Spectrum sharing between wireless medical capsule endoscopy and LTE system

Abstract

Wireless medical capsule endoscopy (WMCE) is an innovative technology that can be used to detect diseases of the human gastrointestinal tract. This technology utilizes a miniature camera capsule (CapCam) as a convenient alternative tool for treating small intestines with no pain and non-invasive method with very low levels of medical hazards compared to traditional methods. The CapCam technology operates in industrial, scientific, and medical (ISM) bands including 915 and 2400 MHz. However, co-channel and adjacent channel bands in the ISM bands are identified for mobile service, represented by long term evolution (LTE) system, on a primary basis (915 MHz) and a co-primary basis (2400 MHz) in the three ITU Regions. Such a condition creates a potential and mutual interference between the CapCam and LTE systems and it can highly affect human health. This paper proposes a model to study the potential interference scenarios between the CapCam and LTE systems in possible shared frequency bands for co-channel and adjacent channel scenarios based on a real urban macrocell (UMa) where line of sight (LOS) and non-LOS (NLOS) conditions are available. In this study, four propagation environment models are involved in estimating the total propagation losses including outdoor propagation, building penetration, indoor propagation, and propagation through a human body. The obtained results using the carrier to interference ratio (CIR), as a spectrum sharing criterion, showed that the interference from the LTE system is dominant. In addition, the concurrent operation of the CapCam and LTE systems with minimum distance seems more likely for the NLOS environment with higher frequency band (2400 MHz) and adjacent frequency scenario. Also, the channel capacity of the LTE and CapCam systems, under various CIR levels, displayed a good agreement with previous studies.