1587 results about "Unicast" patented technology

Provided is a system and method for a multicast routing algorithm to work in infrastructure based mesh networks. It chooses access points, fixed infrastructure gateway nodes connected to each other and/or the global internet via a wired/wireless backbone, as a group of local multicast group leaders to form a multicast group leader cloud. Each local multicast group leader is elected on-demand according to the local multicast group member's request. Each local multicast group leader forms a local multicast tree rooted at this leader connecting all multicast group members associated with the AP. The processes of electing and maintaining local multicast trees rooted at APs enable efficient coordination with underlying unicast routing to exploit the advantages of fixed infrastructure nodes. Therefore, routing overhead and multicast tree convergence time are reduced. The method can support large networks with fast topology change due to fast convergence and reduced routing overhead.

Improved approaches for delivering media programs to viewers (e.g., subscribers) are disclosed. The media programs are typically broadcast in accordance with a schedule. The media program can be delivered to viewers through multicast or unicast. According to one aspect, the media programs are buffered (e.g., cached) in a data packet format such that producing unicasts for particular viewers requires less computation and resources such that more concurrent unicasts are able to be effectively supported.

A power-save method for a network with an access point and an associated power-save client. The access point buffers wireless data that includes a unicast frame and a multicast frame. A periodic scheduled beacon message is transmitted with a unicast indication element and a multicast indication element. The unicast element instructs a client to remain awake to receive a buffered unicast frame, which includes a destination MAC address. The multicast element instructs a client to remain awake following the beacon to receive a buffered multicast frame, which includes a destination multicast address designating a multicast group of which the client is a member. At least one beacon message is designated as a multicast delivery beacon. The buffered multicast frame is transmitted following the designated multicast beacon. The multicast element contains a list of entries, each entry corresponding to either a multicast MAC address, multicast IP address, or client identifier.

Techniques for delivering and receiving multicast content across a unicast network are described. A system that supports delivery and reception of multicast content across a unicast network includes a first device and a second device. The first device may be a destination device or a multicast-enabled router. The second device is multicast-enabled, and may be a multicast-enabled router. The first device determines whether a route between a destination device and a source of multicast packets is multicast-enabled, sends a unicast request message that includes as a destination address an address associated with the source and is marked for interception by a second device based on the determination, and receives the multicast packets as unicast packets from the second device. The second device intercepts the unicast request message and delivers the multicast packets to the requesting device as unicast packets in response to the unicast request message. The unicast request message indicates the address of the source and a group address, i.e., a source/group address pair, associated with the multicast packets that the first device wishes to receive.

A method for deploying interactive applications over a network containing host computers and group messaging servers is disclosed. The method operates in a conventional unicast network architecture comprised of conventional network links and unicast gateways and routers. The hosts send messages containing destination group addresses by unicast to the group messaging servers. The group addresses select message groups maintained by the group messaging servers. For each message group, the group messaging servers also maintain a list of all of the hosts that are members of the particular group. In its most simple implementation, the method consists of the group server receiving a message from a host containing a destination group address. Using the group address, the group messaging server then selects a message group which lists all of the host members of the group which are the targets of messages to the group. The group messaging server then forwards the message to each of the target hosts. In an interactive application, many messages will be arriving at the group server close to one another in time. Rather than simply forward each message to its targeted hosts, the group messaging server aggregates the contents of each of messages received during a specified time period and then sends an aggregated message to the targeted hosts. The time period can be defined in a number of ways. This method reduces the message traffic between hosts in a networked interactive application and contributes to reducing the latency in the communications between the hosts.

A presence tracking architecture for datagram-based protocols. A client application seeking to know the presence or lack thereof of a device and/or service utilizes a standard protocol in a non-intuitive way to trigger notification of the device and/or service before any associated timeout expires. At first presence, a multicast message is broadcast to notify all devices. Subsequently, on-demand notification may be requested by a client application by sending directly (e.g., in unicast) to the device before its timeout has expired a message that is normally only sent in multicast. If capable, the device can then respond normally with a unicast message indicating it is on-line. If the response is not received, the device and/or service is determined to be off-line.

An on-demand video delivery system, comprising: a program center having a content server for receiving and storing media signals representing humanly perceptible video programs and for converting the media signals into coded media data suitable for streaming over the Internet; and a plurality of delivery servers, each connected to the content server and the Internet for establishing an unicast link over the Internet with a respective one of a plurality of set top boxes (STBs) to deliver, upon request made from an STB for a video program, the requested video program by streaming over the Internet using Internet Protocol (IP), wherein each of the STBs includes: a buffer for receiving and temporarily storing a requested video program streamed from a delivery server over the Internet; a decoder for converting the coded media data to humanly perceptible video, and a processor for coordinating presentation of the humanly perceptible video to play on a television while the buffer receives packets of downstream coded media data from the respective delivery server.

