Goran Horvat

GeoHash and UUID identifier for multi-agent systems

This paper documents the case to address the distributed data storage and widely used unique identifiers which are in use from the beginning of databases and backend systems. The importance of uniqueness for object system identifiers is crucial for efficient data retrieval, storage and comparison. We are representing the new method for objects tagging using synergy mechanism between well known Geohash algorithm and Universally Unique Identifiers we call GHUUID (Geohash+UUID) gaining the agent system spatio-temporal identification of all data available. Multi-Agent systems in their nature strongly rely upon distributed databases across vast amount of data. Some of the interoperability issues are solved with usage of semantic web principles which can be cumbersome to implement and maintain. Most systems need the basic space-time correlation which can be the corner stone for the efficient analysis and data aligning regardless of objects stored and their nature.

User authorization system using ZigBee WSN and AVR architecture

This paper shows a development of an RFID (Radio Frequency IDentification) user authorization (access control system) using wireless ZigBee communication network. The system is designed with the topology of one Master and multiple Slave nodes. Idea is to manage a data base on the Master node which is connected to the Slave nodes through a wireless link. Slave node consists of an RFID reader, LCD touch screen and XBee wireless module. Master node communicates with the LabView application through an Ethernet interface. A program development is shown for both nodes, including all the peripheral modules. The proposed systems major advantage over the existing systems is wireless communications. Wireless network uses XBee wireless modules and can be formed as a mesh network, where an end node server as a router, thus extending the range of the network.

Towards an energy efficient SoC computing cluster

High performance computing (HPC) systems are omnipresent in processing huge amounts of data. However, power consumption of these systems is becoming far from negligible, forcing software developers and hardware providers to deviate from usual performance plans, and to address power consumption and costs. As a result, small-scale applications are becoming infeasible to run on those systems, making room for the power-efficient HW newcomers, such as SoC (System on Chip), to take that role. The idea of composing a large number of small SoCs in a computing cluster can result in a powerful, green, and a simple platform capable of delivering enough performance for the small applications while maintaining low energy consumption and costs. In this paper we present a system composed of four LAN-interconnected dual-core ARM based SoC devices, powered by a single power supply. We investigate applicability of such a system by monitoring its performance and energy efficiency and stability while using common HPC paradigms: message passing and thread programming.

Influence of Node Deployment Parameters on QoS in Large-Scale WSN

Quality of Service (QoS) support in large-scale Wireless Sensor Networks (WSNs) is becoming a hot topic in WSN area of research, primarily due to the fact that very complex problems need to be solved using resource constrained WSN nodes. On the other hand, with the large number of nodes in a network, a collective intelligence approach comes into focus for solving various issues. However, as node density and number increases various related problems comes into focus, such as increased RF interference on physical layer, large number of hops in data routing and the overall coverage area issue. All of these parameters are the result of WSN node deployment strategy and their influence on QoS cannot be neglected. To analyze this problem the paper simulated the behavior of large-scale WSN (up to 1000 nodes using OMNeT++) randomly deployed over an area of interest, based on deployment parameters (coverage area, number of nodes and TX power) and in respect to QoS metrics. From simulation results it can be concluded that deployment parameters substantially affects the QoS that a network can support. By choosing optimal deployment parameters it is possible to maximize QoS in a network.

Power consumption and RF propagation analysis on ZigBee XBee modules for ATPC

Wireless Sensor Networks (WSN) are used in various fields with the purpose of establishing low cost network for data exchange. An important aspect in ZigBee WSN study is the reduction of node power consumption in order to reduce the overall power consumption of a network and to reduce the induced CO2 emissions. One approach in power consumption reduction is the Adaptive Transmission Power Control (ATPC), where the end nodes reduce their transmit power in certain conditions. This paper analyses the impact of adaptive power control on the power consumption of Digis XBee PRO WSN modules. To determine the conditions for adaptive power control, this paper presents measurements analysis for indoor RF propagation in order to determine the minimum received signal strength for high data transfer reliability. Sequentially, the impact of radio irregularity on the received signal is shown against numerous factors, and the proposed method for adaptive power control is discussed. It is shown that by implementing ATPC the reduction in power consumption is evident while retaining the data transfer reliability.

Real-time WSN communication for access control applications

One of the persisting requirement in todays Wireless Sensor Networks is the real-time QoS requirement for specific applications. In this paper the analysis of WSN real-time QoS ability for the application of access control backbone communication network was presented in respect to the existing WSN based on ZigBee communication protocol and XBee WSN modules. The real-time communication was analyzed in respect to the round trip time (delay) required for the WSN node to transmit the data to the cluster head, to process the data and return the acknowledge. A rating QoS metrics was proposed based on RTT parameter and various other parameters that have impact on the real-time communication. Further on, the impact of the distance between the End node and the Cluster head is analyzed on XBee WSN modules. The improvement of the QoS is presented by analyzing different hardware and software solutions for the data processing at the Cluster head location and proposing new hardware architecture based on ARM embedded system and Linux OS. It was concluded that by replacing the existing hardware of the Cluster head node it is possible to improve QoS and enable real-time communication for the specific application.

Household power outlet overload protection and monitoring using cost effective embedded solution

With the widespread use of smart house systems monitoring power consumption in household applications is becoming a standard. In this scope a concept of a smart house or a home automation system is often characterized by the ability to control and monitor various household appliances to provide improved convenience, comfort, energy efficiency and security. In recent years costs of smart house systems are being reduced, however even for smaller systems they can be substantial (costs of installation, ongoing costs etc.). In this paper we propose a basic architecture for a smart house system targeted at increased safety and user awareness on power consumption. The main goal here is the design of cost effective solution used for monitoring power consumption at power outlets with the ability of user notification. The system has the ability to report instantaneous power consumption levels and issue a warning of a possible power overload. Communication component was realized using Power Line Communication (PLC) proposed communication protocol. Main advantages of the proposed system include low cost, overload protection and power consumption estimation at each power outlet, increasing user awareness resulting in more effective power consumption.

STFTP: Secure TFTP Protocol for Embedded Multi-Agent Systems Communication

Today’s embedded systems have evolved into multipurpose devices moving towards an embedded multi-agent system (MAS) infrastructure. With the involvement of MAS in embedded systems, one remaining issues is establishing communication between agents in low computational power and low memory embedded systems without present Embedded Operating System (EOS). One solution is the extension of an outdated Trivial File Transfer Protocol (TFTP). The main advantage of using TFTP in embedded systems is the easy implementation. However, the problem at hand is the overall lack of security mechanisms in TFTP. This paper proposes an extension to the existing TFTP in a form of added security mechanisms: STFTP. The authentication is proposed using Digest Access Authentication process whereas the data encryption can be performed by various cryptographic algorithms. The proposal is experimentally tested using two embedded systems based on micro-controller architecture. Communication is analyzed for authentication, data rate and transfer time versus various data encryption ciphers and files sizes. STFTP results in an expected drop in performance, which is in the range of similar encryption algorithms. The system could be improved by using embedded systems of higher computational power or by the use of hardware encryption modules.

Response surface methodology based power consumption and RF propagation analysis and optimization on XBee WSN module

One of the most important issues in wireless sensor networks (WSN) is reduction of power consumption, prolonging the network lifetime (for battery powered networks) or reducing the induced