Efficient algorithm for mobile multicast using anycast group

The authors present a novel and efficient multicast algorithm that aims to reduce delay and communication cost for the registration between mobile nodes and mobility agents and solicitation for foreign agent services based on the mobile IP. The protocol applies anycast group technology to support multicast transmissions for both mobile nodes and home/foreign agents. Mobile hosts use anycast tunnelling to connect to the nearest available home/foreign agent where an agent is able to forward the multicast messages by selecting an anycast route to a multicast router so as to reduce the end-to-end delay. The performance analysis and experiments demonstrated that the proposed algorithm is able to enhance the performance over existing remote subscription and bidirectional tunnelling approaches regardless of the locations of mobile nodes/hosts<br /

Inter-domain traffic routing in vehicular delay tolerant networks

“Copyright © [2010] IEEE. Reprinted from IEEE International Conference on Communications (IEEE ICC 2010). ISSN:1550-3607. This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.”In this paper, we consider the problem of dynamic inter-domain traffic routing between a VDTN and a non-DTN (e.g., Internet). The inter-domain traffic can be classified as inbound and outbound traffic. Our main contribution in this work is the intro- duction of several fault-tolerant routing algorithms for inbound and outbound traffic. Using simulations, we compare the performance of the proposed algorithms in terms of required resources, packet delivery time, and blocking probability.This work was supported in part by the Instituto de Telecomunicações, Next Generation Networks and Applications Group (NetGNA), Covilhã Delegation, Portugal in the framework of the VDTN@Lab Project

Data Collection Method for Mobile Sensor Networks Based on the Theory of Thermal Fields

Many sensor applications are aimed for mobile objects, where conventional routing approaches of data delivery might fail. Such applications are habitat monitoring, human probes or vehicular sensing systems. This paper targets such applications and proposes lightweight proactive distributed data collection scheme for Mobile Sensor Networks (MSN) based on the theory of thermal fields. By proper mapping, we create distribution function which allows considering characteristics of a sensor node. We show the functionality of our proposed forwarding method when adapted to the energy of sensor node. We also propose enhancement in order to maximize lifetime of the sensor nodes. We thoroughly evaluate proposed solution and discuss the tradeoffs

A Markov chain model for drop ratio on one-packet buffers DTNs

Most of the efforts to characterize DTN routing are focused on the trade-off between delivery ratio and delay. Buffer occupancy is usually not considered a problem and most of the related work assumes infinite buffers. In the present work, we focus on the drop ratio for message forwarding considering finite buffers. We model message drops with a continuous time Markov chain (CTMC). To the best of our knowledge, there is no previous work with such approach. We focus on the worst case with 1-packet buffers for message forwarding in homogeneous inter-contact times (ICT) and 2-class heterogeneous ICT. Our main contribution is to link the encounter rate(s) with the drop ratio. We show that the modeled drop ratio fits simulation results obtained with synthetic traces for both cases

A novel middleware based web database model

In this paper, we propose a novel model for web-based database systems based on the multicast and anycast\u27 protocols. In the model, we design a middleware, castway, which locates between the database server and the Web server. Every castway in a distributed system operates as a multicast node and an anycast node independently, respectively. The proposed mechanism can balance the workload among the distributed database servers, and offers the &quot;best&quot; server to serve for a query. Three algorithms are employed for the model: the requirement-based probing algorithm for anycast routing, the atomic multicast update algorithm for database synchronization, and the job deviation algorithm for system workload balance. The simulations and experiments show that the proposed model works very well.<br /

Is Link-Layer Anycast Scheduling Relevant for IEEE802.15.4-TSCH Networks?

