Abstract: A method for establishing an IPCON Mission Critical Data Internet Protocol Connectivity MCData session in a communications network according to the 3GPP MCS 3rd Generation Partnership Program Mission Critical System standard. The network includes an emitting MCData entity, a destination MCData entity and an MCData transport service connected to the emitting and destination MCData entities. The method includes obtaining, from the emitting MCData entity, a DPPK MCData Payload Protection Key and a DPPK-ID MCData Payload Protection Key Identifier, transmitting a SIP-INVITE message comprising the DPPK key and the DPPK-IK key identifier, from the emitting MCData entity to the destination MCData entity via the MCData transport service, authenticating the message, by the destination MCData entity, and determining the DPPK key and the DPPK-ID key identifier, by the destination MCData entity, and establishing an IP tunnel between the emitting MCData entity and the destination MCData entity.

Abstract: A method for distributing a file in a network according to the 3GPP standard includes transmitting, by the first client entity, a file distribution request including the first address, modifying, by the gateway, in the file distribution request, the first address to a second address, transmitting the file distribution request including the second address to the second content server, modifying, by the second content server, the second address in the request to a third address, transmitting the request including the third address to the second client entity, transmitting, by the second client entity, a request to download the file comprising the third address to the content server, receiving, by the second client entity, the file, and storing, by some entities, correspondences between the addresses.

Abstract: A method for discriminating, by a first destination client entity, requests in a communication network according to the 3GPP MCS “3rd Generation Partnership Program Mission-Critical System” standard, wherein the requests received by the destination client entity include a first mission-critical service request originating from the non-controlling server of the second communication group and a second mission-critical service request originating from the non-controlling server of the third communication group, each request received including at least one piece of belonging group information of the non-controlling server emitting the request.

Abstract: A communication network according to the 3GPP MCS (3rd Generation Partnership Project Mission Critical Services) standard includes at least one first communication group, plurality of user devices each having knowledge of the first communication group, at least one first communication group management server managing the first communication group via a group document specific to the first communication group, the first communication group management server allowing each user device of the plurality of user devices to communicate in the first communication group, the global communication group document including at least one group geographical parameter, the group geographical parameter defining a geographical zone in which the user device of the plurality of user devices is affiliated with the first communication group.

Abstract: A method for distributing a file in a network according to the 3GPP standard includes transmitting, by the first client entity, a file distribution request including the first address, modifying, by the gateway, in the file distribution request, the first address to a second address, transmitting the file distribution request including the second address to the second content server, modifying, by the second content server, the second address in the request to a third address, transmitting the request including the third address to the second client entity, transmitting, by the second client entity, a request to download the file comprising the third address to the content server, receiving, by the second client entity, the file, and storing, by some entities, correspondences between the addresses.

Abstract: A method for initiating an MCData communication within a regroup of communication groups, the method being implemented by a network according to the 3GPP MCS standard, wherein an MCData communication may include short data messages or file distribution. In addition, some information is added in the different transmissions to allow additional verifications by the different entities.

Abstract: A method implemented by a client transmitting entity included in a network according to the 3GPP MCS standard, the client transmitting entity being configured to transmit content intended for a client receiving entity included in the network and being affiliated with a same communication group, the method including selecting a security context from among: a security context with endpoint diversity formed by: a long master key identifier formed by the GMK-ID and the DMK-ID, or a short master key identifier formed by the GMK-ID or a short master key identifier formed by the GUK-ID or no master key identifier. A security context without endpoint diversity formed by: a short master key identifier formed by the GMK-ID or no master key identifier.

Abstract: A method implemented by a client transmitting entity included in a 3GPP MCS (3rd Generation Partnership Program Mission Critical Services) standard network, the client transmitting entity being configured to transmit a plurality of contents intended for at least one client receiving entity included in the network, the client transmitting entity and the client receiving entity being affiliated with a same communication group, the method including generating, by the client transmitting entity, a group user key identifier, the group user key identifier being specific to the communication group and being used to encrypt the content, the generation being repeated each time a predetermined event takes place.

Abstract: A method for initiating a communication within a regroup of communication groups, the method being implemented by a network according to the 3GPP MCS standard including at least two systems separated by a gateway hiding or deleting information necessary for initiating a communication in a global communication group to which entities distributed in the at least two systems are affiliated, the method especially including directly transmitting, between a participating server managing the client entity initiating the communication and a non-controlling server of the global communication group, an invite message according to the SIP protocol. Furthermore, some information is added in the different transmissions in order to allow additional checks by the different entities.

Abstract: A system for the transmission of group multimedia data to a set of clients affiliated to a communication group, the communication system including a control entity; a signaling participating entity; a participating entity supporting a unicast distribution service, called unicast entity; a participating entity supporting a broadcast distribution service, called broadcast entity; the communication system including a software bus linking the different participating entities to convey information messages exchanged between the different participating entities, for: enabling each unicast entity to maintain a first list of multimedia clients for each communication group to which has become affiliated at least one multimedia client; maintain a second list of multimedia clients for each geographic zone; and enabling each broadcast entity to maintain a third list of multimedia clients for each communication group to which has become affiliated at least one multimedia client.

Abstract: A system for the transmission of group multimedia data to a set of clients affiliated to a communication group, the communication system including a control entity; a signalling participating entity; a participating entity supporting a unicast distribution service, called unicast entity; a participating entity supporting a broadcast distribution service, called broadcast entity; the communication system including a software bus linking the different participating entities to convey information messages exchanged between the different participating entities, for: enabling each unicast entity to maintain a first list of multimedia clients for each communication group to which has become affiliated at least one multimedia client; maintain a second list of multimedia clients for each geographic zone; and enabling each broadcast entity to maintain a third list of multimedia clients for each communication group to which has become affiliated at least one multimedia client.

Abstract: Each communication occupying a direct mode channel comprises the transmission between mobile terminals of signals distributed into traffic time slots and into regularly dispersed control time slots during which one of the mobile terminals transmits synchronization and signaling signals. Some of the terminals determine standby time slots aligned with the control slots and continuing after the communication, and place themselves in a receive state on the channel during the aligned standby slots, with idle periods between said standby slots.

Abstract: The invention concerns a method whereby each of the communication using the channel comprises transmission between mobile terminals (11-13) of signals distributed into traffic time intervals and uniformly distributed control time intervals during which one of the mobile terminals transmits synchronising and signalling signals. Some at least of the terminals determine standby time intervals aligned on the control intervals and maintained after communication, and are set in reception on the channel during the standby time intervals, with idle periods between said standby time intervals.