Active topology measurements on the African Internet have showed that over 75% of the intraAfrica
traffic destined for Africa's National Research and Education Net- works (NRENs) uses
intercontinental links, resulting in high latencies and data transmission costs. The goal of this
work is to investigate how latency-based path selection using Locator/Identifier Separation
Protocol (LISP) and Software Defined Networking (SDN) in NRENs can be used to reduce
inter-NREN latencies. We present aspects of an experimental prototype implementation for realtime
topology probes to discover lower-latency remote gateways and dynamic configuration of
end-to-end Internet paths. Simulation results indicate that ranking remote ingress gateways, and
dynamic configuration of end-to-end paths between gateways can lower the average latency for
inter-NREN traffic exchange.
Vehicular Ad-hoc Network (VANET) is a multi-hop
wireless ad-hoc network created by using mobile vehicles to
transmit safety message for vehicle drivers. Since vehicles are
mobile so they change their location frequently, therefore; robust
data delivery is a challenging task in the VANET. Due to
frequently network topology change characteristic, selection of a
routing protocol in VANET is challenging task. In this paper
performance of location-based routing protocols Directional-
Location Aided Routing (D-LAR), Location-Aided Routing (LAR)
and DIrectional Routing (DIR) are analyzed to decide best
routing protocol for VANET. LAR protocol limits the route
discovery area in the forward direction using GPS technology
and DIR protocol uses direction information from the baseline
drawn from the source and destination node. The D-LAR
protocol uses concepts of the both LAR and DIR protocols. Using
greedy forwarding approach D-LAR protocol selects next hop
forwarding node in the forward direction of the communication
range. Feasibility of D-LAR protocol has justified through
simulation in NS2 using routing metrics such as node distribution
at the border area of the communication range R, expected one
hop distance ࡱ൫ࡺ(, ࢘)൯ , expected hop counts E(H) between
source and destination node, expected delay E(delay), routing
overhead and packet loss. Through simulation work, it has shown
D-LAR protocol performs better as compared to LAR and DIR
protocol.
A new approach in position-based routing Protocol using learning automata for...ijasa
This document summarizes a research paper that proposes a new position-based routing protocol called PBLA (Position-Based routing protocol using Learning Automata) for vehicular ad hoc networks (VANETs) in urban scenarios. PBLA uses learning automata and traffic information to initially find the best and shortest path to a mobile destination. It has two phases: a learning phase where vehicles learn traffic patterns on streets to assign costs; and a routing phase where the shortest path is found using Dijkstra's algorithm and packets are forwarded between intersections greedily. The performance of PBLA is evaluated against GPSR and GPCR protocols in a simulated urban road network, showing it can efficiently route packets in high mobility V
POSITION BASED ADAPTIVE ROUTING FOR VANETSIJCNCJournal
Routing plays a very significant role in multi hop data dissemination in Vehicular Ad-Hoc Networks
(VANETs). Wehave proposed a Position based Adaptive Routing (PAR) protocol which is scalable for different
network densities in VANETs. This scheme uses Preferred Group Broadcasting (PGB) for route discovery.
In this mode, after broadcasting the request for route discovery the source node starts listening to
the channel. If the packet is not further rebroadcasted by any neighbor in a set timeout, then it repeats the
broadcast. This process is repeated until the request reaches the destination. The destination keeps on accumulating
route requests coming from different paths until predefined time. It then chooses the least cost
path as route reply. It uses the set of traversed anchors for sending the unicast route reply to the source
node. PAR uses Advance Greedy Forwarding (AGF) for data forwarding and greedily forwards the data
packet to the next anchor towards destination node. It switches to carry and forward mode once it finds
partitions in the network. The intermediate vehicle buffers the packet until next junction and switches back
to position based scheme and greedily forwards to next node in range which is closest to the destination. To
have an end to end connectedpath, it uses guards to guard anchors tied to different junction and geographical
locations in the network. The algorithm is scalable and exploits advantages of existing techniques
already developed for specific scenarios in VANET. Results show that the service ratio and packet
delay of PAR are higher than its counterparts.
An Optimal Route Discovery using Biogeography based Optimization for Vehicula...StevePrice20
Vehicular ad hoc network (VANET) is a subdivision of the mobile ad hoc networks which uses the moving vehicles as mobile nodes to form the mobile network. In conventional vehicular communications, the restricted radio frequency bandwidth affects the network performances. Therefore, Visible Light Communication (VLC) is integrated with the growing vehicular ad hoc network to obtain high data rate and less energy consumption during the communication. In this paper, vehicular communication is integrated with visible light communication to avoid the issues caused by the restricted radio frequency bandwidth. Moreover, the Routing using Biogeography Based Optimization (RBBO) is proposed to develop an optimal route between the source vehicles to the destination. This research performs two different communications such as vehicle to vehicle and vehicle to the infrastructure. The performance of the RBBOVLC-VANET method is analyzed by means of throughput, packet delivery ratio, delay and routing overhead as well as these performances are compared with the existing method namely ant colony optimization based routing protocol. The throughput of the routing using the biogeography based optimization method is 589.763 kbps for 500 nodes which is high when compared to the existing method.
Multi-Agent System for Secured and Reliable Routing in VANETRSIS International
In VANET, the emphasis is given on the exchange of
traffic information and road conditions between the vehicles and
thereby preventing the accidents. Distinctive characteristics of
VANET like restricted topology, unpredictable mobility, vehicle
density, varying channel capacity, etc. make VANET
environment exciting for developing efficient routing protocols.
Owing to the dynamic topology in VANET, the routes are
unstable and unreliable for exchange of information among the
vehicles. To enrich the performance and throughput of the
VANETs, the links between nodes must be reliable and stable. In
order to tackle the relaiblity and stability of information
communication this work proposes ‘Multi-agent system for
Secured and Reliable Routing (MSRR) in VANET. The
performance of the proposed scheme is tested in terms of packet
delivery ratio, route reliability, route discovery time and delay.
Design and analysis of routing protocol for cognitive radio ad hoc networks i...IJECEIAES
Multi-hop routing protocol in cognitive radio mobile ad hoc networks (CRMANETs) is a critical issue. Furthermore, the routing metric used in multi-hop CRMANETs should reflect the bands availability, the links quality, the PU activities and quality of service (QoS) requirements of SUs. For the best of our knowledge, many of researchers investigated the performance of the different routing protocols in a homogeneous environment only. In this paper, we propose a heterogeneous cognitive radio routing protocol (HCR) operates in heterogeneous environment (i.e. the route from source to destination utilize the licensed and unlicensed spectrum bands). The proposed routing protocol is carefully developed to make a tradeoff between the channel diversity of the routing path along with the CRMANETs throughput. Using simulations, we discuss the performance of the proposed HCR routing protocol and compare it with the AODV routing protocol using a discrete-event simulation which we developed using JAVA platform.
Improved AODV based on Load and Delay for Route Discovery in MANETIOSR Journals
This document proposes an improved AODV routing protocol for mobile ad hoc networks (MANETs) that considers both node load and routing delay when selecting routes. It calculates a "route weight" based on the average load and delay of the nodes along each potential path from source to destination. The path with the lowest route weight is then selected for routing to help balance traffic loads across the network and minimize delays. Simulation results showed this approach can dynamically balance traffic allocation between paths and optimize resource utilization in the MANET.
ADAPTIVE HANDOVER HYSTERESIS AND CALL ADMISSION CONTROL FOR MOBILE RELAY NODESIJCNCJournal
The aim of equipping a wireless network with a mobile relay node is to support broadband wireless communications for vehicular users and their devices. The high mobility of vehicular users, possibly at a very high velocity in the area in which two cells overlap, could cause the network to suffer from a reduced handover success rate and, hence, increased radio link failure. The combined impact of these problems is service interruptions to vehicular users. Thus, the handover schemes are crucial in solving these problems. In this work, we first present the adaptive handover hysteresis scheme for the wireless network with mobile relay nodes in the high-speed train scenario. Specifically, our proposed adaptive hysteresis scheme is based on the velocity of the train. Second, the handover call dropping probability is reduced by introducing a modified call admission control scheme to support radio resource reservation for handover calls that prioritizes handover calls of mobile relay over the other calls. The proposed solution in which adaptive parameter is combined with call admission control is evaluated by system level simulation. Our simulation results illustrate an increased handover success rate and reduced radio link failures.
Vehicular Ad-hoc Network (VANET) is a multi-hop
wireless ad-hoc network created by using mobile vehicles to
transmit safety message for vehicle drivers. Since vehicles are
mobile so they change their location frequently, therefore; robust
data delivery is a challenging task in the VANET. Due to
frequently network topology change characteristic, selection of a
routing protocol in VANET is challenging task. In this paper
performance of location-based routing protocols Directional-
Location Aided Routing (D-LAR), Location-Aided Routing (LAR)
and DIrectional Routing (DIR) are analyzed to decide best
routing protocol for VANET. LAR protocol limits the route
discovery area in the forward direction using GPS technology
and DIR protocol uses direction information from the baseline
drawn from the source and destination node. The D-LAR
protocol uses concepts of the both LAR and DIR protocols. Using
greedy forwarding approach D-LAR protocol selects next hop
forwarding node in the forward direction of the communication
range. Feasibility of D-LAR protocol has justified through
simulation in NS2 using routing metrics such as node distribution
at the border area of the communication range R, expected one
hop distance ࡱ൫ࡺ(, ࢘)൯ , expected hop counts E(H) between
source and destination node, expected delay E(delay), routing
overhead and packet loss. Through simulation work, it has shown
D-LAR protocol performs better as compared to LAR and DIR
protocol.
A new approach in position-based routing Protocol using learning automata for...ijasa
This document summarizes a research paper that proposes a new position-based routing protocol called PBLA (Position-Based routing protocol using Learning Automata) for vehicular ad hoc networks (VANETs) in urban scenarios. PBLA uses learning automata and traffic information to initially find the best and shortest path to a mobile destination. It has two phases: a learning phase where vehicles learn traffic patterns on streets to assign costs; and a routing phase where the shortest path is found using Dijkstra's algorithm and packets are forwarded between intersections greedily. The performance of PBLA is evaluated against GPSR and GPCR protocols in a simulated urban road network, showing it can efficiently route packets in high mobility V
POSITION BASED ADAPTIVE ROUTING FOR VANETSIJCNCJournal
Routing plays a very significant role in multi hop data dissemination in Vehicular Ad-Hoc Networks
(VANETs). Wehave proposed a Position based Adaptive Routing (PAR) protocol which is scalable for different
network densities in VANETs. This scheme uses Preferred Group Broadcasting (PGB) for route discovery.
In this mode, after broadcasting the request for route discovery the source node starts listening to
the channel. If the packet is not further rebroadcasted by any neighbor in a set timeout, then it repeats the
broadcast. This process is repeated until the request reaches the destination. The destination keeps on accumulating
route requests coming from different paths until predefined time. It then chooses the least cost
path as route reply. It uses the set of traversed anchors for sending the unicast route reply to the source
node. PAR uses Advance Greedy Forwarding (AGF) for data forwarding and greedily forwards the data
packet to the next anchor towards destination node. It switches to carry and forward mode once it finds
partitions in the network. The intermediate vehicle buffers the packet until next junction and switches back
to position based scheme and greedily forwards to next node in range which is closest to the destination. To
have an end to end connectedpath, it uses guards to guard anchors tied to different junction and geographical
locations in the network. The algorithm is scalable and exploits advantages of existing techniques
already developed for specific scenarios in VANET. Results show that the service ratio and packet
delay of PAR are higher than its counterparts.
