Abstract: A pipelined digital data receiver for a cable TV headend which is capable of receiving DOCSIS 1.0 or 1.1 or advanced PHY TDMA or SCDMA bursts having programmable symbol rates and programmable modulation types as well as a host of other burst parameters such at Trellis code modulation on or off, scrambling on or off, various values for Reed-Solomon T number and codeword length. The receiver has an RF section to filter and digitize incoming RF signals. It also has an input section to detect impulse noise and do match filtering and despread SCDMA bursts. A timing recovery section recovers the symbol clock and detects the start of bursts and collisions. A rotational amplifier and equalizer calculate and track gain, phase and frequency offsets and correct symbols and calculates equalization coefficients. A decoder section decodes TCM and non TCM bursts, and a Reed-Solomon decoder section reconstructs RS codewords and uses them to error correct the payload data.

Abstract: Large payload files are selectively partitioned in blocks and the blocks distributed to a plurality of distribution stations at the edge of the network qualified to have the data. Each qualified station decides how much and what portion of the content to save locally, based on information such as network location and environment, usage, popularity, and other distribution criteria defined by the content provider. Different pieces of a large payload file may be available from different nodes, however, when a user requests access to the large payload file, for example, through an application server, a virtual file control system creates an illusion that the entire file is present at the connected node. However, since only selective portions of the large payload file may actually be resident at that node's storage at the time of request, a cluster of distribution servers at the distribution station may download the non-resident portions of the file as the application server is servicing the user. The download may be in parallel and usually from the least congested nodes. New nodes added to the network learn from other nodes in the network what content they should have and download the required content, in a desired amount, onto their local storage devices from the nearest and least congested nodes without interrupting network operation. Each node manages its local storage and decides what content to prune based on information such as usage patterns.

Abstract: A wireless network and serviced mobile station manages VOIP telephony calls by incorporating control information into VOIP datagrams. The control information includes an indication of the data rate of the VOIP payload of the VOIP datagram, the quality of the VOIP payload, requested data rates for subsequent VOIP datagrams, and whether the VOIP payload contains a 'silent' VOIP payload. To avoid conflicting with particular datagram requirements, the control information is inserted into the VOIP datagram between the VOIP datagram and the VOIP payload. A base station servicing the wireless link may override the requested data rate and/or the commanded data rate in order to manage its available wireless bandwidth among a plurality of mobile stations. The frame quality indicator may be set by the servicing physical/mac/link layers(s) of the base station or mobile station to indicate that the VOIP payload was not correctly received.

Abstract: Large payload files are selectively partitioned in blocks and the blocks distributed to a plurality of distribution stations at the edge of the network qualified to have the data. Each qualified station decides how much and what portion of the content to save locally, based on information such as network location and environment, usage, popularity, and other distribution criteria defined by the content provider. Different pieces of a large payload file may be available from different nodes, however, when a user requests access to the large payload file, for example, through an application server, a virtual file control system creates an illusion that the entire file is present at the connected node. However, since only selective portions of the large payload file may actually be resident at that node's storage at the time of request, a cluster of distribution servers at the distribution station may download the non-resident portions of the file as the application server is servicing the user. The download may be in parallel and usually from the least congested nodes. New nodes added to the network learn from other nodes in the network what content they should have and download the required content, in a desired amount, onto their local storage devices from the nearest and least congested nodes without interrupting network operation. Each node manages its local storage and decides what content to prune based on information such as usage patterns.

Abstract: Large payload files are selectively partitioned in blocks and the blocks distributed to a plurality of distribution stations at the edge of the network qualified to have the data. Each qualified station decides how much and what portion of the content to save locally, based on information such as network location and environment, usage, popularity, and other distribution criteria defined by the content provider. Different pieces of a large payload file may be available from different nodes, however, when a user requests access to the large payload file, for example, through an application server, a virtual file control system creates an illusion that the entire file is present at the connected node. However, since only selective portions of the large payload file may actually be resident at that node's storage at the time of request, a cluster of distribution servers at the distribution station may download the non-resident portions of the file as the application server is servicing the user. The download may be in parallel and usually from the least congested nodes. New nodes added to the network learn from other nodes in the network what content they should have and download the required content, in a desired amount, onto their local storage devices from the nearest and least congested nodes without interrupting network operation. Each node manages its local storage and decides what content to prune based on information such as usage patterns.

