123 results about "Wireless multicast" patented technology

A method and system for multicasting data in a communication network (100) to a specific group of user equipments (UEs) (120) that includes a source UE (102). The method provides for communicating (302) at least one FlowID to the specific group (120), the communicating including informing the specific group (120) of a broadcast server's IP address and port number to allow the UEs to set up resources in the network (100) for reception of wireless multicast data. The method also includes allowing (303) the source UE (102) to have a floor control for the specific group (120) that are uniquely identified in the network (100), the allowing being provided by a push server (112). Next, the method provides for receiving the data (304) at the broadcast server (114), from the source UE (102), and then multi-casting the data in non-duplicated packets to the specific group (120).

A method and apparatus for recovering data, comprising establishing a secondary recovery network with a device, detecting data loss and recovering via the secondary recovery network the lost data from the device, the device having correctly received the data, are described. The lost data was sent in a primary wireless multicast network. A method and apparatus for recovering data, comprising receiving data, establishing a secondary recovery network with device and recovering the lost data via said secondary recovery network, are also described. The received data was sent in a primary wireless multicast network.

This document describes multicast communication between wireless devices. A scheduling frame may be wirelessly transmitted by a wireless device. The scheduling frame may include a multicast address indicating a group of intended receiving devices for a payload frame. The scheduling frame may further include scheduling information indicating an order for the group of intended receiving devices to transmit acknowledgement information for the payload frame. A payload frame may also be wirelessly transmitted by the wireless device. The payload frame may include payload information intended for the group of intended receiving devices. Additionally, acknowledgement frames may be wirelessly received by the wireless device from at least a subset of the group of intended receiving devices. The acknowledgement frames may be received according to the order indicated in the scheduling information.

The present invention discloses a locking route method based on next hop routing and source routing, the method is aimed at solving three big technical problems including mobility of nodes, scalability of network and limited energy in the wireless multi-hop network. By using a local broadcast, the locking route method can help the source node, effectively and adaptively track network topology changes resulted from moves of the nodes, find a substitution route, and lock a destination node. In the local broadcast, the propagation of a route control message is limited to only an original route and surrounding neighbor nodes, so that network cost is greatly reduced, and scalability of the network is enhanced, wherein a routing update along the direction from the destination node to the source node can find the substitution route in time according to link quality parameters and node operating parameters, thereby maintaining persistence of the communication, and prolonging useful life of the network as well. The locking route algorithm of the present invention is suitable for all wireless multi-hop networks comprising mobile ad hoc networks, wireless mesh networks and wireless sensor networks.

Disclosed is a supervisory control and data acquisition (SCADA) system using a spread spectrum or licensed frequency data radio network and communication method therefore allowing multiple slave hosts and slave devices or remote terminal unit (RTU) the ability to communicate data connectivity in a wireless network environment.

The disclosure uses a low-cost local wireless network to expand coverage of a multicast service. A user device determines whether a signal strength for a detected wireless multicast service is greater than a threshold, determines whether a low cost local wireless network is available, and communicates with an application server over the low cost local wireless network based on the signal strength being not greater than the threshold and the low cost local wireless network being available. A server receives a request from a user device to send multicast communications to the user device over the low cost local wireless network serving the user device, wherein the user device sends the request based on a signal strength of a detected wireless multicast network being less than a threshold and the low cost local wireless network being available, and communicates with the use device over the low cost local wireless network.

The present invention relates to a method and apparatus, in which a controller (OGI-controller) receives the registration of a terminal from a content provider so as to transmit information via a wireless multicast or broadcast channel, and transmits information to the registered terminal. The method comprises: a service registration step in which the controller registers a service to transmit information provided by the content provider to the terminal, and allocates an identification to a terminal group which will receive the information; a terminal registration step in which the content provider registers the terminal group to the controller; a terminal state checking step in which the controller receives a report on the operating states of the terminals of the registered terminal group; a terminal classifying step in which the controller classifies the terminals on the basis of the operating states of the terminals; and a terminal state reporting step in which the content provider receives a report on the state of the terminal.

The invention relates to a method and a system for transmitting wireless multicast data, which are used for improving the transmission quality of the conventional wireless IPv6 multicast data. The method comprises the following steps of: recording the correlation of a source MAC address in an MLD Report message, a port and a multicast IP address in the MLD Report message into an MLD multicast forwarding table if judging that the MLD Report message received from the port is sent by a wireless user after a home gateway (HGW) starts an MLD monitor; matching a target IP address of an IPv6 multicast data packet with the multicast IP address recorded in the MLD multicast forwarding table after the HGW receives the IPv6 multicast data packet from streaming media; and judging whether the port corresponding to the matched multicast IP address is a wireless port, if so, forwarding the Pv6 multicast data packet to the wire port after replacing the target MAC address of the IPv6 multicast data packet by an MAC address correlated with the wireless port.

