4792
Fast Sensor Placement Algorithms for Fusion-Based Target Detection
Mission-critical target detection imposes stringent performance requirements for wireless sensor networks, such as high detection probabilities and low false alarm rates. Data fusion has been shown as an effective technique for improving system detection performance by enabling efficient collaboration among sensors with limited sensing capability. Due to the high cost of network deployment, it is desirable to place sensors at optimal locations to achieve maximum detection performance. However, for sensor networks employing data fusion, optimal sensor placement is a non-linear optimization problem with prohibitive computational complexity. In this paper, we present fast sensor placement algorithms based on a probabilistic data fusion model. Simulation results show that our algorithms can meet the desired detection performance with a small number of sensors while achieving up to 7-fold speedup over the optimal algorithm.
17432242
Opportunistic Optical Hyperchannel and Its Distributed QoS Assuring Access Control
Light-trail is proposed as a candidate to carry IP traffic over wavelength-division multiplexing optical networks given its capability of enabling high-speed provisioning and accommodating multigranularity traffic. In a light-trail, the optical shutters at the start node and the end node are configured to be in OFF state and the optical shutters at the intermediate nodes are configured to be in ON state. Thus, an optical bus is formed, allowing traffic multiplexing without the state change of any optical shutter. This, however, limits the system throughput and also makes it impossible to implement a fully distributed medium access control (MAC) protocol to assure quality of service (QoS) in a light-trail. With the recent development on ultrafast optical shutter, we propose an improved light-trail architecture, called opportunistic hyperchannel in this paper. In an opportunistic hyperchannel, an intermediate node can dynamically control its optical shutter which makes it possible to design a fully distributed QoS assuring MAC protocol. We then present a QoS assuring distributed dynamic scheduling protocol, namely, minimum source round robin (minSrcRR) protocol, for opportunistic hyperchannels. Theoretical analysis on the effectiveness of the proposed QoS assuring protocol and the worst-case delay bound are also derived in this paper. The simulation results quantitatively demonstrate the advantage of opportunistic hyperchannels and the effectiveness of minSrcRR protocol.
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.
17259450
Routing and wavelength assignment for core-based tree in WDM networks
In this paper, we address the routing and wavelength assignment problem for the core-based tree (CBT) service in a wavelength-division-multiplexing (WDM) network, where k sources need to send data to a common core node. We formally model the problem as a problem of finding k shortest lightpaths from sources to the core with the constraint of wavelength collision free. To address different objectives, we define and study several subproblems. For the feasibility and the minimum total cost problems of k shortest lightpaths, we show how the classical network flow algorithms can be modified and applied efficiently on the network flow model constructed on the transformed wavelength graph. For the minimum max-cost and the constrained feasibility problems, we prove their NP-completeness and propose two efficient heuristic algorithms. Simulation results show that the proposed heuristic algorithms achieve performance very close to the calculated lower bounds.
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
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.
42010730
Cross-layer Routing Design in Cognitive Radio Networks by Colored Multigraph Model
In this paper, the cross-layer design routing in cognitive radio(CR) networks is studied. We propose a colored multigraph based model for the temporarily available spectrum bands, called spectrum holes in this paper. Based on this colored multigraph model, a polynomial time algorithm with complexity O(n2) is also proposed to develop a routing and interface assignment, where n is the number of nodes in a CR network. Our algorithm optimizes the hop number of routing, meanwhile, the adjacent hop interference (AHI) is also optimized locally.