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End-to-end Delay (end-to-end + delay)
Selected AbstractsAODV-RIP: improved security in mobile ad hoc networks through route investigation procedureCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 7 2010Byung-Seok Kang Abstract Most routing protocols in mobile ad hoc networks (MANETs) place an emphasis on finding paths in dynamic networks without considering security. As a result, there are a number of attacks that can be used to manipulate the routing in MANET. A malicious node that sends a modified control message to an intermediate node can disturb the network using a control message. To solve this problem, we introduce AODV protocol with route investigation procedure (AODV-RIP). It uses two additional control messages to defeat security attacks that can occur in AODV routing protocol. When an intermediate node that is on the path between the source node and the destination node receives a control message, it sends a Rroute Investigation Request (IREQ) message to the destination node in order to check the reliability of the control message. According to the existence of Route Investigation Reply (IREP), the intermediate node decides whether it transmits the control message to the source node or not. Consequently, the intermediate node that receives the control message confirms that it is using two additive control messages: IREQ and IREP. Through this investigation procedure, the source node can obtain a reliable path for transmitting data packets to an intentional destination node. The simulation results show an improvement in the packet delivery ratio and end-to-end delay at the expense of a moderate increase of the control message overhead compared with the current routing protocols. Copyright © 2009 John Wiley & Sons, Ltd. [source] Minimisation of end-to-end delay in reconfigurable WDM networks using genetic algorithmsEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 8 2009Ramón J. Durán Barroso A new genetic algorithm (GA) is proposed to design logical topologies for wavelength-routed optical networks (WRONs) with the objective of minimising the end-to-end delay. Two versions of the algorithm, called D-GALD (Delay-optimised Genetic Algorithm for Logical topology Design), have been developed. The first one minimises the average end-to-end delay of the packets transported by the network, while the second one minimises the average delay of the most delayed traffic flow. By means of a simulation study, we show that the logical topologies designed by D-GALD support more than 50 per cent higher traffic load,without causing network instability,than those ones designed by other heuristics. Moreover, the utilisation of D-GALD leads to reductions of up to 15 per cent in the average end-to-end delay and around 30 per cent in the average end-to-end delay of the most delayed traffic flow. Copyright © 2008 John Wiley & Sons, Ltd. [source] QoS-aware fair packet scheduling in IEEE 802.16 wireless mesh networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6-7 2010Yajun Li Abstract In this paper, we address the problem of heterogeneous quality-of-service (QoS) provisioning in IEEE 802.16-based wireless mesh networks. Our objective is to provide a novel service differentiation scheme based on distributed scheduling in the IEEE 802.16-based mesh mode, thereby offering QoS guarantees. We first devise a novel scheme for the traffic class differentiation, which can be implemented at the medium access control layer. We then present a QoS-aware fair packet scheduling (QFPS) algorithm to fulfill the QoS provisioning. With QFPS, a traffic flow with urgent QoS demand is guaranteed to be given priority in wireless resource allocation over those ones with mild QoS requirements. A shorter end-to-end delay is therefore expected to be offered for the traffic flows with time-urgent requirements. Moreover, we propose a new fairness model among different traffic flows traversing the same node. All traffic flows passing through a node are served by the Deficit Round-Robin scheduling algorithm to achieve fairness within the same priority group. The experimental results of the QFPS demonstrate that various traffic flows are provided with a differentiated service that offers QoS guarantees. Copyright © 2009 John Wiley & Sons, Ltd. [source] Expedited forwarding end-to-end delay and jitter in DiffServINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 8 2008Hamada Alshaer Abstract The scheduling disciplines and active buffer management represent the main components employed in the differentiated services (DiffServ) data plane, which provide qualitative per-hop behaviors corresponding to the QoS required by supported traffic classes. In the first part of this paper, we compute the per-hop delay bound that should be guaranteed by the different multiservice scheduling disciplines, so that the end-to-end (e2e) delay required by expedited forwarding (EF) traffic can be guaranteed. Consequently, we derive the e2e delay bound of EF traffic served by priority queuing,weighted fair queuing (PQ,WFQ) at every hop along its routing path. Although real-time flows are principally offered EF service class, some simulations on DiffServ-enabled network show that these flows suffer from delay jitter and they are negatively impacted by lower priority traffic. In the second part of this paper, we clarify the passive impact of delay jitter on EF traffic, where EF flows are represented by renewal periodic ON,OFF flows, and the background (BG) flows are characterized by the Poisson process. We analyze through different scenarios the jitter effects of these BG flows on EF flow patterns when they are served by a single class scheduling discipline, such as first-input first-output, and a multiclass or multiservice scheduling discipline, such as static priority service discipline. As a result, we have found out that the EF per-hop behaviors (PHBs) configuration according to RFCs 2598 and 3246 (IETF RFC 2598, June 1999; RFC 3246, IETF, March 2002) cannot stand alone in guaranteeing the delay jitter required by EF flows. Therefore, playout buffers must be added to DiffServ-enabled networks for handling delay jitter problem that suffers from EF flows. Copyright © 2008 John Wiley & Sons, Ltd. [source] Empirical evaluation of receiver-based TCP delay control in CDMA2000 networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 8 2007Oh-keun Kwon Abstract Wide-area broadband wireless technologies such as CDMA2000 often suffer from variable transfer rate and long latency. In particular, TCP window-based rate control causes excessive buffering at the base station because of the lower transfer rate of the wireless link than that of the wired backhaul link. This performance characteristic of TCP further increases the end-to-end delay, and additional resources are required at the base station. This paper presents a practical mechanism to control the end-to-end TCP delay for CDMA2000 networks (or other similar wireless technologies). The key idea is to reduce and stabilize RTT (round-trip time) by dynamically controlling the TCP advertised window size, based on a runtime measurement of the wireless channel condition at the mobile station. The proposed system has been implemented by modifying the Linux protocol stack. The experiment results, conducted on a commercial CDMA2000 1x network, show that the proposed scheme greatly reduces the TCP delay in non-congested networks, while not sacrificing the TCP throughput in congested networks. Copyright © 2006 John Wiley & Sons, Ltd. [source] Power aware scalable multicast routing protocol for MANETsINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 10 2006R. Manoharan Abstract Multicasting is an effective way to provide group communication. In mobile ad hoc networks (MANETs), multicasting can support a wide variety of applications that are characterized by a close degree of collaboration. Since MANETs exhibit severe resource constraints such as battery power, limited bandwidth, dynamic network topology and lack of centralized administration, multicasting in MANETs become complex. The existing multicast routing protocols concentrate more on quality of service parameters like end-to-end delay, jitter, bandwidth and power. They do not stress on the scalability factor of the multicast. In this paper, we address the problem of multicast scalability and propose an efficient scalable multicast routing protocol called ,Power Aware Scalable Multicast Routing Protocol (PASMRP)' for MANETs. PASMRP uses the concept of class of service with three priority levels and local re-routing to provide scalability. The protocol also ensures fair utilization of the resources among the nodes through re-routing and hence the lifetime of the network is increased. The protocol has been simulated and the results show that PASMRP has better scalability and enhanced lifetime than the existing multicast routing protocols. Copyright © 2005 John Wiley & Sons, Ltd. [source] A framework for network quality monitoring in the VoIP environmentINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 4 2007Ana Flàvia M. de Lima Monitoring speech quality in Voice over IP (VoIP) networks is important to ensure a minimal acceptable level of speech quality for IP calls running through a managed network. Information such as packet loss, codec type, jitter, end-to-end delay and overall speech quality enables the network manager to verify and accurately tune parameters in order to adjust network problems. The present article proposes the deployment of a monitoring architecture that collects, stores and displays speech quality information about concluded voice calls. This architecture is based on our proposed MIB (Management Information Base) VOIPQOS, deployed for speech quality monitoring purposes. Currently, the architecture is totally implemented, but under adjustment and validation tests. In the future, the VOIPQOS MIB can be expanded to automatically analyze collected data and control VoIP clients and network parameters for tuning the overall speech quality of ongoing calls. Copyright © 2006 John Wiley & Sons, Ltd. [source] Study of MANET routing protocols by GloMoSim simulatorINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 6 2005Ashwini K. Pandey This paper compares ad hoc on-demand distance vector (AODV), dynamic source routing (DSR) and wireless routing protocol (WRP) for MANETs to distance vector protocol to better understand the major characteristics of the three routing protocols, using a parallel discrete event-driven simulator, GloMoSim. MANET (mobile ad hoc network) is a multi-hop wireless network without a fixed infrastructure. Following are some of our key findings: (1) AODV is most sensitive to changes in traffic load in the messaging overhead for routing. The number of control packets generated by AODV became 36 times larger when the traffic load was increased. For distance vector, WRP and DSR, their increase was approximately 1.3 times, 1.1 times and 7.6 times, respectively. (2) Two advantages common in the three MANET routing protocols compared to classical distance vector protocol were identified to be scalability for node mobility in end-to-end delay and scalability for node density in messaging overhead. (3) WRP resulted in the shortest delay and highest packet delivery rate, implying that WRP will be the best for real-time applications in the four protocols compared. WRP demonstrated the best traffic scalability; control overhead will not increase much when traffic load increases. Copyright © 2005 John Wiley & Sons, Ltd. [source] Comparison of satellite and cellular architectures for downlink broadcast data transmissionINTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 1 2007Adarsh Sridhar Abstract Traditional voice and video-oriented networks such as the cellular and satellite networks are being increasingly used to carry data traffic. We endeavour to compare the downlink broadcast performance of the two architectures against each other on the basis of energy consumption, end-to-end delay and maximum stable throughput. The architectures are modelled as systems of Geo/G/1 queues. Queuing theory arguments and then sample-path based comparisons are used to show that the satellite architecture while being more energy-efficient has a higher delay and a lower maximum throughput. The variation of energy and delay with the total number of receiver nodes is also studied. Copyright © 2006 John Wiley & Sons, Ltd. [source] | |||||||||||||