An Optimal Route Discovery using Biogeography based Optimization for Vehicula...StevePrice20
Vehicular ad hoc network (VANET) is a subdivision of the mobile ad hoc networks which uses the moving vehicles as mobile nodes to form the mobile network. In conventional vehicular communications, the restricted radio frequency bandwidth affects the network performances. Therefore, Visible Light Communication (VLC) is integrated with the growing vehicular ad hoc network to obtain high data rate and less energy consumption during the communication. In this paper, vehicular communication is integrated with visible light communication to avoid the issues caused by the restricted radio frequency bandwidth. Moreover, the Routing using Biogeography Based Optimization (RBBO) is proposed to develop an optimal route between the source vehicles to the destination. This research performs two different communications such as vehicle to vehicle and vehicle to the infrastructure. The performance of the RBBOVLC-VANET method is analyzed by means of throughput, packet delivery ratio, delay and routing overhead as well as these performances are compared with the existing method namely ant colony optimization based routing protocol. The throughput of the routing using the biogeography based optimization method is 589.763 kbps for 500 nodes which is high when compared to the existing method.
Multi-Agent System for Secured and Reliable Routing in VANETRSIS International
In VANET, the emphasis is given on the exchange of
traffic information and road conditions between the vehicles and
thereby preventing the accidents. Distinctive characteristics of
VANET like restricted topology, unpredictable mobility, vehicle
density, varying channel capacity, etc. make VANET
environment exciting for developing efficient routing protocols.
Owing to the dynamic topology in VANET, the routes are
unstable and unreliable for exchange of information among the
vehicles. To enrich the performance and throughput of the
VANETs, the links between nodes must be reliable and stable. In
order to tackle the relaiblity and stability of information
communication this work proposes ‘Multi-agent system for
Secured and Reliable Routing (MSRR) in VANET. The
performance of the proposed scheme is tested in terms of packet
delivery ratio, route reliability, route discovery time and delay.
Design and analysis of routing protocol for cognitive radio ad hoc networks i...IJECEIAES
Multi-hop routing protocol in cognitive radio mobile ad hoc networks (CRMANETs) is a critical issue. Furthermore, the routing metric used in multi-hop CRMANETs should reflect the bands availability, the links quality, the PU activities and quality of service (QoS) requirements of SUs. For the best of our knowledge, many of researchers investigated the performance of the different routing protocols in a homogeneous environment only. In this paper, we propose a heterogeneous cognitive radio routing protocol (HCR) operates in heterogeneous environment (i.e. the route from source to destination utilize the licensed and unlicensed spectrum bands). The proposed routing protocol is carefully developed to make a tradeoff between the channel diversity of the routing path along with the CRMANETs throughput. Using simulations, we discuss the performance of the proposed HCR routing protocol and compare it with the AODV routing protocol using a discrete-event simulation which we developed using JAVA platform.
Improved AODV based on Load and Delay for Route Discovery in MANETIOSR Journals
This document proposes an improved AODV routing protocol for mobile ad hoc networks (MANETs) that considers both node load and routing delay when selecting routes. It calculates a "route weight" based on the average load and delay of the nodes along each potential path from source to destination. The path with the lowest route weight is then selected for routing to help balance traffic loads across the network and minimize delays. Simulation results showed this approach can dynamically balance traffic allocation between paths and optimize resource utilization in the MANET.
ADAPTIVE HANDOVER HYSTERESIS AND CALL ADMISSION CONTROL FOR MOBILE RELAY NODESIJCNCJournal
The aim of equipping a wireless network with a mobile relay node is to support broadband wireless communications for vehicular users and their devices. The high mobility of vehicular users, possibly at a very high velocity in the area in which two cells overlap, could cause the network to suffer from a reduced handover success rate and, hence, increased radio link failure. The combined impact of these problems is service interruptions to vehicular users. Thus, the handover schemes are crucial in solving these problems. In this work, we first present the adaptive handover hysteresis scheme for the wireless network with mobile relay nodes in the high-speed train scenario. Specifically, our proposed adaptive hysteresis scheme is based on the velocity of the train. Second, the handover call dropping probability is reduced by introducing a modified call admission control scheme to support radio resource reservation for handover calls that prioritizes handover calls of mobile relay over the other calls. The proposed solution in which adaptive parameter is combined with call admission control is evaluated by system level simulation. Our simulation results illustrate an increased handover success rate and reduced radio link failures.
PERFORMANCE ANALYSIS OF WIRELESS MESH NETWORK USING ADAPTIVE INFORMANT FACTOR...IJCSES Journal
Wireless mesh network (WMN) has become an important leading technology which provides several types of useful applications such as community network, broadband home network and internet access, etc. The rise in the size of users in WMN has created a degradation of efficiency in a network especially in dense areas due to the clumsy channel allocation and hence creating many challenges for enhancing the users experience, network quality and throughput. Therefore in this paper, we proposed OCA based AIF model that can access the channel information and then it process to improve the RF channel association. The proposed OCA-AIF will function for each period when some interference is detected via AIF and we further extend this analysis by taking in to consideration the influence of interference to provide a high quality indicator in network. The analysis of result shows the optimization by our proposed approach which increases as per the increment of relay nodes (RNs).
Integrated Resource Adaptive On Demand Geographic Routing (IRA-ODGR) for MANETijsrd.com
It is a big challenge to develop routing protocol that can meet different application needs and optimize routing paths according to the topology change in mobile ad hoc networks. The existing work presented two self-adaptive on-demand geographic routing schemes to build efficient paths based on the needs of user applications and adapt to various scenarios for provide efficient and reliable routing. To overcome the impact due to inaccurate local topology knowledge, the topology information is updated at a node in the specific time periods. The on-demand routing mechanism reduces to control overhead made on geographic routing. The route optimization scheme adapts routing path according to the topology changes and actual data traffic requirements. Adaptive parameter setting scheme is introduced to allow each node to determine and adjust the protocol parameter values independently. However, existing work did not address resource parameters such as energy, bandwidth and data loss. The proposal presents and Integrated Resource Adaptive on Demand Geographic Routing (IRA-ODGR) for MANET. The node energy resource is optimized with path energy consumption rate and bandwidth utilization of the path is analysed. Loss rate is reduced in geographic routing with dynamic routes. The simulation conducted to demonstrate IRA-ODGR routing protocols.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
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Mobile environment pretense a number of novel
theoretical and optimization issues such as position, operation
and following in that a lot of requests rely on them for
desirable information. The precedent works are sprinkled
across the entire network layer: from the medium of physical
to link layer to routing and then application layer. In this
invention, we present outline solutions in Medium Access
Control (MAC), data distribution, coverage resolve issues
under mobile ad-hoc network environment based on
congestion control technique using Transmission Control
Protocol (TCP). In mobile ad-hoc network issues can arise
such as link disconnections, channel contention and recurrent
path loss. To resolve this issue, we propose a Cross Layer
based Hybrid fuzzy ad-hoc rate based Congestion Control
(CLHCC) approach to maximize network performance. Based
on the destination report it regulates the speed of data flow to
control data loss by monitoring the present network status
and transmits this report to the source as advice. The source
adjusts the sending flow rate as per the advice. This is
monitored by channel usage, ultimate delay, short term
throughput.
Performance Analysis of Optimization Techniques for OLSR Routing Protocol for...IRJET Journal
This document discusses optimizing the performance of the Optimized Link State Routing (OLSR) protocol for vehicular ad hoc networks (VANETs) through parameter tuning. It first provides background on VANETs and discusses routing challenges. It then proposes using metaheuristic algorithms like genetic algorithm, particle swarm optimization and simulated annealing to automatically tune OLSR parameters and evaluate the optimized protocol's performance in simulations. The results show the tuned OLSR protocol outperforms the standard OLSR protocol with increased throughput and packet delivery ratio, and reduced delay.
Joint Routing and Congestion Control in Multipath Channel based on Signal to ...IJECEIAES
Routing protocol and congestion control in Transmission Control Protocol (TCP) have important roles in wireless mobile network performance. In wireless communication, the stability of the path and successful data transmission will be influenced by the channel condition. This channel condition constraints come from path loss and the multipath channel fading. With these constraints, the algorithm in the routing protocol and congestion control is confronted with the uncertainty of connection quality and probability of successful packet transmission, respectively. It is important to investigate the reliability and robustness of routing protocol and congestion control algorithms in dealing with such situation. In this paper, we develop a detailed approach and analytical throughput performance with a cross layer scheme (CLS) between routing and congestion control mechanism based on signal to noise ratio (SNR) in Rician and Rayleigh as multipath fading channel. We proposed joint routing and congestion control TCP with a cross layer scheme model based on SNR (RTCP-SNR). We compare the performance of RTCP-SNR with conventional routing-TCP and routing-TCP that used CLS with routing aware (RTCP-RA) model. The analyses and the simulation results showed that RTCP-SNR in a multipath channel outperforms conventional routing-TCP and RTCP-RA.
Adaptive resource allocation and internet traffic engineering on data networkcsandit
This research paper describes the issues of bandwidth allocation, optimum capacity allocation,network operational cost reduction, and improve Internet user experience. Traffic engineering (TE) is used to manipulate network traffic to achieve certain requirements and meets certain
needs. TE becomes one of the most important building blocks in the design of the Internet backbone infrastructure. Research objective: efficient allocation of bandwidth across multiple paths. Optimum path selection. Minimize network traffic delays and maximize bandwidth utilization over multiple network paths. The bandwidth allocation is performed proportionally over multiple paths based on the path capacity.
CROSS LAYER DESIGN APPROACH FOR EFFICIENT DATA DELIVERY BASED ON IEEE 802.11P...pijans
Intelligent Transportation Systems (ITS) have been one of the promising technology that has a great interest attention from many researchers over the world. Vehicular Ad-hoc Network (VANET) communications environment as a part of ITS opens the way for a wide range of applications such as safety applications, mobility and connectivity for both driver and passengers to exploit the transport systems in a smoothly, efficiently and safer way. Several challenging tasks facing adopting VANET functionality for ITS such as modelling of wireless transmission and routing issues. These research issues have become more critical due to the high mobility of vehicles nodes (transmitters and receivers) and unexpected network topology due to the high speed of nodes. In fact, modelling radio propagation channel in VANET environment which considers as one of a stringent communications environment is a challenging task. The selection of a suitable transmission model plays a key role in the routing decisions for VANET. Different propagation models allow calculating the Received Signal Strength (RSS) based on key environmental properties such as the distance between transmitter vehicle and a receiver vehicle, the gain and antenna height of transmitter and a receiver vehicles. Hence, it is useful to calculate RSS and SNR values for a specific propagation model and then these values can be used later for routing decision in order to find the best path with high SNR. This paper evaluates the performance of different transmission models (freespace, two-ray and log-normal) in terms of Receive Signal Strength (RSS). In addition, the performance of such wireless transmission models for vehicular communication in terms of PDR, throughput and delay is evaluated by applying the proposed cross layer routing approach based on IEEE 802.11p. By using MATLAB, the obtained results confirm the best packet delivery ratio for our proposed approach, where it indicates poor quality of DSSS PHY with high number vehicles. The minimum delay achieved when traffic density is decreased.
An Efficient and Stable Routing Algorithm in Mobile Ad Hoc NetworkIJCNCJournal
Mobile Ad hoc Network (MANET) is mainly designed to set up communication among devices in infrastructure-less wireless communication network. Routing in this kind of communication network is highly affected by its restricted characteristics such as frequent topological changes and limited battery power. Several research works have been carried out to improve routing performance in MANET. However, the overall performance enhancement in terms of packet delivery, delay and control message overhead is still not come into the wrapping up. In order to overcome the addressed issues, an Efficient and Stable-AODV (EFST-AODV) routing scheme has been proposed which is an improvement over AODV to establish a better quality route between source and destination. In this method, we have modified the route request and route reply phase. During the route request phase, cost metric of a route is calculated on the basis of parameters such as residual energy, delay and distance. In a route reply phase, average residual energy and average delay of overall path is calculated and the data forwarding decision is taken at the source node accordingly. Simulation outcomes reveal that the proposed approach gives better results in terms of packet delivery ratio, delay, throughput, normalized routing load and control message overhead as compared to AODV.
