Abstract: A control point device that reduces delay in a power-saving wireless network includes a normal data generating unit that generates 1st-type data, a preferential data generating unit that generates 2nd-type data different from the 1st-type data, a determining unit that determines an active period length, a beacon generating unit that generates a broadcasting signal including information corresponding to the determined length of the active period, and a transmitting unit that transmits the broadcasting signal to the terminal on a frame basis. The determining unit shortens the length of the active period when the preferential data generating unit generates the 2nd-type data, and a preferential data period is set in an ex-active period obtained by the shortening of the active period, the preferential data period being a period during which the 2nd-type data is transmitted. The transmitting unit transmits the 2nd-type data to the terminal during the preferential data period.

Abstract: A relay device according to the present invention includes: a receiving unit which receives a frame; a transmitting unit which transmits a frame; a frame determination unit which stores therein the first frame when the frame determination unit determines that the received frame is the first frame; a proxy ACK generation unit which generates a third frame which is a proxy frame of a second frame which is a frame to be transmitted from the receiving device, as a receipt acknowledgement to the first frame; and a communication control unit which: causes the transmitting unit to transmit the third frame; sets an extended active period in the inactive period subsequent to the active period; and transmits the first frame in the extended active period when the receiving unit does not receive the second frame within a predetermined period after reception of the first frame.

Abstract: A control device according to the present invention comprises a receiving unit which receives, in the network, a multi-address message transmitted from each of the terminal devices, a determining unit which determines whether or not the received multi-address message is to be translated into a unicast message to be transmitted to a specified terminal device, based on information contained in the multi-address message, the specified terminal device being included in the terminal devices, a translating unit which translates the multi-address message into the unicast message when the determining unit determines that the multi-address message is to be translated, and a transmitting unit which transmits the unicast message to the specified terminal device.

Abstract: A wireless communication system includes a wireless terminal and a plurality of base stations that can communicate with each other via a predetermined communication path that is different from the wireless communication path to the wireless terminal. The wireless terminal transmits a request signal to one of the base stations to request a response signal from another base station. The one base station transfers the received request signal to the other base station via the predetermined communication path. Upon reception of the request signal transferred from the one base station, the second base station transmits a response signal to the wireless terminal via the predetermined channel. The wireless terminal receives the response signal transmitted from the second base station via the predetermined channel.

Abstract: Provided is a communication apparatus which allows multi-rate control causing less waste of communication band as compared to conventional, the communication apparatus according to the present invention includes: the wireless communication unit for performing wireless communication with the terminal apparatus; a transfer rate setting unit for setting a transfer rate; a beacon generation unit for generating a beacon which is a first control signal; and a control unit for causing the wireless communication unit to wirelessly transmit, for every predetermined period, the beacon, and, to cause the wireless communication unit to wirelessly transmit the beacon, the control unit causes the transfer rate setting unit to set a transfer rate different from the transfer rate previously used for the wireless transmission of the beacon, and causes the wireless communication unit to transmit the beacon to the terminal apparatus.

Abstract: In a receiver, a channel estimation unit estimates channel characteristics of each channel, and a weight generation unit generates a weight matrix used in equalization processing by an equalizer in accordance with the estimated values of channel characteristics for each channel as estimated by the channel estimation unit. Furthermore, a likelihood calculation unit calculates a likelihood indicating a degree of certainty for each transmission stream using the weight matrix generated by the weight generation unit, and an adaptive control unit determines a transmission rate appropriate for transmission of a signal from a transmitter to the receiver in accordance with the likelihood of each transmission stream calculated by the likelihood calculation unit, notifying the transmitter of the determined transmission rate.

Abstract: A relay device receives transfer data from a transfer-source terminal and transfers the received transfer data to a transfer-destination terminal via relaying performed by another relay device. When the transfer data is received, the relay device establishes a direct communication with the other relay device, if information regarding the other relay device is attached to the received transfer data. If information regarding the other relay device is not attached, then the relay device attaches information regarding itself to the transfer data and transfers the resulting transfer data to a wireless control station.

Abstract: An energy controller (10) as a communication device for transmitting and receiving data by transmitting a signal for establishing transmission and reception of the data to network-connected home appliances (11a to 11c), the energy controller (10) including: a power saving control unit which determines a transmission period such that the transmission period during which the signal is transmitted is increased as a power value difference increases, which is a value obtained by subtracting the total power consumption value of a power consumption appliance from available power supply value to the power consumption appliance including the network-connected home appliances (11a to 11c); and wireless communication IF (22) for transmitting the signal containing the information indicating the transmission period to the network-connected home appliances (11a to 11c) in order to set the network-connected home appliances (11a to 11c) in an active state with a period according to the transmission period.

Abstract: The present invention provides a relay apparatus 130 for, even Wan information providing apparatus that distributes a content is changed, assuring a communication quality for the content to be distributed, and preventing a disturbed image from being distributed to a terminal apparatus. If a response packet received from an information providing apparatus having a first domain name indicates a transfer request, the relay apparatus 130 updates a service information table such that a second domain name indicating a second information providing apparatus, included in the response packet, is associated with the first domain name.

