144 results about "Reliable multicast" patented technology

A multi-cloud data replication method includes providing a data replication cluster comprising at least a first host node and at least a first online storage cloud. The first host node is connected to the first online storage cloud via a network and comprises a server, a cloud array application and a local cache. The local cache comprises a buffer and a first storage volume comprising data cached in one or more buffer blocks of the local cache's buffer. Next, requesting authorization to perform cache flush of the cached first storage volume data to the first online storage cloud. Upon receiving approval of the authorization, encrypting the cached first storage volume data in each of the one or more buffer blocks with a data private key. Next, assigning metadata comprising at lest a unique identifier to each of the one or more buffer blocks and then encrypting the metadata with a metadata private key. Next, transmitting the one or more buffer blocks with the encrypted first storage volume data to the first online cloud storage. Next, creating a sequence of updates of the metadata, encrypting the sequence with the metadata private key and then transmitting the sequence of metadata updates to the first online storage cloud.

A multicast repair tree is established, the repair tree having one sender station and a plurality of repair head stations. A repair head station has an affiliated group of member stations. A repair head station retransmits a lost message to its affiliated group of member stations upon receipt from a member station of a NACK message indicating that the selected message was not received. Acknowledgment windows (ACK windows) are established in a member station for transmission of ACK or NACK message by the member station. A number of messages transmitted by the sender station during a transmission window is established. Also a same size of ACK window is established in the receiving stations, with a slot in the ACK window corresponding to each message transmitted by the repair head station. Each receiving station is assigned a slot in the ACK window during which time that receiving station transmits its ACK or NACK messages. Thus the ACK window slots assigned to receiver stations for transmission of ACK/NACK windows are staggered so that different receiver stations transmit their ACKNACK messages at different times. The slot for a particular receiver station to use may be assigned by a random process.

An apparatus, system method, and computer program product that combine the attributes of ALC and NORM for communicating data between devices on a network. A sending device uses multiple data rates on different channels to reliably send data packets and receivers use NACKs to request retransmission of missing or mangled data from the sending device or other receiving devices on the network. The sending device using an active ALC mechanism and the receiving devices use NACK and transmitting mechanisms for transmitting acknowledgements or data from the device. The sending and receiving devices can be located in the same or in different networks for communicating data packets during a data transmission session.

A system for reliable multicast transmission [multicasting data packets] in a packet-based data network includes mechanisms for performing the following: (1) preparing at least one packet comprising a payload portion and multicast route information, an error detection mechanism; (2) transmitting the packet to at least one intermediate node for delivery to at least two destination nodes; (3) waiting for a period of time for at least one acknowledgment signal indicating receipt of the at least one packet by at least one destination node; and (4) retransmitting a packet to a set of destination nodes from which no positive acknowledgment has been received. The multicast routing information includes information for use by the at least one intermediate node to forward the packet to at least two destination nodes.

A compression context for a plurality of packets is established with a receiving device. Each of these packets is associated with one or more reliable multicast protocols, such as the Layered Coding Transform (LCT) protocol, the Asynchronous Layered Coding (ALC) protocol, the FLUTE protocol, the MUPPET protocol, and the NACK-Oriented Reliable Multicast (NORM) protocol. Upon establishment of the compression context, a compressed packet is generated for one of the plurality of packets and transmitted to the receiving device. The compressed packet has a reduced number of bits in its header. Upon receipt, the receiving device decompresses the compressed packet based on the compression context.

A method and system for reliable multicasting on a communication network includes sending Request-to-Send (RTS) signals from a sender node of the network to the receiver nodes, the RTS signals include a set of identifiers corresponding to the receiver nodes. The Clear-to-Send (CTS) signals and Acknowledgment (ACK) signals are sent from the receiver nodes according to an ordering function of the set of identifiers.

A method and apparatus are described including performing hop-by-hop multicasting including network coding of data packets of a portion of content, wherein network coding further includes receiving an encoded data packet of a portion of content from an upstream transmitter, determining if the received encoded data packet is innovative, storing the received encoded data packet responsive to the first determination, determining if a full rank of the encoded data packet of the portion of content has been received, determining if an acknowledgement message for the portion of the content has already been sent to the upstream transmitter responsive to the second determination, sending the acknowledgement message to the upstream transmitter responsive to the third determination and discarding the received encoded data packet responsive to the first determination.

A method and apparatus is disclosed herein for performing multi casting. In one embodiment, the method comprises receiving routing, association, relaying, and/or topology information associated with a plurality of nodes in a multi-hop wireless network, the plurality of nodes communicably coupled in a tree or mesh arrangement via a plurality of broadcast channels; and determining a subset of the plurality of nodes over each broadcast channel on the multi-hop wireless network that is responsible for sending acknowledgment information, in response to receipt or lack of receipt of transmissions, back to senders of transmissions.

