the network. Given fj ∈ F, our
[7] and further developed by [8]–[10]. Here we will present algorithm will output a path Pj assigned for the request,
a brief overview of this theory. with the understanding that Pj = ∅ if it is rejected.
In many situations we must develop efficient algorithms Let λn (t) be the relative load on node n at time t, which is
which have to deal with a sequence of tasks one at a time, a function of the flows currently admitted by our algorithm.
where the efficiency of current decisions is affected by future Flow j’s holding time is denoted by Tj = tF − tS , where
j j
tasks. One classical example is the well-known ski rental we define the maximum holding time
problem, where a ski enthusiast plans on skiing for several T = max {Tj } .
days while weather permits. Our ski fan is faced with two j
options every day, either rent skis for the day at a price of r As mentioned in Section I, the wireless channel is a shared
or buy them at cost b. If we knew that the total number of resource and contention among transmissions from different
days to ski is d, then the optimal decision algorithm would nodes implies that when admitting a flow we must take
be to buy skis if b < rd. Since we have no knowledge of into account the impact of a flow in the network. To better
the future, we have to develop an algorithm that has to make understand this, let us use the simple scenario of Fig. 1.
decisions on a day by day basis and still performs well. To Our linear network of 5 nodes is such that any node can
do that we introduce the concepts of on-line and off-line only communicate with its nearest neighbors, and where the
algorithm. interference range for each node is illustrated as a concentric
Definition 1: An on-line algorithm is an algorithm that circle around each node. There is a flow from node B to node
has to deal with a sequence of requests one at a time, without D that requires a rate of r. Due to the exposed terminal
having the entire sequence available from the beginning. problem, node A cannot transmit while B is transmitting, so
Definition 2: An off-line algorithm is an algorithm that node A’s available capacity is
has complete a priori knowledge of the entire request se- (1)
quence, including future requests, before it outputs its answer u(A) − r = 1 − r,
to solve the problem at hand. (1)
One way to measure the performance of an on-line algo- where = means that the equality follows from equation
rithm is by comparing it against the best possible off-line (1). We use this notation throughout the paper.
algorithm when both have to deal with the same set of re- Thus, when scheduling this flow, we must reserve a rate
quests. The competitive ratio then measures the performance of r in node A for it to remain idle. Similarly, node B must
loss of an on-line algorithm caused by imperfect decisions transmit at a rate r and must remain silent while C is relaying
when compared against an off-line algorithm that can make a packet for this flow, which implies a resource reservation of
perfect decisions since it has complete knowledge of the rate 2r at B. Because of the hidden terminal problem, node
request sequence. E must remain idle while D is receiving a packet, so we
Definition 3: The competitive ratio of an on-line algo- have to reserve a rate of r at this node. Following the lines
rithm is the supremum over all possible request sequences of this argument, it can be checked that we must reserve a
of the performance ratio between the best possible off-line rate of 2r at nodes C and D in order to be able to schedule
algorithm and the on-line algorithm. this flow. These values are shown above each node in Fig. 1.
This means that if an on-line algorithm has a competitive 1 For the case of bidirectional flows, we simply need to split the request
ratio of c then its performance is at least 1/c the perfor- in two unidirectional flows that need to be accepted/rejected simultaneously.
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3. 47th IEEE CDC, Cancun, Mexico, Dec. 9-11, 2008 WeA14.6
Define QT (Pj ) to be the total impact of flow j (routed on
path Pj ) on the network. Thus,
r 2r 2r 2r r
A B
r
C
r
D E QT (Pj ) = Qn (Pj ). (3)
n∈N
Additionally, define QT and Q as follows:
QT = max {QT (Pj )}
j
Fig. 1. Example of resource contention among nodes.
Q = max {Qn (Pj )} . (4)
j,n
We normalize the cost such that for any flow fj ∈ F and
any time such that rj (t) > 0
3r
A
r
B
r
C
r
D
r
E
ρj
t0 t1 t2 t0 1≤ ≤F (5)
QT rj (t)Tj
for F large enough. For example, if we have that rj (t) = rj
for t ∈ [ tS , tF ) and the profit is defined to be proportional
j j
to the bandwidth-holding time product, i.e. throughput, then
Fig. 2. Example of resource contention among nodes under the assumption we can make ρj = QT rj Tj and let F = 1.
of perfect packet transmission scheduling.
