Abstract: A projection code is applied to encode symbols as weighted arithmetic sums of approximately random subsets of binary source bits. Pairs of the symbols are combined to form constellation points, which are sequentially mapped through a constellation to modulate a data signal.

Abstract: Video data from an upload client is received at a hosting node. A request from a download client is received at a bootstrapping node to receive the video data. The download client to receive the video data directly from the hosting node when the hosting node is below a threshold, wherein the threshold is based at least in part on the maximum number of download clients the hosting node can stream to simultaneously. The download client to receive the video data from peers in a peer-to-peer overlay when the hosting node above the threshold.

Abstract: Techniques for data gathering in large-scale wireless sensor networks are described. A data collection device receives aggregate data from at least one sensor node of a group of N sensor nodes. The aggregate data includes M weighted sums. Each of the M weighted sums includes a respective sum of N products each of which being a product of a respective coefficient and a sensor reading from a respective one of the N sensor nodes. M and N are positive integers and M is less than N. Computation is performed on the aggregate data to recover sensor readings from the N sensor nodes.

Abstract: Technologies for switching a set of nodes in an overlay network from one relay tree configuration to another without duplicate packets or packet loss at any of the nodes. A commander node calculates a new relay tree as well as a media stream set configuration for each node in the overlay network, each media stream set corresponding to the new relay tree. Media stream sets include a unique version number or the like that identifies the specific relay tree configuration of which they are a part. Also provided are technologies for associating a media stream with a particular relay tree configuration and the corresponding media stream set of each node in the overlay network.

Abstract: Video data from an upload client is received at a hosting node. A request from a download client is received at a bootstrapping node to receive the video data. The download client to receive the video data directly from the hosting node when the hosting node is below a threshold, wherein the threshold is based at least in part on the maximum number of download clients the hosting node can stream to simultaneously. The download client to receive the video data from peers in a peer-to-peer overlay when the hosting node above the threshold.

Abstract: An application-level multicasting architecture that enables multiple nodes to interact in real time with data packets that are routed based on information about the connection states between the nodes is provided. Each node shares their connection states with other nodes in the same interactive session. The data packets may be routed in the application level using multiple packet transport protocols that are available on the sending node. A particular transport protocol may be selected based on a Quality of Service (QoS) requirement of the data packet. Nodes in the interactive session may relay data packet to other nodes according to a routing map that is created based on the connection states. The application-level multicasting architecture may be implemented for any multiparty interactive application, such as an application for videoconferencing, multiplayer games, distance learning, virtual meeting, and voice communication.

Abstract: Transmission optimization for application-level multicast is described. For each member of a video conference, a multicast tree is generated that represents a data communication configuration of a data source and the other members of a video conference which are data recipients that receive video and audio data from the data source. An end-to-end transmission delay from each data source to each of the respective data recipients is determined, and the available bandwidth between each data source and the respective data recipients is determined. One or more of the multicast trees, each corresponding to a data source, are refined according to the end-to-end transmission delay and available bandwidth for a particular data source to optimize the data communication configuration of the data source in the video conference.

Abstract: Video data from an upload client is received at a hosting node. A request from a download client is received at a bootstrapping node to receive the video data. The download client to receive the video data directly from the hosting node when the hosting node is below a threshold, wherein the threshold is based at least in part on the maximum number of download clients the hosting node can stream to simultaneously. The download client to receive the video data from peers in a peer-to-peer overlay when the hosting node above the threshold.

Abstract: A network can include a number of nodes that link a source node to a sink node. When a first node in a network sends a packet to its downstream node, this information is also received at its upstream node. In response to learning that the first node has sent a packet, the upstream node sends another packet to the first node. In essence, a pull-based transmission approach is used to mitigate congestion and address the funneling effect in data transmission networks such as wireless video sensor networks.

Abstract: Described herein is technology for, among other things, natural network coding in a wireless mesh network. The technology involves wireless mesh network systems, methods and devices based on the natural network coding. By encoding signals in their natural forms using their channel strengths, more efficient transmission of signals is possible in the wireless mesh network.

Abstract: Described is a technology by which a roadside-to-vehicle communication system may be implemented, including via a stateful scheduling with network coding scheme that enhances network capacity. Moving vehicles request and receive data from a roadside access points. Each of the access points operate a stateful scheduling algorithm that serves multiple vehicles by integrating network coding within a timeslot. In one aspect, the state of each vehicle's previously received and retained data is obtained, and used to enhance network capacity by combining as many packets as possible for multiple recipients in network coding.

