Abstract: There is provided a radar apparatus of an electronic scan type configured to transmit an electric wave and calculate an angle of a target based on a phase difference of respective reception signals, thereby detecting a target position. An antenna unit transmits and receives the electric wave and provided with two transmission antennae. A transmission unit alternately transmits an electric wave having a first beam pattern and an electric wave having a second beam pattern from the two transmission antennae. First and second reception units calculate arrival angles and reception levels of reflected waves calculated from respective reception signals which are obtained by receiving the reflected waves by the first and second beam patterns. A comparison unit compares the reception levels by combining the arrival angles of the reflected waves. A determination unit determines whether a target actually exists at the arrival angles in accordance a comparison result.

Abstract: In a radar device including: a transmission antenna group having a plurality of transmission antennas; a reception antenna group having a plurality of reception antennas; and transmission switchover means to transmit transmission waves in a way that sequentially switches over the transmission antennas of the transmission antenna group, the reception antenna group receiving reflected waves, reflected from a target, of transmission waves of the transmission antennas when sequentially transmitting the transmission waves, is made to function as a virtual sub-array corresponding to the transmission antennas. The target is thus detected by executing a space averaging process based on a relative position, to the reception antenna group, of each of the transmission antennas undergoing the transmission switchover with respect to the virtual correlation values corresponding to the plurality of virtual sub-arrays.

Abstract: There is provided a radar apparatus of an electronic scan type configured to transmit an electric wave and calculate an angle of a target based on a phase difference of respective reception signals, thereby detecting a target position. An antenna unit transmits and receives the electric wave and provided with two transmission antennae. A transmission unit alternately transmits an electric wave having a first beam pattern and an electric wave having a second beam pattern from the two transmission antennae. First and second reception units calculate arrival angles and reception levels of reflected waves calculated from respective reception signals which are obtained by receiving the reflected waves by the first and second beam patterns. A comparison unit compares the reception levels by combining the arrival angles of the reflected waves. A determination unit determines whether a target actually exists at the arrival angles in accordance a comparison result.

Abstract: In a radar device including: a transmission antenna group having a plurality of transmission antennas; a reception antenna group having a plurality of reception antennas; and transmission switchover means to transmit transmission waves in a way that sequentially switches over the transmission antennas of the transmission antenna group, the reception antenna group receiving reflected waves, reflected from a target, of transmission waves of the transmission antennas when sequentially transmitting the transmission waves, is made to function as a virtual sub-array corresponding to the transmission antennas. The target is thus detected by executing a space averaging process based on a relative position, to the reception antenna group, of each of the transmission antennas undergoing the transmission switchover with respect to the virtual correlation values corresponding to the plurality of virtual sub-arrays.

Abstract: A method for time-division multiplexing including steps of generating a plurality of first signals and a plurality of second signals to which specific pulse trains for frame synchronization are allocated respectively; generating low speed signals of plural channels including the first and second signals and transmission signals; a conversion step; and time-division multiplexing the low speed signals after the conversion step, thereby obtaining high speed signals. When applied to SDH, for example, the first and second signals may be A1 bytes and A2 bytes respectively, and the transmission signals may ho payload signals. According to one aspect of the invention, at the conversion step, the first and second signals in each channel are panty convened into either of “1/0” alternating signals and “0/1” alternating signals. Consequently, it becomes possible to reduce the number of successive same code and to diminish the deviation of the mark rate.

Abstract: Disclosed is a ring network in which a plurality of transmitting apparatuses are connected in ring form so as to be capable of transmitting in each of upstream and downstream directions, working and protection channels are assigned to each direction and, when failure occurs in a transmission path, a transmit signal is looped back using the protection channel to effect rescue. The ring network includes an insert transmitting apparatus that incorporates a packet, which enters from a lower-order side, into a higher-order signal and transmits the signal to a transmission path, and a drop transmitting apparatus that extracts the packet from the higher-order signal and transmits the packet to another lower-order side. Monitoring is performed to determine whether communication between the insert and drop transmitting apparatus has become unrescuable owing to transmission-path failure.