Abstract: The present invention can prevent a fuzzy image, which is caused due to insufficient bandwidth when the bandwidth necessary for transmitting a content cannot be secured, to be displayed on a display device. When a relay apparatus (100) receives, from a DNS server, a DNS response packet regarding a domain name of a server which transmits a content, a condition judging section (210) in the relay apparatus (100) judges whether a required bandwidth for the content corresponding to the domain name can be secured in a communication path connecting to another relay apparatus (100). If the condition judging section (210) judges that the required bandwidth cannot be secured, a DNS modifying section (250) in the relay apparatus (100) rewrites a reply IP address included in the DNS response packet to an IP address of the relay apparatus (100).

Abstract: One transmission rate of a physical layer (PHY rate) is selected from among a plurality of PHY rates of a protocol stack by calculating one or more effective values of transmission rates of an upper layer of the protocol stack with respect to one or more PHY rates of the plurality of PHY rates respectively, and making a comparison with use of the calculated one or more effective values. Each of the one or more effective values is calculated based on (i) an ideal value of corresponding one of the transmission rates and (ii) a retransmission ratio via the physical layer that corresponds to a reception power value detected in the reception apparatus.

Abstract: A communication control apparatus for controlling communication by repeatedly sending a control signal to other apparatuses at a given time interval, the communication using a protocol that regulates transmissions of an acknowledgement as a receipt for one or more communication packets, and the control signal allocating, within the given time interval, two types of communication periods which are (i) a one-way communication period in which a one-way communication is performed and (ii) a two-way communication period in which a two-way communication is performed. The communication control apparatus determines, based on an occurrence ratio of the transmissions of the acknowledgement, a length of the one-way communication period, and sends the control signal that allocates a plurality of the one-way communication periods each of which has the determined length.

Abstract: When a network system of the present invention performs a bandwidth-guaranteed communication, a terminal device collects information on one or more relay devices on a path to another terminal device via a bandwidth request packet transmitted to the another terminal. When the bandwidth cannot be allocated, a detour path is searched according to the collected relay device information so as to perform the bandwidth-guaranteed communication via the detour path.

Abstract: A CPU 14 detects a value of an output bit rate of media data output from a buffer 17, detects a value of a free space of the buffer 17, and divides a value resulted from subtracting a decrease ratio set value from the detected value of the free space by a saved period. As a result, a value of a decrease ratio is obtained. In order to decrease a value of an input bit rate of media data input to the buffer 17 in accordance with the value of the output bit rate, the CPU 14 decreases the value of the input bit rate based on an upper limit of the input bit value that is a value resulted from adding the detected value of the output bit rate and the calculated value of the decrease ratio.

Abstract: In a receiver 20, a channel estimation unit 203 estimates channel characteristics of each channel, and a weight generation unit 204 generates a weight matrix used in equalization processing by an equalizer 206 in accordance with the estimated values of channel characteristics for each channel as estimated by the channel estimation unit 203. Furthermore, a likelihood calculation unit 205 calculates a likelihood indicating a degree of certainty for each transmission stream using the weight matrix generated by the weight generation unit 204, and an adaptive control unit 211 determines a transmission rate appropriate for transmission of a signal from a transmitter to the receiver 20 in accordance with the likelihood of each transmission stream calculated by the likelihood calculation unit 205, notifying the transmitter of the determined transmission rate.

Abstract: A signal transmitted to an STA 200a from a communication device AP is also received by an STA 200b. Upon reception, the STA 200b measures an RSSI. The STA 200b then creates a state notice frame which includes the measured RSSI, and transmits it to the AP 100. In accordance with the received state notice frame, the AP 100 determines and updates a PHY rate for transmission to the STA 200b. This allows to increase the determination and update frequency of PHY rates than before, resulting in an improved possibility of coping with rapid changes in channel environments.

Abstract: One transmission rate of a physical layer (PHY rate) is selected from among a plurality of PHY rates of a protocol stack by calculating one or more effective values of transmission rates of an upper layer of the protocol stack with respect to one or more PHY rates of the plurality of PHY rates respectively, and making a comparison with use of the calculated one or more effective values. Each of the one or more effective values is calculated based on (i) an ideal value of corresponding one of the transmission rates and (ii) a retransmission ratio via the physical layer that corresponds to a reception power value detected in the reception apparatus.

Abstract: when a network system of the present invention performs a bandwidth-guaranteed communication, a terminal device collects information on one or more relay devices on a path to another terminal device via a bandwidth request packet transmitted to the another terminal. When the bandwidth cannot be allocated, a detour path is searched according to the collected relay device information so as to perform the bandwidth-guaranteed communication via the detour path.

Abstract: A relay device receives transfer data from a transfer-source terminal and transfers the received transfer data to a transfer-destination terminal via relaying performed by another relay device. When the transfer data is received, the relay device establishes direct communication with the other relay device if information regarding the other relay device is attached to the received transfer data. If information regarding the other relay device is not attached, the relay device attaches information regarding itself to the transfer data and transfers the resulting transfer data to a wireless control station.

Abstract: A wireless communication system includes a wireless terminal and a plurality of base stations that can communicate with each other via a predetermined communication path that is different from the wireless communication path to the wireless terminal. The wireless terminal transmits a request signal to one of the base stations to request a response signal from another base station. The one base station transfers the received request signal to the other base station via the predetermined communication path. Upon reception of the request signal transferred from the one base station, the second base station transmits a response signal to the wireless terminal via the predetermined channel. The wireless terminal receives the response signal transmitted from the second base station via the predetermined channel.