A method for distributing a file, by a first client entity, to at least one second client entity in a communication network according to the 3GPP MCS (3rd Generation Partnership Program Mission-Critical System) standard, the first client entity being included in a first system further comprising a first content server and a first file distribution management server, the second client entity being included in a second system further comprising a second content server and a second file distribution management server, the first system and the second system being interconnected through a first gateway included in the first system and through a second gateway included in the second system, the file being stored by the first content server and being associated with a first address in the first system, the network being formed by at least the first system and the second system, the method comprising at least the steps of: - Transmitting, by the first client entity to the first gateway, a file distribution request comprising the first address associated with the file in the first system, - Modifying (21,31), by the first gateway, in the file distribution request, the first address associated with the file in the first system, to a second address (URLG1) associated with the file in the first system, - Storing, by the first gateway, a correspondence between the first address and the second address (URLG1), - Transmitting, by the first gateway to the second content server via the second gateway and the second file distribution management server, the file distribution request comprising the second address (URLG1) associated with the file in the first system, - Modifying, by the second file distribution management server, in the file distribution request, the second address (URLG1) associated with the file in the first system, to a third address associated with the file in the second system, - storing, by the second file distribution management server, a correspondence between the second address (URLG1) and the third address, - Transmitting, by the second content server, the file distribution request including the third address to the second client entity, - transmitting, by the second client entity, a request to download the file to the second content server, the request comprising the third address, - Receiving, by the second client entity, the file. - Transmitting, by the first client entity to the first gateway, a file distribution request comprising the first address associated with the file in the first system, - Modifying (21,31), by the first gateway, in the file distribution request, the first address associated with the file in the first system, to a second address (URLG1) associated with the file in the first system, - Storing, by the first gateway, a correspondence between the first address and the second address (URLG1), - Transmitting, by the first gateway to the second content server via the second gateway and the second file distribution management server, the file distribution request comprising the second address (URLG1) associated with the file in the first system, - Modifying, by the second file distribution management server, in the file distribution request, the second address (URLG1) associated with the file in the first system, to a third address associated with the file in the second system, - storing, by the second file distribution management server, a correspondence between the second address (URLG1) and the third address, - Transmitting, by the second content server, the file distribution request including the third address to the second client entity, - transmitting, by the second client entity, a request to download the file to the second content server, the request comprising the third address, - Receiving, by the second client entity, the file.