Communication method executed in a long-range wireless network and affording low energy consumption wherein terminals communicate with a server by means of gateways (11A, 11b) in a set of gateways according to a communication technology meaning that, when the server receives a message from a terminal via a first gateway, it fixes an instant at which a gateway must relay a response to said message according to an instant of reception of said message by said first gateway, each gateway being associated with a set of terminals comprising at least one terminal using said gateway for communicating with the server, the method implemented by the server comprising: receiving a request coming from a first gateway containing a message sent in a frame, referred to as an uplink frame, by a terminal, referred to as the sending terminal; determining a second gateway different from the first gateway to be used for relaying a response to said message intended for the sending terminal, the second gateway being determined in a subset of gateways in the set of gateways comprising the first gateway and at least one second gateway, each gateway in the subset being capable of relaying to a terminal a response to a message transmitted in an uplink frame by said terminal received by any other gateway in said subset, the gateways in the subset having at least one terminal associated in common and being associated with the sending terminal, the second gateway being determined by executing a choice procedure comprising: preselecting a predefined number of gateways associated with the lowest counter values among the counter values associated with the gateways in said subset representing a number of downlink frames transmitted by the gateways of said subset in response to messages transmitted in uplink frames by terminals; choosing (701, 702) a gateway associated with a value representing a quality of communication with the sending terminal that is higher than or equal to a predefined quality threshold among the gateways in the predefined number of preselected gateways, the chosen gateway becoming the second gateway; transmitting a request containing said response to the second gateway, said response being retransmitted by the second gateway to said sending terminal in a frame, referred to as a downlink frame, at an instant indicated in the request, said instant being indicated in a time reference of the first gateway, the second gateway taking into account a clock difference between the first and second gateways in order to transmit a downlink frame at said instant. receiving a request coming from a first gateway containing a message sent in a frame, referred to as an uplink frame, by a terminal, referred to as the sending terminal; determining a second gateway different from the first gateway to be used for relaying a response to said message intended for the sending terminal, the second gateway being determined in a subset of gateways in the set of gateways comprising the first gateway and at least one second gateway, each gateway in the subset being capable of relaying to a terminal a response to a message transmitted in an uplink frame by said terminal received by any other gateway in said subset, the gateways in the subset having at least one terminal associated in common and being associated with the sending terminal, the second gateway being determined by executing a choice procedure comprising: preselecting a predefined number of gateways associated with the lowest counter values among the counter values associated with the gateways in said subset representing a number of downlink frames transmitted by the gateways of said subset in response to messages transmitted in uplink frames by terminals; choosing (701, 702) a gateway associated with a value representing a quality of communication with the sending terminal that is higher than or equal to a predefined quality threshold among the gateways in the predefined number of preselected gateways, the chosen gateway becoming the second gateway; transmitting a request containing said response to the second gateway, said response being retransmitted by the second gateway to said sending terminal in a frame, referred to as a downlink frame, at an instant indicated in the request, said instant being indicated in a time reference of the first gateway, the second gateway taking into account a clock difference between the first and second gateways in order to transmit a downlink frame at said instant. preselecting a predefined number of gateways associated with the lowest counter values among the counter values associated with the gateways in said subset representing a number of downlink frames transmitted by the gateways of said subset in response to messages transmitted in uplink frames by terminals; choosing (701, 702) a gateway associated with a value representing a quality of communication with the sending terminal that is higher than or equal to a predefined quality threshold among the gateways in the predefined number of preselected gateways, the chosen gateway becoming the second gateway; transmitting a request containing said response to the second gateway, said response being retransmitted by the second gateway to said sending terminal in a frame, referred to as a downlink frame, at an instant indicated in the request, said instant being indicated in a time reference of the first gateway, the second gateway taking into account a clock difference between the first and second gateways in order to transmit a downlink frame at said instant.