An index calculator calculates, for a terminal device, an easiness-of-communication index indicating a degree to which a user using the terminal device recognizes communication, by using information related to the terminal device. A communication circuit receives communication request data of a first communication mode or a second communication mode from a first terminal device originating a call, the communication request data designating a second terminal device as a destination of the call. The communication circuit transmits, when the communication request data of the second communication mode is received and the easiness-of-communication index of the second terminal device meets a predetermined condition, communication request data of the first communication mode to the second terminal device.

A communication unit includes a detecting unit that detects a call instruction from a user as call instruction information; a searching unit that searches for a base station that is connectible, and collects base station information related to the base station; a memory unit that is used to store the base station information; a sending unit that sends connection request information, which indicates a connection request with respect to the base station, and call request information, which indicates a call request; a receiving unit that receives a response from the base station; and a communication control unit that controls connection with the base station.

A communication apparatus and a wireless communication system are provided to perform information transmission between a first communication device group and a second communication device group via wireless communication performed by means of radio waves of mutually different frequencies without being limited by frequency allocation. The communication apparatus includes a first voice input means for inputting a voice emitted from a first communication device that is one constituent element of the first communication device group into a second communication device that is one constituent element of the second communication device group and a second voice input means for inputting another voice emitted from the second communication device that is one constituent element of the second communication device group into the first communication device that is one constituent element of the first communication device group.

A communication apparatus and a wireless communication system are provided to perform information transmission between a first communication device group and a second communication device group via wireless communication performed by means of radio waves of mutually different frequencies without being limited by frequency allocation. The communication apparatus includes a first voice input means for inputting a voice emitted from a first communication device that is one constituent element of the first communication device group into a second communication device that is one constituent element of the second communication device group and a second voice input means for inputting another voice emitted from the second communication device that is one constituent element of the second communication device group into the first communication device that is one constituent element of the first communication device group.

The present disclosure relates to method performed by a mission critical push-to-talk (MCPTT) server, the method comprises: receiving, from a first user equipment (UE), a request for a connection to communicate with one or more second UEs, wherein the request includes at least a first priority score associated with a type of the connection; determining, based on the request, a second priority score corresponding to the first UE, wherein the second priority score is associated with a type information; and performing based on the first priority score and the second priority score one of: approving the request for the connection, or rejecting the request for the connection.

The present disclosure relates to method performed by a mission critical push-to-talk (MCPTT) server, the method comprises: receiving, from a first user equipment (UE), a request for a connection to communicate with one or more second UEs, wherein the request includes at least a first priority score associated with a type of the connection; determining, based on the request, a second priority score corresponding to the first UE, wherein the second priority score is associated with a type information; and performing based on the first priority score and the second priority score one of: approving the request for the connection, or rejecting the request for the connection.

A method and system for completing a call between a first mobile device located at a first communication system and a second mobile device located at a second communication system is provided. A call initiation request including a request to complete a call with the second mobile device is received at a Radio Access Network (RAN) Adaptor (RA) from the first mobile device. The RA determines RAN-specific access parameters for the first mobile device and the second mobile device. The RA sends a call processing call initiation request including the RAN-specific access parameters and call initiation information for the first mobile device and the second mobile device to a cloud-based group call service. The RA establishes resources specific to the RAN in the RA. The resources include first resources at the first communication system and second resources at the second communication system. The call between the first mobile device and the second mobile device is completed using the first resources and the second resources.

A wireless communication system includes a base station and direct wave communication stations that communicate with the base station. At least one of the base station and the direct wave communication stations includes a number-of-bands switching unit that switches, on the basis of a communication state, a number of bands for direct wave communication, by dividing a band for direct wave communication. One of the plurality of direct wave communication stations receives a narrowband carrier in the divided band.

A wireless communication system includes a base station and direct wave communication stations that communicate with the base station. At least one of the base station and the direct wave communication stations includes a number-of-bands switching unit that switches, on the basis of a communication state, a number of bands for direct wave communication, by dividing a band for direct wave communication. One of the plurality of direct wave communication stations receives a narrowband carrier in the divided band.

When a land mobile radio connection is unavailable for a subscriber device, the subscriber device may use an alternative connection. A gateway may be used to allow the subscriber device to connect to the zone controller of a land mobile radio network via an alternative network. The gateway may be configured to perform remote scan and priority operations, similar to the scan operations the subscriber device would ordinarily perform locally. The gateway may receive a scan list from the subscriber device and call notifications from the zone controller. Using the scan list, the gateway may evaluate the call notifications, determine whether they should be sent to the subscriber device, and send them to the subscriber device over the alternative connection. The gateway may be able to adjust the remote scan and priority operations based on receiving different scan lists from the subscriber device or by generating different versions itself.