A method of adapting to delay in a communication link established between a radio access network supervising entity and at least one radio base station communicating with a mobile terminal, wherein at least one further communication link is established between the radio access network supervising entity and at least one further radio base station for performing handover of the mobile terminal, the method comprising the steps of: associating a target Connection Frame Number, CFN, to each transmitted data frame, said target CFN being calculated by offsetting an expected CFN with a counter value corresponding to a current communication link delay; repeatedly determining delay of each communication link (15, 16); identifying, from the determined delay of each communication link (15, 16), the communication link having a greatest delay of the communication links, in case the greatest delay has changed; adapting to the delay of the communication links such that the communication link having a delay smaller than the greatest delay is synchronized with the communication link having the greatest delay by adjusting transmission time of the transmitted frame; and/or adjusting the target CFN of the transmitted frame, said target CFN being calculated by offsetting the expected CFN with a counter value corresponding to the identified greatest delay, wherein, in case the radio base station having the communication link with the greatest delay is no longer to be involved in the handover of the mobile terminal, the delay of each communication link to be adapted is adapted by reducing the target CFN to reflect a greatest delay of a remaining communication link. associating a target Connection Frame Number, CFN, to each transmitted data frame, said target CFN being calculated by offsetting an expected CFN with a counter value corresponding to a current communication link delay; repeatedly determining delay of each communication link (15, 16); identifying, from the determined delay of each communication link (15, 16), the communication link having a greatest delay of the communication links, in case the greatest delay has changed; adapting to the delay of the communication links such that the communication link having a delay smaller than the greatest delay is synchronized with the communication link having the greatest delay by adjusting transmission time of the transmitted frame; and/or adjusting the target CFN of the transmitted frame, said target CFN being calculated by offsetting the expected CFN with a counter value corresponding to the identified greatest delay, wherein, in case the radio base station having the communication link with the greatest delay is no longer to be involved in the handover of the mobile terminal, the delay of each communication link to be adapted is adapted by reducing the target CFN to reflect a greatest delay of a remaining communication link. adjusting transmission time of the transmitted frame; and/or adjusting the target CFN of the transmitted frame, said target CFN being calculated by offsetting the expected CFN with a counter value corresponding to the identified greatest delay, wherein, in case the radio base station having the communication link with the greatest delay is no longer to be involved in the handover of the mobile terminal, the delay of each communication link to be adapted is adapted by reducing the target CFN to reflect a greatest delay of a remaining communication link.