Healthcare & Public Health Sector Coordinating Councils. (n.d.). Working Without Technology: How Hospitals and Healthcare Organizations Can Manage Communication Failure. (Accessed 2/17/2020.) U.S. Department of Health and Human Services, Office of the Assistant Secretary for Preparedness and Response.
This article discusses redundant lower-tech methods for communicating to ensure staff are able to stay in touch in case of a loss of technological capability.