16381531
Collaborative Target Detection in Wireless Sensor Networks with Reactive Mobility
Recent years have witnessed the deployments of wireless sensor networks in a class of mission-critical applications such as object detection and tracking. These applications often impose stringent QoS requirements including high detection probability, low false alarm rate and bounded detection delay. Although a dense all-static network may initially meet these QoS requirements, it does not adapt to unpredictable dynamics in network conditions (e.g., coverage holes caused by death of nodes) or physical environments (e.g., changed spatial distribution of events). This paper exploits reactive mobility to improve the target detection performance of wireless sensor networks. In our approach, mobile sensors collaborate with static sensors and move reactively to achieve the required detection performance. Specifically, mobile sensors initially remain stationary and are directed to move toward a possible target only when a detection consensus is reached by a group of sensors. The accuracy of final detection result is then improved as the measurements of mobile sensors have higher signal-to-noise ratios after the movement. We develop a sensor movement scheduling algorithm that achieves near-optimal system detection performance within a given detection delay bound. The effectiveness of our approach is validated by extensive simulations using the real data traces collected by 23 sensor nodes.
4917598
A Study of Network Throughput Gain in Optical-Wireless (FiWi) Networks Subject to Peer-to-Peer Communications
Optical-Wireless (FiWi) access network is a newly emerged access network architecture which integrates passive optical networks (PONs) with wireless mesh networks (WMNs) to provide the ubiquitous, low cost, high bandwidth last mile Internet access. Though the PON subnetwork of FiWi network can provide high bandwidth, the interference in the wireless subnetwork still limits the throughput of FiWi network if all traffic goes online to the Internet. However, when peer-to-peer communication from one wireless client to another wireless client is introduced, the proposed integration of PONs and WMNs can significantly improve the network throughput. In traditional WMNs, peer-to-peer communication from one wireless client to another wireless client is carried in the wireless network, which is subject to interferences in wireless communications. In FiWi network, peer-to-peer communication can be carried through the wireless-optical-wireless mode in which the traffic is sent from the source wireless client to its nearest ONU, which is then sent to the ONU close to the destination wireless client through the PON subnetwork and then delivered to the destination wireless client. Such wireless-optical-wireless communication mode introduced by FiWi networks can sustain the interference in wireless subnetwork, thus improving the network throughput. This paper aims to study the network throughput gain in FiWi network subject to peer-to-peer communications and parameters which can affect the network throughput gain. We first have a fair modeling of FiWi networks and traditional WMNs. We then present an LP based routing algorithm for FiWi networks. Extensive simulations have been carried to study the network throughput gain in FiWi networks subject to peer-to-peer communications compared with traditional WMNs. The work provides insightful observations for fully utilizing advantages brought by the integration of PONs and WMNs in FiWi networks.
8394501
Handover Cost Optimization in Traffic Management for Multi-homed Mobile Networks
In this paper, we study the traffic management problem for multi-homed mobile networks with the objective of minimizing the overall handover cost. Two different traffic distribution modes are considered in our study: the Fractional Flow Assignment (FFA) mode which assumes the bandwidth demand from one connection is infinitely splittable and can be assigned to different wireless access networks, and the Integral Flow Assignment (IFA) mode which assumes that at any time the bandwidth demand from each connection can only be assigned to a single wireless network. We show that the general FFA problem and the IFA problem are both NP-hard and propose optimal solutions to the four special cases of the FFA problem and heuristic solutions to the general FFA problem and the IFA problem. Extensive simulations are conducted to verify the impact of the capacity-demand ratio on the performance of the proposed solutions.