This document proposes an Enhanced and Integrated Ant Colony-Artificial Bee Colony (EIAC-ABCMR) approach for multicast routing in Vehicular Ad Hoc Networks (VANETs) that satisfies quality of service (QoS) constraints. EIAC-ABCMR determines an optimal multicast tree using a metaheuristic algorithm that integrates ant colony optimization and artificial bee colony algorithms. This prevents stagnation and delayed convergence issues. The algorithm formulates the multicast routing problem as a multi-objective function minimizing delay, cost, jitter while maximizing bandwidth. Simulation results show EIAC-ABCMR outperforms other multicast routing techniques in reducing multicast groups
Analytical average throughput and delay estimations for LTESpiros Louvros
This document summarizes an article that appeared in a journal published by Elsevier. The article proposes an analytical model to estimate average throughput and packet transmission delay for uplink cell edge users in LTE networks. The model uses probability analysis and mathematical modeling to estimate transmission delay and throughput, providing cell planners with an analytical tool for evaluating uplink performance under different conditions. The model accounts for factors like scheduling decisions, resource allocation, channel conditions and buffering that impact transmission delay and throughput for cell edge users.
Simulation based comparison of routing protocols in wireless multihop ad hoc ...IJECEIAES
Routing protocols are responsible for providing reliable communication between the source and destination nodes. The performance of these protocols in the ad hoc network family is influenced by several factors such as mobility model, traffic load, transmission range, and the number of mobile nodes which represents a great issue. Several simulation studies have explored routing protocol with performance parameters, but few relate to various protocols concerning routing and quality of service (QoS) metrics. This paper presents a simulation-based comparison of proactive, reactive, and multipath routing protocols in mobile adhoc networks (MANETs). Specifically, the performance of AODV, DSDV, and AOMDV protocols are evaluated and analyzed in the presence of varying the number of mobile nodes, pause time, and traffic connection numbers. Moreover, Routing and QoS performance metrics such as normalized routing load, routing packet, packet delivery ratio, packet drop, end-to-end delay, and throughput are measured to conduct a performance comparison between three routing protocols. Simulation results indicate that AODV outperforms the DSDV and AOMDV protocols in most of the metrics. AOMDV is better than DSDV in terms of end-to-end delay. DSDV provides lower throughput performance results. Network topology parameters have a slight impact on AODV performance.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Multipath routing protocol for effective local route recoveryIJARBEST JOURNAL
In mobile Ad hoc network, frequent mobility during the data transmission of data
causes route failure which results in route discovery. In this we propose multipath routing protocol
for effective local route recovery in mobile Ad hoc networks. In this protocol each source and
destination pair establishes multiple paths in single route discovery and they are cached in their route
caches. The cached routes are sorted on the basis of their bandwidth availability. In case of route
failure in the primary route, a recovery node which is an over heading neighbor, detects it and
establishes a local recovery path with maximum bandwidth from its route cache. This proposed
technique improves network performance and it prevents frequent collision.
This document summarizes an article that proposes improvements to the Ad hoc On-Demand Distance Vector (AODV) routing protocol for use in Vehicular Ad hoc Networks (VANETs). It first provides background on VANETs and discusses different types of routing protocols used in VANETs, including topology-based, position-based, and hybrid protocols. It then focuses on improvements made to the reactive AODV routing protocol, including adding link layer security checks and a method to reduce packet delay called AODV_BD. The goal of these improvements is to create more stable routes and reduce packet delay for safety communications between vehicles.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Traffic Congestion Prediction using Deep Reinforcement Learning in Vehicular ...IJCNCJournal
In recent years, a new wireless network called vehicular ad-hoc network (VANET), has become a popular research topic. VANET allows communication among vehicles and with roadside units by providing information to each other, such as vehicle velocity, location and direction. In general, when many vehicles likely to use the common route to proceed to the same destination, it can lead to a congested route that should be avoided. It may be better if vehicles are able to predict accurately the traffic congestion and then avoid it. Therefore, in this work, the deep reinforcement learning in VANET to enhance the ability to predict traffic congestion on the roads is proposed. Furthermore, different types of neural networks namely Convolutional Neural Network (CNN), Multilayer Perceptron (MLP) and Long Short-Term Memory (LSTM) are investigated and compared in this deep reinforcement learning model to discover the most effective one. Our proposed method is tested by simulation. The traffic scenarios are created using traffic simulator called Simulation of Urban Mobility (SUMO) before integrating with deep reinforcement learning model. The simulation procedures, as well as the programming used, are described in detail. The performance of our proposed method is evaluated using two metrics; the average travelling time delay and average waiting time delay of vehicles. According to the simulation results, the average travelling time delay and average waiting time delay are gradually improved over the multiple runs, since our proposed method receives feedback from the environment. In addition, the results without and with three different deep learning algorithms, i.e., CNN, MLP and LSTM are compared. It is obvious that the deep reinforcement learning model works effectively when traffic density is neither too high nor too low. In addition, it can be concluded that the effective algorithms for traffic congestion prediction models in descending order are MLP, CNN, and LSTM, respectively.
QUANTILE REGRESSIVE FISH SWARM OPTIMIZED DEEP CONVOLUTIONAL NEURAL LEARNING F...IJCNCJournal
Route path identification on the Internet of Vehicles (IoV) is complicated due to the nature of high dynamic mobility, bandwidth constraints, and traffic load. A vehicle present on the IoV communicates with each other to find the status of the road and location of other vehicles for reliable data transmission. However, the existing routing algorithm does not effectively improve the packet delivery ratio and reduce the delay. To resolve these issues, A Quantile Regressive Fish Swarm Optimized Deep Convolutional Neural Learning (QRFSODCNL) technique is introduced reliable data transmission with minimum end to end delay in IoV. The Deep Convolutional Neural Learning uses multiple layers such as one input layer, three hidden layers, and one output layer for vehicle location identification and optimal route path discovery.
Bam İşimiz Israr Soe 'dir (Myanmar sanatlari, El Sanatları Toptan Mücevherat Perakende Gazze A.Ş.). Paspasan rejim rejim taşlar Ürünleri Halil, Gümüş esyalar, Myanmar Harps, Göl Eşya, cant, oyma, antika ARP Vardır Çünkü 2000 Yılında Dağıtımı Dağıtımı kurulu bira, ayıklanır teaks. İşimiz Si'a San Yolu Yangon Yer almaktadır köşesinde, Yeni Yolu, Universite Caddesi, Malzemeleri İlçesi A.Ş ..
The document contains notes from a math lesson. It lists assignments due on specific dates in December and notes for a warm-up including solving equations and finding areas and circumferences of circles. The lesson defines and provides examples of different types of angles, including adjacent, opposite, vertical, supplementary, complementary, and angles related to a transversal cutting parallel lines like corresponding, alternate interior, and alternate exterior angles. Examples applying these angle concepts are shown.
The document discusses privatizing Mongolia's state-owned assets like ETT by listing them on the Mongolian Stock Exchange (MSE) rather than pursuing expensive international IPOs. Listing ETT on the MSE would cost $250k USD maximum versus $10-15m USD for an international IPO. It would quadruple the MSE market capitalization overnight, attracting foreign interest. Privatizing assets through the domestic exchange follows Mongolia's policy of supporting local businesses and is a smart, low-risk first step before potentially pursuing larger international listings once companies gain experience as public entities.
PERFORMANCE ANALYSIS OF WIRELESS MESH NETWORK USING ADAPTIVE INFORMANT FACTOR...IJCSES Journal
Wireless mesh network (WMN) has become an important leading technology which provides several types of useful applications such as community network, broadband home network and internet access, etc. The rise in the size of users in WMN has created a degradation of efficiency in a network especially in dense areas due to the clumsy channel allocation and hence creating many challenges for enhancing the users experience, network quality and throughput. Therefore in this paper, we proposed OCA based AIF model that can access the channel information and then it process to improve the RF channel association. The proposed OCA-AIF will function for each period when some interference is detected via AIF and we further extend this analysis by taking in to consideration the influence of interference to provide a high quality indicator in network. The analysis of result shows the optimization by our proposed approach which increases as per the increment of relay nodes (RNs).
Integrated Resource Adaptive On Demand Geographic Routing (IRA-ODGR) for MANETijsrd.com
It is a big challenge to develop routing protocol that can meet different application needs and optimize routing paths according to the topology change in mobile ad hoc networks. The existing work presented two self-adaptive on-demand geographic routing schemes to build efficient paths based on the needs of user applications and adapt to various scenarios for provide efficient and reliable routing. To overcome the impact due to inaccurate local topology knowledge, the topology information is updated at a node in the specific time periods. The on-demand routing mechanism reduces to control overhead made on geographic routing. The route optimization scheme adapts routing path according to the topology changes and actual data traffic requirements. Adaptive parameter setting scheme is introduced to allow each node to determine and adjust the protocol parameter values independently. However, existing work did not address resource parameters such as energy, bandwidth and data loss. The proposal presents and Integrated Resource Adaptive on Demand Geographic Routing (IRA-ODGR) for MANET. The node energy resource is optimized with path energy consumption rate and bandwidth utilization of the path is analysed. Loss rate is reduced in geographic routing with dynamic routes. The simulation conducted to demonstrate IRA-ODGR routing protocols.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
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Mobile environment pretense a number of novel
theoretical and optimization issues such as position, operation
and following in that a lot of requests rely on them for
desirable information. The precedent works are sprinkled
across the entire network layer: from the medium of physical
to link layer to routing and then application layer. In this
invention, we present outline solutions in Medium Access
Control (MAC), data distribution, coverage resolve issues
under mobile ad-hoc network environment based on
congestion control technique using Transmission Control
Protocol (TCP). In mobile ad-hoc network issues can arise
such as link disconnections, channel contention and recurrent
path loss. To resolve this issue, we propose a Cross Layer
based Hybrid fuzzy ad-hoc rate based Congestion Control
(CLHCC) approach to maximize network performance. Based
on the destination report it regulates the speed of data flow to
control data loss by monitoring the present network status
and transmits this report to the source as advice. The source
adjusts the sending flow rate as per the advice. This is
monitored by channel usage, ultimate delay, short term
throughput.
Performance Analysis of Optimization Techniques for OLSR Routing Protocol for...IRJET Journal
This document discusses optimizing the performance of the Optimized Link State Routing (OLSR) protocol for vehicular ad hoc networks (VANETs) through parameter tuning. It first provides background on VANETs and discusses routing challenges. It then proposes using metaheuristic algorithms like genetic algorithm, particle swarm optimization and simulated annealing to automatically tune OLSR parameters and evaluate the optimized protocol's performance in simulations. The results show the tuned OLSR protocol outperforms the standard OLSR protocol with increased throughput and packet delivery ratio, and reduced delay.
Joint Routing and Congestion Control in Multipath Channel based on Signal to ...IJECEIAES
Routing protocol and congestion control in Transmission Control Protocol (TCP) have important roles in wireless mobile network performance. In wireless communication, the stability of the path and successful data transmission will be influenced by the channel condition. This channel condition constraints come from path loss and the multipath channel fading. With these constraints, the algorithm in the routing protocol and congestion control is confronted with the uncertainty of connection quality and probability of successful packet transmission, respectively. It is important to investigate the reliability and robustness of routing protocol and congestion control algorithms in dealing with such situation. In this paper, we develop a detailed approach and analytical throughput performance with a cross layer scheme (CLS) between routing and congestion control mechanism based on signal to noise ratio (SNR) in Rician and Rayleigh as multipath fading channel. We proposed joint routing and congestion control TCP with a cross layer scheme model based on SNR (RTCP-SNR). We compare the performance of RTCP-SNR with conventional routing-TCP and routing-TCP that used CLS with routing aware (RTCP-RA) model. The analyses and the simulation results showed that RTCP-SNR in a multipath channel outperforms conventional routing-TCP and RTCP-RA.
