Hitachi, Ltd.

Hitachi Communication Technologies, Ltd.

Keiji Usuba

Shiro Mazawa

Yosuke Takahashi

Akihiko Yoshida

Kiyoshi Kawamoto

Yoshimi Nakagawa

Satoko Araki

Masatoshi Takahashi

Yusuke Yajima

Takashi Mori

Takeshi Sato

Mitsunobu Kimura

Takao Iwata

Seigo Obayashi

An AN (Access Network) controlled by a communication control apparatus and communicating with a AT Access Terminal), wherein the AN receives control information including information for allocating communication information from the communication control apparatus, and the AN transmits transmission cycle information for transmitting the communication information in a predetermined transmission cycle to the AT and allocates the communication information in the predetermined transmission cycle based on the control information received from the communication control apparatus to send the communication information to the AT.

Radio communication apparatus

A radio communication system including: ANs (Access Networks) for wirelessly communicating with an AT (Access Terminal); and a communication control apparatus for controlling the AN, wherein the communication control apparatus includes: a control unit for sending transmission cycle information and control information to the AN, and wherein the AN includes: a memory for storing information necessary for transmitting the communication information to the AT; a control unit for transmitting the transmission cycle information received from the communication control apparatus to the AT, calculating a transmission slot number necessary for sending the communication information in the transmission cycle, determining a transmission timing indicating a period in the predetermined transmission cycle allocated for the communication information, and transmitting the communication information in the determined transmission timing to the AT.

A radio communication system includes a grouping unit for grouping a plurality of base stations into a plurality of groups (Soft Handoff Groups) and a determining unit for selecting base stations belonging to one and the same group selected from the groups produced by the grouping unit and for determining the base stations as base stations to send communication packets to an access terminal.

Radio communication system and base station

In order to realize such communication control as to reliably reconstruct communication information transmitted from a plurality of ANs at a plurality of ATs even when a BCMCS flow is added or deleted, a radio communication system includes a transmitter for transmitting control information necessary for the ATs to receive the communication information from a radio communication system at intervals of a predetermined period, and a controller for controlling to transmit a plurality of pieces of communication information to the ATs at intervals of a constant cycle and in synchronism with a transmission period of the control information.

According to the invention, in a transmission apparatus, there are provided an equipment supervision unit detecting an obstacle in the equipment and a switching control unit controlling the switching operation of transmission lines. When the equipment supervision unit detects condition in which obstacles have occurred in more than one groups of the cross connect unit or the clock unit in which paths provided are disconnected, the same K-bytes as in the case when SF failure is detected are outputted to all the fibers to be inputted to the equipment. Alternatively, an FS-R command is executed to both sides, or Line-AIS is inserted in all the outputted transmission lines, or an output is disconnected, so that the equipment is isolated and the paths provided through a node is relieved.

Transmission equipment for network and network transmission system

The invention has an object of enhancing the service capacity and the operability of a network and simplifying the maintenance and control of the network by adopting a size automatic change mode after a path is set and providing arbitrary pathsize at arbitrary time. To achieve the object, the following means is provided. The service capacity and the operability of a network are enhanced and the maintenance and control of the network are simplified by adopting a size automatic change mode that the size of an input path signal conforms to information written to line overhead H1 and H2 bytes and an output path signal is transmitted with the pathsize the same as the size of the input path signal. A case that receiving path size changes exceeding a band and the fault of a path is caused occurs by providing both modes of fixing pathsize and automating pathsize to a user, flexibly corresponding to various service and automatically changing pathsize. At this time, an operation system identifies the cause, analyzes an influenced range and realizes the simplification of the maintenance and control of the network.

Pathsize control method and operation of transmission apparatus

A bi-directional line switched ring network system including a plurality of optical fiber communications lines and a plurality of nodes connected by the plurality of optical fiber communications lines forming a closed circuit. Each of the nodes performs an addition and a drop of a path between an external communications apparatus and the optical fiber communications lines or permits the path on the optical fiber communications lines to pass through, or performs a change of a direction of the path. A control unit is located in each of the nodes to control the addition, the drop, the pass-through and the direction change of the path. When the path passes through each of the nodes, the control unit sets a time slot number of the path in being inputted into the node and a time slot number of the path in being outputted from the node independently of each other.

Growing community of inventors

Yokohama, Japan

Keiji Usuba