Hitachi, Ltd.

Hitachi Microcomputer Engineering, Ltd.

Hitachi, Ltd. and Hitachi Microcomputer Eng. Ltd.

Yoshihiro Takiyasu

Eiichi Amada

Hidehiko Jusa

Tomoaki Ishifuji

Mitsuo Asai

Mitsuhiro Yamaga

Shuichi Adachi

Genichi Ishii

Toshiki P Tanaka

Kunio Hiyama

Takeshi Onodera

Michio Asano

Kazunori Nakamura

Hirofumi Yamashita

Takahiko Kozaki

Osamu Takada

Taihei Suzuki

Matsuaki Terada

Naoya Kobayashi

Masaru Igawa

Yukiji Yamauchi

Koichi Morita

Masashi Ohno

Haruyuki Nakayama

Ryuichi Ohno

Tomoyuki Ishida

Koichi Kimura

Atsushi Saito

Takehisa Hayashi

Kenichi Wada

Atsushi Takai

Koichi Shibata

Katsuyoshi Onishi

Miho Iwanaga

Shigeru Matsuzawa

Nagatoshi Usami

Nozomu Hirose

Seiichi Ozaki

Tatsuhito Iiyama

Yasuhiko Hatekeyama

Fumio Sukegawa

Mikiko Sato

Satoru Hirayama

A WEB server includes a control unit for HTTP server, a table of addresses of VOD servers, and a table of identifiers of video data. The control unit accesses these tables, in response to a request from a user of a terminal device for a display of video data, to retrieve therefrom an address of a video server and an identifier of a title of video data related to information on a WEB page accessed by the user, then transfers the address and the identifier to the terminal device. This enables the user of a video-on-demand system to easily obtain video data associated with information on the WEB server.

Method of and an apparatus for controlling a web server, a web server control program, and a storage medium on which the web server control program is stored

A video displaying method of displaying, on a display unit, contents of video files. Each of the video files is composed of a plurality of images. The video displaying method includes the steps of extracting, from one of the video files, a plurality of images at predetermined intervals from the images composing the video file; displaying the extracted images on the display unit; in response to a selection of one image from the displayed images, reproducing the video file including the selected image beginning at a position of the selected image in the video file; and displaying the reproduced video file on the display unit.

Video searching method, apparatus, and program product, producing a group image file from images extracted at predetermined intervals

A video searching method, and apparatus, having a function of representing a video file are provided such that the contents of video files stored in a storage device may be recognized definitely and rapidly. The video searching apparatus includes a computer, a storage device, a device for controlling them, and a display device. The apparatus includes a software resource for producing a group image formed of at least two still images of scenes representing the contents of each of video files stored in the storage device. In the apparatus, the size of the group image is changed at any time. In response to manipulation of the group image, file operation such as deletion, movement or name change of a corresponding video file is performed.

Video searching method and apparatus, video information producing method, and storage medium for storing processing program thereof

A multimedia database system effectively retrieves the contents in an optional storage position of an optional medium among a large amount of video and audio media. When a user puts an annotation to a specific range of a medium, the system registers an annotation object comprising the object ID of the target medium, specific range, and annotation information in a table. Next, when an annotation is put to a specific range of a medium once, the system automatically produces annotation objects for all media in the citation relation to it. The system manages the link relation between the citation destination and the citation source by a management table which is newly installed. The system retrieves the table and displays an annotation list coincident with the retrieval condition.

Retrieval method and system of multimedia database

A frequency hopping communication system having a plurality of wireless mobile stations and at least one base station. Each wireless mobile station is operated to communicate according to a communication frame format generated by a base station. The system performing slow frequency hopping by keeping a frequency hopping interval within each frame. The hopping pattern of a frequency is designated at a field located at the tail of each communication frame by the base station.

Frequency-hopping communication system and communication station

In a method of increasing the network use efficiency of computer communication and reducing the limitation of byte stream in a transmit/receive request, a virtual circuit is established between protocol modules such as applications for providing the communication function between software to mate one transmit request with one receive request. By returning an acknowledgement in a unit of request, any vain acknowledgement can be avoided and even in the case of asynchronous transmission/reception, a request which is completed in transmission/reception can be ended immediately, thus permitting efficient data transfer. Even when the transmit request length and the receive request length differ from each other, reliable communication of a request having a smaller request length can be ensured between mating transmit and receive requests. Further, in the case of synchronous transmission/reception, by copying only the latter half of a transmission buffer and returning a virtual ACK to the transmitting side when reception of the former half ends, the acknowledgement need not be waited for, thus permitting efficient data transfer.

Communication method with attaching identifiers to receive request and

When an access request is generated from a client in a network file server comprising a computer including a communication controller connected to at least one client through a network and transferring information on a plurality of addresses inside a main storage device as one packet to at least one client, the main storage device having a buffer, a central processing unit and an input/output bus for mutually connecting the communication controller, the central processing unit and the main storage device, and a secondary storage device connected to the computer, an area for storing the data corresponding to this access request is allocated into the buffer of the main storage device. The data corresponding to the access request is read out from the secondary storage device, is transferred to the buffer and is stored in the allocated area. A header for the data in the allocated area in the buffer, the address and size of the header and the address and size of the data are generated in the main storage device on the basis of the access request. As the address and size of the header and the address and size of the data are reported to the communication controller, the data inside the allocated area in the buffer are transferred as one packet to at least one client by the communication controller.