Abstract: A scalable content delivery network (SCDN) employs a parallel download mechanism to ensure that a demanded file is present at a station in time for user consumption. This mechanism is used in solving the content caching and storage problem for applications such as video-on-demand, which is commonly perceived as a tough problem in the industry. In the network, files are divided into smaller units called tracks according to the nature of data contained in each of them. Tracks are further divided into smaller equally sized units called block files. This division builds the foundation for parallel download. A sequence server provides a lock-free mechanism for multiple threads or processes to access data atomically. The sequence server allows clients to gain sequential access to data, or to find out whether the sequence has been violated so that they can retry their operation or take corrective action. Advantages of the invention include the ability to handle distribution of large files and process sequencing.

Abstract: A network interface device includes host interface logic, arranged to receive from a host processor a frame of outgoing data that includes outgoing header information and outgoing payload data, and to separate the header information from the payload data. A transmit protocol processor is coupled to read and process the outgoing header information from the outgoing header memory so as to generate at least one outgoing packet header in accordance with a predetermined network protocol. Transmit logic is coupled to receive and associate the at least one outgoing packet header with the outgoing payload data from the outgoing data memory, so as to generate at least one outgoing data packet for transmission over a network in accordance with the protocol.

Abstract: A method for processing packets with encrypted data received by a client from a server through at least one network wherein the data packets comprise at least an encryption header (46 ) and payload (45), extracting the encryption header (54, 55; 69) from a data packet, extracting and decrypting the encrypted payload to form a clear data, generating a clear data packet segment. Secure packet-based transmission of content data from a server to at least one client comprises retrieving a clear data packet comprising an unencrypted payload, dividing the unencrypted payload into one or more segments, applying an encrypted algorithm to each segment to generate encrypted segments (47), generating encryption header for each encrypted segment composing a packet with encrypted data for each encrypted segment comprising the encrypted header (46), a data packet header and transmission of each of the composed packets to the client.

Abstract: A robust Media Access Controller, MAC, scheme for network stations (12) operating in an OFDM transmissions network (10). The MAC scheme uses robustly transmitted frame control information to ensure network synchronization for media access. The frame control information can occur in a frame (80) in a first frame control field (98) before the frame's payload (82) and in a second frame control field (102) after the frame's payload (82), or in a third access priority (144) to convey channel access prioritization for QoS.

Abstract: A method of generating protocol data units in a radio link control layer, which is set to an unacknowledged mode or an acknowledged mode, is disclosed. After producing a payload unit by segmenting and/or concatenating one or more service data units received from a higher layer, a protocol data unit including a sequence number corresponding to the payload unit and a protocol data unit including the payload unit itself are generated and transmitted separately to a media access control layer through a pair of different channels. Therefore, the PDUs having the sequence number can be transmitted in a low rate in order to reduce the its error rate, and the other PDUs having data can be transmitted in a higher rate to increase the data processing rate.

Abstract: We consider the regulation control problem for a two-degree-of-freedom (2-DOF), underactuated overhead crane system. Inspired by recently designed passivity-based controllers for underactuated systems, we design several controllers that asymptotically regulate the gantry position and payload position. Specifically, utilizing LaSalle's invariance set theorem, we first illustrate how a simple proportional-derivative (PD) controller can be utilized to asymptotically regulate the overhead crane system. Motivated by the desire to achieve improved transient performance, we then design a two nonlinear controllers that increase the coupling between the gantry position and payload position.

