CLAIMS
[Claim 1] A wireless communication apparatus comprising:
a network control unit that is capable of periodically outputting a downward route control message concerning route information, including a validity period, of the wireless communication apparatus;
an application data processing unit to output upward data;
a wireless transmitting and receiving unit to transmit the downward route control message output from the network control unit and the upward data output from the application data processing unit through an upward route from the wireless communication apparatus toward the gateway, and receive a delivery acknowledgment message in reply to the transmitted upward data; and
a wireless control unit to cause periodic transmission of the downward route control message to be temporarily suspended if the delivery acknowledgment message is input via the wireless transmitting and receiving unit.
[Claim 2] The wireless communication apparatus according to claim 1,
wherein the wireless control unit causes the periodic transmission of the downward route control message to be resumed if a predetermined time period has elapsed after causing the periodic transmission of the downward route control message to be temporarily suspended.
[Claim 3] The wireless communication apparatus according to claim 1 or 2,
wherein the wireless transmitting and receiving unit transmits the downward route control message and the upward data to another wireless communication

apparatus or the gateway, which is a next apparatus of the wireless communication apparatus on the upward route, and receives the delivery acknowledgment message from the next apparatus in reply to the transmitted upward data, and
wherein the wireless control unit causes the periodic transmission of the downward route control message to be temporarily suspended if the delivery acknowledgment message from the next apparatus is input via the wireless transmitting and receiving unit.
[Claim 4] The wireless communication apparatus according to any one of claims 1 to 3,
wherein the wireless control unit instructs the network control unit to temporarily suspend output of the downward route control message.
[Claim 5] The wireless communication apparatus according to claim 4,
wherein the wireless control unit instructs the network control unit to resume the periodic transmission of the downward route control message if a predetermined time period has elapsed after causing the periodic transmission of the downward route control message to be temporarily suspended.
[Claim 6] The wireless communication apparatus according to any one of claims 1 to 5, further comprising:
a downward route management unit to store route information, including a validity period, of a downstream wireless communication apparatus in association with an identifier that identifies the downstream wireless communication apparatus, the route information being notified by a downward route control message from the downstream wireless communication apparatus, the downstream wireless communication apparatus

being another wireless communication apparatus existing further downstream than the wireless communication apparatus in a downward direction from the gateway,
wherein upon storing the route information of the downstream wireless communication apparatus in the downward route information management unit, the network control unit starts counting of the validity period thereof,
wherein upon receiving upward data transmitted from the downstream wireless communication apparatus being a generation source that has generated the data, the wireless transmitting and receiving unit transmits the delivery acknowledgment message,
wherein when the upward data transmitted from the downstream wireless communication apparatus being the generation source is input via the wireless transmitting and receiving unit, the wireless control unit instructs the network control unit to update the route information of the downstream wireless communication apparatus being the generation source, and
wherein upon being instructed by the wireless control unit to update the route information of the downstream wireless communication apparatus being the generation source, the network control unit stops counting of the validity period of the route information of the downstream wireless communication apparatus being the generation source, and then newly starts the counting.
[Claim 7] The wireless communication apparatus according to claim 6,
wherein the wireless control unit instructs the network control unit to update route information of a downstream wireless control apparatus that has forwarded the upward data transmitted from the wireless communication apparatus being the generation source, said downstream wireless communication apparatus existing on a

route from the downstream wireless communication apparatus being the generation source to the wireless communication apparatus, and
wherein the network control unit stops counting of the validity period, according to an instruction from the wireless control unit, of the route information of the downstream wireless communication apparatus that has forwarded the upward data, and then newly starts the counting.
[Claim 8] The wireless communication apparatus according to any one of claims 1 to 7, further comprising:
an intermittent control information holding unit to hold intermittent control information indicating whether a next wireless communication apparatus of the wireless communication apparatus on the upward route performs intermittent control,
wherein the wireless control unit determines whether the next wireless communication apparatus performs the intermittent control, based on the intermittent control information in the intermittent control information holding unit, and if the next wireless communication apparatus performs the intermittent control, instructs the wireless transmitting and receiving unit to transmit the upward data to the next wireless communication apparatus after a message to notify wake-up of the next wireless communication apparatus is input via the wireless transmitting and receiving unit.