Abstract: This document describes Real-Time Transport Protocol (RTP) payload formats for carrying each of MPEG-4 Audio and MPEG-4 Visual bitstreams without using MPEG-4 Systems. For the purpose of directly mapping MPEG-4 Audio/Visual bitstreams onto RTP packets, it provides specifications for the use of RTP header fields and also specifies fragmentation rules. It also provides specifications for Multipurpose Internet Mail Extensions (MIME) type registrations and the use of Session Description Protocol (SDP).

Abstract: This memo describes how to carry dual-tone multifrequency (DTMF) signaling, other tone signals and telephony events in RTP packets.

Abstract: Based on existing technology used in image and video watermarking, we have developed a robust audio watermarking technique. The embedding algorithm operates in frequency domain, where the magnitudes of the Fourier coefficients are slightly modified. In the temporal domain, an additional scale parameter and gain function are necessary to refine the watermark and achieve perceptual transparency. Watermark detection relies on the Symmetrical Phase Only Matched Filtering (SPOMF) cross-correlation approach. Not only the presence of a watermark, but also its cyclic shift is detected. This shift supports a multi-bit payload for one particular watermark sequence. The watermarking technology proved to be very robust to a large number of signal processing “attacks” such as MP3 (64 kb/s), all-pass filtering, echo addition, time-scale modification, resampling, noise addition, etc. It is expected that this approach may contribute in a wide variety of existing (e.g. monitoring and copy protection) and future applications.

Abstract: The frame of data that is decoded is one of a set of frames that represent a packet of information words, and that additionally represent coded control words preceding and following the packet. The frames each include a master transition and a payload field. The payload field either is composed exclusively of ones of the information words, or includes a TYPE word that defines the structure of the payload field. The master transition is in a first state when the payload field is composed exclusively of ones of the information words, and is otherwise in a second state. In the method, a determination is made of whether the master transition is in the first state. When the master transition is in the first state, the payload field is adopted as a block of received data. When the master transition is not in the first state, the TYPE word is extracted from the payload field, the payload field is expanded in response to the TYPE word, and the payload field, after expansion, is adopted as a block of received data.

Abstract: A method and corresponding apparatus for communicating a controller area network (CAN) message between a sending node (10a), attached to a sending CAN network (14a), and a receiving node (10b, 18), where the sending and receiving nodes are interconnected by a TCP/IP network (16) the sending node (10a) extract the payload from a CAN message, embeds the CAN message payload in a TCP/IP data field of the TCP/IP frame, determines the address on the TCP/IP network of the receiving node corresponding to the CAN message identifier in the routing form table, and transmits the TCP/IP frame over the TCP/IP network (16) the receiving node (10b, 18) extracts the CAN message payload from the TCP/IP frame, and alters the identifier of the CAN message payload. In the case the receiving node (10b) is attached to a receiving CAN network, the altered identifier coresponds to the CAN message content of the receiving CAN network. Otherwise and if the receiving node (18) hosts a browser, the altered identifier corresponds to the CAN message content according to the preference of the user of the browser. The altering is performed by reference node (10a).

Abstract: A frame forwarding scheme for network stations operating in a shared medium data transmissions network. The frame forwarding scheme uses payload encapsulating delimiters and control information in the payload to enable a frame originating from a first station and intended for a second station to be forwarded to the second station by an intermediate station. The first station selects a station as an intermediate station for purposes of frame forwarding based on the data transmission quality or reliability to be achieved using that station as an intermediate station.

Abstract: A cell processing pipeline is described having a plurality of stages for cell reassembly. The cell has a cell header and a cell payload. One of the stages is configured to parse packet header information located within the cell payload.

Abstract: Data is hidden in an information signal by encoding payload in to relative positions and/or polarities of multiple (possibly equal) embedded watermarks. The payload is retrieved by computing the correlation between the watermark(s) and the signal as a function of the position. The distance between peaks of the correlation function represents the payload. In order to precisely detect said distance, even if the peaks are smeared, the correlation function in a window (w1) around one peak (p1) is compared with the correlation function in a similar window (w2) around another peak (p2). This is done for different positions of said windows. The distance (k) between the windows (37, 38) for which the correlation functions most resemble each other is the distance representing the payload.

