Repeater, wireless communication system, control method and recording medium

A method of controlling a repeater which is connected to a network and which relays a communication of a wireless communication device, the method comprising:

• a packet reception step of receiving a packet transmitted from a sender wireless communication device to a recipient wireless communication device from the network or the sender wireless communication device;
• a transmission step of transmitting the packet received in the packet reception step to the recipient wireless communication device;
• a packet storing step of storing, as a first packet, all of or a predetermined part of the packet transmitted to the recipient wireless communication device;
• and
• a packet selection step of comparing all of or a predetermined part of the first packet stored in the packet storing step with all of or a predetermined part of a second packet, other than the first packet received in the packet reception step, and discarding the second packet when the first and second packets match under a predetermined condition;
• wherein when the packet reception step receives a second packet which has the same sender as the first packet and which does not match the first packet under a predetermined condition, the packet selection step excludes all of or a predetermined part of the stored first packet from a comparison target with all of or a predetermined part of the second packet and
• wherein when the packet reception step receives a second packet matching the first packet under a predetermined condition prior to transmitting the first packet, the packet selection step compares an error rate of the first packet with an error rate of the second packet, and replaces the first packet stored in the packet storing step with the second packet when the second packet has a smaller error rate than the error rate of the first packet.

A wireless communication system comprising sender and recipient repeaters connected to a network, and sender and recipient wireless communication devices which communicate with each other via the repeaters, wherein:

• the network transmits data or a packet between the sender and recipient repeaters;
• the sender repeater comprises:
• a reception unit that receives a packet transmitted from the sender wireless communication device to the recipient wireless communication device;
• an acquisition unit that acquires identification information of the recipient repeater having a communication area where the recipient wireless communication device which is a destination of the packet received from the sender wireless communication device is present;
• and
• a transmission unit that transmits the received packet to the recipient repeater specified by the identification information acquired by the acquisition unit via the network when the recipient repeater specified by the identification information differs from itself;
• and
• the recipient repeater comprises:
• a packet reception unit that receives a packet transmitted from the sender wireless communication device to the recipient wireless communication device from the network or the sender wireless communication device;
• a transmission unit that transmits the packet received by the packet reception unit to the recipient wireless communication device which is a destination of the packet;
• a packet storing unit that stores, as a first packet, all of or a predetermined part of the packet transmitted to the recipient wireless communication device;
• and
• a packet selection unit that compares all of or a predetermined part of the first packet stored by the packet storing unit with all of or a predetermined part of a second packet, other than the first packet received by the packet reception unit, and discards the second packet when the first and second packets match under a predetermined condition;
• wherein when the packet reception unit receives a second packet which has the same sender as the first packet and which does not match the first packet under a predetermined condition, the packet selection unit excludes all of or a predetermined part of the stored first packet from a comparison target with all of or a predetermined part of the second packet and
• wherein when the packet reception unit receives a second packet matching the first packet under a predetermined condition prior to transmitting the first packet, the packet selection unit compares an error rate of the first packet with an error rate of the second packet, and replaces the first packet stored in the packet storing unit with the second packet when the second packet has a smaller error rate than the error rate of the first packet.

A non-transitory computer-readable recording medium storing a control program for a repeater connected to a network and relaying a communication of a wireless communication device, the control program allowing a computer to function as:

• a packet reception unit that receives a packet transmitted from a sender wireless communication device to a recipient wireless communication device from the network or the sender wireless communication device;
• a transmission unit that transmits the packet received by the packet reception unit to the recipient wireless communication device which is a destination of the packet;
• a packet storing unit that stores, as a first packet, all of or a predetermined part of the packet transmitted to the recipient wireless communication device;
• and
• a packet selection unit that compares all of or a predetermined part of the first packet stored by the packet storing unit with all of or a predetermined part of a second packet, other than the first packet received by the packet reception unit, and discards the second packet when the first and second packets match under a predetermined condition;
• wherein when the packet reception unit receives a second packet which has the same sender as the first packet and which does not match the first packet under a predetermined condition, the packet selection unit excludes all of or a predetermined part of the stored first packet from a comparison target with all of or a predetermined part of the second packet, and
• wherein when the packet reception unit receives a second packet matching the first packet under a predetermined condition prior to transmitting the first packet, the packet selection unit compares an error rate of the first packet with an error rate of the second packet, and replaces the first packet stored in the packet storing unit with the second packet when the second packet has a smaller error rate than the error rate of the first packet.