Abstract: There is provided a communication system directed to inhibiting degradation of the efficiency of transmission of user information and improving the communication quality. A correspondence table management unit creates a correspondence table based on table forming information. A buffer status value acquiring unit acquires a buffer status value of a buffer that issues a transmission event. A notice information setting unit compares a size relation between status information about past buffer status values for the buffer and a current buffer status value acquired, and sets notice information on a bit basis. A terminal-side notice information management memory stores and manages the notice information as the status information. A notice information sending unit sends the notice information to notify an upper device of the buffer status. A table forming information sending unit sends the table forming information. A control-side notice information management memory receives and manages the notice information.

Abstract: A subscriber-line-terminating apparatus for dynamically allocating band portions to a plurality of terminal apparatuses includes an in-buffer-information-amount receiving unit for receiving an in-buffer-information amount from each of the terminal apparatuses; an insufficient-band-computing unit for computing an insufficient band portion required by each of the terminal apparatuses; an in-buffer-information-amount-proportional-band-allocating unit for allocating a band portion corresponding to the in-buffer-information amount to each of the terminal apparatuses and a past-use-band-allocating unit for allocating a past-use band part to each of the terminal apparatuses as a past-use band portion based on a first past-use band variable of the terminal apparatus.

Abstract: In a system where a plurality of terminal units are connected to a network unit via an optical transmission line and packets are transmitted in units of cells according to polling information, polling request information including the number of variable-length packets stored in the buffer of each of the terminal unit, the number of cells composing each variable-length packet and the number of remaining cells of a packet being read is created, polling information corresponding to a time slot allocated according to the polling request information is transmitted from the shared band control unit of the network unit, and bands are allocated to the plurality of terminal units.

Abstract: Disclosed is a ring network in which a plurality of transmitting apparatuses are connected in ring form so as to be capable of transmitting in each of upstream and downstream directions, working and protection channels are assigned to each direction and, when failure occurs in a transmission path, a transmit signal is looped back using the protection channel to effect rescue. The ring network includes an insert transmitting apparatus that incorporates a packet, which enters from a lower-order side, into a higher-order signal and transmits the signal to a transmission path, and a drop transmitting apparatus that extracts the packet from the higher-order signal and transmits the packet to another lower-order side. Monitoring is performed to determine whether communication between the insert and drop transmitting apparatus has become unrescuable owing to transmission-path failure.

Abstract: The present invention provides a method for time-division multiplexing. This method comprises a step of generating a plurality of first signals and a plurality of second signals to which specific pulse trains for frame synchronization are allocated respectively; a step of generating low speed signals of plural channels including the first and second signals and transmission signals; a conversion step; and a step of time-division multiplexing the low speed signals after the conversion step, thereby obtaining high speed signals. When the present invention is applied to SDH for example, the first and second signals may be Al bytes and A2 bytes respectively, and the transmission signals may be payload signals. According to one aspect of the invention, at the conversion step, the first and second signals in each channel are partly converted into either of “1/0” alternating signals and “0/1” alternating signals.

Abstract: There is provided a communication system directed to inhibiting degradation of the efficiency of transmission of user information and improving the communication quality. A correspondence table management unit creates a correspondence table based on table forming information. A buffer status value acquiring unit acquires a buffer status value of a buffer that issues a transmission event. A notice information setting unit compares a size relation between status information about past buffer status values for the buffer and a current buffer status value acquired, and sets notice information on a bit basis. A terminal-side notice information management memory stores and manages the notice information as the status information. A notice information sending unit sends the notice information to notify an upper device of the buffer status. A table forming information sending unit sends the table forming information. A control-side notice information management memory receives and manages the notice information.

Abstract: The present invention relates to a line terminating equipment for allotting a transmission bandwidth to a plurality of terminals at one end of a subscriber line section of an access network. In the line terminating equipment, requisite bandwidths of the individual terminals are computed as an increasing function of receipt information content which is content of transmission information precedingly received from the terminals and untransmitted information content notified by the terminals. The transmission bandwidth to be allotted to each terminal is determined in a manner which is decided according to a comparison result of magnitude between a total requisite bandwidth and a transmission bandwidth of a transmission channel. Therefore, in a communication system to which the present invention is applied, the transmission bandwidth is allotted effectively, flexibly, and efficiently to all the terminals, which enhances total reliability as well as service quality and transmission quality.

