A method for an application function, AF, device in a wireless cellular network comprising the steps of: determining with a processing unit of the AF device that an application service requires confirmation that a transmission path for corresponding application service media is available; sending an authorization request for the application service, generated by the processing unit of the AF device, through a network interfacing unit of the AF device to a policy and charging rule function, PCRF, server, the authorization request indicating that the application service requires confirmation that the transmission path for the corresponding application service media is available; the method being characterized in that: the authorization request additionally either indicates that the AF device will wait or indicates that the AF device will not wait for the confirmation that the transmission path for the corresponding application service media is available, for progressing with the set up of a session for said application service; and where waiting for the confirmation is indicated, receiving, at the network interfacing unit of the AF device and from the PCRF server, an authorization response for the application service, the authorization response being also a confirmation message confirming that the transmission path is available for the corresponding application service media; and only upon receiving said confirmation message, progressing at the processing unit with the set up of the application service session; and where not waiting for the confirmation is indicated, receiving, at the network interfacing unit of the AF device and from the PCRF server, an authorization response for the application service; upon receiving said authorization, progressing at the processing unit of the AF device with the set up of the application service session; and receiving, at the network interfacing unit of the AF device and from the PCRF server, a confirmation message confirming that the transmission path is available for the corresponding application service media. determining with a processing unit of the AF device that an application service requires confirmation that a transmission path for corresponding application service media is available; sending an authorization request for the application service, generated by the processing unit of the AF device, through a network interfacing unit of the AF device to a policy and charging rule function, PCRF, server, the authorization request indicating that the application service requires confirmation that the transmission path for the corresponding application service media is available; the authorization request additionally either indicates that the AF device will wait or indicates that the AF device will not wait for the confirmation that the transmission path for the corresponding application service media is available, for progressing with the set up of a session for said application service; and where waiting for the confirmation is indicated, receiving, at the network interfacing unit of the AF device and from the PCRF server, an authorization response for the application service, the authorization response being also a confirmation message confirming that the transmission path is available for the corresponding application service media; and only upon receiving said confirmation message, progressing at the processing unit with the set up of the application service session; and receiving, at the network interfacing unit of the AF device and from the PCRF server, an authorization response for the application service, the authorization response being also a confirmation message confirming that the transmission path is available for the corresponding application service media; and only upon receiving said confirmation message, progressing at the processing unit with the set up of the application service session; and where not waiting for the confirmation is indicated, receiving, at the network interfacing unit of the AF device and from the PCRF server, an authorization response for the application service; upon receiving said authorization, progressing at the processing unit of the AF device with the set up of the application service session; and receiving, at the network interfacing unit of the AF device and from the PCRF server, a confirmation message confirming that the transmission path is available for the corresponding application service media. receiving, at the network interfacing unit of the AF device and from the PCRF server, an authorization response for the application service; upon receiving said authorization, progressing at the processing unit of the AF device with the set up of the application service session; and receiving, at the network interfacing unit of the AF device and from the PCRF server, a confirmation message confirming that the transmission path is available for the corresponding application service media.