3020928
Mobility-Assisted Spatiotemporal Detection in Wireless Sensor Networks
Wireless sensor networks (WSNs) deployed for mission-critical applications face the fundamental challenge of meeting stringent spatiotemporal performance requirements using nodes with limited sensing capacity. Although advance network planning and dense node deployment may initially achieve the required performance, they often fail to adapt to the unpredictability of physical reality. This paper explores efficient use of mobile sensors to address the limitations of static WSNs in target detection. We propose a data fusion model that enables static and mobile sensors to effectively collaborate in target detection. An optimal sensor movement scheduling algorithm is developed to minimize the total moving distance of sensors while achieving a set of spatiotemporal performance requirements including high detection probability, low system false alarm rate and bounded detection delay. The effectiveness of our approach is validated by extensive simulations based on real data traces collected by 23 sensor nodes.
42271256
A Meta Service Description Assisted Service Discovery Protocol for MANETs
The ability to discover services offered in Mobile Ad-Hoc Networks (MANETs) is the major prerequisite for effectively utilizing these services. Caching service advertisements is an essential component in service discovery protocols for MANETs. To fully utilize the advantage of the cached service advertisements, the cached service description can be advertised with the local service description in a vicinity, which however will increase packet size. To reduce packet size, a better solution is to representing the cached service advertisements with a meta service description. In this paper, we introduce a fine-grained group-based meta service description scheme and propose an efficient service discovery protocol: Meta Service Description Assisted Service Discovery Protocol (MSDASDP) for MANETs, where the number of forwarding nodes of request packets is minimized with the help of the fine-grained meta service description. Simulation results both show that MSDASDP is an effective, efficient, and prompt service discovery protocol for MANETs
12834413
Traffic regulation under the percentile-based pricing policy
With the emerging concept of utility computing, appropriate business models are becoming more and more important for the Internet services. Internet Service Providers (ISP) measure IP network usage for billing in different ways. Percentile-based pricing policy is one of the common billing methods. Percentile-based measurement allows the ISP to bill the customer for the maximum bandwidth used during the billing period while forgiving a small amount of bandwidth spiking. In this paper, we investigate how a customer can regulate the traffic volume under the constraint of a predetermined budget such that the amount of band-width spiking is within the range that the ISP can tolerate. Optimal solutions are presented for the offline case where the traffic demands in each small period are given. A traffic scheduling algorithm is given for the online case where the traffic demands in each small period are unknown in advance. Computations are conducted to illustrate the effectiveness of our solutions.
13553414
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.
2128602
Programming Overlay Networks with Overlay Sockets
The emergence of application-layer overlay networks has inspired the development of new network services and applications. Research on overlay networks has focused on the design of protocols to maintain and forward data in an overlay network, however, less attention has been given to the software development process of building application programs in such an environment. Clearly, the complexity of overlay network protocols calls for suitable application programming interfaces (APIs) and abstractions that do not require detailed knowledge of the overlay protocol, and, thereby, simplify the task of the application programmer. In this paper, we present the concept of an overlay socket as a new programming abstraction that serves as the end point of communication in an overlay network. The overlay socket provides a socket-based API that is independent of the chosen overlay topology, and can be configured to work for different overlay topologies. The overlay socket can support application data transfer over TCP, UDP, or other transport protocols. This paper describes the design of the overlay socket and discusses API and configuration options. The overlay socket has been used to develop a variety of applications, from multicast-file transfer programs, to multicast video streaming systems.
5372457
Traffic Engineering with AIMD in MPLS Networks
We consider the problem of allocating bandwidth to competing flows in an MPLS network, subject to constraints on fairness, efficiency, and administrative complexity. The aggregate traffic between a source and a destination, called a flow, is mapped to label switched paths (LSPs) across the network. Each flow is assigned a preferred ('primary') LSP, but traffic may be sent to other ('secondary') LSPs. Within this context, we define objectives for traffic engineering, such as fairness, efficiency, and preferred flow assignment to the primary LSP of a flow ('Primary Path First', PPF). We propose a distributed, feedback-based multipath routing algorithm that attempts to apply additive-increase and multiplicative-decrease (AIMD) to implement our traffic engineering objectives. The new algorithm is referred to as multipath-AIMD. We use ns-2 simulations to illustrate the fairness criteria and PPF property of our multipath-AIMD scheme in an MPLS network.