Abstract: A method and apparatus for directly creating a buffer of contiguous payload data from an incoming variable-length data stream utilizes a host controller for providing direct memory access (DMA) to a host computer memory. Payload data and header data from the data stream are stored contiguously in separate buffers in host memory. DMA descriptors, through appropriate software drivers, instruct the DMA engine of host controller to separate payload data and header data of each incoming packet on the data stream and place it in respective buffers in host memory. Thus, two separate logical buffers may be directly created from a single incoming logical variable-length data stream. Payload data is written directly and contiguously to host memory without the need for memory copies and the associated use of main processor resources.

Abstract: 40 Gbit/s packet wavelength routing and 2.5 Gbit/s header replacement is demonstrated using an ultra-high-speed wavelength converter. Burst-mode bit error rate measurements are performed on both the header and payload before and after wavelength routing, with <4 dB penalty in the payload and <2.5 dB penalty in the header.

Abstract: The invention pertains to a communication system (300) including one or more communication channels (10), each channel comprising a transmitter unit (20) and a receiver unit (40). Each transmitter unit (20) is connected through an optical fibre link (30) to its associated receiver unit (40). In operation, each receiver unit (20) receives payload data from its associated sending client and adds overhead data to the payload data to generate corresponding aggregate data (600). The aggregate data of each transmitter unit (20) is conveyed through the fibre link (30) to its associated receiver unit (40) which receives the aggregate data, decodes it to separate the payload data from the overhead data and then outputs the payload data to its associated receiving client. The receiver unit (40) interprets the overhead data and uses it for controlling and managing the payload data in the system (300). The one or more channels of the system (300) are capable of adapting to the bit data rate of their associate payload data; thus, the channels are capable of operating mutually asynchronously, thereby circumventing a need for justification in the aggregate data. Moreover, each transmitter unit (20) is operable to add the overhead data to the payload data when generating the aggregate data so that the number of payload bits relative to the number of overhead bits is in a fixed ratio of 31:1. Such a fixed ratio renders the aggregate data simpler to decode and bit error rate easier to determine therefrom.

Abstract: To achieve a transparent service parameter exchange between networks using a circuit-oriented protocol and networks using a packet-oriented protocol, there is provided a service parameter interworking method adapted to achieve a service parameter exchange between the networks by mapping circuit-switched service parameters into related packet-switched parameters or vice versa and then forwarding payload data between the different networks using the mapping result

Abstract: A received data stream is formed into a stream of packets, each packet comprising a payload section of data and an overhead section. In forming the packets, a template overhead section is created for use by the stream of packets and this template is applied to the data to form the packets. This avoids the need to individually pass packets through a routing stack, thus reducing the processing demands on the processor which constructs the data packets and reducing the transmission delay experienced by data. The template overhead section can be formed by sending a packet through a routing stack. Another aspect describes apparatus for processing packets where a first processor processes signalling packets and a second processor processes real-time data packets. The first processor can be used to create the template overhead section before passing the template information to the second processor where it can be used in forming the real-time data packets.

Abstract: Within a transmission channel in a frequency domain transmission medium, a plurality of non-contiguous channel portions are selected for data transmission. The selected channel portions are separated in frequency by unused channel portions. A transmitter generates a data frame of predetermined length for transmission, comprising a payload and an error detection portion. The frame length is equal to the length which would map for transmission into a symbol in the transmission channel if the entire channel were selected for transmission. The payload contains a header and a data portion, into which the transmitter inserts data bytes and a number of padding bytes. Block coding error correction is performed on the padded payload to generate error detection bytes to fill the error detection portion. The frame is then mapped into the frequency domain for transmission such that the header, data and error detection bytes map into the selected channel portions and the padding bytes map into the unused channel portions and are not transmitted. At a receiver, the padding bytes are reinstated and error detection performed to correct transmission errors in the header and the data. The corrected data is then extracted from the frame.

