Search results for " computing"
showing 10 items of 2075 documents
Performance of H.264 compressed video streams over 802.11b based MANETs
2004
We address the problem of video streams transmission in 802.11b based mobile ad-hoc networks (MANETs). Through the study of the delivery of a live encoded video stream, we expose the characteristics of different routing protocols and the infeasibility to provide QoS. The analysis shows the impact of a MANET on H.264 real-time video flows in terms of packet loss, end-to-end delay, jitter and distortion, and the behavior of H.264 error resilience tools in order to determine their effectiveness on such network scenarios. The results show that video traffic has demands that are hard to be met by a standard MANET, and that improvements are required in terms of routing protocols and QoS provision…
ECAR: an Energy/Channel Aware Routing Protocol For Cooperative Wireless Sensor Networks
2011
International audience; The proliferation of low power networks like Wireless Sensor Networks (WSN) rose up new challenges. Power conservation and channel quality become the most important parameters. Obviously, hop count based routing protocols are no more adapted to such networks having power limitations and channel problems. Several alternatives were suggested to cope with these constraints. In MAC layer for example, cooperative protocols were designed to enhance the channel use: the neighbor nodes help the source to retransmit its packets. However, if the path proposed by the routing protocol contains poor channels, the cooperative communications will not save all the packets. Therefore…
NICE-MRP: a Near-Optimal Radio-Interference Aware Multi-path Routing Protocol for MANETs
2013
International audience; Nowadays, with the miniaturization of communication devices, dense and highly mobile ad-hoc networks are very common. Besides, more and more devices have several radio interfaces. In such an environment, multi-path routing should be considered. Yet, only few multi-path ad-hoc routing protocols take into account the radio-interferences which might arise between two geographically close routes. Moreover, they generally only forbid the addition of interfering paths rather than looking for a different, more optimized, solution. This paper presents NICE-MRP, a novel multi-path routing protocol for mobile ad-hoc networks giving efficient solutions with respect to physical …
Distributed routing and channel allocation in multi-channel multi-hop ad hoc networks
2013
In this paper, we propose a novel routing protocol which is integrated with channel assignment for multi-channel multi-hop wireless ad hoc networks. In such a network, each node is equipped with three transceivers. One is always tuned on a control channel which is responsible for control and broadcast messages, and the other two perform as transmitter and receiver respectively for traffic flows on different data channels. The routing protocol works in an on-demand manner, and the proposed routing discovery process selects a path that potentially traverses nodes with lighter traffic load and lower number of carried flows. With a given number of non-overlapping channels, the optimal solution …
RBCR: a Relay-Based Cooperative Routing Protocol for Cooperative Wireless Sensor Network
2011
International audience; In wireless sensor networks several constraints decrease communications performances. The main objective of this paper is to present a multi-objective routing algorithm RBCR that computes routing path based on the energy consumption and channel qualities. Additionally, the channel qualities are evaluated based on the presence of relay nodes. Compared to AODV and AODV associated to a cooperative MAC protocol, RBCR provides better performances.
A combined relay-selection and routing protocol for cooperative wireless sensor networks
2012
International audience; In wireless sensor networks several constraints decrease communications performances. In fact, channel randomness and energy restrictions make classical routing protocols inefficient. Therefore, the design of new routing protocols that cope with these constraints become mandatory. The main objective of this paper is to present a multi-objective routing algorithm RBCR that computes routing path based on the energy consumption and channel qualities. Additionally, the channel qualities are evaluated based on the presence of relay nodes. Compared to AODV and AODV associated to a cooperative MAC protocol, RBCR provides better performances in term of delivery ratio, power …
Distance Constrained Mapping to Support NoC Platforms Based on Source Routing
2010
Efficient NoC is crucial for communication among processing elements in a highly parallel processing systems on chip. Mapping cores to slots in a NoC platform and designing efficient routing algorithms are two key problems in NoC design. Source routing offers major advantages over distributed routing especially for regular topology NoC platforms. But it suffers from a serious drawback of overhead since it requires whole communication path to be stored in every packet header. In this paper, we present a core mapping technique which helps to achieve a mapping with the constraint over the path length. We have found that the path length constraint of just 50% is sufficient in most cases. We als…
A Network Protocol to Enhance Robustness in Tree-Based WSNs Using Data Aggregation
2007
This paper proposes a data gathering strategy for wireless sensor networks and an implementation based on the IEEE 802.15.4 standard. The algorithm combines the benefits of single-path and multi-path routing strategies in a hybrid solution which makes use of alternative paths when necessary. We adopt a caching and retransmission technique, which exploits some peculiar features of data aggregation, with the use of implicit acknowledgments of reception. The paper also discusses simulation results that show how the mentioned techniques, combined with exploitation of the features of the IEEE 802.15.4 standard have been used to obtain an efficient protocol that takes energy consumption into acco…
Accurate reliability and availability models for direct interconnection networks
2001
Fault tolerance in multicomputer interconnection networks has been traditionally studied by determining the worst possible combination of faulty components that causes its failure and then assuming that this will occur. But, the probability of the worst possible combination is usually low, and the routing algorithm may be able to find a route between source and destination nodes. The network dependability parameters computed according to this approach will be underestimated. In this paper we propose a methodology for accurately evaluating interconnection network dependability. In addition, we apply it to obtain an accurate estimation of the reliability and availability parameters in a 2-D m…
QoS Multi-tree Based Routing Protocol for Inter-mesh Infrastructure Communications
2016
Part 5: Network Protocols; International audience; Quality of service (QoS) in wireless mesh networks (WMN) is an active area of research, which is driven by the increasing demand for real-time and multimedia applications, such as VoIP (Voice over IP) and VoD (Video on Demand). In this paper, we propose a QoS multi-tree based routing protocol for wireless mesh environments, named Inter-Mesh Infrastructure Proactive Routing (IMPR). It is a proactive multi-tree routing protocol enabling QoS guarantee for communications from/towards the Internet network through the Mesh Gateway (MG) of the mesh infrastructure. We describe and analyze the simulation results of different scenarios conducted on t…