Packet Ratio Research Articles

Performance analysis model for real-time Ethernet-based computer numerical control system

In order to optimize the embedded system implementation for Ethernet-based computer numerical control (CNC) system, it is very necessary to establish the performance analysis model and further adopt the codesign method from the control, communication and computing perspectives. On the basis of analyzing real-time Ethernet, system architecture, time characteristic parameters of control-loop etc, a performance analysis model for real-time Ethernet-based CNC system was proposed, which is able to include the timing effects caused by the implementation platform in the simulation. The key for establishing the model is accomplished by designing the error analysis module and the controller nodes. Under the restraint of CPU resource and communication bandwidth, the experiment with a case study was conducted, and the results show that if the deadline miss ratio of data packets is 0.2%, then the percentage error is 1.105%. The proposed model can be used at several stages of CNC system development.

Experimental Analysis of AODV and DSR over TCP and CBR Connections with Varying Speed and Node Density in VANET

ehicular adhoc network or VANET is special types of adhoc network consists of moving cars referred to as nodes; provide a way to exchange any information between cars without depending on fixed infrastructure. For efficient communication between nodes various routing protocols and mobility models have been proposed based on different scenarios. Due to rapid topology changing and frequent disconnection makes it difficult to select suitable mobility model and routing protocols. Hence performance evaluation and comparison between routing protocols is required to understand any routing protocol as well as to develop a new routing protocol. In this research paper, the performance of two on-demand routing protocols AODV & DSR has been analyzed by means of packet delivery ratio, loss packet ratio & average end-to-end delay with varying speed limit and node density under TCP & CBR connection.

TRUCE – An Adaptive Trust Management Algorithm Over MANET for Service-Based Mobile Computing Environments

ABSTRACT Managing trust in a distributed MANET is challenging when collaboration or cooperation is critical to achieve mission and system goals such as reliability, availability, scalability, or reconfigurability. This paper discusses initiation and updation of trust values (called as TRUCE Value) over a defined trust model for mobile ad hoc networks. Each node {ni, where i ∈ 1, 2, 3, .., m} is assigned a trust level initially, while trust levels are updated dynamically based on behavior of nodes {n1, n2, .., nm} using threat detection tools and metrics, such as Intrusion Detection Systems (IDSs) (Zhang et al. (2002), between all nodes in the network. The node {nj} neighboring to a node {nk} exhibiting suspicious behavior can initiate trust reports, and based on an average set of trust reports, the node's {nj} trust value is modified. These defined trust reports are propagated through the network using one of TRUCE (proposed methods). A similar acceptable set of trust nodes can join together to evaluate the security of routes {r} from source to destination nodes. Using these trust levels as a guide, the source node can then select a route that meets the security requirements of the message to be transmitted. This paper focuses on design, development of Trust evaluation, assignment algorithm termed TRUCE over a dynamic, highly insecure MANET network. Also, it demonstrates the procedure of establishing a collaborative, dynamic trust model and uses this model as an example to enhance the security of message routing in mobile ad hoc networks. Performance by simulation reveals that existing malicious nodes behave with vulnerability over MANET routing protocols such as DSR and AODV, but TRUCE with proposed trust-based node incentive mechanism performs better than DSR in terms of packet successful delivery ratio and mean number of packets dropped.

Design and evaluation of a query-based jamming detection algorithm for wireless sensor networks

