Long term spectrum survey of the 2.4 GHz ISM band in multiple hospital environments

Wireless technology has become an invaluable facilitator in many aspects of daily life. Healthcare environments in particular have gained noticeable agility and flexibility by integrating wireless functionality into various medical equipment. As of late, chipsets designed to implement communication standards in the Industrial, Scientific and Medical (ISM) band have become inexpensive and widely available, making wireless-enabled medical devices reach increased number of users. However, the sharp increase in the number of operating nodes now occupying the ISM band has resulted in a cluttered spectrum with limited resources in many environments. In this paper, we report on a long term spectrum survey of the ISM band in both an intensive care unit (ICU) and a post-surgery recovery room (RR). Both spaces were concurrently surveyed for 28 consecutive days capturing spectrum occupancy on every weekday four times. Results indicate that spectrum occupancy patterns are location dependent. Examined sub-channels with significant correlation in activity pattern corresponded mainly to IEEE 802.11 channels 1, 6, and 11. Low daily duty cycle is indicated at a maximum of 5.17% at RR and 3.11% at ICU.