Nippon Telegraph and Telephone Corporation

Yushi Shirato

Naoki Kita

Kota Ito

Kazuto Goto

Hideyuki Tsuboi

Mizuki Suga

Hideki Toshinaga

Chunhsiang Huang

Atsushi Ota

Yutaka Imaizumi

Takeshi Onizawa

Nobuaki Otsuki

Shuki Wai

An installation candidate presentation device extracts, for each of one or more installation candidates that are candidates for an installation place of a first wireless device, by using planar map data indicating a planar map of a region including the installation candidates, and a target building at which second wireless devices are to be installed, respectively, an outline range of the building, which is visible from the installation candidate. The installation candidate presentation device calculates, for each installation candidate, by using three-dimensional map data indicating a three-dimensional map obtained by measuring the same region as the planar map data, area of part of a wall surface corresponding to the extracted outline range, the part being visible from the installation candidate, and calculates a total of the area calculated for the building in the region. The installation candidate presentation device presents an installation candidate selected based on the calculated total.

Installation candidate presentation method, installation candidate presentation apparatus and program

A communication system includes a central station device and a base station device. The central station device includes: a plurality of signal processing units, each generating an electrical signal of a wireless signal by performing signal processing corresponding to a wireless system; a conversion unit that generates an optical signal by performing intensity modulation on the electrical signal; and a signal processing control unit that controls the conversion unit to generate an optical signal in which a plurality of the electrical signals are multiplexed. The base station device includes: an electrical signal generation unit that receives the optical signal generated in the central station device via an optical transmission path and converts the received optical signal into a plurality of electrical signals; and a plurality of antenna devices, each wirelessly transmitting the wireless signal according to the electrical signal generated by the electrical signal generation unit.

Communication system, communication method, accommodation station device and base station device

On two-dimensional map data indicating buildings serving as candidates for installing terminal station devices, locations of base station installation structures serving as candidates for installing base station devices are set as base station candidate locations, and for each of the base station candidate locations, buildings that have other buildings between themselves and the base station candidate location are selected as visibility detection subject buildings. The heights of the buildings are set at an identical length, a higher position than the buildings is set as an installation altitude of the base station devices, and for each selected visibility detection subject building, a visibility range of the visibility detection subject building from the installation altitude of the base station device in the base station candidate location is detected. Three-dimensional point cloud data acquired by photographing a region including the base station installation structures and the buildings are narrowed down on the basis of the detected visibility ranges, and using the narrowed-down point cloud data, the visibility of the buildings from the base station candidate locations is determined.

Station placement designing method and station placement designing apparatus

A base station apparatus includes a centralized station apparatus and a plurality of access points connected to the centralized station apparatus via optical fibers. Based on propagation delay times in the optical fibers, the centralized station apparatus performs grouping such that access points, among a plurality of access points, with a difference in propagation delay time within a threshold value, belong to the same group. The plurality of access points perform connection processing for each of the groups, to communicate with wireless terminals subordinate to the plurality of access points.

Base station apparatus, communication method, and aggregate station apparatus

A wireless communication device is presented. The wireless communication device includes: a high-frequency circuit; and an analog signal processing circuit that performs gain adjustment such that a gain for each of the plurality of antenna elements, in case of a signal transmission or in case of a signal reception, is a predetermined value being dependent on a position of the antenna element. The analog signal processing circuit includes a first splitter/combiner between the high-frequency circuit and the plurality of antenna elements. For each antenna element in the plurality of antenna elements, a second splitter/combiner is coupled to a particular antenna element in the plurality of antenna elements and, for each antenna element in the plurality of antenna elements, two or more phase shifters of a given M system are connected in parallel with each other and coupled between the first splitter/combiner and a corresponding second splitter/combiner.

Wireless communication device and wireless communication method

An accommodation station transmission unit modulates light to generate an optical signal based on an RF signal and outputs the generated optical signal, a base station transmission unit obtains the optical signal from an input port, demultiplexes the obtained optical signal for each wavelength, outputs the demultiplexed optical signals from output ports of corresponding wavelengths from among a plurality of output ports allocated to each of the wavelengths of the light, and demodulates the RF signal by converting the optical signals output by the output ports into electrical signals, a plurality of transmission antennas emit the demodulated RF signal, and a reflect array or a transmit array receives the RF signal emitted by each of the transmission antennas and forms a transmission beam in a different direction for each position of the transmission antenna that is a transmission source of the RF signal for each RF signal.

Wireless transmitting system, wireless receiving system, base station apparatus, wireless communication system, wireless transmitting method, and wireless receiving method

An allocation method for allocating individual downlink data signals to positions on a time axis when a base station transmits the individual downlink data signals to a plurality of terminal stations. The allocation method includes provisionally allocating individual downlink data signals of the individual downlink data signals for terminal stations having long propagation delay times to positions of relatively early timings and provisionally allocating individual downlink data signals of the individual downlink data signal for terminal stations having short propagation delay times to positions of relatively late timings, changing the positions such that, when it is estimated that a collision will occur when receiving response signals transmitted from the terminal stations, it is estimated that a collision will not occur, in the provisionally allocating, and fixing, as the positions of the individual downlink data signals on the time axis, the positions changed in the changing of the positions.

Allocation method and signal processing apparatus

A station placement design method includes: extracting candidates for an installation location of a wireless base station from point group data in accordance with designated conditions for an installation location of a wireless base station; determining presence/absence of visibility between a plurality of designated wireless terminal stations and the candidates for an installation location of a wireless base station based on the point group data and generating a first list including information in which the candidates for an installation location of a wireless base station and wireless terminal stations determined to have presence of visibility for the candidates for an installation location of a wireless base station are associated with each other; generating a second list including information representing combinations of the candidates for an installation location of a wireless base station that enable all of the plurality of designated wireless terminal stations to be accommodated based on the first list; and sorting the second list in order from the smallest number of the candidates for an installation location of a wireless base station to the largest.

