Abstract: A peer-to-peer novel video streaming scheme is described in which each peer stores and streams videos to the requesting client peers. Each video is encoded into multiple descriptions and each description is placed on a different node. If a serving peer disconnects in the middle of a streaming session, the system searches for a replacement peer that stores the same video description and has sufficient uplink bandwidth. Employing multiple description coding in a peer-to-peer based network improves the robustness of the distributed streaming content in the event a serving peer is lost. Video quality can be maintained in the presence of server peers being lost. The video codec design and network policies have a significant effect on the streamed video quality. The system performance generally improves as the number of descriptions M for the video increases, which implies that a higher video quality can be obtained with the same network loading.

Abstract: Scheduling methods and apparatus are provided for buffered crossbar switches with a crosspoint buffer size as small as one and no speedup. An exemplary distributed scheduling process achieves 100% throughput for any admissible Bernoulli arrival traffic. Simulation results also showed that this distributed scheduling process can provide very good delay performance for different traffic patterns. The simulation results also showed that packet delay is very weakly dependent on the switch size, which implies that the exemplary distributed scheduling process can scale with the number of switch ports.

Abstract: A distributed and opportunistic medium access control (MAC) layer protocol for randomized distributed space-time coding (R-DSTC), which may be deployed in an IEEE 802.11 wireless local area network (WLAN), is described. Unlike other cooperative MAC designs, there is no need to predetermine, before packet transmission, which stations will serve as relays. Instead, the MAC layer protocol opportunistically recruits relay stations on the fly. Network capacity and delay performance is much better than legacy IEEE 802.11g network, and even cooperative forwarding using one relay station. Avoiding the need to collect the station-to-station channel statistics considerably reduces overhead otherwise required for channel measurement and signaling.

Abstract: Scheduling techniques for use with buffered crossbar switches, without speedup, which can provide 100% throughput are described. Each input/output may keep track of the previously served VOQ/crosspoint buffer. The queue lengths of such VOQs and the queue lengths of VOQs corresponding to a uniform probability selection output (e.g., from a Hamiltonian walk schedule) are used to improve the schedule at each time slot.

Abstract: A peer-to-peer novel video streaming scheme is described in which each peer stores and streams videos to the requesting client peers. Each video is encoded into multiple descriptions and each description is placed on a different node. If a serving peer disconnects in the middle of a streaming session, the system searches for a replacement peer that stores the same video description and has sufficient uplink bandwidth. Employing multiple description coding in a peer-to-peer based network improves the robustness of the distributed streaming content in the event a serving peer is lost. Video quality can be maintained in the presence of server peers being lost. The video codec design and network policies have a significant effect on the streamed video quality. The system performance generally improves as the number of descriptions M for the video increases, which implies that a higher video quality can be obtained with the same network loading.

Abstract: Data is transmitted from a source wireless device to a destination wireless device by: (a) discovering node-to-node wireless channel conditions in a wireless network; (b) determining at least one of (A) wireless relay devices, (B) modulation schemes, and (C) transmission rates using the discovered node-to-node channel conditions; (c) signaling at least some of the determined information to the determined wireless relay devices; (d) receiving, with each of the wireless relay devices, a transmission of the data from the source wireless device; and (e) transmitting, with each of the wireless relay devices, a randomized, space-time encoded, part of the received data, to the destination device using the signaled at least some of the determined information

Abstract: In a live video P2P system using substream trading, a peer device's video quality is generally commensurate with its upload rate. Such substream trading provides in a P2P live video streaming system provides incentives and can accommodate a variety of video coding schemes. In particular, substream trading with layered video has many desirable properties, including differentiated service, short start-up delays, synergies across peer device types, and protection against free-riders.

Abstract: Multiple cooperative relays operate in a highly mobile environment and form a virtual antenna array. Multiple independent streams of data can be simultaneously transmitted in parallel to the destination receiver. Thus a higher spatial multiplexing gain can be obtained. Such exemplary embodiments might do so by allowing each relay to transmit a linear combination of antenna waveforms according to an independently and randomly generated coefficient vector. This randomized cooperation scheme may be useful in an environment in which a group of relay devices are close to the source device, and can therefore receive information at a high rate. Each relay device that receives the information without errors splits it into multiple streams. For example, if the relay devices receive B symbols and the number of streams is K, each stream contains B/K symbols. Each relay device then generates a random linear combination of all the streams and transmits this output simultaneously with the other relay devices.

Abstract: A peer-to-peer novel video streaming scheme is described in which each peer stores and streams videos to the requesting client peers. Each video is encoded into multiple descriptions and each description is placed on a different node. If a serving peer disconnects in the middle of a streaming session, the system searches for a replacement peer that stores the same video description and has sufficient uplink bandwidth. Employing multiple description coding in a peer-to-peer based network improves the robustness of the distributed streaming content in the event a serving peer is lost. Video quality can be maintained in the presence of server peers being lost. The video codec design and network policies have a significant effect on the streamed video quality. The system performance generally improves as the number of descriptions M for the video increases, which implies that a higher video quality can be obtained with the same network loading.

