ISM band aggregate interference in BAN-working environments

Estimating the aggregate interference is required in order to predict the performance of a wireless system in its working environment. Body Area Networks (BANs) for healthcare applications are becoming a reality, allowing patients to be monitored continuously without forcing them to stay in bed. Hospital, and in particular the emergency ward, is a harsh environment for wireless communications. The information over the air in a hospital is very important. The increasing number of wireless medical devices makes the ISM (Industrial, Scientific and Medical) band particularly crowded. If new smart BANs have to correctly operate in hospital, coexistence with the existing wireless devices must be accurately investigated, starting with studying the interference in the operating frequency band. In this paper we propose an interference model based on real measurements carried out in the emergency ward of a modern city hospital. The measurements are used to derive the main parameters (first and second order statistics) of the probability density function of the aggregate interference.