摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
In a network system having a plurality of LANs each connecting a plurality of terminals interconnected, a LAN interconnection switching unit for switching and relaying data receives data frames from LANs and sends out a call set-up frame including a call number assigned to a combination of source and destination terminal addresses and addresses of relaying interconnection switching units. The data received from LAN is segmented into packets, which are sent out together with the call number. The interconnection switching unit switches and relays data by using data frame error detection scheme in the LAN. Information for controlling a switching sequence is added to the data frame from the LAN to prevent the interruption by the packet having a different call number.