Abstract: Methods and apparatus for data communication are disclosed. An example method includes encoding a first plurality of transmitting frames, where a header segment of each frame is encoded in accordance with a fixed set of header encoding parameters and a payload segment of each frame is encoded in accordance with a first set of a variable set of payload encoding parameters. The example method also includes transmitting the first plurality of transmitting frames to a receiving station and receiving a request from the receiving station to change the first set of payload encoding parameters to a second set of the variable set of payload encoding parameters. The example method further includes selecting the second set of payload encoding parameters based on the request and encoding a second plurality of transmitting frames, where a header segment of each frame of the second plurality of transmitting frames is encoded in accordance with the fixed set of header encoding parameters and a payload segment of each frame of the second plurality of transmitting frames is encoded in accordance with the second set of payload encoding parameters. The example method still further includes transmitting the second plurality of transmitting frames to the receiving station.

Abstract: A data channel to transmit data from a transmitter to one or more of a plurality of receivers, each of which intermittently reports to the transmitter its reception quality of signals transmitted by the transmitter. The transmitter transmits the data in frames which include at least one block. Each block includes the same predefined number of traffic symbols, and includes a header portion and a payload portion. The header portion of each block is packaged for transmission in a robust manner, enhancing the probability that each receiver will be able to recover it and the header portion includes information required to recover the payload portion. The payload portion is, in accordance with the reception quality reported by the intended receiver, packaged to make efficient use of the transmission resources while ensuring a reasonable probability that the intended receiver will be able to recover the payload. The header portion can include indications of the modulation, forward error correction and repetition utilized to package the payload and can indicate the length of the payload.

Abstract: A method for selecting frame encoding parameters to improve transmission performance for a transmitting frame being transmitted from a transmitting station to a receiving station over a transmission medium of a frame-based communications network, the transmitting frame having a header segment and a payload segment, the header segment being transmitted using a fixed set of encoding parameters such that the header segment can be received and decoded by all stations on the network, the payload segment being transmitted using a variable set of payload encoding parameters, the transmitting station sending the transmitting frame using one set of the variable set of payload encoding parameters at a time. The receiving station receives and decodes the header and payload segments of each transmitting frame. The decoding includes computing frame statistics. A plurality of sets are selected from the variable set of payload encoding parameters to form a possible set of payload encoding parameters. For each set of payload encoding parameters in the possible set of payload encoding parameters, an estimate of network performance characteristics expected if the transmitting station were to transmit the transmitting frame using that set of payload encoding parameters is generated based upon the frame statistics. A set of payload encoding parameters having optimized network performance characteristics is selected based upon estimates of expected network performance for each set of payload encoding parameters in the possible set of payload encoding parameters. The frame statistics include a slicer maximum squared error for the header segment and a slicer maximum squared error for the payload segment.

Abstract: Embodiments of the present invention relate to methods and systems of managing delivery of a network service. In an embodiment, a data packet including a service address and a payload is received. A plurality of network applications associated with the service address of the data packet are identified. The plurality of network applications associated with the service address include a first network application and a second network application, where the first network application is different than the network application. At least the payload of the data packet is sent to the first network application, and a first network application response packet is received from the first network application. A second network application packet is sent to the second network application, and the second network application packet is based at least in part on the first network application response packet.

Abstract: Large payload files are selectively partitioned in blocks and the blocks distributed to a plurality of distribution stations at the edge of the network qualified to have the data. Each qualified station decides how much and what portion of the content to save locally, based on information such as network location and environment, usage, popularity, and other distribution criteria defined by the content provider. Different pieces of a large payload file may be available from different nodes, however, when a user requests access to the large payload file, for example, through an application server, a virtual file control system creates an illusion that the entire file is present at the connected node. However, since only selective portions of the large payload file may actually be resident at that node's storage at the time of request, a cluster of distribution servers at the distribution station may download the non-resident portions of the file as the application server is servicing the user. The download may be in parallel and usually from the least congested nodes. New nodes added to the network learn from other nodes in the network what content they should have and download the required content, in a desired amount, onto their local storage devices from the nearest and least congested nodes without interrupting network operation. Each node manages its local storage and decides what content to prune based on information such as usage patterns.

