Industrial Technology Research Institute

Chiung-Shien Wu

Gin-Kou Ma

Muh-Rong Yang

A medium access control (MAC) protocol for controlling data communication in a multi-channel communication system (e.g., a wideband code division multiple access system). The protocol provides a procedure for transmitting, via a plurality of data links and control links, data packets between a first station (e.g., a base station) and one or more second stations (e.g., mobile stations). The protocol includes initial transmission of one or more data request packets each having a preamble code and a cyclic redundant code from the second stations to the first station, subsequent transmission of one or more channel assignment commands from the first station to one or more of the second stations based on the data request packets processed by the first station, and final transmission of one or more data packets from the one or more of the second stations to the first station based on the channel assignment commands. The data and request packets, which are respectively transmitted over a forward control link and a plurality of reverse control links, are respectively encoded by a predetermined number of scrambling codes.

Medium access control protocol for a multi-channel communication system

A transport protocol that meets the requirements and performance for multimedia data transfer in a wireless link includes a transmitting/sending station and a receiving station. The inventive protocol is referred to as the Burst-oriented Transport with Time-bounded Retransmission (BTTR). This scheme uses a large transmission window for sending/receiving a burst of time-sensitive data and, within this window, several smaller observation windows are used for dynamic error retransmission. There is a time limitation on each retransmission such that the burst of data can be received in a timely manner, and thus trading some packet losses (still in an acceptable range) for delay and throughput performance. Specifically, the wireless network includes a wireless station for transmitting data over a wireless link. The sending station transmits a plurality of sequential data packets to the receiving station, wherein each plurality of sequential data packets form a respective Group-of-Packet (GOP). The receiving station detects whether any of the received data packets in each current GOP are corrupted before receipt of all data packets in the current GOP. The receiving station then transmits a negative acknowledgement (ACK) packet to the sending station before the receipt of all data packets in the current GOP, if at least one data packet in the current GOP is corrupted. Note that the ACK packet indicates which data packets are corrupted. In addition, the sending station selectively retransmits the data packets based on the indication of the received ACK packet before transmitting the next GOP to the receiving station.

Data transfer method for wire real-time communications

A scalable server architecture for use in implementing scaled media servers capable of simultaneous real-time data stream retrieval for large numbers of subscribers. A scalable server includes a plurality of stream pumping engines each accessing a particular storage device of a storage subsystem, and a server processor which receives retrieval requests from subscribers and directs the stream pumping engines to retrieve the requested data streams. Each of the stream pumping engines may include a storage controller coupled to its corresponding storage device for directing retrieval of the requested stream therefrom, a network controller for supplying the retrieved stream to a client network, and a processor for directing the operation of the storage and network controllers. Each of the stream pumping engines may also include a shared memory accessible by the corresponding stream pumping engine processor and the server processor. The shared memory facilitates communication with other stream pumping engines via the server processor and server system bus. A scaled media server may be implemented by cross-connecting several scalable servers with a plurality of stream multiplexers. Each of the stream multiplexers can include a separate packet input unit for processing the packets of each media stream such that two distinct levels of transmission priority are provided and quality of server restrictions are satisfied for all streams.

Scalable architecture for media-on demand servers

A cable network is provided with at least one bridge that is connected to a first cable segment of the cable network. The bridge receives from a shared communication medium a first carrier signal, having a first carrier frequency that is allocated for intra cable segment packet communication, containing packets modulated thereon. The bridge demodulates selected packets originating in the first cable segment from the first carrier signal. The bridge modulates each of the demodulated packets, that are destined outside of the first cable segment, onto a second carrier signal having a second carrier frequency. The bridge then transmits the second carrier signal on an upstream link of the common shared medium.

Growable architecture for high-speed two-way data services over CATV

Scalable architecture for media-on-demand servers

A method and apparatus for storage and retrieval of multiple data streams in a multimedia distribution system. A given data stream is separated into a plurality of portions, and the portions are stored in a multi-disk storage system with Y disks each having X zones such that the ith portion of the given stream is stored in zone (i mod X) of disk (i mod Y). The number X of zones per disk and the number Y of disks are selected as relatively prime numbers. The stored data are retrieved using Y independent retrieval schedulers which are circulated among the Y disks over a number of scheduling intervals. Each retrieval scheduler processes multiple requests separated into X groups, with the requests of each group accessing the same disk zone during a given scheduling interval. The retrieval schedulers are also configured such that the retrieval requests of a given retrieval scheduler access the same disk during a given scheduling interval. The data stream placement technique in conjunction with the retrieval schedulers provide sequential-like parallel retrieval suitable for supporting real-time multimedia data distribution for large numbers of clients.

Media server for storage and retrieval of voluminous multimedia data

A method and system are disclosed for scheduling the assignment and writing of cells from cell sources into a outgoing bitstream transmitted from each device of an ATM communications network. The timeslots are organized into fixed length cycles which cycles each have a sequence of N timeslots, where N is an integer &gt;1. Furthermore, each cycle is divided into at least one round comprising a variable length subsequence of the timeslots of the cycle. During each timeslot of a uniform timeslot clock, at least one subset of the sources is identified. Each subset corresponds to a round. One cell from each subset is assigned to, and written into, a respective timeslot of the corresponding round. During each timeslot of the timeslot clock, each of the sources is assigned a priority state depending on how many cells of that source have been previously assigned to timeslots during the current cycle and whether or not that source has a cell available for assignment to a round during that timeslot. The highest priority state assigned to any source during each timeslot is identified. One of the cells of each source with the identified highest priority state are assigned to, and written into, a timeslot of a corresponding round, in a round-robin fashion, to form the subsequence of cells of that round.

Growing community of inventors

Hsinchu, Taiwan

Chiung-Shien Wu