Nippon Telegraph and Telephone Corporation

Chunhsiang Huang

Naoki Kita

Yushi Shirato

Atsushi Ota

Kazuto Goto

Tatsuya Fukui

Go Yazawa

Hideaki Kimura

Kota Ito

Yutaka Imaizumi

Nobuaki Otsuki

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

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.

Wireless relay system, wireless relay method and base station apparatus

SeNBs generate first identification information for specifying wireless access networks on the basis of system information provided in a notification from a relay communication device, wirelessly transmit the first identification information to UE, and notifiy an MeNB of second identification information for specifying wireless resources, utilization of which is permitted, via the relay communication device. The MeNB sets, in a signal directed to an SeNB selected from the SeNBs in the first identification information received from the UE, the first identification information of the SeNB, sets the second identification information of the selected SeNB in the signal directed to the UE, and transmits the signal to the relay communication device. The relay communication device transfers the signal received from the master base station to the SeNB in accordance with the first identification or the second identification information set in the signal. The SeNB wirelessly transmits the signal transferred from the relay communication device and directed to the UE.

Wireless communication system, relay communication device and communication control method

A wireless communication system which includes first and second wireless station apparatuses having a plurality of antenna elements and performs directivity forming. For Tand Tsuch that T=N&#xd7;Tand T=N&#xd7;Twith a predetermined period T, the wireless communication system performs the steps of sequentially switching Ntypes of directional beams at intervals of period Tand transmitting signals while performing switching with an identical directional beam switching pattern maintained over period T, sequentially switching Ntypes of directional beams at intervals of period Tand receiving signals over the period Tor more while performing switching with an identical directional beam switching pattern maintained over the period T, searching for a directional beam having a highest reception level among those acquired over a predetermined period, and setting the searched directional beam as a directional beam to be used.

Apparatus search for optimal directional beams

An object is to provide a communication device, a communication method, and a program that make it possible to suppress an increase in the communication band due to communication via a GWR when Dual Connectivity is implemented, without making an additional setting on base stations. A communication device according to the present invention enables a communication packet to be transferred through a path that is shorter than conventional paths, and can therefore suppress an increase in the communication band. Also, this short cut of the communication path need only be set on the communication device, and need not be additionally set on the base stations.

Growing community of inventors

Musashino, Japan

Chunhsiang Huang