Jamming attacks, which are the main cause of data corruption and network blockages in wireless sensor networks (WSNs), are one of the most serious threats for WSNs. This type of attack not only blocks the ongoing communication in the network, but also causes the wireless nodes to exhaust their energy much earlier than expected. A countermeasure must be deployed against jamming attacks, especially in military and medical applications in which security breaches cannot be tolerated. In this paper, we have designed a new query-based jamming detection algorithm (QUJDA) to detect jamming attacks occurring in WSNs. QUJDA is an attack detection mechanism, which uses an anomaly-based approach and operates in a distributed manner. It separates attacking cases from natural network conditions by the help of packet delivery ratio, bad packet ratio, and the amount of energy consumption parameters. QUJDA enables sensor nodes to operate with their neighbors in a collective sense in order to achieve higher detection rates. QUJDA was evaluated and analyzed over 3 parameters: detection rates, false-positive rates, and communication overheads. According to the simulation results obtained, all critical jamming attacks can be detected with 97% or above detection rates, along with 0.95% or lower false positive rates. In addition, QUJDA only charges about 13% extra communication overhead to the network message traffic of the sensor nodes.

Bio-inspired routing protocol for mobile ad hoc networks

A mobile ad hoc network (MANET) is a non-centralised, multihop, wireless network that lacks a common infrastructure. It therefore needs self-organisation. The MANETs are autonomous, adaptive and dynamic. In MANETs, multihop routing allows multiple routes between the source and destination to be established. This study speaks about a bio-inspired routing protocol for these networks based on AntHocNet. The design for the protocol lies in a heuristic, based on swarm intelligence, which takes into account the limited resources and highly dynamic environment, as well as the restriction on the exchange of routing information. So, the key aspects of the proposed protocol are the disjoint-link and disjoint-node routes, separation between the regular pheromone and the virtual pheromone in the diffusion process and the exploration of routes, taking into consideration the number of hops in the best routes which the authors have previously found out. The simulation results show that the protocol has lower overhead and higher delivered packet ratio than AntHocNet. Likewise, these results indicate that the routing satisfies multiple and independent quality of service constraints and can deal with faults, which provides better load balancing.

Empirical study of CSMA, MACA and EMACA Protocols to Support QoS under varying conditions of Pause Time in Ad-hoc Wireless Network by resources of DSR Routing Protocol

routing protocol was used to evaluate the MACA and EMACA performance. Results show that the EMACA simulation performs well as compared to MACA in sense of Throughput, Total Packet Receive, Drop Packet Ratio and Average Jitter under varying conditions of Pause Time. In this paper we will try to change route selection mechanism proactively. We will also define a link stability parameter in which a stability value is assigned to each link. Given this feature, destination node can estimate stability of routes and can select the best and more stable route. Therefore we can reduce the delay and jitter of sending data packets. We have evaluated the operation of DSR through detailed simulation on a variety of movement and communication patterns, and through implementation and significant experimentation in a physical outdoor ad- hoc networking testbed we have constructed, and have demonstrated the excellent performance of the protocol.

Location-Aided Gateway Advertisement and Discovery Protocol for VANets

Intelligent transportation systems (ITSs) are gaining momentum among researchers. ITS encompasses several technologies, including wireless communications, sensor networks, voice and data communication, real-time driving-assistant systems, etc. These state-of-the-art technologies are expected to pave the way for a plethora of vehicular network applications. However, ITS faces difficult issues when trying to widely deploy such networks and applications. The interconnection of different networks, even in the case of the Internet, is one of the main difficulties that is delaying the wide spread of vehicular networks. In this paper, we present a novel gateway discovery technique for vehicular ad hoc networks (VANets). Our protocol aims to provide an efficient hybrid adaptive Location-Aided Gateway Advertisement and Discovery (LAGAD) mechanism for VANets. First, it permits gateway clients to discover nearby gateways; then, gateways keep advertising themselves to their clients to permit client information about the route toward the discovered gateway without having to resort to reactive route discovery. We discuss the implementation of our algorithm and present its proof of correctness, in addition to the performance evaluation demonstrated through an extensive set of simulation experiments using a Manhattan mobility model. Our results indicate that our LAGAD scheme is scalable and that a significant success rate could be achieved using our algorithm while guaranteeing low response time (on the order of milliseconds) and low bandwidth usage when compared with other gateway discovery approaches. Moreover, our results indicate that LAGAD achieves a high delivery ratio of data packets, as well as a low end-to-end delay, and permits duplicate and ordered data packet reception at the destination gateway.