A system and method for use at an intermediate network device employs Virtual Local Area Network (VLAN) designations as Internet Protocol version 6 (IPv6) link identifiers, and maps VLAN designations to IPv6 site identifiers (IDs). The system also generates a compacted look-up address based on the destination address specified within a received network message, such as an IPv6 packet. For a network message having a link-local unicast destination address, the VLAN ID associated with the port on which the message was received is encoded within the corresponding look-up address. For a network message having a site-local unicast address, the VLAN ID associated with the port on which the message was received is used to derive a site ID which is then encoded within the corresponding look-up address. For a network message having a multicast destination address, if the address's scope value is between hexadecimal “2” and “4” inclusive, the VLAN ID associated with the port on which the message was received is encoded within the corresponding look-up address. If the scope value is between hexadecimal “5” and “D”, inclusive, the VLAN ID associated with the port on which the message was received is used to derive a site ID which is then encoded within the corresponding look-up address. The look-up addresses are applied to a forwarding information base (FIB) to derive the outbound interface(s) from which the message is to be forwarded.

A virtual stream (VS) in a basic service set (BSS) in a wireless local area network (WLAN) that exists solely within the medium access control (MAC) sublayer of the WLAN. The VS includes a unidirectional path in the wireless network between a station sourcing a quality of service (QoS) session and at least one station receiving the QoS session in the same BSS. The VS is defined by a VS identifier (VSID) that is unique within and local to the BSS, an address of the sourcing station, and an address of the at least one receiving station. The VS can be a virtual down-stream (VDS), a virtual up-stream (VUS) or a virtual side-stream (VSS). The VS can be a unitcast or a multicast VS.

A method and associated systems for enhanced isolation and security hardening among multi-tenant workloads. An agent running on a processor of a networked computer system on which multicast and broadcast communications have been disabled captures an address-resolution query message from a querying tenant, converts the query message to a unicast message, and forwards the converted unicast query message to a switch. The switch forwards the converted unicast message to a redirection device and in response receives an address-resolution response message only after the redirection device verifies that the query and response messages comply with security policies. The switch forwards the address-resolution response to the querying tenant in conformance with security policies.

A method is provided for efficiently multiplexing interlaced broadcast traffic over a wireless network. The multiplexing scheme organizes unused slots in at least some base stations so that unicast traffic employing hybrid ARQ may be delivered therein.

System and methods for confining multicast routing trees to within single zones of a multi-zone communication systems, thereby enabling faster convergence of the trees relative to trees spanning multiple zones. Separate multicast routing trees are established using different multicast addresses in a source zone and one or more listening zones. Packets for a call distributed by routers (104, 116) of a packet network within the source zone via a source zone multicast address are received by a source zone packet duplicator (132). The source zone packet duplicator forwards the packets, via routers (116, 118, 120, 122) of the packet network using unicast routing, to various listening zone packet duplicators (136, 138). The listening zone packet duplicators, upon receiving the packets, separately distribute the packets within their respective zones via the packet network using different multicast addresses of the listening zones. The source zone and listening zones may be redefined during the call as the source changes or moves to different zones.

Methods and systems for simultaneous transmission of simulcast and single cast information over a hybrid point to multipoint communication systems, including the steps of: selecting an area to be ubiquitously covered by a common channel; assigning a first wireless client to the common channel; assigning a second wireless client to a first private channel; setting a first hybrid converter and a second hybrid converter having an aggregated coverage area that comprises the selected area; connecting the first hybrid converter using an orthogonal multi-carrier transmission having a first frequency and the second hybrid converter using an orthogonal multi-carrier transmission having a second frequency to a centralized synchronizing communication controller via a shared signal wired distribution line; converting, by using the first hybrid converter, the first frequency transmission to a third orthogonal multi-carrier wireless transmission having a third frequency; converting, by using the second hybrid converter, the second frequency transmission to a fourth orthogonal multi-carrier wireless transmission having the third frequency; and creating a downlink ubiquitous coverage in the selected area by transmitting the third and the fourth transmissions, each comprising a common MAP over a first sub-channel, a common payload over a second sub-channel, and a first private payload and a second private payload, correspondingly, over a third sub-channel, wherein the third and fourth transmissions are at least partially coverage-overlapping and are synchronizing and bandwidth allocating a first wireless client and a second wireless client.

Conventional video conference porting sytems access the analog video conference output streams, reconverting these streams back into digital data streams for transmission over the Internet. This significantly degrades these streams. Other conventional video conference porting sytems access the digital data streams, but can only output these streams as a multicast. A pseudo-end point can be connected to a multi-point control unit managing a video conference just as the end point of a participant to the video conference is connected. The pseudo-end point device receives the digital data just as the participating end points receive the digital data. The pseudo-end point is connected to a video conference standard module, which is connectable to manyt pseudo-end points, each acting as a pseudo-participant in a different video conference. The video conference standard module transmits the received digital data as a multicast to one or more unicast servers, and zero, one or more multicast clients.