Abstract: Described is continuous network coding, in which a relay sends probability data comprising a continuous number for use as parity data. The node receives streams of bits sent from sources towards a destination, and computes the probability data based on current noise data and/or fading data. A selected set of the bits (all or some subset thereof) are combined, e.g., XOR-ed or concatenated, and send to the destination. Phase modulation is performed to convey probability information based on the probability data. The destination demodulates the signal to obtain the probability information, and combines the probability information with the data directly received from sources to perform joint decoding. The number of bits in the set of selected bits may be adaptively chosen based on current channel conditions, e.g., increased when the channel conditions from the sources directly to a destination are poor relative to the channel conditions via the relay.

Abstract: Systems and methods for estimating available bandwidth with multiple overloading streams are described. In one aspect, a set of packets are communicated by a probing sender to a receiver. The packets are sent at multiple sending rates. At least two of the sending rates result in multiple overloading streams of packets being sent to the receiver. The probing sender receives a set of queuing delay information from the receiver. The queuing delay information is based one-way delay measurements corresponding to receipt by the receiver of at least two pairs of successive packets of the packets. The probing sender estimates available bandwidth of the network based on the received queuing delay information and multiple sending rates associated with the multiple overloading streams of packets.

Abstract: The techniques and mechanisms described herein are directed to controlling communication paths between conference members in a decentralized multi-party conference that supports a full mesh architecture. Several check points are tested in order to handle concurrency issues and to ensure quality of service. First, a check is made to determine whether any pending communication paths exist between the two systems. Second, a check is made to determine whether one of the systems is in the process of leaving the multi-party conference. Third, a check is made to determine whether a maximum number of conference members already exist in the conference. Upon failing any of these checks, the communication path between the two systems fails. Upon success, the new system initiates the joining process with each of the other members in the conference in order to maintain the full mesh architecture.

Abstract: Described is a communication mechanism that provides push-to-talk functionality for mobile and desktop computing environments. Mobile and desktop computers are configured as client computers in a client/server architecture. Some of the client computers are configured to handle multiple push-to-talk sessions simultaneously. If multiple streams from different sessions are active at the same time, the client computer may determine which of these overlapped streams to record and then record them for later playback. A server handles the registration of the client computers, manages the multiple sessions for each of the client computers, and performs a floor control process so that each push-to-talk session operates in a half-duplex mode.

Abstract: Technologies for switching a set of nodes in an overlay network from one relay tree configuration to another without duplicate packets or packet loss at any of the nodes. A commander node calculates a new relay tree as well as a media stream set configuration for each node in the overlay network, each media stream set corresponding to the new relay tree. Media stream sets include a unique version number or the like that identifies the specific relay tree configuration of which they are a part. Also provided are technologies for associating a media stream with a particular relay tree configuration and the corresponding media stream set of each node in the overlay network.

Abstract: Video data from an upload client is received at a hosting node. A request from a download client is received at a bootstrapping node to receive the video data. The download client to receive the video data directly from the hosting node when the hosting node is below a threshold, wherein the threshold is based at least in part on the maximum number of download clients the hosting node can stream to simultaneously. The download client to receive the video data from peers in a peer-to-peer overlay when the hosting node above the threshold.

Abstract: Systems and methods for estimating available bandwidth with multiple overloading streams are described. In one aspect, a set of packets are communicated by a probing sender to a receiver. The packets are sent at multiple sending rates. At least two of the sending rates result in multiple overloading streams of packets being sent to the receiver. The probing sender receives a set of queuing delay information from the receiver. The queuing delay information is based one-way delay measurements corresponding to receipt by the receiver of at least two pairs of successive packets of the packets. The probing sender estimates available bandwidth of the network based on the received queuing delay information and multiple sending rates associated with the multiple overloading streams of packets.

Abstract: An application-level multicasting architecture that enables multiple nodes to interact in real time with data packets that are routed based on information about the connection states between the nodes is provided. Each node shares their connection states with other nodes in the same interactive session. The data packets may be routed in the application level using multiple packet transport protocols that are available on the sending node. A particular transport protocol may be selected based on a Quality of Service (QoS) requirement of the data packet. Nodes in the interactive session may relay data packet to other nodes according to a routing map that is created based on the connection states. The application-level multicasting architecture may be implemented for any multiparty interactive application, such as an application for videoconferencing, multiplayer games, distance learning, virtual meeting, and voice communication.

Abstract: Systems and methods are described for implementing an application-level routing protocol for multiparty audio-video conferencing. In one implementation, application-level per-stream routing techniques separately control audio data and video data between conference members hosted on a network. Different audio application-level multicast (ALM) trees are generated by each member, are dynamically updated according to shortest-path-first selection of data delivery paths, and are used to send audio data to the other members of the videoconference. Likewise, different video ALM trees are generated by each member, are dynamically updated according to broadest-path-first selection of data delivery paths, and are used to send video data to the other members of the videoconference. Separate audio and video ALM trees for each member can utilize IP multicast in segments of the network in which IP multicast is enabled.