Propagation issues affecting the deployment of GSM 1800-based personal telemedicine equipment

The increasing need for remote vital-signs monitoring in applications such as the care of post day-surgery patients recovering at home or in emergency trauma signalling from accident sites has resulted in the growth of telemedicine. The transmission of human vital-signs for remote expert analysis now takes place on a world-wide basis, via PSTN lines, private radio networks and over UHF cellular telephony systems. The basic parameters that may be transmitted range from simple heart rate and body temperature, to full-bandwidth ECG waveforms and blood glucose measurements, the latter being an essential parameter in the care of diabetic patients. A telemedicine link must provide close to 100 % reliability to be effective: in normal telephony an element of dropout may be tolerated. Cellular networks such as GSM 900 and DCS 1800, ITS 1900 and third generation (3G) systems may have reliability problems because of body-antenna interaction, nearby pedestrian traffic and in-building propagation effects leading to weak signal provision. This is especially true in rural areas where base station density is lower