Abstract: Improved distribution of video information in an infrastructure-based wireless network is provided. A wireless channel condition between the video server node and each of the plurality of receiver nodes is measured (or accepted, or otherwise determined). Each of the plurality of receiver nodes are assigned into one of a first group and a second group using the measured wireless channel conditions, wherein receiver nodes assigned to the first group have, on average (e.g., on average over time), a better measured wireless channel condition than that of receiver nodes assigned to the second group. At least some (e.g., one or more) of the receiver nodes of the first group of nodes are selected to serve as relay nodes. Video information (e.g., N layers) is then transmitted wirelessly from the video server node for reception by each of the receiver nodes assigned to the first group. Each of the selected relay nodes then transmit at least a part (e.g.

Abstract: Wireless protocols that employ a helper node are adapted so that they may take advantage of authentication security (and perhaps encryption security). Thus, such protocols may be used with security protocols such as 802.11i protocol (or the like) for example.

Abstract: MD-FEC is considered an efficient way to generate a large number of descriptions. However, typically, MD-FEC introduces significant redundancy across streams. MD-FEC encoded streams (descriptions) are adapted based on feedback. Specifically, the bits sent in each description by a supplying peer are adapted based on the number of available descriptions in its receiving peer. The adaptive delivery eliminates unnecessary bits in the original MD-FEC streams (descriptions), and significantly reduces the consumed uplink bandwidth at supplying peers. The saved bandwidth can be used to accommodate more video sessions or for other applications.

Abstract: A distributed incentive mechanism is provided for peer-to-peer (P2P) streaming networks, such as mesh-pull P2P live streaming networks. Video (or audio) may be encoded into multiple sub-streams such as layered coding and multiple description coding. The system is heterogeneous with peers having different uplink bandwidths. Peers that upload more data (to a peer) receive more substreams (from that peer) and consequently better video quality. Unlike previous approaches in which each peer receives the same video quality no matter how much bandwidth it contributes to the system, differentiated video quality, commensurate with a peer's contribution to other peers, is provided, thereby discouraging free-riders.

Abstract: When it is advantageous to do so, a wireless LAN station sends data packets to a destination station via an intermediate station, instead of to the destination station directly. That is, the intermediate station, which serves as a helper to the source, forwards packets received from the source station to the intended destination station. This cooperative data transmission approach can result in system performance improvement, as long as the total time consumed by two-hop transmission (i.e., transmission via the helper station) is less than direct transmission. Such a determination may be made using rate information stored at each station. Specifically, using the rate information, signaling needed to set up a transmission, the amount of data to be transmitted, etc., transmitting the data directly and via a help station may be compared.

Abstract: Scheduling techniques for use with buffered crossbar switches, without speedup, which can provide 100% throughput are described. Each input/output may keep track of the previously served VOQ/crosspoint buffer. The queue lengths of such VOQs and the queue lengths of VOQs corresponding to a uniform probability selection output (e.g., from a Hamiltonian walk schedule) are used to improve the schedule at each time slot.

Abstract: When it is advantageous to do so, a wireless LAN station sends data packets to a destination station via an intermediate station, instead of to the destination station directly. That is, the intermediate station, which serves as a helper to the source, forwards packets received from the source station to the intended destination station. This cooperative data transmission approach can result in system performance improvement, as long as the total time consumed by two-hop transmission (i.e., transmission via the helper station) is less than direct transmission. Such a determination may be made using rate information stored at each station. Specifically, using the rate information, signaling needed to set up a transmission, the amount of data to be transmitted, etc., transmitting the data directly and via a help station may be compared.

Abstract: An exhaustive service dual round-robin matching (EDRRM) arbitration process amortizes the cost of a match over multiple time slots. It achieves high throughput under nonuniform traffic. Its delay performance is not sensitive to traffic burstiness, switch size and packet length. Since cells belonging to the same packet are transferred to the output continuously, packet delay performance is improved and packet reassembly is simplified.

Abstract: An exhaustive service dual round-robin matching (EDRRM) arbitration process amortizes the cost of a match over multiple time slots. It achieves high throughput under nonuniform traffic. Its delay performance is not sensitive to traffic burstiness, switch size and packet length. Since cells belonging to the same packet are transferred to the output continuously, packet delay performance is improved and packet reassembly is simplified.

Abstract: A packet network employs flow control providing assigned rates to sessions in accordance with a general max-min (GMM) rate allocation. The GMM rate allocation accounts for the minimum cell rate and peak cell rate requirements for each session. For one case, a centralized flow control algorithm is employed that sorts sessions based on increasing minimum cell rate. The centralized flow control algorithm employs an iterative process of increasing the rate of the smallest rate session and adding sessions to the process when the smallest rate session equals the next higher rate session. The rates are increased until the rate either reaches the peak cell rate of the session or the link saturates. For a second case, a distributed flow control algorithm is employed with a distributed protocol within the network to allocate capacity of network links to sessions. For the distributed flow control algorithm, an iterative process of rate allocation uses a modified version of the Consistent Marking method.