Abstract: A subscriber-line-terminating apparatus for dynamically allocating band portions to a plurality of terminal apparatuses includes an in-buffer-information-amount receiving unit for receiving an in-buffer-information amount from each of the terminal apparatuses; an insufficient-band-computing unit for computing an insufficient band portion required by each of the terminal apparatuses; an in-buffer-information-amount-proportional-band-allocating unit for allocating a band portion corresponding to the in-buffer-information amount to each of the terminal apparatuses and a past-use-band-allocating unit for allocating a past-use band part to each of the terminal apparatuses as a past-use band portion based on a first past-use band variable of the terminal apparatus.

Abstract: A cross-point type switch includes a plurality of basic elements arranged in rows and columns so as to form a matrix arrangement of the basic elements. Each of the basic elements includes a plurality of input ports, output ports, expanded input ports and expanded output ports. A write/read part is connected to a common memory and has the function of writing data into the common memory and reading out the data from the common memory. A selector part selectively outputs either the data read out from the common memory or data from the expanded input ports to the output ports. The expanded output ports are directly connected to the input ports.

Abstract: When input signals from a plurality of input ports are selected and are inserted into the time slots to be output from a single output port and to insert respective signal data into time slots in synchronization with a synchronizing signal, the apparatus is so constructed that selector units (5-i) are provided to correspond to input ports (1-i), and a synchronizing signal generating unit (4) is provided to output, synchronously, a synchronizing signal and selecting signal information for designating a selector unit (5-i); the selector unit (5-i) being provided with a determining unit (6) for determining whether or not the selecting signal information designates the selector.

Abstract: A switch includes a plurality of memories respectively having write terminals connected to input ports and output terminals, each of the memories including an input acknowledgement signal generating block for generating an input acknowledgement signal when data is received thereto. A multiplexer, which is coupled between the read terminals of the memories and an output port, connects one of the memories to the output port in response to a port number signal. An output controller, which is coupled to the memories and the multiplexer, receives the input acknowledgement signal from each of the memories in order of receipt and generating the port number signal so that data stored in the memories is selected by the multiplexer in order of receipt of the input acknowledgement signal.

Abstract: A communication system containing a master station and a plurality of slave stations. The master station receives a request from one of the plurality of slave stations and memorizes one or more requests from one or more slave stations. The master station also sends a request sending allowance signal which addresses one of the plurality of slave stations to give an allowance to send a request for sending data, and sends a data sending allowance signal which addresses one of the plurality of slave stations to give an allowance to send data, according to a request which is memorized. Each of the slave stations detects a request sending allowance signal which addresses its own slave station, and a data sending allowance signal which addresses its own slave station. Each of the slave stations also sends a request for sending data to the master station when its own slave station detects a request sending allowance signal which addresses its own slave station.

Abstract: A communication system including a master station, a plurality of slave stations each for communicating with the master station, a two-way transmission line connecting the master station and the plurality of slave stations. Each of the slave stations sends a request for further communication with the master station, to the master station when its own slave station is allowed to communicate with the master station and its own slave station has the above request. The master station detects the request for further communication with the master station in a signal sent from a slave station, and memorizes the slave station from which the request for further communication with the master station is detected, until an allowance signal is sent to the slave station from the master station corresponding to the memorizing of the slave station.

Abstract: A coded transmission system wherein each bit of transmitted data having a logical value is coded depending on a coded result of a preceding bit. The coded transmission system contains a sender-side apparatus, a transmission line, and a receiver-side apparatus. In the sender-side apparatus, a resetting bit and a message are generated; a code of a bit last transmitted which is necessary to code a bit which is to be transmitted next is memorized in a first preceding code memorizing circuit; and the content of the first preceding code memorizing circuit is reset to an initial code responding to the resetting bit. A coding circuit receives the resetting bit and the message, codes each bit of the message in accordance with a predetermined coding rule and the content of the first preceding code memorizing circuit, and codes the resetting bit to a predetermined resetting code which is different from the codes used in the coding of the message.