Acknowledged data transmissions in wireless sensor network with optimized sensor energy consumption

This paper describes communication method for use in a wireless sensor network, which focus on a bidirectional communication with prevention of data loss and minimization of a power consumption of the wireless sensor. The method described was successfully tested and verified on an existing installation of a wireless sensor network. The power consumption is a key parameter for a disposable, battery powered, wireless sensor with small dimensions. Small dimensions lead to a very limited amount of energy available for the sensor. Together with the requirement for a maximized life time of the sensor, an energy efficient data transmission algorithm is a key component, which significantly affects life time of the sensor. The sensor used for testing of the algorithm was disposable, hermetically sealed, battery powered, human body wireless temperature sensor, which should provide at least one year of operation with measurement period of sixty seconds. The impact of described algorithm on total sensor power consumption increases with lowering communication period. Sensors with extended functionality, which will focus on other different physiological signals are planned for development as part of the system in future. These sensors will produce higher amount of data and require data transfers with shorter periods. Therefore described power saving method is important. Intended area of use of the system is in hospitals, elderly care facilities, rehabilitation units, spas and even households.