Station placement designing method, station placement designing apparatus and program

An accommodation station transmission unit modulates light based on an RF signal to generate an optical signal and outputs the generated optical signal, a base station transmission unit demultiplexes the output optical signal for each of wavelengths, outputs the demultiplexed optical signals, converts the demultiplexed optical signals into electrical signals to demodulate the RF signal, outputs the demodulated RF signal, and each of first ports of a matrix operation unit including the plurality of first ports and a plurality of second ports and configured to use each of the first ports as a reference port and perform, on signals obtained by the reference ports, a BFN matrix operation of performing phase changes that are different for each of positions of the reference ports and cause each of phases of signals output from the plurality of second ports to have a linear inclination receives the demodulated RF signal and forms transmission beams in different directions for each of wavelengths by a plurality of transmission antennas emitting the RF signal output by each of the second ports of the matrix operation unit.

An interference evaluation method for evaluating, over an area, radio-wave interference that occurs between a first radio station and a second radio station includes: a distinguishing step of acquiring information indicating topographic cross-sections of respective azimuths centered about the first radio station, and distinguishing the topographic cross-section into a segment in which there is visibility from the position of the first radio station and a segment in which there is no visibility from the position of the first radio station; and a specification step of specifying a position at which a desired interference amount is reached based on a distance between the first radio station and the second radio station in a segment distinguished as having visibility from the position of the first radio station, and specifying a position at which the desired interference amount is reached by evaluating the radio-wave interference for each square of an evaluation target region segmented into squares in a segment distinguished as having no visibility from the position of the first radio station.

Interference evaluation method, interference evaluation apparatus and interference evaluation program

Using an array antenna in which a spacing between adjacent antenna elements is constant, each of combinations of two antenna elements in positions symmetrical relative to a center of an array is connected by wire connections in two paths, and a path length between the antenna elements in the combination of two antenna elements is the same in all of the combinations: a phase adjustment amount is calculated for each wire connection aside from a reference wire connection on the basis of an arrival direction of a wireless signal received by one antenna element in the combination of two antenna elements and a re-radiation direction of a wireless signal transmitted as a re-radiated wave by the other antenna element corresponding to the one antenna element, taking into account a phase difference between a signal transmitted by the wire connections connected to the one antenna element and a signal transmitted by the reference wire connection; and phase rotation is applied to the signal transmitted by the wire connections aside from the reference wire connection in accordance with the calculated phase adjustment amount.

Relay apparatus and relay method

Point cloud data between a base station device and a terminal station device is acquired as a point cloud data group. A radius of a first Fresnel zone defined by the base station device and the terminal station device at each position where the point cloud data group is acquired is calculated. A region specified by the radius at each position where the point cloud data group is acquired is scanned to detect the point cloud data, and a non-line-of-sight region is extracted. A ratio of a total area of all the extracted non-line-of-sight regions to an area of a region constructed by the first Fresnel zone is calculated. A received power is estimated based on the calculated ratio between the areas. Whether or not there is a line of sight between the base station device and the terminal station device is determined based on the received power.

Station placement designing method, station placement designing apparatus and station placement designing program

A derivation method includes: a transmission step of transmitting, to a wireless terminal, a first radio-wave signal according to an optical signal with a first wavelength and a second radio-wave signal according to an optical signal with a second wavelength; a communication start time information acquisition step of acquiring information on a first communication start time and information on a second communication start time; a reception time information acquisition step of acquiring information on a first reception time and information on a second reception time; a transmission time period derivation step of deriving a first round trip time and deriving a second round trip time; and an optical fiber length derivation step of deriving an optical fiber length, based on the first round trip time, the second round trip time, a group velocity or a group delay time of the optical signal with the first wavelength, and a group velocity or a group delay time of the optical signal with the second wavelength.

Derivation method, communication system and accommodation station apparatus

In two-dimensional map information showing communication equipment installation structures on which communication equipment is installed, roads, and buildings, a narrow region between the buildings is detected based on a distance of an interval of the buildings adjacent to each other and a predetermined length and a connection line connecting the buildings is imparted to an opened portion of the detected narrow region, a line-of-sight detection line is extended with any one of the communication equipment installation structures set as a start point and the line-of-sight detection line is rotated around the start point, intersections of the line-of-sight detection line and a contour line of the building or the connection line is detected and the intersection at a shortest distance from the start point among the detected intersections is detected as a line-of-sight intersection, and, when the line-of-sight intersection and another line-of-sight intersection belong to the same building, a line-of-sight range line along the contour line of the building is imparted to between the two line-of-sight intersections.

Perspective detection method, perspective detection apparatus and perspective detection program

Provided is a wireless relay system including multiple terminal station apparatuses and a base station apparatus. The base station apparatus includes: a base station reception unit that respectively receives pieces of upstream data traffic from the multiple terminal station apparatuses; an encoding unit that, if pieces of upstream data traffic that require mutual forwarding in opposite directions are present in the respective pieces of upstream data traffic, performs network encoding on the respective pieces of upstream data traffic such that the pieces of upstream data traffic are pieces of data traffic of mutually identical content; and a base station transmission unit that simultaneously transmits encoded data traffic as downstream data traffic to the multiple terminal station apparatuses. The terminal station apparatuses each include: a terminal station transmission unit that transmits the upstream data traffic to the base station apparatus; a terminal station reception unit that receives the encoded data traffic; and a decoding unit that decodes the encoded data traffic using the upstream data traffic.

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Musashino, Japan

Yushi Shirato