Adaptive resource allocation and internet traffic engineering on data networkcsandit
This research paper describes the issues of bandwidth allocation, optimum capacity allocation,network operational cost reduction, and improve Internet user experience. Traffic engineering (TE) is used to manipulate network traffic to achieve certain requirements and meets certain
needs. TE becomes one of the most important building blocks in the design of the Internet backbone infrastructure. Research objective: efficient allocation of bandwidth across multiple paths. Optimum path selection. Minimize network traffic delays and maximize bandwidth utilization over multiple network paths. The bandwidth allocation is performed proportionally over multiple paths based on the path capacity.
CROSS LAYER DESIGN APPROACH FOR EFFICIENT DATA DELIVERY BASED ON IEEE 802.11P...pijans
Intelligent Transportation Systems (ITS) have been one of the promising technology that has a great interest attention from many researchers over the world. Vehicular Ad-hoc Network (VANET) communications environment as a part of ITS opens the way for a wide range of applications such as safety applications, mobility and connectivity for both driver and passengers to exploit the transport systems in a smoothly, efficiently and safer way. Several challenging tasks facing adopting VANET functionality for ITS such as modelling of wireless transmission and routing issues. These research issues have become more critical due to the high mobility of vehicles nodes (transmitters and receivers) and unexpected network topology due to the high speed of nodes. In fact, modelling radio propagation channel in VANET environment which considers as one of a stringent communications environment is a challenging task. The selection of a suitable transmission model plays a key role in the routing decisions for VANET. Different propagation models allow calculating the Received Signal Strength (RSS) based on key environmental properties such as the distance between transmitter vehicle and a receiver vehicle, the gain and antenna height of transmitter and a receiver vehicles. Hence, it is useful to calculate RSS and SNR values for a specific propagation model and then these values can be used later for routing decision in order to find the best path with high SNR. This paper evaluates the performance of different transmission models (freespace, two-ray and log-normal) in terms of Receive Signal Strength (RSS). In addition, the performance of such wireless transmission models for vehicular communication in terms of PDR, throughput and delay is evaluated by applying the proposed cross layer routing approach based on IEEE 802.11p. By using MATLAB, the obtained results confirm the best packet delivery ratio for our proposed approach, where it indicates poor quality of DSSS PHY with high number vehicles. The minimum delay achieved when traffic density is decreased.
An Efficient and Stable Routing Algorithm in Mobile Ad Hoc NetworkIJCNCJournal
Mobile Ad hoc Network (MANET) is mainly designed to set up communication among devices in infrastructure-less wireless communication network. Routing in this kind of communication network is highly affected by its restricted characteristics such as frequent topological changes and limited battery power. Several research works have been carried out to improve routing performance in MANET. However, the overall performance enhancement in terms of packet delivery, delay and control message overhead is still not come into the wrapping up. In order to overcome the addressed issues, an Efficient and Stable-AODV (EFST-AODV) routing scheme has been proposed which is an improvement over AODV to establish a better quality route between source and destination. In this method, we have modified the route request and route reply phase. During the route request phase, cost metric of a route is calculated on the basis of parameters such as residual energy, delay and distance. In a route reply phase, average residual energy and average delay of overall path is calculated and the data forwarding decision is taken at the source node accordingly. Simulation outcomes reveal that the proposed approach gives better results in terms of packet delivery ratio, delay, throughput, normalized routing load and control message overhead as compared to AODV.
This document proposes an Enhanced and Integrated Ant Colony-Artificial Bee Colony (EIAC-ABCMR) approach for multicast routing in Vehicular Ad Hoc Networks (VANETs) that satisfies quality of service (QoS) constraints. EIAC-ABCMR determines an optimal multicast tree using a metaheuristic algorithm that integrates ant colony optimization and artificial bee colony algorithms. This prevents stagnation and delayed convergence issues. The algorithm formulates the multicast routing problem as a multi-objective function minimizing delay, cost, jitter while maximizing bandwidth. Simulation results show EIAC-ABCMR outperforms other multicast routing techniques in reducing multicast groups
Analytical average throughput and delay estimations for LTESpiros Louvros
This document summarizes an article that appeared in a journal published by Elsevier. The article proposes an analytical model to estimate average throughput and packet transmission delay for uplink cell edge users in LTE networks. The model uses probability analysis and mathematical modeling to estimate transmission delay and throughput, providing cell planners with an analytical tool for evaluating uplink performance under different conditions. The model accounts for factors like scheduling decisions, resource allocation, channel conditions and buffering that impact transmission delay and throughput for cell edge users.
Simulation based comparison of routing protocols in wireless multihop ad hoc ...IJECEIAES
Routing protocols are responsible for providing reliable communication between the source and destination nodes. The performance of these protocols in the ad hoc network family is influenced by several factors such as mobility model, traffic load, transmission range, and the number of mobile nodes which represents a great issue. Several simulation studies have explored routing protocol with performance parameters, but few relate to various protocols concerning routing and quality of service (QoS) metrics. This paper presents a simulation-based comparison of proactive, reactive, and multipath routing protocols in mobile adhoc networks (MANETs). Specifically, the performance of AODV, DSDV, and AOMDV protocols are evaluated and analyzed in the presence of varying the number of mobile nodes, pause time, and traffic connection numbers. Moreover, Routing and QoS performance metrics such as normalized routing load, routing packet, packet delivery ratio, packet drop, end-to-end delay, and throughput are measured to conduct a performance comparison between three routing protocols. Simulation results indicate that AODV outperforms the DSDV and AOMDV protocols in most of the metrics. AOMDV is better than DSDV in terms of end-to-end delay. DSDV provides lower throughput performance results. Network topology parameters have a slight impact on AODV performance.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Multipath routing protocol for effective local route recoveryIJARBEST JOURNAL
In mobile Ad hoc network, frequent mobility during the data transmission of data
causes route failure which results in route discovery. In this we propose multipath routing protocol
for effective local route recovery in mobile Ad hoc networks. In this protocol each source and
destination pair establishes multiple paths in single route discovery and they are cached in their route
caches. The cached routes are sorted on the basis of their bandwidth availability. In case of route
failure in the primary route, a recovery node which is an over heading neighbor, detects it and
establishes a local recovery path with maximum bandwidth from its route cache. This proposed
technique improves network performance and it prevents frequent collision.
This document summarizes an article that proposes improvements to the Ad hoc On-Demand Distance Vector (AODV) routing protocol for use in Vehicular Ad hoc Networks (VANETs). It first provides background on VANETs and discusses different types of routing protocols used in VANETs, including topology-based, position-based, and hybrid protocols. It then focuses on improvements made to the reactive AODV routing protocol, including adding link layer security checks and a method to reduce packet delay called AODV_BD. The goal of these improvements is to create more stable routes and reduce packet delay for safety communications between vehicles.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Traffic Congestion Prediction using Deep Reinforcement Learning in Vehicular ...IJCNCJournal
In recent years, a new wireless network called vehicular ad-hoc network (VANET), has become a popular research topic. VANET allows communication among vehicles and with roadside units by providing information to each other, such as vehicle velocity, location and direction. In general, when many vehicles likely to use the common route to proceed to the same destination, it can lead to a congested route that should be avoided. It may be better if vehicles are able to predict accurately the traffic congestion and then avoid it. Therefore, in this work, the deep reinforcement learning in VANET to enhance the ability to predict traffic congestion on the roads is proposed. Furthermore, different types of neural networks namely Convolutional Neural Network (CNN), Multilayer Perceptron (MLP) and Long Short-Term Memory (LSTM) are investigated and compared in this deep reinforcement learning model to discover the most effective one. Our proposed method is tested by simulation. The traffic scenarios are created using traffic simulator called Simulation of Urban Mobility (SUMO) before integrating with deep reinforcement learning model. The simulation procedures, as well as the programming used, are described in detail. The performance of our proposed method is evaluated using two metrics; the average travelling time delay and average waiting time delay of vehicles. According to the simulation results, the average travelling time delay and average waiting time delay are gradually improved over the multiple runs, since our proposed method receives feedback from the environment. In addition, the results without and with three different deep learning algorithms, i.e., CNN, MLP and LSTM are compared. It is obvious that the deep reinforcement learning model works effectively when traffic density is neither too high nor too low. In addition, it can be concluded that the effective algorithms for traffic congestion prediction models in descending order are MLP, CNN, and LSTM, respectively.
QUANTILE REGRESSIVE FISH SWARM OPTIMIZED DEEP CONVOLUTIONAL NEURAL LEARNING F...IJCNCJournal
Route path identification on the Internet of Vehicles (IoV) is complicated due to the nature of high dynamic mobility, bandwidth constraints, and traffic load. A vehicle present on the IoV communicates with each other to find the status of the road and location of other vehicles for reliable data transmission. However, the existing routing algorithm does not effectively improve the packet delivery ratio and reduce the delay. To resolve these issues, A Quantile Regressive Fish Swarm Optimized Deep Convolutional Neural Learning (QRFSODCNL) technique is introduced reliable data transmission with minimum end to end delay in IoV. The Deep Convolutional Neural Learning uses multiple layers such as one input layer, three hidden layers, and one output layer for vehicle location identification and optimal route path discovery.
Bam İşimiz Israr Soe 'dir (Myanmar sanatlari, El Sanatları Toptan Mücevherat Perakende Gazze A.Ş.). Paspasan rejim rejim taşlar Ürünleri Halil, Gümüş esyalar, Myanmar Harps, Göl Eşya, cant, oyma, antika ARP Vardır Çünkü 2000 Yılında Dağıtımı Dağıtımı kurulu bira, ayıklanır teaks. İşimiz Si'a San Yolu Yangon Yer almaktadır köşesinde, Yeni Yolu, Universite Caddesi, Malzemeleri İlçesi A.Ş ..
The document contains notes from a math lesson. It lists assignments due on specific dates in December and notes for a warm-up including solving equations and finding areas and circumferences of circles. The lesson defines and provides examples of different types of angles, including adjacent, opposite, vertical, supplementary, complementary, and angles related to a transversal cutting parallel lines like corresponding, alternate interior, and alternate exterior angles. Examples applying these angle concepts are shown.
The document discusses privatizing Mongolia's state-owned assets like ETT by listing them on the Mongolian Stock Exchange (MSE) rather than pursuing expensive international IPOs. Listing ETT on the MSE would cost $250k USD maximum versus $10-15m USD for an international IPO. It would quadruple the MSE market capitalization overnight, attracting foreign interest. Privatizing assets through the domestic exchange follows Mongolia's policy of supporting local businesses and is a smart, low-risk first step before potentially pursuing larger international listings once companies gain experience as public entities.
SOTM : A Self Organized Trust Management System for VANET csandit
Security and trust management in Vehicular Adhoc NETworks (VANET) is a crucial research domain
which is the scope of many researches and domains. Although, the majority of the proposed trust
management systems for VANET are based on specific road infrastructure, which may not be present in all
the roads. Therefore, road security should be managed by vehicles themselves. In this paper, we propose a
new Self Organized Trust Management system (SOTM). This system has the responsibility to cut with the
spread of false warnings in the network through four principal components: cooperation, trust
management, communication and security.
-Carpeta O Medio Mariño: cadernos informativos e fichas de traballo: o medio, as plantas, as aves, os peixes, os crustáceos, os moluscos, varios, o home (1994-95)
The Asian Development Bank Capacity Building Technical Assistance Project aimed to improve road maintenance, education, and information systems in Mongolia. It worked with VicRoads of Australia and Monconsult of Mongolia to provide training and establish systems. Road maintenance techniques were demonstrated and the gap between investment and maintenance was a challenge. Education efforts included training, developing an online masters in road management, and working with international universities. Road information systems were installed to track contracts and provide public information. Continued utilization of these systems and developing careers in engineering were encouraged to further progress.