Cooperative communications based on trust model for mobile ad hoc networks

Wireless networks provide a realm in which cooperation among large numbers of egoists can be attained. As the non-cooperative behaviours of nodes will significantly degrade the network performance, effective cooperation incentive of nodes has become a hot issue in cooperative communication. Although a reputation system can stimulate nodes to cooperate with each other, the recommendation-based trust model may cause a decline in network performance, because of fake recommendation, convergence of iteration and node redemption. To address the above issues, a topology transform-based recommendation trust model is proposed to relieve the malicious effects on the accuracy of recommendation trust, which stem from fake recommendation. Some mathematical analysis and simulation results reveal that the global trust of this proposed trust model has convergence characteristic, and the reputation system with this model can more effectively stimulate node cooperation and performs better in terms of packet successful delivery ratio and mean number of packets dropped. Moreover, the topology transform-based recommendation trust algorithm makes this reputation system more suitable for large-scale networks.

Toward Systematical Data Scheduling for Layered Streaming in Peer-to-Peer Networks: Can We Go Farther?

Layered streaming in P2P networks has become a hot topic recently. However, the feature makes the data scheduling quite different from that for nonlayered streaming, and it hasn't been systematically studied yet. In this paper, first, according to the unique characteristics caused by layered coding, we present four objectives that should be addressed by scheduling: throughput, layer delivery ratio, useless packets ratio, and subscription jitter prevention; then a three-stage scheduling approach LayerP2P is designed to request data, where the min-cost flow model, probability decision mechanism, and multiwindow remedy mechanism are used in Free Stage, Decision Stage, and Remedy Stage, respectively, to collaboratively achieve the above objectives. With the basic version of LayerP2P and corresponding experiment results achieved in our previous work, in this paper, more efforts are put on its mechanism details and analysis to its unique features; besides, to further guarantee the performance under sharp bandwidth variation, we propose the enhanced approach by improving the Decision Stage strategy. Extensive experiments by simulation and real network implementation indicate that it outperforms other schemes. LayerP2P has also been deployed in PDEPS Project in China, which is expected to be the first practical layered streaming system for education in P2P networks.

Optical MAN ring performance with traffic aggregations

We propose to study end to end delays in slotted optical MAN (Metropolitan Area Networks) ring networks. Edge nodes interconnect the fibre of the MAN and the client layer. We propose a mechanism based on IP traffic aggregations with QoS requirements in order to build optical packets. IP packet aggregation is performed in a loop manner by always beginning the aggregation cycle with the highest priority class. In order to overcome the drawbacks of the strict priority discipline, an algorithm depicting a probabilistic priority discipline is presented. The aggregation technique leads to increasing the filling ratio of an optical packet, and consequently, the bandwidth efficiency of an optical network. We present an analytical model in order to evaluate the performance of the aggregation mechanism. Secondly, we study the performance of the optical MAN ring with different packet formats. The MAC protocol is based on the “empty slot” procedure. Different queueing models based on the GI/G/1 queues with server interruptions are presented in order to compute mean packet delays according to the rank nodes.

MAC Enhancement to Support Quality of Services (QoS) in Ad Hoc Wireless Networks: EMACA (Enhancement of Multiple Accesses with Collision Avoidance)

