Patent ID: 8368929

Claim:
An information processing apparatus linked to a network, the information processing apparatus comprising: a central processing unit (CPU) disposed in a main control unit; a power management unit to control a power-supply mode to the CPU; a physical layer to communicate a packet to and from the network; a packet engine unit to generate a packet having a given frame structure and to transmit the packet to the network via the physical layer; a packet filter to receive a packet from the network via the physical layer, and detect a packet having a given frame structure that is receivable by the packet filter; and a transmission control unit to control timing of transmission of the packet generated by the packet engine unit, the packet being transmitted with a given timing, wherein the power-supply mode including at least a normal mode, and a low-power mode that stops power supply at least to the CPU and the power management unit supplies power to the physical layer, the packet filter, and the packet engine unit while the information processing apparatus is in the low-power mode, wherein the packet engine unit includes an identification data generator to generate identification data used for distinguishing each one of packets to-be-transmitted to the network, a message data generator to generate message data for each one of packets to be transmitted to the network, and a packet frame generator to generate a packet frame prepared by combining the identification data generated by the identification data generator and the message data generated by the message data generator, wherein, during the low-power mode, the transmission control unit transmits the packet frame generated by the packet engine unit at a preset transmission time interval, the packet engine unit generates a first packet automatically, the first packet requesting a response from the network, the packet filter detects a second packet, received from the network as a response to the first packet transmitted to the network, when a given time elapses after the first packet is transmitted and the packet filter does not receive the second packet from the network, the transmission control unit instructs re-transmission of the first packet for a given number of times, and the identification data generator updates the identification data when the first packet is re-transmitted and the second packet is received via the packet filter.