Finally, we assume that rate requirements are small enough
compared to node capacity. Specifically,
This example gives the intuition for the following defini- min {u(n)} (1) 1
n
tion. Let Qn (Pj ) be the impact of flow j on node n if path rj (t) ≤ = (6)
Q log µ Q log µ
Pj is used. Formally,
where
Qn (Pj ) = I{n′ ∈Pj } I{n′ =dj } + I{n′ ∈HTn (Pj )} , µ = 2 (1 + QT T F ) , (7)
n′ ∈Nn
(2) and log means log2 .
where Nn is the set of nodes within interference range of Later we will prove in Section VI that (6) is a necessary
node n (including node n itself), HTn (Pj ) is the set of nodes condition for any algorithm to achieve logarithmic competi-
in Nn that need to receive a transmission for flow j that node tive ratio.
n cannot sense –that is, hidden terminal transmissions–, and
I{} is the indicator function defined as V. A LGORITHM
1 if statement = T RU E The main goal is to develop an admission control and
I{statement} = . routing algorithm that enforces capacity constraints, that is
0 if statement = F ALSE
As an example, in Fig. 1 we have that for path P = λn (t) ≤ 1 f or all t and n ∈ N . (8)
{B, C, D}, QA (P ) = 1, QC (P ) = 2, and QE (P ) = 1.
It must be noted that this definition is only an upper bound and maximizes profit:
on the actual impact of a flow in a given node, and can ρj .
only be improved by assuming a specific, possibly ideal, j:Pj =∅
transmission scheduling algorithm. To illustrate this, in Fig. 2
we assume that there is a flow from node A to E and that Furthermore, the algorithm cannot rely on knowledge
we schedule node transmissions such that nodes A and D about future flows to make admission decisions and once
simultaneously transmit at time t0 , node B transmits at t1 , a flow has been admitted no rerouting is allowed and no
and C is scheduled to transmit at time t2 . In this case, the flow is to be interrupted.
impact of the flow on node C is 3 instead of 4, as estimated To do that, it will sequentially analyze flows from F and
using Qn (Pj ). 2 decide whether to admit them or not.
Finding methods for estimating Qn (Pj ) has been an active
A. Definition
topic of research. For related work, the reader is referred to
[1], [11], [14]. The decision rule for admitting flow fj ∈ F and assigning
a path is:
2 It must be highlighted that for the ease of explanation we have assumed
that due to the exposed terminal problem a node cannot transmit while 1) For all t ∈ [ tS , tF ), n ∈ N let the cost of node n at
j j
another in its interference neighborhood is transmitting. If a certain physical time t be
layer technology does not preclude such transmissions, the definition of
(1)
Qn (Pj ) should be modified accordingly and the results in the rest of the cn (t) = u(n) µλn (t) − 1 = µλn (t) − 1. (9)
paper still apply with minor modifications.
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4. 47th IEEE CDC, Cancun, Mexico, Dec. 9-11, 2008 WeA14.6
2) If there exists a path Pj from node sj to dj such that Lemma 3: Let AOA be the set of indices of accepted
rj (t) requests by the optimal off-line algorithm but rejected by
Qn (Pj ) cn (t) ≤ ρj (10) the ACR algorithm. Let m = max AOA . Then
u(n)
n∈N tS ≤t<tF
j j
ρj ≤ cn (t, m).
then route fj using Pj and set j∈AOA n t
rj (t) (Due to lack of space, the proofs of the Lemmas will be
λn (t) ← λn (t) + Qn (Pj ) (11) presented in a longer version of the paper.)
u(n)
Now, we are ready to prove the following:
for all n ∈ N , tS ≤ t < tF .
j j Theorem 1: The ACR algorithm enforces capacity con-
Note that straints and achieves a competitive ratio of O(log(QT T F )).
rj (t)
Qn (Pj ) (Due to lack of space, the proof of the Theorem will be
u(n) presented in a longer version of the paper.)
is the fraction of node n’s capacity that would be used by Remark: It is important to highlight that for the lemmas
flow j. Thus, the algorithm compares the link cost weighted and theorem of this section we only assume that Qn (Pj ) ≥ 1,
by this quantity to the profit and admits the call if the cost but the precise definition given in (2), which depends on the
is less than or equal to the profit. assumptions about the physical layer, is only used in the
following sections.
B. Performance Guarantees
Now that the wireless model and the algorithm are defined, VI. O PTIMALITY
we can use the techniques developed for wireline networks in
Now we will prove that no other algorithm can achieve
[4]. We will first proceed to prove that our algorithm enforces
a better competitive ratio than the ACR algorithm in an
capacity constraints, which from now on we will call the
asymptotic sense and that assumption (6) is a necessary
Admission Control and Routing (ACR) algorithm. In other
condition to achieve a good competitive ratio. To do that, we
words, if the ACR algorithm decides to admit a flow request,
will first show that even if flow rates are small enough, the
then there is sufficient available capacity.
profit of the optimal off-line algorithm will exceed the profit
Lemma 1: Capacity constraints are enforced by the ACR
of any on-line algorithm that is oblivious to the future by a
algorithm. That is,
factor of Ω(log(QT T F )). Finally, we will present stronger
λn (t) ≤ 1 f or all t and n ∈ N . bounds for the case when flow rates are allowed to be
(Due to lack of space, the proof of the Lemma will be relatively large, showing that the competitive ratio degrades
presented in a longer version of the paper.) when we allow large rates.