Ad hoc wireless network (AWN) is a collection of mobile hosts forming a temporary network on the fly, without using any fixed infrastructure [1], [2], [3], [4], [5], [6]. QoS (Quality of Service) is the idea that transmission rates, error rates, and other characteristics can be measured, improved, and to some extent guaranteed in advance in ad hoc network however in particular concern for the continuous transmission of high bandwidth video and multimedia information this kind of content dependably transmitting is difficult in public networks using ordinary best effort‖ protocols [1], [2], [3], [4], [7], [8]. MACA (Multiple Accesses with Collision Avoidance) Protocol is a Contention based Sender initiated Protocol which uses Three way handshaking means that RTS—CTS—Data packet exchange [2]. It used in network congestion avoidance to help in determining the correct sending rate by binary exponential back off (BEB) Algorithm in which if a packet transmitted by a node is lost, the node uses the binary exponential back-off (BEB) algorithm to back off a random interval of time before retrying which is then also inadequate trustworthy because of data sending acknowledgement is not received, hence Enhancement of Multiple Accesses with Collision Avoidance (EMACA) Protocol based on MACA with some modifications over it have been proposed. Instead of three way handshaking in MACA, EMACA protocol propose five way handshaking RTS – CTS – DSSI – DSSI_ACK – DATA Sending - ACK. A comparative study was done on QualNet 4.0 Version simulator [9], [10] over MACA & EMACA. AODV routing protocol was used to evaluate the MACA and EMACA performance [4], [5], [11]. Results show that the EMACA simulation performs well as compared to MACA in sense of Throughput, Total Packet Received and Drop Packet Ratio under varying conditions of no. of nodes and pause time.

Smart delivery: a cooperative multi-agent framework for optimised delivery service

Agent technology offers a large number of unique features which makes it a potential choice for implementing real world applications. Owing to their tremendous capabilities, it is regarded as a promising paradigm for future distributed computing. In this paper, we have proposed smart delivery: a cooperative multi-agent framework for optimised delivery service to transfer packets from source to destinations in randomly varying environment in the most efficient way with the help of mobile agents. We are considering packet moving problem in 2D environment consisting of packets and destinations. The task of each mobile agent is to move the packet from the source to the destination. Simulated environment is dynamically generated with varying graph size (i.e., number of nodes in graph), packet ratio and number of destinations. Packets and destinations are randomly placed in the graph and the graph is divided into societies to encourage an efficient and manageable environment for the agents to work in parallel and share expertise within and outside the society. The proposed framework uses decentralised approach and based on layered agent architecture and once initialised manages all the activities autonomously with the help of mobile agents.

The slow start power controlled MAC protocol for mobile ad hoc networks and its performance analysis

We propose and evaluate the performance of a new MAC-layer protocol for mobile ad hoc networks, called the Slow Start Power Controlled (abbreviated SSPC) protocol. SSPC improves on IEEE 802.11 by using power control for the RTS/CTS and DATA frame transmissions, so as to reduce energy consumption and increase network throughput and lifetime. In our scheme the transmission power used for the RTS frames is not constant, but follows a slow start principle. The CTS frames, which are sent at maximum transmission power, prevent the neighbouring nodes from transmitting their DATA frames at power levels higher than a computed threshold, while allowing them to transmit at power levels less than that threshold. Reduced energy consumption is achieved by adjusting the node transmission power to the minimum required value for reliable reception at the receiving node, while increase in network throughput is achieved by allowing more transmissions to take place simultaneously. The slow start principle used for calculating the appropriate DATA frames transmission power and the possibility of more simultaneous collision-free transmissions differentiate the SSPC protocol from the other MAC solutions proposed for IEEE 802.11. Simulation results indicate that the SSPC protocol achieves a significant reduction in power consumption, average packet delay and frequency of RTS frame collisions, and a significant increase in network throughput and received-to-sent packets ratio compared to IEEE 802.11 protocol.

Quality improvement of the dual-wavelength signals in DLOB via power equalization

The data packet buffering can be implemented in dual loop optical buffer (DLOB) through cross-phase modulation (XPM) between the control signal and the data packets. However, the output equality of dual wavelength signals will degrade due to the unbalanced gain and phase shift. This problem can be resolved by power equalization using the saturation characteristics of SOA. The data packets with 2.5 Gb/s can be buffered in DLOB for 16 cycles corresponding to 16.5 μs.The extinction ratio of the output packet is 8 dB while the S/N is 8.1 dB.