International audienceWith the wide adoption of low-power wireless transmissions , industrial networks have started to incorporate wireless devices in their communication infrastructure. Specifically, IEEE802.15.4-TSCH enables slow channel hopping to increase the robustness, and relies on a strict schedule of the transmissions to increase the energy efficiency. Anycast is a link-layer technique to improve the reliability when using lossy links. Several receivers are associated to a single transmission. That way, a transmission is considered erroneous when none of the receivers was able to decode and acknowledge it. Appropriately exploited by the routing layer, we can also increase the fault-tolerance. However, most of the anycast schemes have been evaluated by simulations, for a sake of simplicity. Besides, most evaluation models assume that packet drops are independent events, which may not be the case for packet drops due to e.g. external interference. Here, we use a large dataset obtained through an indoor testbed to assess the gain of using anycast in real conditions. We also propose a strategy to select the set of forwarding nodes: they must increase the reliability by providing the most independent packet losses. We demonstrate using our experimental dataset that anycast improves really the performance, but only when respecting a set of rules to select the next hops in the routing layer

QoS BASED ENERGY EFFICIENT ROUTING IN WIRELESS SENSOR NETWORK

A Wireless Sensor Networks (WSN) is composed of a large number of low-powered sensor nodes that are randomly deployed to collect environmental data. In a WSN, because of energy scarceness, energy efficient gathering of sensed information is one of the most critical issues. Thus, most of the WSN routing protocols found in the literature have considered energy awareness as a key design issue. Factors like throughput, latency and delay are not considered as critical issues in these protocols. However, emerging WSN applications that involve multimedia and imagining sensors require end-to-end delay within acceptable limits. Hence, in addition to energy efficiency, the parameters (delay, packet loss ratio, throughput and coverage) have now become issues of primary concern. Such performance metrics are usually referred to as the Quality of Service (QoS) in communication systems. Therefore, to have efficient use of a sensor node’s energy, and the ability to transmit the imaging and multimedia data in a timely manner, requires both a QoS based and energy efficient routing protocol. In this research work, a QoS based energy efficient routing protocol for WSN is proposed. To achieve QoS based energy efficient routing, three protocols are proposed, namely the QoS based Energy Efficient Clustering (QoSEC) for a WSN, the QoS based Energy Efficient Sleep/Wake Scheduling (QoSES) for a WSN, and the QoS based Energy Efficient Mobile Sink (QoSEM) based Routing for a Clustered WSN. Firstly, in the QoSEC, to achieve energy efficiency and to prolong network/coverage lifetime, some nodes with additional energy resources, termed as super-nodes, in addition to normal capability nodes, are deployed. Multi-hierarchy clustering is done by having super-nodes (acting as a local sink) at the top tier, cluster head (normal node) at the middle tier, and cluster member (normal node) at the lowest tier in the hierarchy. Clustering within normal sensor nodes is done by optimizing the network/coverage lifetime through a cluster-head-selection algorithm and a sleep/wake scheduling algorithm. QoSEC resolves the hot spot problem and prolongs network/coverage lifetime. Secondly, the QoSES addressed the delay-minimization problem in sleep/wake scheduling for event-driven sensor networks for delay-sensitive applications. For this purpose, QoSES assigns different sleep/wake intervals (longer wake interval) to potential overloaded nodes, according to their varied traffic load requirement defined a) by node position in the network, b) by node topological importance, and c) by handling burst traffic in the proximity of the event occurrence node. Using these heuristics, QoSES minimizes the congestion at nodes having heavy traffic loads and ultimately reduces end-to-end delay while maximizing the throughput. Lastly, the QoSEM addresses hot spot problem, delay minimization, and QoS assurance. To address hot-spot problem, mobile sink is used, that move in the network to gather data by virtue of which nodes near to the mobile sink changes with each movement, consequently hot spot problem is minimized. To achieve delay minimization, static sink is used in addition to the mobile sink. Delay sensitive data is forwarded to the static sink, while the delay tolerant data is sent through the mobile sink. For QoS assurance, incoming traffic is divided into different traffic classes and each traffic class is assigned different priority based on their QoS requirement (bandwidth, delay) determine by its message type and content. Furthermore, to minimize delay in mobile sink data gathering, the mobile sink is moved throughout the network based on the priority messages at the nodes. Using these heuristics, QoSEM incur less end-to-end delay, is energy efficient, as well as being able to ensure QoS. Simulations are carried out to evaluate the performance of the proposed protocols of QoSEC, QoSES and QoSEM, by comparing their performance with the established contemporary protocols. Simulation results have demonstrated that when compared with contemporary protocols, each of the proposed protocol significantly prolong the network and coverage lifetime, as well as improve the other QoS routing parameters, such as delay, packet loss ratio, and throughput