The proof of the competitiveness of the ACR algorithm The techniques used here are again similar to the ones
is done in two steps. In Lemma 2 we prove that the total developed for wireline networks in [4], but rely on the unique
network cost is at most within a factor of the accrued gain, characteristics of wireless networks, specially to find worst
and in Lemma 3 we prove that the profit due to requests case scenarios in Lemmas 4 and 7.
rejected by the ACR algorithm and accepted by the optimal Lemma 4: Any on-line algorithm has a competitive ratio
off-line algorithm is bounded by the total network cost. These of Ω(log QT ).
two results then imply that the profit of the ACR algorithm is Lemma 5: Any on-line algorithm has a competitive ratio
within a factor of the profit accrued by the off-line algorithm, of Ω(log T ).
and hence the competitive ratio is bounded. Lemma 6: Any on-line algorithm has a competitive ratio
For the following two lemmas, define λn (t, j) to be the of Ω(log F ).
relative load on node n at time t when only the first j − 1 (Due to lack of space, the proofs of the Lemmas will be
flow requests have been either admitted or rejected. That is, presented in a longer version of the paper.)
(11) ri (t) (1) Hence, we have just proved the following.
λn (t, j) = Qn (Pi ) = Qn (Pi )ri (t), (12) Theorem 2: Any on-line algorithm has a competitive ratio
i<j
u(n) i<j of Ω(log(QT T F )).
with the understanding that Pi = ∅ if fi ∈ {f1 , f2 , . . . , fj−1 } Proof: It is a direct consequence of Lemmas 4, 5 and
is rejected. 6.
Similarly, and from (9), let cn (t, j) be defined as For the proof of Theorem 2 we assume that (6) holds.
We will now proceed to prove that if this bound does
cn (t, j) = µλn (t,j) − 1. (13) not hold then no on-line algorithm can achieve logarithmic
Lemma 2: Let AACR be the set of indices of accepted competitive ratio.
1
flows by the ACR algorithm and k be the index of the last Lemma 7: If we allow requests of rate up to 4k then the
1
flow request in F. Then, competitive ratio is Ω(QT ) for any positive integer k.
4k
1
Lemma 8: If we allow requests of rate up to k then the
2 log µ ρj ≥ cn (t, k + 1). 1
j∈AACR t n
competitive ratio is Ω(T k ) for any positive integer k.
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5. 47th IEEE CDC, Cancun, Mexico, Dec. 9-11, 2008 WeA14.6
1
Lemma 9: If we allow requests of rate up to k then the is the cost of using edge e for routing flow fj . It must be
1
competitive ratio is Ω(F k ) for any positive integer k. noted that (15) decouples the cost of an edge from the path
(Due to lack of space, the proofs of the Lemmas will be cost, allowing a distributed implementation of a shortest path
presented in a longer version of the paper.) algorithm to find the optimal route. Furthermore, for every
Therefore, we have the following theorem. edge e ∈ E we only need to gather information from the
1 local set Ns(e) Nd(e) to find Ce (j). It must be noted that
Theorem 3: If we allow requests of rate up to 4k then the
1 1
competitive ratio is Ω(QT + T 4k + F 4k ) for any positive
4k
1 for any admission algorithm this is the minimal information
integer k. that must be gathered and updated in order to check resource
Proof: This follows from Lemmas 7, 8 and 9. availability, since the transmission in this link will affect the
Thus, in order to achieve logarithmic competitive ratio we load of all nodes in the set Ns(e) Nd(e) .
need to let k be greater than
VIII. C ONCLUSIONS
log(QT T F )
.
4 log(log(QT T F )) We have developed a model for QoS routing in multi-hop
VII. D ISTRIBUTED I MPLEMENTATION wireless networks which allows us to derive an algorithm
with provable performance guarantees using competitive
In its present form, checking
analysis. We proved that our algorithm has a performance
rj (t) close to that of an omniscient off-line algorithm that has
Qn (Pj ) cn (t) ≤ ρj
u(n) complete a priori knowledge of the entire sequence of flow
n∈N tS ≤t<tF
j j
arrivals (including the future) and their bandwidth requests.
in the ACR algorithm requires first to specify a path Pj Our algorithm makes no statistical assumptions on the flow
from source to destination and then its associated cost can be arrival pattern or other parameters of the arriving requests.
calculated. Since we ideally would like to use the minimum We also proved that no other algorithm performs better
cost path, this means that it would be required to first identify in an asymptotic sense of the competitive ratio. Finally,
all possible paths and then find the cost for each one of them. we showed that our algorithm is amenable to a distributed
The contribution of this section is to show how this can implementation.
be implemented using a distributed algorithm that can find
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