Abstract: Retransmission of packets in a TCP network is measured by monitoring packets traversing bearer links between nodes and examining the sequence number within its connection of each packet. For each TCP connection being monitored a next expected sequence number (NESN) value is maintained and compared with the actual sequence number of a packet in that connection. If the sequence number is less than the NESN, a retransmission count is incremented by the size of the retransmitted TCP payload; if it is greater than the NESN, a loss counter is incremented by the size of the lost TCP payload. The resulting counts of the lost and retransmitted TCP payload, of the lost and retransmitted packets, enable accurate measurements to be made even at a point remote from the sending node. Comparison of counts from spaced points in a network can enable the location of a fault to be determined at least approximately.

Abstract: Watermarking is a technique for embedding imperceptible labels in audio/visual content. Important parameters for any watermarking scheme are imperceptibility, robustness, security, payload, error rates and complexity. In the past few years enormous progress has been made with respect to most of these parameters, except maybe for the latter one. We address this topic of complexity by presenting an efficient method for detecting a spatial video watermark directly in an MPEG video stream. The naive approach would be to do a full MPEG decoding and then apply spatial watermark detection. However, such a full decoding approach would imply large memory and processing resources. We show that, at the cost of a slight decrease of performance, large reductions in complexity are possible. More in particular we show how high speed MPEG parsing, high speed inverse DCT processing and motion compensation can be avoided. On a more abstract level, this paper would like to encourage others to give more prominence to embedding and detection complexity as an important parameter in the design of watermarking schemes.

Abstract: Method and apparatus for synchronizing the transmitting side and the receiving side in an IP network that uses a stream encryption algorithm are disclosed. A sequence number is introduced into the payload of each packet at the transmitting side and transmitted with the packets. Upon receipt at the receiving side, the sequence number is extracted from the payload and used to synchronize the receiving side to the transmitting side. An error detection mechanism is used to detect when the synchronization is lost and a recovery procedure is initiated. The length of the sequence number is made sufficiently long to cope with any jitter variations in the IP network. This sequence number length is dynamically adjustable based on the amount of jitter detected in the network.

Abstract: The motion control problem for cooperating flexible robot arms manipulating a large rigid payload is considered. An output that depends on the payload position and contributions from the joint motion of each arm is constructed whose rate yields the passivity property with respect to a special input. The input is a combination of the torques from each arm and contains a free load-sharing parameter. The passivity property is shown to depend on the payload mass properties, and in cases where the payload is large, a passivity-based controller combining feedforward and feedback as elements is devised, which yields tracking. An experimental facility consisting of two planar 3-DoF arms is used to implement the strategies. Good tracking is observed and compared with simulation predictions for closed-loop flexible multibody systems.

Abstract: A crane control system (10) and method providing a way to generate crane commands responsive to a desired payload motion to achieve substantially pendulation-free actual payload motion. The control system (10) and method apply a motion compensator (26) to maintain a payload (14) in a defined payload configuration relative to an inertial coordinate frame. The control system (10) and method can further comprise a pendulation damper controller (27) to reduce an amount of pendulation between a sensed payload configuration and the defined payload configuration. The control system (10) and method can further comprise a command shaping filter (37) to filter out a residual payload pendulation frequency from the desired payload motion.

Abstract: This memo describes how to carry dual-tone multifrequency (DTMF) signaling, other tone signals and telephony events in RTP packets.

Abstract: A computer-based system is configured for generating a first data structure having entries representing respective network nodes having layer 2 and layer 3 network addresses. The system generates a second data structure, having a plurality of data packet headers, by selecting source and destination pairs from the first data structure and combining the respective layer 2 and layer 3 network addresses from the respective selected source and destination pairs with randomly-generated numbers representing layer 3 payload data. The second data structure is supplied to a switch model configured for parsing the layer 3 network addresses according to selected hash functions. Hence, the computer-based system is able to evaluate the selected hash functions based on a time-independent analysis, eliminating the necessity of building an actual network in hardware or simulating network traffic over a period of time.

Abstract: Coding gain is used to configure a communication system using a programmable error correction scheme. A best available error correction configuration is selected from among several configurations to provide an optimal coding gain performance for a given line or set of line characteristics and a given communication system. Payload is calculated for each of several error correction configurations, and the configuration providing the highest payload for a target bit error rate is selected. Use of gross gain to configure the communication system further provides an optimal configuration.