This document provides an introduction to Instagram, including who uses it, why businesses should use it, how to join, and the basics of using it. It explains that Instagram is an online photo and video sharing social media platform used by millions, especially millennials, to connect and engage followers. It recommends businesses use Instagram to attract followers, increase engagement, and help with search engine optimization. The document concludes by providing contact information to learn more about achieving results on Instagram from a marketing expert.
The document discusses key cost and sales concepts for food and beverage operations. It defines different types of costs like fixed, variable, and controllable costs. It also discusses how to calculate important metrics like average sales, cost percentages, and cost-to-sales ratios. Maintaining an understanding of these concepts and monitoring costs and sales ratios is important for restaurants to control costs and ensure profitability.
Lysbilder som viser gangen i beviset for transversalsetningen, grunnlaget for setningen om at "i formlike trekanter er forholdet mellom tilsvarende sider konstant".
International Journal of Engineering and Science Invention (IJESI)inventionjournals
This document summarizes a research paper on improving traffic detection algorithms using an extended floating car data (xFCD) system. The xFCD system collects data from vehicles including location, speed, direction and visual data from a forward-facing camera. It is tested under different lighting and traffic conditions. The paper investigates using xFCD data and information from road sensors to construct a hybrid model characterizing traffic states. A traffic detection algorithm is proposed to improve network performance metrics like throughput, delivery ratio and packet delay. Simulation results show the proposed approach improves these metrics compared to existing methods.
Vehicle Ad Hoc Networks (VANETs) have become a viable technology to improve traffic flow and safety on the roads. Due to its effectiveness and scalability, the Wingsuit Search-based Optimised Link State Routing Protocol (WS-OLSR) is frequently used for data distribution in VANETs. However, the selection of MultiPoint Relays (MPRs) plays a pivotal role in WS-OLSR's performance. This paper presents an improved MPR selection algorithm tailored to WS-OLSR, designed to enhance the overall routing efficiency and reduce overhead. The analysis found that the current OLSR protocol has problems such as redundancy of HELLO and TC message packets or failure to update routing information in time, so a WS-OLSR routing protocol based on improved-MPR selection algorithm was proposed. Firstly, factors such as node mobility and link changes are comprehensively considered to reflect network topology changes, and the broadcast cycle of node HELLO messages is controlled through topology changes. Secondly, a new MPR selection algorithm is proposed, considering link stability issues and nodes. Finally, evaluate its effectiveness in terms of packet delivery ratio, end-to-end delay, and control message overhead. Simulation results demonstrate the superior performance of our improved MR selection algorithm when compared to traditional approaches.
Vehicle Ad Hoc Networks (VANETs) have become a viable technology to improve traffic flow and safety on the roads. Due to its effectiveness and scalability, the Wingsuit Search-based Optimised Link State Routing Protocol (WS-OLSR) is frequently used for data distribution in VANETs. However, the selection of MultiPoint Relays (MPRs) plays a pivotal role in WS-OLSR's performance. This paper presents an improved MPR selection algorithm tailored to WS-OLSR, designed to enhance the overall routing efficiency and reduce overhead. The analysis found that the current OLSR protocol has problems such as redundancy of HELLO and TC message packets or failure to update routing information in time, so a WS-OLSR routing protocol based on improved-MPR selection algorithm was proposed. Firstly, factors such as node mobility and link changes are comprehensively considered to reflect network topology changes, and the broadcast cycle of node HELLO messages is controlled through topology changes. Secondly, a new MPR selection algorithm is proposed, considering link stability issues and nodes. Finally, evaluate its effectiveness in terms of packet delivery ratio, end-to-end delay, and control message overhead. Simulation results demonstrate the superior performance of our improved MR selection algorithm when compared to traditional approaches.
WS-OLSR: MULTIPOINT RELAY SELECTION IN VANET NETWORKS USING A WINGSUIT FLYING...IJCNCJournal
The routing protocol is considered the backbone of network communication. However, mobility and
bandwidth availability make optimizing broadcast message flooding a problem in an Optimized Link State
Routing (OLSR)-based mobile wireless network. The selection of Multi-Point Relays (MPRs) has lately
been proposed as a potential approach that has the added benefit of eliminating duplicate re-transmissions
in VANET networks. Wingsuit Flying Search (WFS) is one of the swarm intelligent metaheuristic
algorithms, it enables one to find the minimum number of MPR. In this study, a novel methodology based
on (WFS) is called WS-OLSR (Wingsuit Search-OLSR). The (WS-OLSR) is investigated to enhance the
existing MPR-based solution, arguing that considering a cost function as a further decision measure will
effectively compute minimum MPR nodes that give the maximum coverage area possible. The enhanced
MPR selection powered by (WFS) algorithm leads to decreasing MPR count required to cover 95% of
mobile nodes, increasing throughput , and decreasing topology control which mitigates broadcasting storm
phenomenon in VANETs.
WS-OLSR: Multipoint Relay Selection in VANET Networks using a Wingsuit Flying...IJCNCJournal
The routing protocol is considered the backbone of network communication. However, mobility and bandwidth availability make optimizing broadcast message flooding a
problem in an Optimized Link State Routing (OLSR)-based mobile wireless network. The selection of Multi-Point Relays (MPRs) has lately been proposed as a potential approach that has the added benefit of eliminating duplicate re-transmissions in VANET networks. Wingsuit Flying Search (WFS) is one of the swarm intelligent metaheuristic
algorithms, it enables one to find the minimum number of MPR. In this study, a novel methodology based on (WFS) is called WS-OLSR (Wingsuit Search-OLSR). The (WS-
OLSR) is investigated to enhance the existing MPR-based solution, arguing that considering a cost function as a further decision measure will effectively compute minimum MPR nodes that give the maximum coverage area possible. The enhanced MPR selection powered by (WFS) algorithm leads to decreasing MPR count required to cover 95% of mobile nodes, increasing throughput , and decreasing topology control which mitigates broadcasting storm phenomenon in VANETs
A Systematic Review on Routing Protocols for VANETsIRJET Journal
This document provides a systematic review and comparative analysis of 10 routing protocols for vehicular ad hoc networks (VANETs). It summarizes the key methods, benefits, and conclusions of each protocol. The protocols use various techniques like clustering, machine learning, Q-learning, firefly algorithm, and particle swarm optimization to address the challenges of frequent topology changes in VANETs. Simulation results show the protocols improve metrics like packet delivery ratio, end-to-end delay, and network throughput compared to other existing protocols. In conclusion, an efficient routing protocol is needed to meet the unique requirements of VANETs and achieve good performance.
Quick Routing for Communication in MANET using Zone Routing Protocolijceronline
rnational Journal of Computational Engineering Resaerch 2014, Volume 4 ~ Issue 11 (November 2014)
Abstract
The paper discusses the voltage control of a critical load bus using dynamic voltage restorer (DVR) in a distribution system. The critical load requires a balanced sinusoidal waveform across its terminals preferably at system nominal frequency of 50Hz .It is assumed that the frequency of the supply voltage can be varied and it is different from the system nominal frequency. The DVR is operated such that it holds the voltage across critical load bus terminals constant at system nominal frequency irrespective of the frequency of the source voltage. In case of a frequency mismatch, the total real power requirement of the critical load bus has to be supplied by the DVR. Proposed method used to compensate for frequency variation, the DC link of the DVR is supplied through an uncontrolled rectifier that provides a path for the real power required by the critical load to flow .A simple frequency estimation technique is discussed which are Discrete Fourier transform (DFT), ANN controller. The present work study the compensation principle and different control strategies of DVR used here are based on DFT, and ANN Controller .Through detailed analysis and simulation studies using MATLAB. It is shown that the voltage is completely controlled across the critical load.
Multipoint Relay Path for Efficient Topology Maintenance Algorithm in Optimiz...IJCNCJournal
The Optimal Link State Routing (OLSR) protocol employs multipoint relay (MPR) nodes to disseminate topology control (TC) messages, enabling network topology discovery and maintenance. However, this approach increases control overhead and leads to wasted network bandwidth in stable topology scenarios due to fixed flooding periods. To address these challenges, this paper presents an Efficient Topology Maintenance Algorithm (ETM-OLSR) for Enhanced Link-State Routing Protocols. By reducing the number of MPR nodes, TC message generation and forwarding frequency are minimized. Furthermore, the algorithm selects a smaller subset of TC messages based on the changes in the MPR selection set from the previous cycle, adapting to stable and fluctuating network conditions. Additionally, the sending cycle of TC messages is dynamically adjusted in response to network topology changes. Simulation results demonstrate that the ETM-OLSR algorithm effectively reduces network control overhead, minimizes end-to-end delay, and improves network throughput compared to traditional OLSR and HTR-OLSR algorithms.
Multipoint Relay Path for Efficient Topology Maintenance Algorithm in Optimiz...IJCNCJournal
The Optimal Link State Routing (OLSR) protocol employs multipoint relay (MPR) nodes to disseminate topology control (TC) messages, enabling network topology discovery and maintenance. However, this approach increases control overhead and leads to wasted network bandwidth in stable topology scenarios due to fixed flooding periods. To address these challenges, this paper presents an Efficient Topology Maintenance Algorithm (ETM-OLSR) for Enhanced Link-State Routing Protocols. By reducing the number of MPR nodes, TC message generation and forwarding frequency are minimized. Furthermore, the algorithm selects a smaller subset of TC messages based on the changes in the MPR selection set from the previous cycle, adapting to stable and fluctuating network conditions. Additionally, the sending cycle of TC messages is dynamically adjusted in response to network topology changes. Simulation results demonstrate that the ETM-OLSR algorithm effectively reduces network control overhead, minimizes end-to-end delay, and improves network throughput compared to traditional OLSR and HTR-OLSR algorithms.
EFFICIENT MULTI-PATH PROTOCOL FOR WIRELESS SENSOR NETWORKSijwmn
Wireless sensor networks are useful for streaming multimedia in infrastructure-free and hazardous environments. However, these networks are quite different from their wired counterpart and are composed of nodes with constrained bandwidth and energy. Multiple-path transmission is one of the methods for ensuring QoS routing in both wired and wireless environment. Directed diffusion, a well known wireless sensor network protocol, only routes packets through a single path, which barely meets the throughput requirement of multimedia data. Instead, we propose a multipath algorithm based on directed diffusion that reinforces multiple routes with high link quality and low latency. This algorithm retains the merits of the original directed diffusion algorithms, including its energy efficiency and scalability. A hybrid metric of link quality and latency is used as the criterion for path selection. In order to select disjoint paths, we propose a scheme for reinforced nodes to respond negatively to multiple reinforcement messages. We use the NS-2 simulation tool with video trace generated by Multiple Description Coding (MDC) to evaluate the performance. The results show that our algorithm gives better throughput and delay performance, i.e higher video quality, than standard directed diffusion that transmits over a single path, with low overheads and energy consumption.
Cross Layer based Congestion Free Route Selection in Vehicular Ad Hoc NetworksIJCNCJournal
The document summarizes a research paper that proposes a new routing technique called CFRS-CP for vehicular ad hoc networks (VANETs) to reduce network congestion. The technique estimates congestion probability at each node based on factors like neighbor density, link quality, MAC overhead, and vehicle velocity. It then uses the estimated probabilities to select the least congested route for data transmission. Simulation results showed the proposed method decreases delay by 32% and improves packet delivery ratio by 30% and throughput by 45% compared to existing protocols.
