We propose the implementation of a wireless sensor network applied to automation control applications, when the guarantee of a delay delivery for the complete reception of messages is necessary. The 802.15.4 wireless standard network offers possibilities of management of the bandwidth. This paper presents the method to guarantee the deadline transmission of periodic messages. For external messages (crossing the network from clusters to its destination), this average latency is used as a parameter of the routing protocol decision balance between energy saving and delay transmission. In this last case, a QoS method all over the network has to be installed to maintain a bounded end to end transmission delay. This work is still in progress. A specific Matlab simulator has been developed, principles of this routing method are mentioned at the end of this paper.
Wireless networks come in force into the market of computer communications. Unfortunately, several standards coexist (e.g., IEEE 802.11, Bluetooth, HomeRF, HIPERLAN), leading to various types of products. The purpose of this article is to present an overview of those standards and to establish a comparative evaluation. We mainly focus on the medium access control protocols and their ability to support the quality of service required by multimedia applications. Those protocols generally support two modes of operation, a random access mode for asynchronous traffic and a polling mode for real-time synchronous traffic. This article analyzes each protocol's ability to support user QoS requirements. Medium access Decentralized for Decentralized for Centralized Decentralized Centralized type for infra-asynchronous traffic asynchronous traffic structure topology Centralized otherwise Centralized otherwise Medium access Decentralized for Decentralized for Centralized Decentralized Centralized with type for ad hoc asynchronous traffic asynchronous traffic election of an AP topology only only for the control of the medium Centralized No No Yes No No if optional direct communication communication Communication Yes if upper layer Yes if upper layer Yes if upper layer Yes Yes if upper layer with out-of-routing is employed routing is employed routing is employed routing is employed range devices Solution for RTS and CTS frames Only one AP used Frequency hopping Active signaling Each neighbor uses hidden node a different channel problem frequency Continued on next page
In 1995 we have presented a new approach to intelligent control based on Restricted Coulomb Energy (RCE) concept which derives from Radial Basis Function (RBF) like neural network.A parallel implementation of adaptive process control using this technique has been discussed.In this paper we present a Zero Instruction Set Computer (ZISC) based parallel implementation of the real time inteffigent adaptive control (using REF like neural network). We expose the architecture of our parallel neumi controller discussing the neurones consumption (use up) in learning phase and it's capabilities in the operation phase (relaxation). Analysis of feature space (parameter space) mapping obtained from experimental validation and experimental results are presented validating our concepts.
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