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.

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 CO ₂ 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 Digi's 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.

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 system's 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.

Power Line Communication (PLC) or Broadband over Power Line (BPL) is an interesting approach in establishing last mile broadband access in rural areas. The most interesting aspect regarding PLC is the ability to use existing infrastructure for signal transmission, reducing deployment costs. Until recently the biggest problem for PLC was the low distance coverage and low data rate which was eliminated with the introduction of new standards. However, even thought new standards guarantee high data rates the practical implementation of these technologies for the use as a last mile solution is not present. In this paper we propose a basic set of measurements conducted on a laboratory test bed for the purpose of analyzing the possibility of PLC use in last mile broadband access. The measurements include the analysis of two contemporary PLC technologies in several scenarios versus TCP and UDP throughput. By analyzing given results it can be concluded that PLC has the ability to replace LAN network as a last mile solution, however it has some disadvantages primarily being the shared medium (power line). These results in UDP packet drop and increased TCP delay when large number of clients uses the network.

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