CROSS LAYER BASED CONGESTION FREE ROUTE SELECTION IN VEHICULAR AD HOC NETWORKSIJCNCJournal
For creating a mobile network, the moving cars consider as nodes in the Vehicular Ad-Hoc Networks
(VANETs). Each participating car is turned into a wireless router in the VANETs that allows the
connecting and creating a network. To improve the comfort and safety of driving of automotive users, the
vehicular environment system develops in the vehicular environment systems using the wireless access. The
channel congestion causes the degradation of quality of service in such cases with higher vehicle density.
The real-time and reliable communication is required for various safety applications of VANETs. The
dense traffic network has included one of the major challenges as avoiding the communication channels’
degradation. To provide the network with efficient operation, most of the studies are recommended to use
the appropriate congestion control methods. It’s important to note that many congestion control
mechanisms are not implemented for event-driven real-time safety messages. Based on the congestion
probability approach estimation, CFRS-CP-Congestion free route selection is introduced for minimizing
the total number of data flow packets that passing through the congested nodes. At each node, the
congestion probability is estimated using the proposed technique of CFRS-CP based on link quality, MAC
overhead, neighbour density & vehicle velocity. Then, the estimated congestion probability is used for
route assessment. The estimated probability value is appended to the control packets for comparison. All
the available routes are assessed based on the estimated congestion probability which results in congestion
free routing path for every round of data communication. The simulation results prove that the proposed
method decreases end to end delay by 32% and improves PDR up to 30% and throughput up to 45%
compared to the existing protocols.
An Enhanced DSR Protocol for Improving QoS in MANETKhushbooGupta145
Ad hoc network is a network without centralized administration in which different users can communicate and exchange information. In such a structure, all the nodes participate in order to achieve the network and ensure the travel of the information. Hence, multihopping techniques are used to achieve this task. The communication reliability within an ad hoc network and how the different nodes act are managed by routing protocols. Nowadays, different types of protocols exist. Nevertheless, the source routing ones, based on information known at the source of the communication, seem to attract more studies. Source routing protocols had shown interesting results in realistic scenarios in areas such as military battlefields or airport stations.
This Paper deals with DSR Protocol and is focused on the multipath aspect of this routing protocol. Since, it is necessary to understand that multipath techniques enhance reliability and can ensure security. We have simulated a new multipath algorithm. The solution had been evaluated with the network Simulator 2. Since we want to know how our protocol reacts in different mobility cases, the random waypoint model which allows us to present relevant results, due to the fact this situation is taken into account.
Simulation results show that the multipath protocol behaves better than DSR, the main actual reactive protocol. The Proposed protocol MSR performs well in high mobility by using much less overhead than DSR. Additionally, it is interesting to see that DSR without any modifications manage poorly in high mobility situation.
A Machine Learning based Network Sharing System Design with MPTCPIJMREMJournal
The information and communication technologies (ICT) integrate different types of wireless communication to
provide IT-enabled services and applications. The great majority end devices are equipped with multiple network
interfaces such as Wi-Fi and 4G. Our goal is to integrate the available network interfaces and technologies to
enhance seamless communication efficiency and increase resources utilization. We proposed a heterogeneous
network management algorithm based on machine learning methods which includes roaming and sharing
functions. The roaming function provides the multiple network resources in physical and media access control
layers. The sharing function supports multiple network resources allocation and the service handover process
based on the Multi-Path TCP protocol. The simulation result also shows that the proposed scheme can increase
the network bandwidth utilization effectively. The sharing system could be used in home, mobile and vehicular
environments to realize ubiquitous social sharing networks.
A Machine Learning based Network Sharing System Design with MPTCPIJMREMJournal
1) The document describes a machine learning-based network sharing system that uses Multipath TCP to integrate multiple network interfaces and allocate bandwidth resources for multiple users.
2) The system includes roaming and sharing functions, where roaming chooses the best network and sharing allocates resources across available networks.
3) A heterogeneous network management algorithm is proposed that monitors network status, predicts handovers between networks, and uses a machine learning approach to optimize resource utilization and load balancing across different network interfaces.
ACR: A CLUSTER-BASED ROUTING PROTOCOL FOR VANET ijwmn
Clustering is a technique used in network routing to enhance the performance and conserve the network
resources. This paper presents a cluster-based routing protocol for VANET utilizing a new addressing
scheme in which each node gets an address according to its mobility pattern. Hamming distance technique
is used then to partition the network in an address-centric manner. The simulation results show that this
protocol enhances routing reachability, whereas reduces routing end-to-end delay and traffic received
comparing with two benchmarks namely AODV and DSDV.
ACR: A CLUSTER-BASED ROUTING PROTOCOL FOR VANET ijwmn
Clustering is a technique used in network routing to enhance the performance and conserve the network resources. This paper presents a cluster-based routing protocol for VANET utilizing a new addressing scheme in which each node gets an address according to its mobility pattern. Hamming distance technique is used then to partition the network in an address-centric manner. The simulation results show that this protocol enhances routing reachability, whereas reduces routing end-to-end delay and traffic received
comparing with two benchmarks namely AODV and DSDV.
Energy- Aware QoS Based Routing Protocols for Heterogeneous WSNs: A Survey ...............................1
Sridevi S., Rumeniya G. and Usha M.
Optimization of Outsourcing ICT Projects in Public Organizations; Case Study: Public Center of Iranian
ICT Studies ................................................................................................................................................. 20
Majid Nili Ahmadabadi, Abbas Bagheri and Fariba Abolghasemi
An Optimized CBIR Using Particle Swarm Optimization Algorithm ......................................................... 40
Subhakala S., Bhuvana S. and Radhakrishnan R.
Study of Satisfaction Assessment Techniques for Textual Requirements .............................................. 56
K. S. Divya, R. Subha and Dr. S. Palaniswami
Survey of MAC Protocols for Heterogeneous Traffic in Wireless Sensor Networks ............................... 67
Sridevi S., Priyadharshini R. and Usha M.
Harnessing Social Media for Business Success. Case Study of Zimbabwe ............................................... 80
Musungwini Samuel, Zhou Tinashe Gwendolyn, Zhou Munyaradzi and Ruvinga Caroline
Quality Platforms for Innovation and Breakthrough................................................................................ 90
Dr. Hima Gupta
Development of Virtual Experiment on Waveform Conversion Using Virtual Intelligent SoftLab ...... 107
Bhaskar Y. Kathane
An Efficient Machine Learning Optimization Model for Route Establishment Mech...IJCNCJournal
Internet of Things (IoT) provides interconnection of various wireless communication devices, which offers both ubiquitous accessibility of devices and in-built intelligence capacity. IoT offers interaction with devices and provides sufficient capability advantages of networking and socialization with consideration of intermediate devices. RPL (Routing Protocol for low-power and Lossy Networks) is an attractive model for effective routing techniques in the wireless medium. The increase in demand for wireless systems in terms of energy, reliability, stability, and scale routing IPv6 over 6L0WPAN is being adopted. This research developed an optimized machine learning model (WOABC) routing protocol for route establishment in IoT networks. The constructed RPL routing protocol incorporates an optimization approach for the identification of the best and worst routes in the network. The proposed WOABC evaluates the routing path for data transmission between nodes through optimization techniques for effective route establishment. The optimization of routes is performed with whale optimization techniques. The developed whale optimization technique is incorporated in machine learning networks. Also, the proposed WOABC utilizes an optimization membership function for the identification of the optimal path in the network. The performance of the proposed WOABC is compared with existing techniques such as RPL and Speed – IoT. The comparative analysis showed that the performance of the proposed WOABC is ~3% increased throughput. The performance of the proposed WOABC is significant compared with the existing RPL routing protocol.
AN EFFICIENT MACHINE LEARNING OPTIMIZATION MODEL FOR ROUTE ESTABLISHMENT MECH...IJCNCJournal
Internet of Things (IoT) provides interconnection of various wireless communication devices, which offers
both ubiquitous accessibility of devices and in-built intelligence capacity. IoT offers interaction with
devices and provides sufficient capability advantages of networking and socialization with consideration of
intermediate devices. RPL (Routing Protocol for low-power and Lossy Networks) is an attractive model for
effective routing techniques in the wireless medium. The increase in demand for wireless systems in terms
of energy, reliability, stability, and scale routing IPv6 over 6L0WPAN is being adopted. This research
developed an optimized machine learning model (WOABC) routing protocol for route establishment in IoT
networks. The constructed RPL routing protocol incorporates an optimization approach for the
identification of the best and worst routes in the network. The proposed WOABC evaluates the routing path
for data transmission between nodes through optimization techniques for effective route establishment. The
optimization of routes is performed with whale optimization techniques. The developed whale optimization
technique is incorporated in machine learning networks. Also, the proposed WOABC utilizes an
optimization membership function for the identification of the optimal path in the network. The
performance of the proposed WOABC is compared with existing techniques such as RPL and Speed – IoT.
The comparative analysis showed that the performance of the proposed WOABC is ~3% increased
throughput. The performance of the proposed WOABC is significant compared with the existing RPL
routing protocol.
Similar to Reducing Latency in African NRENS Using Performance-Based LISP/SDN Traffic Engineering (20)
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The Department of Veteran Affairs (VA) invited Taylor Paschal, Knowledge & Information Management Consultant at Enterprise Knowledge, to speak at a Knowledge Management Lunch and Learn hosted on June 12, 2024. All Office of Administration staff were invited to attend and received professional development credit for participating in the voluntary event.
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Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
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zkStudyClub - LatticeFold: A Lattice-based Folding Scheme and its Application...Alex Pruden
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Must Know Postgres Extension for DBA and Developer during MigrationMydbops
Mydbops Opensource Database Meetup 16
Topic: Must-Know PostgreSQL Extensions for Developers and DBAs During Migration
Speaker: Deepak Mahto, Founder of DataCloudGaze Consulting
Date & Time: 8th June | 10 AM - 1 PM IST
Venue: Bangalore International Centre, Bangalore
Abstract: Discover how PostgreSQL extensions can be your secret weapon! This talk explores how key extensions enhance database capabilities and streamline the migration process for users moving from other relational databases like Oracle.
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Our team offers a wide range of services, including assistance, support, consulting, 24/7 operations, and expertise in all relevant technologies. We help organizations improve their database's performance, scalability, efficiency, and availability.
Contact us: info@mydbops.com
Visit: https://www.mydbops.com/
Follow us on LinkedIn: https://in.linkedin.com/company/mydbops
For more details and updates, please follow up the below links.
Meetup Page : https://www.meetup.com/mydbops-databa...
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Blogs: https://www.mydbops.com/blog/
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Monitoring and Managing Anomaly Detection on OpenShift.pdfTosin Akinosho
Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
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5th LF Energy Power Grid Model Meet-up SlidesDanBrown980551
5th Power Grid Model Meet-up
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Power Grid Model
The global energy transition is placing new and unprecedented demands on Distribution System Operators (DSOs). Alongside upgrades to grid capacity, processes such as digitization, capacity optimization, and congestion management are becoming vital for delivering reliable services.
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Power Grid Model is currently being applied in a wide variety of use cases, including grid planning, expansion, reliability, and congestion studies. It can also help in analyzing the impact of renewable energy integration, assessing the effects of disturbances or faults, and developing strategies for grid control and optimization.
What to expect
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2. 84 Computer Science & Information Technology (CS & IT)
notably in Mtunzini, Maputo, Dar es Salaam, Nairobi, Kampala and Kigali, and interconnecting
them with broadband cross-border links to create a regional research network. So far, the intra-
Africa interconnection serves six NRENs: TENET (South Africa), MoRENet (Mozambique),
TERNET (Tanzania), KENET (Kenya), RENU (Uganda) and RwEdNet (Rwanda). Furthermore,
transcontinental links between Nairobi and the Ubuntunet Alliance PoP in Amsterdam, as well as
from Cape Town to London, have been established, thereby linking UbuntuNet Alliance with
GEANT, the European research network (Figure 1).
