Reliable communication between rescuers during interventions using textile antenna systems

The safety of on-duty firefighters in indoor environments could be increased by ensuring reliable, high-data rate communication in potentially life-threatening situations. This increases their situational awareness, strengthens their decision making and decreases response time by ensuring efficient indoor communication of sensor data, biometric data, pictures or videos. Therefore, a real-life rescue operation was replicated by means of two simultaneously moving firefighters in an office environment. These wideband channel sounder measurements were performed at 3.6 GHz with 80 MHz bandwidth. Four Ultra-Wideband Substrate Integrated Waveguide cavity-backed slot textile antennas were integrated in the front, back, left shoulder and right shoulder sections of the firefighters' jackets, providing up to 4×4 MIMO communication. For this indoor environment, we extract the pertinent OFDM parameters using the RMS delay spread and 50% correlation bandwidth of the sixteen individual SISO channels. Furthermore, we calculate the potential SISO-, 2×2 MIMO- and 4×4 MIMO-OFDM capacities and corresponding data rates. Finally, we show that the 4×4 MIMO setup is more energy efficient and increases both the link reliability and link quality.