Lubomir Mraz

Comprehensive Performance Analysis of ZigBee Technology Based on Real Measurements

Although the ZigBee technology is massively deployed the performance question still remains unanswered. There is a lack of serious performance evaluations and thus this paper provides a comprehensive and unbiased study of the ZigBee PRO technology. An extensive real measurement was conducted to accomplish this task. We found out a big performance gap among ZigBee implementations even though they are compliant with the ZigBee standard. The presented results and analysis could be beneficial for many wireless sensor network developers.

Measurement of LowPAN Network Coexistence with Home Microwave Appliances in Laboratory and Home Environments

Due to a low installation cost of communication infrastructure, Low Power Wireless Area Networks (low PAN) presents an efficient solution for home and building automation. The low PANs operate in a microwave radio band that is often shared by several home appliances. Laptops, wireless routers, cordless phones and microwave ovens occupy the 2.4 GHz band without any channel allocation and thus interoperability with the low PAN systems presents a significant challenge. Therefore, we have performed several laboratory experiments to study the coexistence of low PAN devices with WiFi equipped laptop, WiFi router and microwave oven. The performance evaluation was based on a measurement of Packet Delivery Ratio (PDR) metric. Results shows that presence of the home appliances in the low PAN environment significantly affects the low PAN communication efficiency. Furthermore, we have deployed Zigbee based wireless network in the home environment to study the communication performance in area perturbed by common home radio interferences and obstacles. The lessons learned from network deployment are also presented within the paper.

SensMap: Web framework for complex visualization of indoor & outdoor sensing systems

Technology of Wireless Sensor Networks as a part of Internet of Things world has experienced very dramatic development boom in recent decades. One can say that technology for smart sensing, even the wireless one is already in its mature state. With the huge mass of IoT data that will appear in the Internet in the next years, the rise of novel web-cloud services has been fomented. In this paper we introduce novel web-based Visualization Framework called SensMap that serves for user-friendly interpretation of IoT data stored in the Xively web-cloud. The SensMap framework offers three different visualization perspectives based on the location of sensor devices. These perspectives together with the operation fundamentals of the SensMap are introduced within this paper.

Energy Efficient Public Key Cryptography in Wireless Sensor Networks

As Wireless Sensor Networks are getting to be more applied in commercial solutions (e.g. Smart Grid and Energy Saving Outdoor Lighting) the more important issue, is to provide proper security. This paper gives a comprehensive study of threats faced by Low Rate Wireless Personal Area Networks defined by IEEE 802.15.4. Although several security protocols have been developed to address this issue most of them are aimed just for a particular layer or application. Furthermore, they usually introduce great overhead in terms of energy and communication. Our effort is not just to point out security problems, but to propose energy efficient solution. We introduce and analyze energy efficient system providing symmetric key cryptography and public key cryptography so that both are possible to compute with help of advanced encryption standard hardware accelerator. We show that this hardware based solution is more than 100 times more energy efficient than purely software solution.

Energy demands of 802.15.4/ZigBee communication with IRIS sensor motes

Limited energy sources of nodes in wireless sensor networks require a careful consideration of energy consumption of all processes during the sensors deployment. To analyze energy consumption and to predict a lifetime of a network, a comprehensive energy model based on commercial products is necessary. Therefore, we have focused on the analysis of energy consumption during RF communication with particular 802.15.4 compliant nodes. We have designed experimental testbed and explored the scenario of node association and data transmission. For the measurement we used IRIS sensor nodes with 802.15.4/Zigbee protocol stack and shunt connection. The results show that energy consumption cannot be calculated only from datasheet values of current drain and length of a packet but intervals of listening and waiting between transmissions play important role as well.

Comprehensive Performance Analysis of Lightweight Mesh and Its Comparison with ZigBee Pro Technology

As there is a rising demand on energy efficiency the proper network stack is an essential for every wireless sensor network application. This paper gives a comprehensive view on performance comparison of

Open-packet analyser platform for wireless sensor networks based on IEEE 802.15.4

\hbox {Atmel}^{\circledR }

Handheld Analyzer of IEEE 802.15.4 PHY and MAC Frames

Atmel® Lightweight Mesh (LWM) and ZigBee Pro technology based on extensive real measurements. We focused mainly on application layer throughput, routing latency and self-healing capability. Although the LWM clearly outperforms ZigBee Pro in most aspects, the LWM has particular drawbacks. Particularly, the LWM provides smaller footprint and faster stack processing along with higher application throughput. The most notable throughput difference where the LWM outperforms the BitCloud was by as much as thirteen times.