542 results about "Multicast communication" patented technology

Network configuration hierarchy information is maintained using flexible mechanisms and methods for establishing routes and transferring information between nodes in ad-hoc data communication networks using on-demand multicast and unicast techniques. Communication nodes use network topology information to build and maintain a dynamically mobile, wireless, ad-hoc network capable of efficiently routing both unicast and multicast traffic. Network nodes that facilitate the collection and distribution of network topology and routing data are dynamically selected, configured, and maintained. Network traffic overhead necessary for maintaining and distributing network routing table information is held to a minimum and efficiently distributed across the network, thereby reducing the potential for network traffic bottlenecks due to network overhead processes.

A system and method for providing a broadcast to a receiver via a communication network. In particular, the broadcast is received via at least one global multicast channel. At least one local multicast channel is associated with the global multicast address. Then, a communication link is established between the receiver and the local multicast channel, and the broadcast is routed from the global multicast channel to the local multicast channel to provide the broadcast to the receiver. The number of the receivers which are receiving the broadcast may be determined. The receiver may include an Internet Protocol (IP) interface which enables the receiver to receive the broadcast via an IP-type multicast communication. The receiver may also be wireless, and can receive the broadcast in a first subnet using a multicast communication. Prior to the receiver moving to a second subnet, a request is generated by the receiver to receive the broadcast in the second subnet. After receiving the request, the broadcast is provided to the wireless receiver in the second subnet using the multicast communication.

A multicast communication system for small groups using a protocol to indicate to routers receiving a packet according to the protocol to perform the following process: (1) determining a next hop for each of the destination nodes listed in the packet received; (2) partitioning the destination nodes into groups according to the next hop determined for each destination node in the preceding step; (3) replicating the packet such that there is at least one copy of the packet for each of the next hops; (4) modifying the list of addresses for the destination nodes such that the list of addresses for each of the next hops includes only the addresses for the destination nodes to be routed in that next hop; and (5) transmitting the modified copies of the packet to the next hops found in the previous steps for routing to the addresses included in each packet.

Device, system and method of multicast/broadcast communication. For example, an apparatus in accordance with an embodiment of the invention includes a transmitter to transmit, in response to an incoming multicast communication frame received from a multicast communication source, a multicast acknowledgment frame indicating receipt of the incoming multicast communication frame.

A mobile ad hoc network (MANET) may include a plurality of mobile nodes each including a wireless communications device and a controller connected thereto. The controller may operate in accordance with a multi-layer protocol hierarchy. More particularly, at an upper protocol layer, the controller may establish a quality-of-service (QoS) threshold. Furthermore, at at least one intermediate protocol layer below the upper protocol layer, the controller may select between unicast and multicast communications modes based upon the QoS threshold. As such, at a lower protocol layer below the at least one intermediate protocol layer, the controller may cooperate with the wireless communications device to transmit data to at least one destination mobile node based upon the selected communications mode.

A system, device, and method for controlling access in a multicast communication network uses a centralized host authentication scheme to prevent unauthorized hosts from joining a shared multicast distribution tree. Each authorized host is allocated a unique authentication key, which is used by the designated router to encode the PIM join message and by the rendezvous point router to authenticate the PIM join message. If the PIM join message is authentic, then each PIM router from the rendezvous point router to the designated router establishes appropriate multicast routes to route multicast packets to the host. If the PIM join message is not authentic, then multicast packets are prevented from reaching the host.

A message system for delivering data in the form messages between message clients comprises a server cluster with a group of client manager nodes and a group of independent message manager nodes. The client manager nodes have the function of managing client connections, whereas the message manager are configured to store and distribute messages. The system further comprising communication channel means in the form of a multicast messagebus for providing a multicast communication channel between said at least one client manager node and said at least one message manager node. The system guarantees delivery of a message by storing it until a receiver is ready to consume it.

In a multicast communication network, each of the nodes stores a table containing distances between each of the multicast communication nodes and the other multicast communication nodes. When receiving a destination list, the node sequentially selects a node having a shortest distance from the destination list by referring to the table to generate a multicast route. Communication is made through the multicast route.

A multistage interconnect network (MIN) capable of supporting massive parallel processing, including point-to-point and multicast communications between processor modules (PMs) which are connected to the input and output ports of the network. The network is built using interconnected switch nodes arranged in 2 [log_b N] stages, wherein b is the number of switch node input/output ports, N is the number of network input/output ports and [log_b N] indicates a ceiling function providing the smallest integer not less than log_b N. The additional stages provide additional paths between network input ports and network output ports, thereby enhancing fault tolerance and lessening contention.

Methods and apparatus for implementing a robust unicast/broadcast/multicast protocol are provided. In one aspect, a method of avoiding collision of intra-basic service set unicast, broadcast or multicast transmissions notifies stations in the basic service set of a reserved transmit opportunity for a unicast, broadcast or multicast transmission. Transmissions from at least one station in the basic service set are deferred until after the reserved unicast, broadcast or multicast transmit opportunity.

The present invention relates to multicast communication systems and in particular to the implementation of a random access uplink channel, which can be used, e.g., for transmission of acknowledgement messages for received data. In order to prevent frequent collisions on said channel, the transmission of acknowledgement messages is spread at least over time or, additionally, with regard to another distinguishing channel property, e.g. a RACH sub-channel or RACH-signature.

