摘要:
A first wireless terminal station transmits beam transmission direction identification information in all directions. A second wireless terminal station receives the transmission direction identification information, combines reception direction identification information and the transmission direction identification information, and transmits directivity direction combination information to a wireless base station. The first and the second wireless terminal stations form directional beams in directions indicated by the directivity direction combination information to thereby perform a direct communication.
摘要:
A first wireless terminal station transmits beam transmission direction identification information in all directions. A second wireless terminal station receives the transmission direction identification information, combines reception direction identification information and the transmission direction identification information, and transmits directivity direction combination information to a wireless base station. The first and the second wireless terminal stations form directional beams in directions indicated by the directivity direction combination information to thereby perform a direct communication.
摘要:
A base station of a radio communication system emits a radio wave having the same frequency by time division toward a plurality of specific areas from a plurality of antenna elements by using a multiple-beam antenna to form a plurality of spot beams, and transmits broadcast information through a plurality of beacon channels. Upon reception of the broadcast information, a terminal that exists in any one of the plurality of specific areas selects an optimum beacon channel, and transmits a communication establishment request and a bandwidth request to the base station through a request channel corresponding to information for identifying the antenna element, which is included in the broadcast information received through the selected optimum beacon channel. Upon reception of the requests, the base station schedules, when a channel is to be allocated, a channel allocation time including downlink and uplink data bandwidths and the like.
摘要:
A base station of a radio communication system emits a radio wave having the same frequency by time division toward a plurality of specific areas from a plurality of antenna elements by using a multiple-beam antenna to form a plurality of spot beams, and transmits broadcast information through a plurality of beacon channels. Upon reception of the broadcast information, a terminal that exists in any one of the plurality of specific areas selects an optimum beacon channel, and transmits a communication establishment request and a bandwidth request to the base station through a request channel corresponding to information for identifying the antenna element, which is included in the broadcast information received through the selected optimum beacon channel. Upon reception of the requests, the base station schedules, when a channel is to be allocated, a channel allocation time including downlink and uplink data bandwidths and the like.
摘要:
A radio tag is arranged in each of a plurality of radio tag areas. The radio tag areas can be parking lots. A radio tag reader is configured to perform radio communications with the radio tags. The radio tag reader performs radio communications with each radio tag and based on the radio communication determines whether an object, which can be a vehicle, is present in the radio tag area corresponding to the radio tag.
摘要:
Within a communication system in which an ARQ control is exercised, in a transmission-side communication apparatus 11, a transmission scheduling unit 113 determines a transmission amount to be transmitted to a reception-side communication apparatus 21; an erasure correction encoding unit 112 performs an erasure correction encoding process on an information packet group that is made up of a plurality of packets to be transmitted so as to generate one or more erasure correction coded packets that fit the transmission amount instructed by the transmission scheduling unit 113 and specifies the one or more erasure correction coded packets as a unit of delivery confirmation; and a modulating unit 115 transmits a transmission data signal that has been generated by performing a predetermined modulation process on each of the erasure correction coded packets. In the reception-side communication apparatus 21, an erasure correction decoding unit 213 generates the information packet group by performing an erasure correction decoding process on the received signal and also generates, in the case where the erasure correction decoding process has successfully been performed, a delivery confirmation signal for each unit of delivery confirmation, the delivery confirmation signal indicating that reception of the transmission data signal has been completed, so that the generated delivery confirmation signal is transmitted to the transmission-side communication apparatus 11.
摘要:
A reception processing unit measures reception states of input reception signals of each of a plurality of channels, generates local channel reception information, and applies a reception processing to the input reception signals to generate decoded signals. A media-access-control unit generates transmission frames for each of the channels using transmission data. A transmission processing unit generates radio signals including each of the transmission frames. A channel-information processing unit generates local feedback information, and inserts the local feedback information generated into at least one of the radio signals that are transmitted by the radio communication apparatus.
摘要:
An electromagnetic clutch includes a first rotatable member for connection to an external driving source and a second rotatable member for connection to a driven member. An annular magnetic member is connected to the second rotatable member through a plurality of leaf springs. A third rotatable member is connected to the second rotatable member to limit the axial movement of the annular magnetic member. A plurality of connecting and absorbing devices are fixedly disposed between the annular magnetic member and the third rotatable member. These devices absorb vibration and impact forces when the annular magnetic member is attracted to the first rotatable member. A device is provided for preventing the destruction of the connecting and absorbing device due to the impact force and vibration created upon engagement of the electromagnetic clutch.
摘要:
A coverage map for a wireless network is generated. The network includes a server communicating with clients in a coverage area. The clients are mobile devices. At the server, location and reliability information from each client is received. The server then constructs and maintains the coverage map according to the location and reliability information. The coverage map is used to deliver telematic information from the server to the clients in response to requests by the clients.
摘要:
A communication method for a CSMA network including a radio terminal and a base station supporting RTS/CTS, includes: the base station transmitting an RTS frame to the radio terminal during a transmission-suspend-period in which the radio terminal suspends transmission to prevent a collision of packets; the radio terminal transmitting an RTR frame to the base station after the transmission-suspend-period has elapsed; and the base station transmitting a data frame to the radio terminal in response to the RTR frame.