Radio characterization for ISM 2.4 GHz wireless sensor networks for judo monitoring applications

In this work, the characterization of the radio channel for ISM 2.4GHz Wireless Sensor Networks (WSNs) for judo applications is presented. The environments where judo activity is held are usually complex indoor scenarios in terms of radiopropagation due to their morphology, the presence of humans and the electromagnetic interference generated by personal portable devices, wireless microphones and other wireless systems used by the media. For the assessment of the impact that the topology and the morphology of these environments have on electromagnetic propagation, an in-house developed 3D ray-launching software has been used in this study. Time domain results as well as estimations of received power level have been obtained for the complete volume of a training venue of a local judo club’s facilities with a contest area with the dimensions specified by the International Judo Federation (IJF) for international competitions. The obtained simulation results have been compared with measurements, which have been carried out deploying ZigBee-compliant XBee Pro modules at presented scenario, using approved Judogis (jacket, trousers and belt). The analysis is completed with the inclusion of an in-house human body computational model. Such analysis has allowed the design and development of an in house application devoted to monitor the practice of judo, in order to aid referee activities, training routines and to enhance spectator experience.This work has been supported by the Spanish Government: TEC2013-45585-C2-1-R and TIN2011-28347-CO1-02

Analysis, characterization and modeling of interference sources on wireless communication systems in complex indoor scenarios

This research work presents a novel methodology of assessing wireless interferences on Wireless Sensor Networks (WSN) by the aid of an in-house developed 3D Ray Launching method, which is a novel deterministic approach for radio propagation prediction in complex environments. Firstly, the 3D Ray Launching simulation procedure has been validated by means of comparing the simulation results with radio propagation measurements within different complex scenarios. Afterwards, a novel point of view regarding the traditional use of radio propagation models is presented: its use for assessing wireless interferences between different deployed wireless networks and WSNs, instead of only predicting the radio propagation of the transceivers belonging to a wireless communication system. The obtained results show that the assessment of potential wireless interferences will be a major issue in order to deploy optimally WSNs, even more taking into account that in a future framed by the Smart City concept and the so called Internet of Things (IoT) along the appearance of 5G systems, the quantity of wireless transceivers is expected to be huge. Once the methodology for the assessment of the interferences between wireless communication systems has been performed, a further step has been taken in order to analyze the interferences created by electrical devices which do not belong to wireless communication systems. For that purpose, a novel hybrid simulation method based on the 3D Ray Launching algorithm and Equivalent Sources has been developed in order to obtain computational models for the estimation of radiated emissions of potential wireless interference sources. Specifically, a common domestic microwave oven has been chosen as the interference source under analysis