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Topology control is one of the key technologies in ad hoc network. Recently some topology control algorithms focus on reducing the end-to-end delay have been proposed. However, they do not consider the delay which is caused by contending for the shared channel and collision at MAC layer. In this paper, we put forward a new delay model to character the link delay which is composed by the transmission...
An ad hoc wireless network has a dynamic nature that leads to constant changes in its network topology. As a consequence, the routing problem becomes more complex and challengeable, and it probably is the most addressed and studied problem in ad hoc networks. Based on the routing information update mechanism Ad hoc wireless networks routing protocols are classified into Proactive, Reactive and Hybrid...
Wireless Mesh Networks (WMNs) are primarily viewed as access networks, with traffic flowing in and out of the mesh via gateways. However, in many scenarios, point-to-point (P2P) traffic within the WMN is also important, with the approach used to handle this traffic affecting the performance of not only the P2P flows, but all other traffic as well. This work studies the handling of P2P traffic in the...
In delay tolerant networks (DTNs), the lack of continuous connectivity, network partitioning, and long delays make design of network protocols very challenging. Previous DTN research mainly focuses on routing and information propagation. However, with large number of wireless devices' participation, how to maintain efficient and dynamic topology of the DTN becomes crucial. In this paper, we study...
With the promotion of IP packet applying to distributed communications network, the capacity of self-organizing network will be an urgent need. The single-channel single-interface model does not meet the requirements of complex systems. In this paper, we build a distributed network topology which refers to features of military communications network, and implement M-ZRP which supports multi-channel...
Most reactive routing protocols hoc wireless networks rely on a broadcast algorithm known as flooding for route discovery. With flooding, many copies of each message are retransmitted unnecessarily resulting in a sub-optimal resource consumption. Given that mobile devices usually have limited power and computational resources, it is of the utmost importance to reduce the resource consumption of each...
An overview of a theoretical study of distributed coordination between nodes in a Mobile Ad-hoc Network (MANET) is presented with preliminary simulation observations. The main focus is placed on using an average consensus control law and its stability guarantees. First a linear control law is discussed, based on the Laplacian matrix of the underlying graph depicting the topology of a network of agents...
Wireless Mesh network (WMN) are dynamically self-organizing and self-configured, with the nodes in the network automatically establishing an ad-hoc network and maintaining the mesh connectivity. The ability to use multiple-radios and multiple channels can be cashed to increase aggregate throughput of wireless mesh network. Thus the efficient use of available interfaces and channels becomes the key...
In this paper, an improved AODV - PWAODV (Piggyback and Weighted neighbor stability Ad hoc On-demand Distance Vector routing) protocol with lower route cost and smaller delay is presented. In the algorithm we introduce a piggyback mechanism and weighted neighbor stability algorithm. Essentially, the route cost can be reduced greatly by the use of piggyback mechanism and the link stability algorithm...
Energy efficient topology in Ad-hoc networks can be achieved mainly in two different ways. In the first method, network maintains a small number of nodes to form a connected backbone and the remaining nodes sleep to conserve energy. This method is effective for low traffic networks. Energy efficiency in the second method is achieved by power control technique. This technique is effective in high traffic...
The inherent uncertainty in wireless mobile ad hoc networks (MANET), due to nodal mobility, unstable links, and limited resources, frequently renders routing paths unusable. Due to the unpredictable movement of mobile nodes, the network topology of a mobile ad hoc network changes frequently. It will directly cause the routes to be broken and greatly degrade the network performance. However, selecting...
A wireless ad-hoc network is an autonomous system of wireless routers, fixed or mobile those communicate with each other via radio links without the support of any fixed wired infrastructure. In such a topology, communication is achieved by use of multiple hop paths between the sender and the receiver. Wireless ad-hoc networks constitute a typical paradigm of networks whose performance and operability...
Routing is one of the most important challenges regarding mobile ad hoc networks (MANETs). Having no fixed infrastructure along with frequent network topology changes, as a result of nodes mobility, necessitate routing protocols to operate under cooperation of all network nodes. Lack of cooperation in routing can lead to performance reduction and even network denial of service. Uncooperative behavior...
We present a multi-channel MAC protocol for ad hoc networks, for nodes equipped with a single half-duplex transceiver, combining the use of OFDMA and CDMA. To ease OFDMA channel management the network is clustered. Channel groups are defined by a resolvable balanced incomplete block design (BIBD) to minimize interference. Unique CDMA codes are assigned to each cluster. Clusterheads manage and assign...
Cognitive radio ad hoc networks (CRAHNs) solve the problem of spectrum utilization when the licensed or primary user (PU) activity changes over time. This affects not only the spectrum availability, but also the network topology, making the analysis of scaling laws very challenging. Currently, the effect of PU activity on the network scaling laws has not been theoretically analyzed, to the best of...
A Vehicular Ad Hoc Network (VANET) not only experiences highly mobile and frequently disconnected, but may also have to deal with rapid changes of network topologies, especially when accidents and road traffic jams happen. In this paper, we propose a novel approach to address this issue. Due to the intermittent connectivity in VANET, we adopt the idea of carry and forward, where a moving vehicle carries...
Current trends in applications, services and socializing increase demands for network infrastructures, capable of supporting real-time traffic and Quality of Service (QoS). In this work, we aim at improving the inherently stringent wireless multi-hop network structure, based on the notion of inverse Topology Control (iTC). Taking into account socially-induced network churn operations, we focus on...
Doing research on mobile ad hoc network (MANET) security involves several constraints, some of which are wireless environment's attributes, such as bandwidth and delay, and the correctness of network topology. Testing and evaluating using real wireless devices are costly and somehow impractical, so many tools have been developed in order to create media by which researchers can deeply investigate...
Without any pre-existing fixed network infrastructure with rapid configuration of wireless connections on-the-fly, network topology in MANETs keep on changing rapidly. Thus achieving data transmissions between wireless nodes in MANETs with improved QoS parameters become a challenging issue. To achieve this one has to concentrate on the routing protocol they choose. In our paper we proposed an algorithm...
Increasing spectral efficiency has been a constant challenge in wireless communications. Many military and commercial applications require that wireless networks operate in dynamic environments and provide high data rates. Multiuser detection (MUD) has been demonstrated to increase spectral efficiency by increasing spectrum reuse. Most MUD research to date has focused on the physical layer (PHY) technology...
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