Data transmission method and apparatus

A method for performing a data transmission between end terminals (1, 6) of a telecommunication network, said method comprising the steps of:

• a) initiating said data transmission from at least one of said end terminals (1, 6) using a first data bearer;
• b) switching said data transmission to a second data bearer;
• and
• c) using a subscriber identity, obtained from the data transmission with said first data bearer, for gathering subscriber charging data.

An apparatus for performing a data transmission between end terminals (1, 6) of a telecommunication network, said apparatus comprising:

• a) switching control means (55) for controlling a transmitting means (51) so as to initiate said data transmission using a first data bearer;
• and
• b) detecting means (54) for detecting a predetermined bearer need condition;
• c) wherein said switching control means (55) is arranged to control said transmitting means (51) so as to switch to said second data bearer in response to the detection result of said detection means (54).

An apparatus for performing a data transmission between end terminals of a telecommunication network, said apparatus comprising:

• a) switching control means (55) for controlling a transmitting means (51) so as to initiate said data transmission using a first data bearer;
• and
• b) detecting means (54) for detecting a subscriber identity from the data transmission with said first data bearer;
• c) wherein said switching control means (55) is arranged to gather subscriber charging data by using said detected subscriber identity.