Computer network system for packet-transferring data between computers,

In a video storage and delivery apparatus and corresponding system, video data items are simultaneously supplied to a plurality of users while guaranteeing the time axis and the picture quality of the video data. The apparatus includes a frame address table which indicates a storage location in the apparatus of each frame of video data to start a special reproduction or a reproduction at a desired frame and a control unit controlling a switch bus connecting a plurality of video storage and delivery apparatuses to a plurality of channels so as to conduct data transfers via the switch bus between the apparatuses and between video reproduction devices of the users. From an optical disk data storage storing video data, a plurality of video data items are read in a timesharing fashion to be temporarily stored in a magnetic disk device or a semiconductor memory, thereby delivering the video data items therefrom to the users.

Video storage and delivery apparatus and system

In a wireless communication system having a plurality of base stations connected through a control line and a plurality of mobile terminals, one of base stations (a master base station) informs a carrier frequency hop timing to the other base stations (slave base stations) through the control line. Each slave base station generates a wireless communication frame used inside of each cell and switches the carrier frequency of the wireless communication frame in synchronous to the timing indicated by the master base station. Each movable terminal receives an identifier of a frequency hopping sequence from a control information field of the wireless communication frame, hops to one carrier frequency selected among a frequency hopping sequence corresponding to this identifier, and transmit or receive the data through the field following the control information field of the wireless communication frame.

Frequency hopping wireless communication system and communication

A wireless network is provided for restricting the number of mobile terminal devices which are managed by the base station device for wireless communication with one another. The base station device has a mobile terminal confirming database for registering mobile terminal devices allowed to be subscribers to the wireless network, and a mobile terminal managing database for registering presently-managed mobile terminal devices. The wireless transfer request from one of the mobile terminal devices is tested to determine whether the request-issuing mobile terminal device is one of the subscribers. If the request is accepted, then the identification of the request-issuing mobile terminal device is registered into the managing database.

Wireless LAN system capable of re-transmission under management of a

A wireless communication system includes a plurality of wireless terminals and a base station for periodically generating a fixed-length communication frame composed of an information field which includes a plurality of information slots, and first and second control fields which are arranged preceding the information field and each of which includes a plurality of time slots. Each time slot of the first control field of each communication frame is used for allowing the base station to send control data for designating a terminal which is to make the transmission or reception of data in one information slot of the information field, and each time slot of the second control field thereof is used for allowing one wireless terminal to send control data indicating a requirement for assignment of an information slot for data transmission. Each wireless terminal, when receiving control data inclusive of an address of that terminal in the i-th time slot of the first control field of each communication frame, makes the reception or transmission of data in the i-th information slot in the information field of that communication frame. When the control data is not found out in the first control field, the power source of a reception unit of the wireless terminal is turned off during a period of time until the next communication frame is generated.

Wireless communication system and wireless terminal device using fixed

In a communication system having a base station for controlling a transmission right and a plurality of substations, a substation having data to be transmitted transmits the number of necessary fragments and its address to a request field of a communication frame. The base station uses a plurality pair of fragment slots and reply slots following the request field in the communication frame to transmit an address of a substation permitted to transmit data, to each fragment slot. The substation permitted to transmit data transmits the address of a destination substation and the data to a predetermined field following the address in one fragment slot. The destination station transmits a reply signal indicating the reception state of the data to the reply slot paired with the fragment slot. If the base station detects from the reply signal that the destination station failed in receiving the data, the base station instead of the substation first transmitted the data transmits the destination address and data received at the fragment slot to the next fragment slot.

Method of wireless communication between base station and mobile station

In a system control information transmission system in a ring LAN system, each of a plurality of data transmission devices transmits a transmission frame including a user information transmission area and a system control information transmission area to an adjacent data transmission device at peculiar periods independent of the state of the system, i.e., a failure in the system. The system control information transmission area in the transmission frame is used to transmit system control information only required to be relayed to a downstream data transmission device.

Transmission system of system of system control information in a ring

A high-speed ring LAN capable of accommodating at least one public network having a signal transmission rate of 155.57 MHz, and at least one sub-LAN having a signal transmission rate of 100 MHz. The high-speed LAN has a signal transmission rate of 155.52 Mbps .times.n (n is an even number). SONET (Synchronous Optical NETwork) subframes each comprising a 9 bytes .times.9 section overhead area and a 261 bytes .times.9 virtual container 4 (VC-4) area flow in a time-divisional n-multiplexed format. The respective node devices inserted in the transmission path have one or more ports to accommodate sub-LANs or public networks. Information is exchanged in units of a fixed-length packet between a received SONET subframe and an asynchronous port whereas information is exchanged in units of a byte between the SONET subframe and a synchronous port.

High-speed ring lan system

In a local area network composed of transmission lines for interconnecting a plurality of subordinate networks including synchronous apparatuses and a plurality of nodes which connect the subordinate networks to the transmission lines, information is transferred using a fixed length frame, a clock source which generates an independent clock signal and a circuit which generates a fixed length frame with the oscillation frequency of the clock source as a reference are provided in each node so as to adopt an independent clocking system, and distribution of a common synchronizing clock required for synchronous apparatuses is made by transmission while embedding transition point information of a synchronizing clock in a specific space in the fixed length frame. Further, each node generates a fixed length transmission frame with an independent clock signal, and on the other hand, there are provided in each node, from the requirement that information quantity applied to a network is made constant, a circuit for extracting a received clock, a storage device for storing received information temporarily, and an information outgoing quantity control circuit in which information quantity which is sent out in one frame is increased when the information quantity stored in the storage device becomes more than a predetermined first reference value and information quantity which is sent out in one frame is decreased when the information quantity stored in the storage device becomes less than a predetermined second reference value.

Independent clocking local area network and nodes used for the same

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Higashimurayama, Japan

Yoshihiro Takiyasu