애드혹 네트워크에서 에너지 소비 균형을 고려한 적응형 라우팅 프로토콜

ad-hoc네트워크에서 네트워크의 생존시간을 연장하기 위해서는 네트워크 트래픽 부하를 전체 네트워크에 골고루 분산시켜 노드당 평균 에너지 소모율을 균일하게 유지할 수 있어야만 한다. 본 논문에서는 노드의 에너지 잔량 및 사용 빈도 등을 고려해 경로를 설정하는 수정 AODV 프로토콜을 제안하였다. 또한 경로 재설정 과정에서 생성되는 엄청난 양의 AODV 제어 메시지 발생으로 인한 에너지 소모를 줄이기 위해 출발지 노드의 버퍼에 다중 경로 정보를 저장하도록 하였다. 링크 단절 시 경로 재설정 과정 전에 경로 테이블에 저장된 경로 정보를 활용할 수 있도록 하였다. 본 논문에서 제안한 알고리즘의 성능 평가를 위해 기존 AODV 및 에너지 기반 라우팅 프로토콜인 MMBCR방식과 전체 노드의 에너지 잔량, 네트워크 생존시간 및 데이터 패킷 수신율 등 3가지 평가 항목을 사용해 비교하였다. To increase the lifetime of ad-hoc networks, a ratio of energy consumption for each node should be kept constant by equally distributing network traffic loads into all of the nodes. In this paper, we propose a modified AODV routing protocol to determine a possible route by considering a remaining battery capacity of a node and the degree of its usage. In addition, to reduce the amount of energy consumption during the path rediscovery process due to the huge amount of the AODV control messages the limited number of possible routes are stored into a routing table of a source node. When some links of a route fail, another possible path can be looked up in the table before the route discovery process should be initiated. We have tested our proposed method with a conventional AODV and a MMBCR method which is one of the power-efficient energy routing protocols based on the three performance metrics, i.e., the total remaining battery capacity, network lifetime and the ratio of data packets received by the destination node to compare their performance.

HOPNET: A hybrid ant colony optimization routing algorithm for mobile ad hoc network

Mobile ad hoc network (MANET) is a group of mobile nodes which communicates with each other without any supporting infrastructure. Routing in MANET is extremely challenging because of MANETs dynamic features, its limited bandwidth and power energy. Nature-inspired algorithms (swarm intelligence) such as ant colony optimization (ACO) algorithms have shown to be a good technique for developing routing algorithms for MANETs. Swarm intelligence is a computational intelligence technique that involves collective behavior of autonomous agents that locally interact with each other in a distributed environment to solve a given problem in the hope of finding a global solution to the problem. In this paper, we propose a hybrid routing algorithm for MANETs based on ACO and zone routing framework of bordercasting. The algorithm, HOPNET, based on ants hopping from one zone to the next, consists of the local proactive route discovery within a node’s neighborhood and reactive communication between the neighborhoods. The algorithm has features extracted from ZRP and DSR protocols and is simulated on GlomoSim and is compared to AODV routing protocol. The algorithm is also compared to the well known hybrid routing algorithm, AntHocNet, which is not based on zone routing framework. Results indicate that HOPNET is highly scalable for large networks compared to AntHocNet. The results also indicate that the selection of the zone radius has considerable impact on the delivery packet ratio and HOPNET performs significantly better than AntHocNet for high and low mobility. The algorithm has been compared to random way point model and random drunken model and the results show the efficiency and inefficiency of bordercasting. Finally, HOPNET is compared to ZRP and the strength of nature-inspired algorithm is shown.

