A method for a communication system comprising an electronic device and a plurality of gateways (120, 12p, ..., 12N), the electronic device and each gateway being adapted for transmitting and receiving frames on a radio frequency band, each gateway being connected to a same central server , a first frame being sent by the electronic device to the central server, the frame comprising an identifier of the electronic device, each gateway receiving said frame and transmitting the received frame, in association with an identifier of the gateway, to the central server, a response delay being predefined for responding to the first frame, the method enabling selection by the central server of a gateway among the plurality of gateways for sending a second frame to the electronic device in response to the first frame, the method being executed by the central server and being characterised in that it comprises the steps of: - receiving the first frame from a first gateway. - determining a moment of sending and a duration of the second frame that is to be sent in response, - creating a list in association with the identifier of the electronic device, the list comprising the identifier of the first gateway, - triggering a waiting delay during which, if the central server receives from an other gateway another frame sent by the electronic device, then: - adding to the list the identifier of the other gateway that transmitted the frame, - at the expiry of the waiting delay, choosing at least one gateway the identifier of which is included in the list and, for this gateway: - finding planning data for frame sending by said gateway, and - checking whether selection criteria, dependent on the moment of sending and on the duration of the second frame, as well as on the planning data for frames sending of the gateway, are met, if the selection criteria are met, then selecting said gateway for sending the second frame in response to the first frame to the electronic device. - receiving the first frame from a first gateway. - determining a moment of sending and a duration of the second frame that is to be sent in response, - creating a list in association with the identifier of the electronic device, the list comprising the identifier of the first gateway, - triggering a waiting delay during which, if the central server receives from an other gateway another frame sent by the electronic device, then: - adding to the list the identifier of the other gateway that transmitted the frame, - adding to the list the identifier of the other gateway that transmitted the frame, - at the expiry of the waiting delay, choosing at least one gateway the identifier of which is included in the list and, for this gateway: - finding planning data for frame sending by said gateway, and - checking whether selection criteria, dependent on the moment of sending and on the duration of the second frame, as well as on the planning data for frames sending of the gateway, are met, if the selection criteria are met, then selecting said gateway for sending the second frame in response to the first frame to the electronic device. - finding planning data for frame sending by said gateway, and - checking whether selection criteria, dependent on the moment of sending and on the duration of the second frame, as well as on the planning data for frames sending of the gateway, are met, <EOS>