Abstract: A method, apparatus, article of manufacture, and a memory structure communicating information, particularly information transferred to and from an Internet host. The apparatus comprises a radio port control unit (106), comprising a router (532), and a stub (530). The router (532) is communicatively coupled to transmit and receive messages with an Internet host and communicatively coupled to a packet forwarding module (402) to accept SU-sourced messages and to provide SU-addressed messages to the packet forwarding module (402) in a first data transfer protocol. The stub (530) is coupled between the router (532) and the packet forwarding module (402) to translate messages from the first data transfer protocol to a second data transfer protocol and to translate messages from the second data transfer protocol to the first data transfer protocol. The method comprises the steps of receiving a data packet having a data payload, determining if the data payload is a loss-sensitive message or a delay-sensitive message, configuring the data packet to indicate that an acknowledge message is required if the day payload is a loss-sensitive message and configuring the data packet to indicate that the acknowledgement message is not required if the data payload is a delay sensitive message, and transmitting the data packet.

Abstract: A method and a device for transferring capability information, which method comprises storing (61) the capability information of the device; placing (63) said capability information in the payload part of a message before the message is transferred to a protocol stack, the method comprising a header part and a payload part; processing (64) the message containing the capability information according to a specific protocol stack; and transmitting (65) said message.

Abstract: Streams of data including explicit synchronization patterns (such as entire T1/E1) are transmitted utilizing an unstructured data format, while streams not containing explicit synchronization patterns (such as fractional T1/E1) are sent utilizing a structured data format, i.e., the data structure itself provides for circuit alignment at the receiving end. In addition, SDH VC-12 frames are transmitted over the IP network by encapsulating the entire frame (payload and overhead) into an RTP packet. Furthermore, the clock is reconstructed (clock recovery) from the packet stream at the receiver's side.

Abstract: This document describes an RTP payload format for the transportation of encoded and multiplexed MPEG-4 streams. MPEG-4 is a standard whose aims are to define a generic way to code natural or synthetic scenes. MPEG-4, among other things, supports a normative interface to Intel- lectual Property Management and Protection Systems. MPEG-4 also gives methods to synchronise and multiplex several MPEG-4 encoded streams. RTP, on the other hand, is a protocol that has been especially writ- ten for multimedia stream over the IP network, and to use RTP for the carriage of MPEG-4 data does make sense, enabling such applica- tions as Video on demand or Multicast Teleconferencing. This specification is produced by members of the IST/OPENISE proj- ect. Internet-Draft RTP Payload Flexmultiplexed MPEG-4 Streams 10/03/00 Comments are solicited and should be addressed to the working group's mailing list at openise-platform@telecom.ntua.gr and/or the authors.

Abstract: A method, apparatus, article of manufacture, and a memory structure for translating an input data packet from an input format to at least one output data packet in an output format. The method comprises the steps of reading a series of data packets in the input format, the data packets including a data type identifier, wherein at least some of the data packets include first time synchronization data and at least some of the data packets include payload data; identifying data packets of interest in the series of data packets according to data type using the data type identifier; identifying data packets from the data packets of interest having time synchronization information; generating second time synchronization information from the first time synchronization information for the data packets having time synchronization information, and generating at least one output data packet in the output data format having the second time synchronization information. In one embodiment, the method further comprises the steps of identifying data packets from the data packets of interest having payload data, and assembling at least one output data packet in the second format having the payload data.

Abstract: A method of communication between computing entities in a local area network operating an CSMA protocol in an environment where reflections of omni-directional transmissions from a plurality of objects cause multi-path fading includes data packets being transmitted having a header at a first, lower data rate, followed by transmission of payload data at a second, higher data rate. Where the packets are not confirmed to be received, the packet is retransmitted a predetermined number of times before the transmitting entity reduces the payload data rate of the packet and retransmits the packet. If the retransmitted lower payload data rate packet is not confirmed to be received within the predetermined number of transmissions at the lower rate, the packet is dropped.