A method supports scalable and reliable multicast in a wireless network with a large bandwidth-delay product. In this method, acknowledgement packets from different receivers experiencing the same number of data packets lost are assigned the same time slots. This method can be combined with other loss recovery techniques, such as forward error correction (FEC) recovery, proactive protection, feedback suppression and collision detection. Scalability is achieved as bandwidth usage relates only to the number of packets transmitted, rather than the number of receivers.

A technique for reliably multicasting a message within a router network is provided. At least one special router in the network has associated persistent storage for logging a message being routed to one or more clients. When a message is received at this logger node, the logger places the message in persistent storage and sends a logging acknowledgment back to those routers to which the message was originally routed, as well as back towards the source of the message. The logger acknowledgment includes the message id, the logger id, and a logging number. When the logger acknowledgment is received by a router, it looks up the routing information from the original message, and sends the acknowledgment to those neighboring routers to which the original message was sent, excluding the link from which the logger acknowledgment was received. If the original message corresponding to the logger acknowledgment was buffered at this router waiting to be delivered, the message is then delivered to its client nodes. Processes for recovering from node or link failure within the router network, and for at most once delivery of messages, at least once delivery of messages, and exactly once delivery of messages are also provided.

According to one embodiment of the invention, wireless spectrum and battery power conservation is achieved through an adaptable multicast group communication scheme. This involves a method for controlling the multicast transmission rate based on a first operation of receiving information from a multicast receiving device that is a member of a multicast group. Based on this information and potentially other information from other member devices, the modulation and coding rate for the multicast group is altered.

A method and apparatus are described including performing hop-by-hop multicasting including network coding of data packets of a portion of content, wherein network coding further includes encoding data packets of a portion of content, multicasting said network coded data packets to downstream receivers, determining if an acknowledgement message has been received from at least one of the downstream receivers, determining if acknowledgement messages have been received from all of the downstream receivers responsive to the first determination.

A “Wi-Fi Multicaster” provides a practical and efficient Wi-Fi multicast system for environments having potentially large numbers of Wi-Fi clients. Significantly, the Wi-Fi Multicaster does not require any changes to the 802.11 protocol, or to the underlying Wi-Fi infrastructure. In various embodiments, the Wi-Fi Multicaster uses pseudo-broadcast, and augments it with destination control, association control and optional proactive FEC (forward error correction) to improve multicast performance. More specifically, the Wi-Fi Multicaster system converts multicast packets to targeted unicast transmissions. To minimize the amount of airtime consumed, the Wi-Fi Multicaster uses destination control in combination with various algorithms for association control. Further, in various embodiments, the Wi-Fi Multicaster includes an adaptive, proactive FEC scheme to reduce overall packet losses. Finally, to overcome the challenges posed by encryption protocols such as 802.1x, the Wi-Fi Multicaster uses a “virtual multicast interface” that allows clients to “share” a common key for each multicast.

A system and method of providing a reliable and efficient multicast data transfer mechanism in a communication network. The mechanism includes a plurality of computer nodes and one or more data system managers wherein each of computer nodes and each of data system managers are connected through the said communication network. The method generally comprises the steps of setting up of an association among one or more computer nodes as senders and one or more computer nodes as receivers using a combination of unicast and multicast protocols and transmitting one or more packets of data through the said multicast protocol by one or more senders to one or more receivers. The receivers may collaborate among themselves to ensure delivery of said one or more packets of data reliably to the collaborating receivers.

A system for reliable multicast distribution includes a primary content engine and a backup content engine sender. The primary content engine sender sends out a multicast message of content to selected content engine receivers. The sender waits for negative acknowledgments from the selected content engine receivers declaring that content was not received. If a negative acknowledgment is received, the sender resends the multicast message a predetermined number of times. If the content is still not received after the number of multicast passes is exhausted, the sender sends out unicast messages to those receivers still requesting content. If the primary sender does not respond to a negative acknowledgment, the receiver sends a second negative acknowledgment to the backup multicast sender. The backup responds with the data requested in the negative acknowledgment and so is able to begin data distribution at the point where the primary sender left off without maintaining synchronicity with the primary sender.

Method and apparatus for reliable multicast communication over wireless network are provided. According to embodiments of the invention, the method includes determining a priority category for a multicast communication to be transmitted. The method includes designating, for the multicast communication, one of the multicast communication recipients as a leader based on the priority category and multicast diagnostics information received from the multicast communication recipients. The leader is assigned to transmit to the multicast communication source an acknowledgment frame indicating receipt of a multicast communication frame received from the source.

The invention discloses a data reliable multicast method based on FDMA (frequency division multiple Access)/DAMA(demand assigned multiple access) satellite communication system. The data reliable multicast method based on FDMA/DAMA satellite communication system is applicable to a data transmission system of an FDMA/DAMA satellite communication network; aiming at the limited satellite communication system resources and the bidirectional broadcasting characteristics of a satellite, a communication flow combining multicast transmission and polling is provided, and the reliable and efficient satellite multicast transmission is realized.