New multicast scheme based on dynamic mobility prediction in mobile IPv6 environment

A new mobile multicast scheme called mobility prediction based mobile multicast(MPBMM) was proposed. In MPBMM, when a mobile node (MN) roams among subnets during a multicast session, MN predicts the next subnet, to which MN will attach, by the information of its position and mobility speed, consequently speeds up the handoff procedure. Simulation results show that the proposed scheme can minimize the loss of multicast packets, reduce the delay of subnet handoff, decrease the frequency of multicast tree reconfiguration, and optimize the delivery path of multicast packets. When MN moves among subnets at different speeds (from 5 to 25 m/s), the maximum loss ratio of multicast packets is less than0.2%, the maximum inter-arrival time of multicast packets is 117 ms, so the proposed scheme can meet the QoS requirements of real-time services. In addition, MPBMM can support the mobility of multicast source.

An Energy-Efficient Broadcast Scheme for Multihop Wireless Ad Hoc Networks Using Variable-Range Transmission Power

This letter proposes a broadcast scheme for use in ad hoc networks using variable-range transmission power. Preserving energy and ensuring a high delivery ratio of broadcast packets are crucial tasks for broadcasting in ad hoc networks. Using individual broadcast relaying nodes to dynamically vary the transmission range can help saving power and reduce interference during communication. We analyzed the performance of the proposed scheme and compared it to other prevalent broadcast schemes for wireless ad hoc networks based on common-range transmission power.

The behavior of TCP over DOCSIS-based CATV networks

This paper studies the impact of the data-over-cable service interface specification (DOCSIS) media-access control (MAC) protocol on the performance of the transmission control protocol (TCP) in hybrid fiber coax (HFC) broadband access networks. We find that the asymmetry ratio expressed in existing work cannot adequately explain the behavior of TCP in DOCSIS-based networks. To better capture the effect of DOCSIS on TCP, we express the asymmetry ratio (denoted by eta) in another way (denoted by k), considering the time-division multiple-access-like MAC layer operation of DOCSIS. When eta>1, TCP behaves as in a symmetric network, and when etales1, the system acts as in an asymmetric network, and the performance of TCP degrades. We find that the number of simultaneous TCP transfers significantly affects the asymmetry ratio. When the number of active transfers is below two times the maximum number of pending requests in a transmission period, the value of eta is larger than one, regardless of the value of k. However, when the number of active transfers becomes very large, the effect of DOCSIS on TCP becomes negligible, and the asymmetry ratio is determined by the bandwidth ratio of the channels times the length ratio of data and acknowledgement packets. Based on eta, we develop the round-trip delay of sending a data packet for both one-way and two-way transfers, and discuss the buffer requirement at the head end. The accuracy of the analytical model is validated by ns-2 simulations. The analytical result can provide useful guidelines in the design of slot allocation or scheduling mechanisms for any DOCSIS-based broadband access networks, including the emerging IEEE 802.16 WiMAX networks

On the Performance of the HSLS Routing Protocol for Mobile Ad hoc Networks

The area of mobile ad hoc networks has recently attracted much scientific interest, as a very appealing research area with many open issues and still unsolved problems. One of the main issues that concerns researchers is the development of routing algorithms that present good performance and face a hostile environment. Many routing protocols have been proposed, attempting to minimize routing overhead, or to reduce the energy consumed by nodes in order to maximize their lifetime. A critical issue, though, is the development of routing protocols that have the ability to maintain their good characteristics at an acceptable level as the network population grows, an ability known as scalability. FSR, ZRP, HierLS and FSLS protocol family are only a sample of scalable algorithms that have been proposed so far. The HSLS protocol is a member of the FSLS family that is proved to scale the best among the algorithms of the FSLS protocol family. In this paper we propose a mechanism to enhance the already good characteristics of the HSLS protocol aiming at the reduction of routing overhead of the original protocol. This new scheme, which we called AFHSLS, exploits the so-called border nodes, in order to deliver routing packets to their destinations. The new algorithm is proved through simulations to significantly reduce routing overhead, with minor or practically no effect on other metrics, such as packet delivery ratio and delay of data packets.