Abstract: In one embodiment, a system and method for receiving information over a power line in accordance with the HomePlug specification is described. The receiver side of the method involves separation of the data within a payload of an incoming frame into a plurality of blocks. Thereafter, both frame control symbols and data within the blocks are processed by Frame Control Forward Error Correction (FEC) decoding logic.

Abstract: A system and method are disclosed for providing encryption of location data transmitted from a wireless device to a wireline network server. In one embodiment, the wireless device encrypts a payload, adds a header to the payload to form a data packet, encrypts the payload and the header of the data packet, and transmits the encrypted data packet.

Abstract: A network interworking facility ( 24 ) advantageously interworks Ethernet and ATM networks ( 22, 26 ) having different protocols to permit the data from in one network to pass to the other and vice versa without the need for the source in to account for the protocol of the destination. Upon receipt of an information frame from the source, the interworking facility forms a second frame of a format compatible with the destination network and including the information payload from the first frame. The interworking facility also maps the destination address incorporated in the origin frame to a corresponding destination address of a format compatible with the destination network to facilitate forwarding of the second frame to the destination.

Abstract: We consider the problem of determining the transport capacity of point-to-point and broadcast channels implemented on top of a network that enforces max-min fair bandwidth allocations in its routers. Our main finding is that the use of inefficient codes to represent data that is intended to be used solely for network control operations (such as routing, sequencing, etc.), gives rise to the unintended creation of a covert channel. Sources can encode some information for their destinations into network control bits (on top of the standard method of encoding data into payload bits), by means of a mechanism which we refer to as the generation of "phantom" packets. Although phantoms provide only a marginal bandwidth increase, they could have potentially vast reaching implications in terms of security issues.

Abstract: A method and system of routing variable-length packet data across a wave division multiplex (WDM) communications network having a plurality of data communications channels comprises inverse-multiplexing each data packet into a respective frame. Each frame includes a label block containing label information of the frame, and two or more respective payload blocks having a predetermined length. The label block contains encoded routing information, a start time, and, possibly an end time, and is transmitted over a label channel of the communications network. The start time preferably indicates a delay between launching a first bit of the label clock and the first bit of the payload blocks. The end time may be a bit count indicative of the location of the last bit of the data packet within the frame. The data packet is divided into a plurality of data segments, each of which is transported across the network within a respective payload block. Each payload block is transmitted over a respective separate data channel of the communications network. Routing control of the frame may be handled using the multi-protocol label switch (MPLS) protocol.

Abstract: A method for selecting frame encoding parameters to improve transmission performance for a transmitting frame being transmitted from a transmitting station to a receiving station over a transmission medium of a frame-based communications network is provided, the transmitting frame having a header segment and a payload segment, the header segment being transmitted using a fixed set of encoding parameters such that the header segment can be received and decoded by all stations on the network, the payload segment being transmitted using a variable set of payload encoding parameters, the transmitting station sending the transmitting frame using one set of the variable set of payload encoding parameters at a time. The receiving station receives and decodes the header and payload segments of each transmitting frame. The decoding includes computing frame statistics. A plurality of sets from the variable set of payload encoding parameters are selected to form a possible set of payload encoding parameters. For each set of payload encoding parameters in the possible set of payload encoding parameters an estimate of network performance characteristics expected if the transmitting station were to transmit the transmitting frame using that set of payload encoding parameters is generated based upon the frame statistics. A set of payload encoding parameters having optimized network performance characteristics is selected based upon the estimates of expected network performance for each set of payload encoding parameters in the possible set of payload encoding parameters.

Abstract: Embodiments of the present invention relate to methods and systems of delivering a network service. In an embodiment, a data packet including a service address and a payload is received. A plurality of network applications associated with the service address of the data packet are identified. The plurality of network applications associated with the service address include a first network application, a second network application, and a third network application. At least the payload of the data packet is sent to the first network application and the second network application. A second network application response packet is received from the second network application. A third network application packet is sent to the third network application, and the third network application packet is based at least in part on the second network application response packet.

