摘要:
A VoIP system has a VoIP server and plural clients. The client transmits paging data as multicast packets addressed at a specific multicast address, to other clients. In response to a request from the client, the VoIP server transmits multicast packets of MOH data to the other clients. At this time, whether the other clients can receive multicast packets is determined. To the clients that are determined to be capable of receiving multicast packets, transmission data is sent in the form of multicast packets. To the client which belongs to a router and is determined to be incapable of receiving multicast packets, the transmission data is sent as unicast packets. It is thus possible for the VoIP system to support paging and MOH in the form of multicast packets, with respect to clients incapable of receiving multicast.
摘要:
A first wireless LAN base station is in an active state. A second wireless LAN base station is in a power off state or a power save mode. The first wireless LAN base station and the second wireless LAN base station are disposed in the same support area. When a fault occurs in the first wireless LAN base station and a communication state of the wireless LAN deteriorates, the first wireless LAN base station detects the fault and places the second wireless LAN base station in the active state. When the first wireless LAN base station confirms that the second wireless LAN base station has been placed in the active state, the first wireless LAN base station sends setting thereof to the second wireless LAN base station. When the first wireless LAN base station confirms that the setting of the second wireless LAN base station is the same as the setting of the first wireless LAN base station, the first wireless LAN base station enters the power off state or the power save mode.
摘要:
In a wireless LAN communication system, a communication mode is automatically switched between an infrastructure mode and an ad-hoc mode. Communication between two stations is started in the infrastructure mode. Packets transmitted in an infrastructure network are monitors to detect a packet transmitted to an access point and addressed, as a final destination, to one's own station or a destination station. If such a packet is detected, it is determined that a transmitting or source station is in a state that allows an ad-hoc communication. A channel searcher of the access point searches for available channels of an ad-hoc network. A switching controller selects one of the available channels and transmits information indicating the selected channel to the source and destination stations. In response to receiving the information indicating the selected channel, the source and destination stations starts direct communication using the selected channel of the ad-hoc network. The selection of the channel may be performed by a station. Associated data may be stored in a temporary data storage unit.
摘要:
According to an embodiment, previous data group input time is subtracted from current data group input time in order to obtain a difference time each time a data group is input. The difference time is subtracted from a packet transmission interval in order to obtain an interval difference. The interval difference is added to a total difference time. If the total difference time is not greater than the first predetermined value, then the input data group is transmitted as a packet. Otherwise, the input data group is discarded and the total difference time is initialized to a value obtained by subtracting the packet transmission interval from the first predetermined value, if the total difference time is greater than the first predetermined value.
摘要:
An ADSL modem connected to the telephone line is disclosed, which even in the case where a plurality of ADSL modems are connected to a single telephone line installed in a SOHO application or in the home of an ordinary user, a stable high-speed data communication can be realized without superposing the signals between the ADSL models or without causing any impedance mismatch. An ADSL band signal detector (11) detects whether the ADSL frequency band is occupied by another ADSL modem connected to the telephone line or not. Upon detection that the ADSL frequency is so occupied, a control unit (12, 13) suppresses the application of the signal energy to the ADSL frequency band.
摘要:
A critical threshold value of the number of connections of VoIP communication by a wireless LAN is set to an access point apparatus. The access point apparatus records identification information of terminals each of which has transmitted a request for connection of VoIP communication. After the number of terminals whose identification information have been recorded reaches the critical threshold value, the access point apparatus transmits a packet indicating release an association to a terminal whose identification information is newly recorded.
摘要:
Defrosting operation is possible by causing refrigerant discharged from a compressor to flow to an outdoor heat exchanger, and returning the refrigerant passed through the outdoor heat exchanger to the compressor through a water-heat exchanger, while operating a pump. Quick defrosting operation is possible by causing refrigerant discharged from a compressor to flow to an outdoor heat exchanger, and returning the refrigerant passed through the outdoor heat exchanger directly to the compressor, while stopping a pump. The temperature of water that has flowed into a water-heat exchanger is detected. According to the detected temperature, the defrosting operation using hot water and quick defrosting operation are selectively executed.
摘要:
A frame transmitting method and device insert a channel identifier into predetermined free bytes of parallel channel signals whose phases are different from each other without a phase adjustment, and convert the parallel channel signals into a serial signal to transmit a frame. A frame receiving method and device convert a serial signal whose phase is not adjusted on the transmission side into parallel channel signals, detect a frame pattern from a single channel signal within the parallel channel signals to detect a channel identifier inserted into a predetermined free byte of the single channel signal, and further rearrange channels between all of the parallel channel signals without a phase adjustment, based on the channel identifier.
摘要:
Defrosting operation is possible by causing refrigerant discharged from a compressor to flow to an outdoor heat exchanger, and returning the refrigerant passed through the outdoor heat exchanger to the compressor through a water-heat exchanger, while operating a pump. Quick defrosting operation is possible by causing refrigerant discharged from a compressor to flow to an outdoor heat exchanger, and returning the refrigerant passed through the outdoor heat exchanger directly to the compressor, while stopping a pump. The temperature of water that has flowed into a water-heat exchanger is detected. According to the detected temperature, the defrosting operation using hot water and quick defrosting operation are selectively executed.
摘要:
The process in an xDSL transceiver transfers into a fast retraining sequence when the cause of an error on a telephone circuit is a change from an off hook state to an on hook state of a telephone instrument, a signal indicating an inversion of polarity of a signal on the telephone circuit, a change from an on hook to an off hook and when a handshake waiting time has passed without detecting a predetermined signal on the telephone circuit, or when the predetermined signal is detected within the handshake waiting time. The handshake waiting time can be updated in accordance with a dial pulse width, the maximum number of digits in the dial pulse signal, and the maximum number of pulses in one digit, or depending on whether or not the dial pulse comes from NTT.