Robustness of IoT Gateway Deployment in Smart Hospitals

This paper studies the deployment problem of Bluetooth Low Energy (BLE) gateways, and proposes an effective algorithm for it to support e-Healthcare services in hospitals or daycare centers. With the acceleration of aging, demands for elder care services have increased dramatically. Gateway deployments for Internet of Things (IoT) play an important role to support such services over remote intelligent healthcare platforms, in particular when allowing patients wearing wireless medical devices to walk freely in wards or indoor spaces. The gateway deployment problem becomes much more complicated under this condition due to obstacles and human bodies in the way between the gateways and the patients. In addition, the hardware specification of a gateway and the signal shadowing by patients themselves also limit the connectivity capacity of a gateway. These motivate us to study a design that takes all the factors of indoor floor plan, radio propagation attenuation, user densities, and human body signal shadowing into the consideration of gateway deployment. Particular features of our proposed algorithm include: 1) guaranteeing a full signal coverage; 2) accounting for patients' self-shadowing effects; and 3) adapting to non-uniform user densities in different spaces of indoor environments. The average user service continuity degree can reach up to 0.99 in indoors with various sizes of room spaces and user densities. Moreover, performances of the average gateway serving load implies the selected locations to deploy gateways are adequate.