A method is described for receiving a multicast in user devices in a network issuing a request to join a multicast group, identifying multicast data packets associated with the multicast group, monitoring transmissions of the multicast data packets to determine whether the identified multicast data packets are being transmitted in an already established unicast session and establishing a unicast session and processing multicast data packets if an already established unicast session does not exist A method is described for receiving a multicast transmission in user devices in a network establishing a unicast session with a dedicated terminal, identifying multicast data packets associated with a multicast group, monitoring transmissions of the multicast data packets and processing the multicast data packets by the dedicated terminal. Additonally, an apparatus is described for accepting a request to join a multicast group, for identifying multicast data packets associated with the multicast group, establishing a unicast session, for encapsulating said multicast data packets in a unicast frame and for forwarding the unicast frame via the unicast session.

Unicast endpoint clients (110, 111, 115) on an IP Unicast network (107, 108) are provided access to Multicast sessions on an IP Multicast network (101) through a Multicast-Unicast gateway server (120, 121). The server obtains information about sessions on the Multicast network and makes such information available to a Unicast client on the Unicast network upon request by the client. Upon being presented with a list describing the subject matter of each session, the user at the Unicast client selects the session to which he or she wants to join, which causes the Multicast-Unicast server to join the appropriate session on behalf of the requesting client for each media type in which the joining client wants to be a participant. The server then sets a bi-directional Unicast User Datagram Protocol (UDP) stream between itself and the client. All packets then received by the server from the Unicast client are address-translated to the appropriate Multicast session address. In addition, all packets received by the server on the Multicast session address are address-translated and sent to the Unicast client. The Unicast client is then able to participate in the Multicast session as both a sender and a receiver of packets to and from other Unicast and Multicast clients which are active during the session. Further, the Unicast client is capable of creating a new session, recording a session in the network for later retrieval and playback, and creating and accessing low bandwidth versions of existing sessions.

A packet-switched data network is disclosed that includes a dynamic resource reservation adjustment module that adjusts unicast data flows in reserved resources of the data network to maintain an optimal level of QoS for an application session. A receiver node obtains a reservation for a plurality of unicast packet flows from various routers on the data network. The receiver node also makes a partial reservation for a predetermined amount of bandwidth on each respective router to compensate for one of the unicast packet flows if a respective router experiences a bottleneck.

A head-end in a data-over-cable system transmits a multicast message in a downstream channel to all the cable modems in a particular MAC layer. The message includes an address field that contains an upstream channel multicast MAC address that identifies a particular channel, and is used to send a multicast message for which only cable modems transmitting in the upstream direction in that channel are to respond. When the message is received by the cable modems, the cable modems compare the upstream channel multicast MAC address with addresses stored in a memory. If a match is found, indicating that the cable modem happens to transmit in the upstream direction in the particular channel, it processes the message. If no match is found, the message is discarded. The upstream channel multicast MAC address helps noise avoidance or redundancy problems associated with a particular channel to be quickly remedied, and avoids the head-end from having to send out a large number of unicast messages in order to communicate with all the modems sharing a given upstream channel.

Methods and apparatus for use in reducing power consumption in battery-powered mobile communication devices in wireless local area networks (WLANs) are described. In one illustrative example, a mobile device in a WLAN is configured to normally refrain from receiving broadcast messages so that it may remain in a low power mode of operation. A network server is configured to convert broadcast messages into unicast messages for receipt by the mobile device only if the message or protocol type of the broadcast message is one in which the mobile device needs to process. As the mobile device is still configured to receive unicast messages, it will receive and decode such a unicast message and process the broadcast information within it accordingly. Advantageously, battery power is conserved at the mobile device.

A method of hybrid route discovery in a mesh network is described. The method comprises the optional designation of a root node of the mesh network and formatting a route request message at an originating mesh point, where the route request messages include a hop limit parameter. If a root node has been configured, the route request is responded to with a message that describes the route to the root. If a direct route between two nodes is required, the route request message is broadcast from the originating mesh point, and the hop limit parameter limits the number of times the route request message will be forwarded. The originating mesh point receives a unicast route reply message from a neighboring mesh point, after the neighboring mesh point received the route request message. Finally, a route connecting the originating mesh point and the destination mesh point is established.

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.

A method ensures that multicast packets follow the same loop-free path followed by unicast packets in a packet communication network. The communication network includes at least one first area interconnected through at least one area border node (“ABN”) to a second area. Each ABN has a first level port connected to each first area and a second level port connected to the second area. Each multicast packet forwarded includes a header having a root-id identifying a root of a multicast tree. A data packet is received at an ABN. Responsive to receiving a multicast packet at a second level port of an area border node, the root-id of the multicast packet is examined and if the multicast packet is to be forwarded over at least one of the first level ports, a different root-id is substituted into the packet before the packet is forwarded over the first level port.

A protocol associated with an Internet protocol version six (IPv6) network address included within a network packet provides both unicast and anycast addressing, while having the same bit locations and bit functions associated with a top-level aggregation identifier, a next-level aggregation identifier, and a site-level aggregation identifier. A prefix associated with the three most significant bits of the network address identifies the network address as being a unicast address, an anycast address, or both a unicast and an anycast address. The prefix that identifies the network address as being both a unicast and an anycast address allows routers to have smaller routing tables.