Abstract: A method and signal therfor embodied in a carrier wave for sending information from transmit stations to receive stations over a transmission medium of a frame-based communications network. The information is sent in transmit frames having a frame format comprising a fixed rate header, followed by a variable rate payload, followed by a fixed rate trailer. The fixed rate header includes a preamble. The preamble has a repetition of four symbol sequences for facilitating power estimation, gain control, baud frequency offset estimation, equalizer training, carrier sensing and collision detection. The preamble also includes a frame control field. The frame control field has scrambler control information for frame scrambling initialization, a priority field to determine the absolute priority a transmit frame will have when determining access to the transmission medium, a payload encoding field which determines constellation encoding of payload bits in the variable rate payload, and a header check sequence for providing a cyclic redundancy check. The variable rate payload is transmitted pursuant to dynamic adjustable frame encoding parameters for improving transmission performance for a transmit frame being transmitted from a transmitting station to a receiving station. The header also includes a destination address field, a source address field and an ethertype field.

Abstract: An approach for managing system capacity of a satellite communications system is disclosed. A satellite communications system provides communication services to a region. A terminal ( 101, 103 ) is located within the region and is configured to transmit and receive signals over a satellite ( 105 ) having a payload that processes the signals. The terminal ( 101, 103 ) has a predetermined profile that includes service class information and rate information. A hub ( 107 ) is configured to receive system capacity resource configuration data that reflect capacity requirements of a service provider and to determine partitioning of system capacity over the region based upon the system capacity resource configuration data. The hub ( 107 ) transmits configuration information to the payload of the satellite ( 105 ) according to the determined partitions. The terminal ( 101, 103 ) is configured to transmit a bandwidth request message to the payload. The payload selectively allocates bandwidth in response to the request message based upon the configuration information.

Abstract: The quality of a channel for each of a plurality of receive antennas (301) is determined in part by examining data collected during reception of test data. Substantially simultaneously, payload data is also used to evaluate channel quality for at least one antenna (301). A quality metric calculated (308) for any given antenna is the result of measurements made upon the test and payload data. Parameters used to calculate the quality metric are preferably divided into two sets of non-identical parameters, those based on the test data and those based on the payload data. These parameters preferably include jitter, received signal strength, CRC errors and synchronization errors. By continuously updating quality metrics based on both test and payload data, more reliable assessments can be made of the various antennas being used. As a result, antenna selection is rendered commensurately more reliable thereby improving received signal quality.

Abstract: This document describes a RTP (Real-Time Protocol) payload format for transporting MPEG (Moving Picture Experts Group) 1 or 2, layer III audio (commonly known as "MP3"). This format is an alternative to that described in RFC 2250, and performs better if there is packet loss.

Abstract: A system and method for superimposing a sequence number of a packet into the CRC segment of the packet thereby allowing more bandwidth in the payload portion of the packet for carrying data is described. Also described is a method of acquiring additional information on the type of error in a packet, e.g., data transmission errors or sequence errors, from analyzing a CRC error. For example, a reported CRC error can be the result of the receipt of a packet with a sequence number the receiver is not expecting (which is a normal occurrence on transmission links due to transmitters resending packets that a receiver has already accepted) or can result from a real error in the transmission of a packet.. A first error code check (CRC) value is calculated for the payload segment of a data packet. A second CRC value is calculated for the sequence number of the data packet. The first CRC value and the second CRC value are combined thereby creating a third CRC value. The third CRC value is then combined with the payload segment of the data packet thereby creating a data packet that can be transmitted across the link.

Abstract: A method for storing streaming media data in a cache memory includes receiving the streaming media data from a streaming media server, the streaming media data comprising a series of packets of media data, the packets of media data including header data and payload data, separating the header data from payload data, storing a portion of the header data in a session data object in the cache memory, and storing the payload data in a first plurality of data objects in the cache memory, wherein each data object of the first plurality of data objects is directly addressable in the cache memory via an associated object handle, and wherein each data object of the first plurality of data objects stores a portion of the payload data.