Fig. 1. The UbuntuNet Alliance regional network
The establishment of multiple PoPs, multiple intra-Africa Internet links, as well as multiple
transcontinental links, provides new opportunities for implementing multipath routing and traffic
engineering mechanisms with the aim of improving performance of traffic exchange among
Africa's NRENs. NRENs could implement mechanisms that would allow them to announce to
each other, and make use of multiple Internet attachment points to exchange traffic. One protocol
that allows edge networks to exchange traffic over multiple Internet gateways is the
Locator/Identifier Separation Protocol (LISP) [2, 3]. LISP allows edge networks to announce
3. Computer Science & Information Technology (CS & IT) 85
multiple Internet gateways, known as Route Locators (RLOCs), and to influence the selection of
incoming paths. Through a mapping system, LISP allows networks to announce preferences for
multiple RLOCs. The availability of multiple locators for the same destination increases path
diversity[4] and enable multipath routing, as source networks can select among multiple gateways
to reach a destination network.
This paper demonstrates the potential for performance improvement in the Pan-African NRENs
by employing, at the network edge, traffic engineering techniques that are based on end-to-end
multipath ranking. Using a Software Defined Network (SDN) experimental topology, and a LISP
mapping system, the paper examines the potential for dynamically ranking egress and ingress
links between multihomed NRENs based on end-to-end path metrics. The objective is to
minimize latency for two-way delay sensitive traffic flows (e.g. real-time classroom streaming
and video conferences between universities), and minimize intercontinental bandwidth utilization.
2. BACKGROUND AND RELATED WORK
Given the opportunities for traffic engineering provided by the multiple intra-continental and
transcontinental links provided by the Africa Connect network, one way of improving the
performance and optimization of traffic exchange across African NRENs is to enable dynamic
selection of optimal traffic exchange routes based on application QoS needs. For example, path
selection for delay sensitive applications can be made based on prevailing end-to-end latencies
through either the intercontinental transit links or through the intra-Africa links.
2.1 LISP-based Multipath Traffic Engineering
The Locator/Identifier Separation Protocol (LISP) [3] simplifies multihoming. LISP divides the
Internet's address space into two - locally routable Endpoint IDentifiers (EIDs) and global Route
LOCators (RLOCs). By separating the host address space from the locator address space, LISP
introduces a level of indirection that allows networks to specify preferences for multiple ingress
gateways (locators). The availability of multiple locators for the same destination increases path
diversity since the source networks are able to forward traffic for a particular destination through
multiple remote locators (gateways).
Thus, additional end-to-end performance gains can be achieved with the ability to dynamically
select the ingress link at the destination network. In Figure 2, for example, edge networks A and
B are multi-homed to networks x,q and y,z respectively. Depending on how the routing is done in
the Internet core, the choice of the egress link by network A, i.e. (A,x or A,q), has potential to
influence selection of ingress link towards B i.e. 3,y or 4,z. Since each end-to-end path has its
own unique path metrics in terms of bandwidth, delay, and loss, selection of particular egress and
ingress links at A and B impacts the overall quality of the end-to-end path.
4. 86 Computer Science & Information Technology (CS & IT)
Fig. 2. Multihomed Networks A and B, multihomed through providers (x,q) and (y,z) respectively
One prominent work that uses LISP for traffic engineering is the ISP-Driven Informed Path
Selection(IDIPS) [5]. IDIPs is a request/response service where centralized server nodes perform
network measurements towards popular destinations, and clients request path rankings for a set of
sources and destinations. The IDIPS server ranks the available paths based on a client's ranking
preference and measured path metrics. In IDIPS implementation, path ranking is further
influenced by the destination's preferences in the locator mapping. The selected paths therefore
reflect not only the source network's ranking criteria, but also the destination's preferences for
incoming traffic.
2.2 SDN-based Path Enforcement
One challenge with inter-domain multi-path routing and end-to-end traffic engineering is with
regard to enforcement of paths across different domains. Software Defined Networking (SDN)
provides new opportunities for flexible management of Internet routing and packet forwarding
[6]. An SDN-based IXP [7] allows IXP participants to have access to an SDN controller and to
write policies that override the default policies of the IXP's BGP route server. SDN has three
important characteristics that are useful for interdomain traffic engineering [7]. Firstly, in contrast
to traditional switches that forward traffic based only on the destination MAC address, SDN
enables packet forwarding based on multiple header fields. Secondly, an SDN controller
consolidates control messages from multiple remote networks, such that source and destination
networks can remotely configure forwarding paths through a controller. Thirdly, the controller's
direct control of the data plane enables dynamic/programmatic configuration of the forwarding
tables. With these SDN opportunities, it is possible to allow edge networks some control over
selection of inter-domain forwarding paths at Internet exchange points, thereby having more
control on the end-to-end paths.
3. A MODEL FOR PERFORMANCE-BASED PATH SELECTION
The traffic engineering framework depicted in Figure 3 is based on the ability of traffic source
gateways to select the destination's ingress link based on metrics of the edge-to-edge path. This
requires that the source gateway should have a mechanism for learning the destination's multiple
ingress links.
5. Computer Science & Information Technology (CS & IT) 87
Fig. 3. LISP/SDN Multi-Path Traffic Engineering Model
In summary, the model works in the following manner: For each new traffic flow from a local
source node to some remote network, the source network queries the LISP mapping system
(through an RLOC lookup API) to obtain the destination network's RLOCs. After obtaining the
remote RLOCs, a Locator Ranking module performs active measurements towards remote
RLOCs. The Locator Ranking module uses the network metrics obtained from the active
measurements to rank the local and remote gateways, after which it updates the local mapping
cache. For each new traffic flow, the source network selects the egress and ingress gateways
based on the rankings in the mapping cache. Once the egress and ingress links are selected, a
Circuit Pusher module is invoked to configure, through an Open Flow SDN control, an end-to-
end switching path between the source and destination RLOCs via the selected egress/ingress
links. If no mapping exists in the mapping cache for a destination network, the RLOC Mapping
module is invoked to perform the lookup, after which the RLOC Ranking module performs the
ranking.
3.1 Path Performance Measurement
The key network metrics in this model are end-to-end latency, jitter and packet loss. Latency,
measured as round trip time (RTT) for traffic to move from source to destination, and for the
acknowledgement packet to be received by the sender, is an important characteristic that affects
the performance and responsiveness of Internet applications. Jitter, on the other hand, is the
variation in latency over time between a traffic source and destination node. Packet loss is a
measure of the percentage of packets lost along the data path for each traffic flow. To obtain
traffic characteristics of the network in terms of the key path metrics, active measurement
techniques are used. In particular, a ping-based tool is used for sending probe packets, from each
edge-network gateway, to the destination networks' RLOCs. Upon retrieving the destination
network's RLOCs from the mapping server, the source gateway sends a ping probe, through each
of its egress links, to each of the destination's RLOCs. By analysing the solicited responses,
topological characteristics such as round-trip-times, jitter and packet loss are obtained. The values
obtained from the responses are used to rank the different paths.
6. 88 Computer Science & Information Technology (CS & IT)
3.2 LISP-based Path Ranking
With LISP, multihomed edge networks are able to achieve some degree of path diversity, as
multiple alternate gateways become visible between source and destination networks. Achieving
optimal end-to-end performance in such environments requires that the source and destination
networks should be able to evaluate the alternate paths, and to dynamically select both the source
network's egress link and the destination network's ingress link. In particular, the source network
needs a way of discovering and evaluating end-to-end links through alternate egress and ingress
links.
The routing cost for an edge-to-edge path can be modelled as a vector comprising the measured
performance metrics and the network RLOC preferences [8]. Let P(Axy); P(Byx) be the
performance cost vectors for the two edge networks A and B, with respect to forwarding traffic
through their access links x and y respectively. The performance cost P from each edge network
comprises a set of end-to-end path metrics K, (eg. latency, packet loss, jitter) weighted by
variable _, such that:
To calculate the total cost, T(Axy); T(Byx), the source preference cost (ɸ(x)) is combined with the
performance cost P, using a variable scaling factor λ:
In LISP implementation, selection of the local egress RLOC as well as the remote ingress RLOC
is determined by priority and weight values recorded in RLOC records that are retrieved from the
mapping system and stored in a local cache. If multiple locators for the same destination exist, the
priority values, ranging from 0 to 255, are used to select the locator that is most preferred. In this
work, the calculated path costs are translated into RLOC priority values using a log function that
scales the costs into values between 0 and 255. The egress-ingress RLOC pair that has the lowest
resultant cost is the one that is used for the outgoing traffic flow between the locator pair. While
the mapping remains valid, all subsequent matching flows between the locator pair uses the
cached locator ranking. The cached locator mapping remains valid for a configurable TTL period
of 60 seconds, after which the mapping and locator ranking process is repeated.
7. Computer Science & Information Technology (CS & IT) 89
3.3 End-to-end Path Configuration
Each edge network gateway has a Circuit Pusher, an SDN module for setting up end-to-end
circuits between locators. After the source gateway has selected both the local and remote
locators, it invokes the SDN module to configure, through an SDN network controller, a
unidirectional end-end circuit between locators. This is achieved by installing flow entries on all
switches that are part of the shortest path between two selected locators. The installed path is
unidirectional because each source gateway independently performs RLOC lookups and path
ranking, and sets up a circuit toward the remote RLOC.
4. TESTBED IMPLEMENTATION
The overarching purpose of this study is to evaluate the extent to which LISP and SDN can
support dynamic selection of end-to-end paths between multi-homed edge networks. The
objective was therefore to assess network performance in a topology that uses a dynamic
performance-based path selection, versus static default path routing. Figure 4 depicts the testbed
implementation.
Fig. 4. SDN/LISP Traffic Engineering for dual homed NRENs
4.1 Topology
The testbed was built using a LISP-based SDN simulated network consisting of an SDN
(Openflow) controller, an Open flow switch, and a LISP mapping server. The topology was built
in a virtual environment, using the Mininet network emulator [9]. Mininet allows the creation of
virtual hosts, switches, controllers and links. Furthermore, Mininet nodes run a standard Linux
kernel and net-work stack, and can therefore run real network applications. The switches and
network controllers are based on the standard SDN protocol Open Flow. An Internet-like
topology was built in Mininet and was used together with a LISP mapping system and LISP
transit routers (xTRs), which are based on an open source implementation of LISP called Open
LISP[10]. The interconnection among the edge networks is through ISPs that interconnect at a
common Internet exchange point. More specifically, the network was designed with the following
features:
8. 90 Computer Science & Information Technology (CS & IT)
• 48 routers connected to the IXP switch; the routers represent participant networks at the
IXP. The JINX has, as of December 2014, 48 participant networks.
• Each IXP participant has 10 edge networks connected to it, and each edge network is
dual-homed and serves a total of 5 hosts, representing campus networks. In total, there
were 1,200 end hosts as potential sources and destinations for traffic flowing through the
IXP fabric.
• To simulate multi-homing, each edge network is connected to two provider networks
present at the IXP. The primary link represents the intra-Africa link and is configured
with lower latency, while the secondary link represents an transcontinental link and is
configured with higher latency.
• The access links between the edge networks and the provider networks are configured
with band-width evenly distributed between 2 Mbps and 4 Mbps. The links between the
IXP participants (provider networks) and the IXP are equally provisioned with bandwidth
of 100 Mbps.
• The end-to-end latencies are modelled on latencies measured for traffic exchanged
between African NRENs. Round trip latencies in this experiment are distributed between
60 ms and 700 ms.
4.2 Network Traffic
A realistic evaluation of a network model requires emulating the network with traffic that
characteristically resembles the traffic pattern of the emulated networks. This is important, as a
major scalability issue with centralized network architectures, such as the Open flow controllers
and LISP mapping systems, hinges on their ability to cope with the traffic flow characteristics in
the network [11].
