 reserved for the public safety use: Option 1: The mobile operator takes the full responsibility for public safety including radio connectivity, core network, and application servers. Option 2: The mobile operator takes care of radio and core network, while the public safety operator takes care of the public-safety-related services. Option 3: The mobile operator provides access to their radio network, while the public safety operator runs its own packet core network and services. This option can be implemented with Multi-Operator Core Network (MOCN) or roaming architecture. Option 4: The public safety operator has dedicated spectrum available. The radio net- work is built by the mobile operator by reusing its existing cell sites and potentially also existing base stations. Option 5: The public safety operator takes care of the complete network rollout including radio, core, and services. Different options can also be mixed in different parts of the network, for example, using dedicated spectrum in the busy areas while sharing the spectrum in low-traffic areas. LTE public safety activity started in the United States in 2012 when FirstNet got the responsibility to coordinate the use of Band 14 at 700 MHz, and many other gov- ernments are proceeding to use LTE networks for public safety. The United Kingdom selected one of the existing mobile operators to offer LTE network services for the 16 LTE-Advanced Evolution public Emergency Service Network (ESN). Safenet in Korea is provided by the mobile operators on dedicated spectrum at 700 MHz. Nedaa, the Dubai Government secure networks provider, uses LTE for the public safety network. The public safety operator in Finland has its own services and packet core, and uses commercial mobile networks for radio connectivity. LTE-based public safety is underway globally with multiple different deployment models. Public safety is one of the first use cases where a critical service is run on top of mobile networks. Many other critical services will be run on top of 5G networks. L