Emergency communication system
An emergency communication system may be a product that is owned by the organization using it (for example, a paging network for a hospital), or it may be a service that is owned  by a third-party (for example, a cellular carrier’s network). Each has good and bad properties; however, services have some major problems for emergency communications, even though many people think differently. Using SMS as one example, due to the way cellular networks are built, text messaging services would not be able to send a large number of communications in a short amount of time, making SMS service a poor emergency communication method.