Researchers have characterized Internet traffic based on flow metrics such as byte volume, packet
volume, flow duration, and flow inter-arrival time. The percentage of UDP traffic has increased
with the advent of many UDP based P2P applications and streaming multimedia, which transport
large volumes of data[12]. In 2009, a CAIDA survey showed that the ratio of UDP to TCP traffic
was almost 0.21 in terms of packet numbers, 0.11 in terms of byte count, and 3.09 in terms of
flows.
The length of data flows impacts the relative latency introduced at the controller and,
furthermore, the number of active flows has implications for the size of the forwarding tables
maintained at each Open Flow forwarding device. For example, a characterization of university
campus network traffic [13] established that 21.4% of the traffic was carried by flows longer than
10 minutes, 12.6% by flows longer than 20 minutes, and nearly 2% was carried by flows longer
than 100 minutes. Short flows are bursty and have flow speeds ranging from 1 Bps to over 10
kBps, while longer flows are slower, around 50 Bps for 40 min flows, [13].
The test traffic for the experiment is therefore based on the following Internet traffic
characteristics:
1. Protocol flow: UDP to TCP ratio: 3:1
2. Flow Duration:
- 0 - 2 sec : 45% of all the traffic
- 2 sec - 5 mins : 55% of all the traffic
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3. Flow inter-arrival time: 4 ms - 40 ms (or 25 to 250 new flows per sec)
4. Flow rate:
- Short flows (0 - 60 sec) : 1 Bps - 10 kBps
- Medium flows (1 min - 5 mins) : 100 Bps - 50 Bps
4.3 Test Traffic Generation
Some of the most widely used traffic generators include Iperf, PackETH, D-ITG, and Ostinato
[14,15]. PackETH [16] is a stateless packet generator designed for Ethernet networks, and
supports a number of protocols including UDP, TCP and ICMP. Iperf[17] is mostly used for
evaluating topology parameters such as bandwidth, delay, window size and packet loss, for both
TCP and UDP traffic. Iperf provides an estimation of received and transmitted data rates.
Ostinato[14] is a user level traffic generator tool that supports UDP and TCP protocols at multiple
rates. DITG (Distributed Internet Traffic Generator) [18] can generate Internet traffic with a user
defined packet inter-departure times. This work made use of D-ITG for traffic generation and for
obtaining performance metrics.
5. RESULTS
A key objective of the RLOC ranking was to discover and direct traffic flows through lower
latency paths towards multi-homed remote networks. TCP traffic is particularly impacted by
network round-trip-times, and this paper has considered performance of TCP traffic when RLOC
ranking and dynamic path configuration is employed. Furthermore, the evaluation also considers
how jitter is affected due to path ranking and circuit configuration.
5.1 Round Trip Times
The key results from a series of experiments suggest that in cases where the paths towards the
different RLOCs of an edge network have significantly different RTTs, latency based ranking and
selection of RLOCs does help to lower the overall latency in the network. Figure 5 shows the
RTT dispersion and mean for TCP traffic in a LISP/SDN topology, with each flow lasting
between 1sec and 300 sec. The vertical lines represent the dispersion of flow RTTs over the time
interval, with each traffic flow RTT averaged over 2 sec intervals. The instantaneous average
RTT for all the flows is indicated by the blue and red lines. The results show that RLOC ranking
results in a 20 % lower overall latency compared to the default gateway forwarding.
The performance gains from RLOC ranking appear to diminish significantly with increased
network load. As the network gets more congested, the observable gain from RLOC ranking is
significantly reduced. This can be explained from the fact that as the network links get more
congested, the otherwise shorter links begin to exhibit equally higher RTTs. With higher RTTs,
many of the probe packets time-out, prompting the egress RLOC to forward packets towards the
destination's default RLOC. Even when the probe packets generate responses, the RTT values of
the otherwise shorter paths tend to be just as high, thereby being ranked lower and resulting in
selection of the other paths for traffic forwarding. Figure 6 shows the dispersion and mean of the
RTT at the point when the network is congested. Figure 7 and Figure 8 further illustrates the
RLOC ranking effects in normal network operation and when there is congestion.
10. 92 Computer Science & Information Technology (CS & IT)
Fig. 5. Round-trip times for network operating with LISP gateway ranking vs non-path ranking LISP
operation
5.2 Jitter
Apart from latency, jitter is another key metric that affects performance of interactive Internet
applications. Some causes of Internet jitter include congestion in the core network as well as in
the access links. Results from the simulation network suggest that RLOC ranking and dynamic
path configuration does increase the overall jitter in the network. Given a network topology and
traffic profile, RLOC ranking in a LISP network results in higher overall jitter than when no
RLOC ranking is employed. Figure 9 shows the jitter for both RLOC ranking and the normal
LISP operation. On average, RLOC probing is seen to increase jitter by 20 %. The jitter can be
attributed to the delay experienced by some packets during the time the local gateway performs
path measurement and ranking.
However, as the network reaches congestion point, both the RLOC ranking and non-ranking
scenarios experience similarly higher jitter. This is illustrated in Figure 10, where jitter for both
ranking and non-ranking LISP operations have their average jitter increase significantly. As
congestion occurs, the probe engine fails to discover any lower latency RLOCs and resorts to
using default paths.
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Fig. 6. Round trip times for path ranked and non-path ranked LISP operation at network congestion point
Fig. 7. RTT without congestion
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Fig. 8. RTT with congestion
Fig. 9. Jitter with no congestion
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Fig. 10. Jitter with congestion
6. DISCUSSION
6.1 RLOC Ranking During Congestion
The RTT results show that the RLOC ranking mechanism fails to produce positive results under
network congestion. In general, centralized systems are venerable to performance bottlenecks
under system overload. For instance, inter-arrival times of traffic flows have implications on the
performance of centralized network controllers [11]. In an Open Flow network architecture, for
example, a scalability challenge stems from the fact that the first packet of each flow is forwarded
to a central controller, which is responsible for determining and configuring the forwarding path
for the flow. Similarly, for LISP, the egress gateway performs a lookup from a mapping server to
determine each new flow's destination network's RLOC. In either case, the flow inter-arrival time
has a scalability impact on the network, as higher rates for new flows result in bottlenecks at the
SDN and LISP controllers, thereby introducing latency and jitter. Although the scalability and
performance bottleneck would affect both the ranking and normal LISP operations, the RLOC
ranking mechanism would experience more severe impact as it is dependent on receiving replies
from probe packets, which take longer when there is congestion. One way of dealing with RLOC
ranking during congestion is to reduce the amount of probing required by using historical per-
formance information to select the RLOCs. Also, the amount of probing needs to be reduced by
performing ranking only for critical flows (eg. delay intolerant applications).
6.2 Effects of RLOC Ranking on Jitter
The observed jitter in the experiments reveals that the process of RLOC ranking and path
configuration does increase the overall jitter in the network. One way of minimising the jitter is to
reduce the path setup time. In the presented model, a new end-to-end path is not setup until path
14. 96 Computer Science & Information Technology (CS & IT)
probing/ranking and SDN path configuration is complete. Reducing jitter would require pre-
ranking the RLOCs, so that new flows don't wait too long before circuits are set up. Pre-ranking
of paths could be based on RLOC performance history as well as known traffic characteristics in
the network.
6.3 Model Limitations
One challenge with the model presented in this paper is the assumption that NRENs are
multihomed. This is true to a large extent as, in general, campus networks that are part of NRENs
have more than one Internet attachment points; a specific network attachment point for traffic
destined within the NRENs' network and another for traffic destined to non-NREN networks.
Where an NREN has only one Internet attachment point, it can still appear multi-homed by
performing prefix de-aggregation and announcing separate prefixes with different RLOCs. This
would enable them to still benefit from multipath traffic engineering.
Another challenge is to do with independent selection of the remote RLOCs by the source
network, which could result in violation of the destination network's preferences and policies.
This could negatively impact on the destination's policies. For edge networks that have some
form of cooperation, such as the case with NRENs within the UbuntuNet Alliance, a mutually
beneficial approach would be to employ some level of coordination in selection of gateways.
While each NREN would aim to optimize traffic cost and QoS performance (latency),
collectively, the NRENs can optimize the performance of some common preferred applications.
Balancing the individual NREN's optimization objectives with those of the peering domains
requires coordination and routing cooperation among the peers. For UbuntuNet Alliance, benefits
from this level of cooperation could include better performance of the network applications,
reduction in usage of intercontinental links, as well as reduction in the cost of inter-NREN traffic
exchange.
7. CONCLUSION AND FUTURE WORK
Results from this study show that through dynamic ranking of the local and remote LISP locators,
a source network can perform traffic engineering towards a destination without requiring any
form of cooperation in the network. It is evident that by leveraging LISP capabilities through
integration with SDN, there is potential for improving traffic exchange performance. This how-
ever implies granting NRENs more exibility and control of routing and traffic engineering across
Internet exchange points, such as to be able to dynamically select routing paths among multiple
ingress and egress links. This could have important applications for NRENs that experience high
bandwidth costs [19]. The ability to perform multipath routing has potential to over significant
performance enhancements and cost savings. For example, delay-sensitive applications such as
VoIP, can be mapped onto lower latency intra-continental links, while traffic for bandwidth
intensive _le-sharing applications can be routed through higher capacity inter-continental links.
Furthermore, by using Openow's ability to customize the packet forwarding rules, and by
appropriately matching packets into ows using header tags, it is possible to set up application
specific traffic engineering mechanisms. With this capability, a group of NRENs can jointly form
traffic engineering strategies specifically for certain applications of common interest, e.g. inter-
university video streaming, or access to e-library sites within the domain.
15. Computer Science & Information Technology (CS & IT) 97
This paper has motivated for and described a performance based traffic engineering mechanism
that involves path measurement, gateway ranking, and SDN-based edge-to-edge path
configuration. While Internet infrastructure being implemented by the UbuntuNet Alliance
through the Africa Connect project has great potential to improve traffic exchange among African
NRENs, the inability of traditional protocols to fully take advantage of the available path
diversity remains a challenge. For this reason, African NRENs should, apart from implementing
the physical interconnectivity, also consider appropriate traffic engineering mechanisms to allow
individual NRENs to discover and use optimal inter-NREN paths. However, a globally optimal
solution requires coordination and collaboration among several domains that form part of the end-
to-end path. Future work will investigate mechanisms that would enable African NRENs to
perform collaborative performance based and application specific traffic engineering.
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AUTHORS
Josiah Chavula is a PhD candidate at the Hasso-Plattner-Institute in Computer
Science, at the University of Cape Town. His research focuses on Internet
performance and traffic engineering in Africa's National Research and Education
Networks (NRENs). He is interested in approaches for achieving flexible
collaborative Internet traffic engineering using Software Defined Networking
(SDN). He obtained a Master of Science degree (Networking and Internet Systems)
from Lancaster University (UK), and a BSc (Computer Science) from University of
Malawi.
Melissa Densmore is a Senior Lecturer in the Department of Computer Science at
University of Cape Town. Melissa completed her PhD at University of California,
Berkeley in Information Management and Systems, a 3 year ethnographic study of
the use of Internet and mobile technologies by health practitioners and NGO staff
in a health financing program in Uganda, has an MSc in Data Communications,
Networks and Distributed Systems from University College London, and holds a
BA in Computer Science from Cornell University.
Hussein Suleman is an Associate Professor in Computer Science at the University
of Cape Town. His research is situated within the Centre for ICT for Development
(ICT4D) and the Digital Libraries Laboratory. Hussein's main research interests are
in digital libraries, ICT4D, information retrieval, cultural heritage preservation,
Internet technology, high performance computing and computer science education.
He completed his undergraduate degrees and MSc at the then University of
Durban-Westville (now University of Kwazulu-Natal) and finished a PhD at
Virginia Tech in 2002, in the area of component-based digital libraries.