Abstract IEEE802.15.4 is a standard which specifies the physical and medium access control for low-rate, low-cost, lowpower Wireless Personal Area Networks (LR-WPANs). However, this protocol suffers from several types of collisions; In spite of being able to avoid data packets colliding with each other by using CSMA/CA, the risk of beacon collisions still remains specially in a cluster-tree network topology that... IEEE802.15.4 is a standard which specifies the physical and medium access control for low-rate, low-cost, lowpower Wireless Personal Area Networks (LR-WPANs). However, this protocol suffers from several types of collisions; In spite of being able to avoid data packets colliding with each other by using CSMA/CA, the risk of beacon collisions still remains specially in a cluster-tree network topology that exist more then one coordinator. In order to solve this problem, we propose a novel fixed channel management scheme using MCSP (Multi-Canal Scheduling Protocol). The key objective in this work is to minimize energy consumption within the network by reducing the effects of collisions that may occur if the clusters operate on the same frequency. By using a newly proposed method, MCSP use two beacon avoidance mechanisms: it starts by the fact of dividing of the hole network into a number of sub networks according to the number of the channels exists in order to avoid the inter sub networks beacon frame collisions inside, and in other side, it use the mechanism of beacon frame scheduling for each sub network in order to avoid the intra sub networks beacon frame collisions. We also evaluate the performance of the proposed scheme through simulation. The simulation results demonstrate that the proposed scheme can minimize the possibility of beacon collisions by efficiently managing the multiple available channels. while the dissipated power consumption of PAN coordinator that uses MCSP is more than the PAN that use the classical IEEE 802.15.4. Read More Read Less

Abstract An adaptive algorithm for fair bandwidth allocation, low latency and maximum CPU utilization is proved to be a promising approach for designing system-on-chip for future applications. Adaptive arbitration focuses on user oriented as well as system oriented performance therefore it is more advantageous then the other conventional arbitration algorithms for several reasons; these include fair bandwidth allocation among different masters,... An adaptive algorithm for fair bandwidth allocation, low latency and maximum CPU utilization is proved to be a promising approach for designing system-on-chip for future applications. Adaptive arbitration focuses on user oriented as well as system oriented performance therefore it is more advantageous then the other conventional arbitration algorithms for several reasons; these include fair bandwidth allocation among different masters, simple design and low cost over head. This article provides a comprehensive picture of research and developments in dynamic arbitration algorithm for masters according to the different traffic behavior. The papers published in standard journals are reviewed, classified according to their objectives and presented with a general conclusion. Read More Read Less

Abstract We propose to enlarge research in cSON (community Semantic Overlay Network) a semantic overlay network that requires an organization of peers into communities. cSON is developed for an efficient research in unstructured Peer-to- Peer (P2P) system. In this paper, a community is composed of one super-peer (e.g. the administrator of the community) and of several peers: the super-peer describes a... We propose to enlarge research in cSON (community Semantic Overlay Network) a semantic overlay network that requires an organization of peers into communities. cSON is developed for an efficient research in unstructured Peer-to- Peer (P2P) system. In this paper, a community is composed of one super-peer (e.g. the administrator of the community) and of several peers: the super-peer describes a domain (e.g. ontology) and a peer (with its own data schema) joins one community which is in accordance with its own domain. One challenge in cSON is how to efficiently extend the scope of the research to all communities (and not only to neighboring communities). We propose an algorithm that builds, starting from the administrator of a community, a Maximal-affinity Covering Tree (MCT). The obtained MCTs are used later by queries in order to search in each community the pertinent peers. We give a performance evaluation concerning the creation of a MCT and we compare then our routing algorithm with the one (called baseline) which consists to send queries to only neighboring communities which are able to treat them. Read More Read Less

Abstract Wireless Sensor Networks (WSNs) consist of a large number of Wireless Nodes (WNs) each with sensing, processing, communication and power supply units to monitor the real-world environment information. The WSNs are responsible to sense, collect, process and transmit information such as pressure, temperature, position, flow, vibration, force, humidity, pollutants and biomedical signals like heart-rate and blood pressure. The ideal WSNs... Wireless Sensor Networks (WSNs) consist of a large number of Wireless Nodes (WNs) each with sensing, processing, communication and power supply units to monitor the real-world environment information. The WSNs are responsible to sense, collect, process and transmit information such as pressure, temperature, position, flow, vibration, force, humidity, pollutants and biomedical signals like heart-rate and blood pressure. The ideal WSNs are networked to consume very limited power and are capable of fast data acquisition. The problems associated with WSNs are limited processing capability, low storage capacity, limited energy and global traffic. Also, WSNs have a finite life dependent upon initial power supply capacity and duty cycle. The WSNs are usually driven by a battery. Therefore, the primary limiting factor for the lifetime of a WN is the power supply. That is why; each WN must be designed to manage its local power supply of energy in order to maximize total network lifetime [5]. The life expectancy of a WSN for a given battery capacity can be enhanced by minimizing power consumption during the operation of the network. The CS theory solves the aforementioned problem by reducing the sampling rate throughout the network. A combination of CS theory to WSNs is the optimal solution for achieving the networks with low-sampling rate and low-power consumption. Our simulation results show that sampling rate can reduce to 30% and power consumption to 40% without sacrificing performances by employing the CS theory to WSNs. This paper presents a novel sampling approach using compressive sensing methods to WSNs. First, an overview of compressed sensing is presented. Second, CS in WSNs is investigated. Third, the simulation results on the sampling rate in WSNs are shown. Read More Read Less