Aspects of a method and system for an operating system (OS) virtualization-aware network interface card (NIC) are provided. A NIC may provide direct I/O capabilities for each of a plurality of concurrent guest operating systems (GOSs) in a host system. The NIC may comprise a GOS queue for each of the GOSs, where each GOS queue may comprise a transmit (TX) queue, a receive (RX) queue, and an event queue. The NIC may communicate data with a GOS via a corresponding TX queue and RX queue. The NIC may notify a GOS of events such as down link, up link, packet transmission, and packet reception via the corresponding event queue. The NIC may also support unicast, broadcast, and/or multicast communication between GOSs. The NIC may also validate a buffered address when the address corresponds to one of the GOSs operating in the host system.

An approach for establishing secure multicast communication among multiple members that participate in a multicast group is disclosed. In one feature, multiple multicast proxy service nodes (MPSNs) are defined and control when members join or leave the multicast group. The MPSNs are logically represented by a first binary tree in which each node of the first binary tree is associated with a domain of a directory service and one or more of the MPSNs. A second binary tree is created that has leaf nodes representing each member. The second binary tree is stored in a domain of the directory service with a root node that represents one or more of the MPSNs. The members can each establish multicast communication and serve as a key distribution center. When a member joins the multicast group, a new group session key is determined by replicating a branch of the second binary tree.

A multicast scalable video communication server (MSVCS) is disposed in a multi-endpoint video conferencing system having multicast capabilities and in which audiovisual signals are scalably coded. The MVCVS additionally has unicast links to endpoints. The MSVCS caches audiovisual signal data received from endpoints over multicast communication channels, and retransmits the data over either unicast or multicast communication channels to an endpoint that requests the cached data.

A system, method, and wireless device for dynamically selecting a wireless information communication mode for wireless communication of information to at least one wireless device (104). The method includes receiving at least one request for wireless communication of information to at least one wireless device (104). The method further comprises selecting, based at least in part on a total number of wireless devices to receive the wireless communication of information, a mode of wireless communication of information to the at least one wireless device (104). The mode of wireless communication being selected from at least one of a wireless information broadcast communication mode, a wireless information multicast communication mode, and a wireless information unicast communication mode. The at least one wireless device (104) is wireless notified to set its current wireless communication mode to the selected mode of wireless communication to receive the wireless communication of the information.

Multiple paths in a communication network are provided between at least one source node and at least one destination node. The network arrangement may thus support either unicast transmission of data or multicast transmission. Measurements are made at nodes of the network to determine a partial network cost for data traversing the links in the multiple paths. An optimization procedure determines a distribution of the network traffic over the links between the at least one source node and the at least one destination node that incurs the minimum network cost.

A method of inter-area rekeying of encryption keys in secure mobile muiticast communications, in which a Domain Group Controller Key Server (Domain GCKS) distributes Traffic Encryption Keys (TEK) to a plurality of local Group Controller Key Servers (local GCKS), and said local Group Controller Key Servers forward said Traffic Encryption Keys, encrypted using Key Encryption Keys (KEK_i, KEK_j) that are specific to the respective local Group Controller Key Server (local GCKS_i, GCKS_j), to group members, said local Group Controller Key Servers (GCKS_i, GCKS_j) constituting Extra Key Owner Lists (EKOL_i, EKOL_j) for group key management areas (area_i, area_j) that distinguish group members (MM_i, MM_j) possessing Key Encryption Keys (KEK_i, KEK_j) and situated in the corresponding group key management area (area_i, area_j) from group members (MM_ij) possessing Key Encryption Keys (KEK_i) that were situated in the corresponding group key management area (area_i) but are visiting another area (area_j).

A method for building a hierarchical multicast tree which is centered around a specific node in an Internet Protocol (IP) communications network. The method on a subnetwork comprising dynamically electing a subnetwork leader node for each subnetwork using multicast communications confined to the subnetwork. Receiving a configuration file containing a list of all the network addresses of the nodes in a network. Receiving a number of permissible connections each subnetwork leader node in the network is permitted with other subnetwork leader nodes. And establishing a multicast connection between each subnetwork leader node as identified in the configuration file so that there is a multicast connection path from each subnetwork leader node for each subnetwork and a subnetwork containing a network leader node. In another embodiment, a system and computer readable medium is disclosed to carry out the above method.

Multicast communication frames for a plurality of channels corresponding to television programs and so on received from an uplink line 130 are subjected to limitation with respect to a total reception amount or limitation according to priorities and sent out from a first priority control section 192, then forwarded onto a backplane bus 128 as ATM cells from an ATM SAR 134. DSL subscriber line termination units 127 refer to their own local multicast distribution tables 211 obtained on the basis of a global multicast distribution table 205 to thereby duplicate as many copies of the ATM cells of the channels concerned as required and send them to corresponding DSL lines.

A presence table stores therein presence information. A storage unit stores therein in associated manner a terminal identifier unique each of a plurality of terminals and an encryption key to be used for multicast communication within a multicast group. A receiving unit receives a subscription request message from a first terminal from among the terminals. The subscription message includes the terminal identifier of the first terminal, and a request requesting subscription to the presence information present in the storage unit. An acquiring unit acquires the encryption key from the storage unit by using the terminal identifier of the first terminal. A transmitting unit transmits acquired encryption key to the first terminal.

A method and apparatus for multicast communications in a multi-hop relay network are described including sending an extended request message, wherein the request message includes a multicast connection identification, multicast distribution tree information and a path identification and receiving an extended response message. Correspondingly, a method and apparatus for multicast communications in a multi-hop relay network are described including receiving an extended request message, wherein said request message includes a multicast connection identification, multicast distribution tree information and a path identification and sending an extended response message.