A method, apparatus and system for opportunistic multicasting are described. In one embodiment, an apparatus for use in a wireless multicast system comprises: a storage to store channel state and/or rate information received from the plurality of receivers; an optional encoder to generate encoding blocks from the original multicast/broadcast content; a transmitter to broadcast information over a broadcast channel to receivers in the plurality of receivers for each transmission time slot; and a controller coupled to the storage and the transmitter to adapt transmission rates of the transmitter to cause the transmitter to transmit at different rates for different transmission time slots, wherein the controller determines a transmission rate of the transmitter that broadcasts the encoded information, based on the channel state information associated with the broadcast channel and received from the plurality of receivers and based on a subset of receivers in the plurality of receivers targeted to reliably receive a broadcast transmission over the broadcast channel during said each transmission time slot.

The invention provides a local cooperation method in wireless multicasting. During multicasting to a user, a mobile base station is divided into four stages: a first stage: the mobile base station broadcasts a certain number of data packets to the user; a second stage: the idle non-multicasting user codes the received data packets in the network and then forwards the data packets to the multicasting user, and the multicasting user repairs the data packets first time by utilizing the forwarded data packets; a third stage: the user in the multicasting group retransmits the data packets in a cooperation manner, and the error packet list of the multicasting user is split by a network coding method to obtain a local retransmission strategy, and the local retransmission of the data packets is performed according to the strategy; and a fourth state: when receiving the report, the mobile base station judges whether the data packets are retransmitted or not according to the feedback of the user. By adopting the method, the retransmission request of the multicasting user to the mobile base station is reduced, the retransmission relay is reduced, the retransmission times are lowered, the retransmission efficiency is improved, the retransmission load of the mobile base station is lightened, the honeycomb link resource is saved, and the utilization rate of the wireless resource is improved.

The invention discloses a multicast retransmission method based on network codes, and mainly solves the problem that the retransmission efficiency of the prior art is not high. The multicast retransmission method based on the network codes comprises the following steps: originating nodes broadcast data packets to destination nodes, the destination nodes carry out decoding to received signals and feed back the receiving status information of the data packets to the originating nodes, the originating nodes generate an originating end packet receiving status matrix according to the feedback information and then search matching groups by processing the matrix, the originating nodes carry out network code combination to the matching groups to generate combined groups and retransmit the combined groups, and each destination node carries out decoding to the received signals to acquire the retransmitted combined groups of the codes and recovers the lost group of each node from the combined groups. The multicast retransmission method based on the network codes can effectively reduce the average retransmission times of lost groups, obviously improves retransmission efficiency, and can be used for wireless multicast or broadcast network.

The invention discloses a wireless multicast method of a data center. All-directional antennas are added on top routers of data center network frames; multicast data between the frames are transmitted through wireless channels; and multicast data transmission between inner servers in the frames are transmitted through existing wired links. With the advantage of one to multiple transmission of wireless networks, the multicast data between frames can be transmitted through wireless mode; characteristics of gathering devices of the data center network are adequately employed to solve the problem of insufficient covering area of wireless networks; all frame top routers expected to receive multicast data can be guaranteed to receive data, so that channel utilization is improved, wireless multicast properties are improved, and the wireless multicast properties are no longer limited by a worst channel; and adaptive forward frame routers and corresponding data rate are selected to forward data with a trade-off between transmission rate and transmission arrange, so that the wireless multicast properties are improved.

A fault remediation system for fielded wireless mobile devices addresses field failure data collection, consolidation of field failure data, and an information services platform so that the players in a wireless/mobile broadcast/broadband application/service value chain to respond to field failure problems in a consistent and automated manner from wireless/mobile devices over wireless multicast and or wireless broadband networks. An elegant and extremely flexible mechanism enables the failure data collection from a targeted set of wireless/mobile devices. In addition, sophisticated mechanisms identify targeted set of devices that should participate in field failure data collection based on user specified operational requirements (e.g., selected OEM, device configuration type, subscribers to a specific wireless broadband serve, failure occurrence certain time limits, etc.). The fault data logging on the mobile device is vertically integrated to allow diagnosis and assignment to a responsible party for fixing, testing, and release with subsequent certification and deployment.

An adaptive and scalable packet error correction apparatus and method in a wireless multicast network is provided. Each retransmission request from a receiver contains a round number and the number of repairs sent in that round. At each receiver, there are two counters for counting the rounds sent out on the network and the number of repairs that have been required. A receiver on the wireless multicast network listens to the ARQ requests sent by other receivers to update the two counters and determines whether its request should be suppressed or be sent out.

The invention relates to the technical field of wireless networks, and discloses a wireless multi-hop network congestion control method and system based on the RTT. The wireless multi-hop network congestion control method comprises the steps that a notification option containing a timestamp is carried by the last TCP message of sending data; a response ACK message corresponding to the notification option is received; the RTT value of TCP communication at the time is calculated according to the reception condition of the response ACK message, and a theoretical package sending rate is calculated according to the RTT value; the theoretical package sending rate and the current actual package sending rate are compared, the network congestion condition is judged accordingly, and the current actual package sending rate is adjusted correspondingly. The package loss type of a wireless network is accurately learnt through an explicit congestion notification mechanism, the congestion level of the network is predicted according to the package sending rate, congestion control and congestion avoidance are conducted dynamically, the handling capacity of a TCP in a wireless multi-hop environment is improved effectively, and the overall performance of the wireless network is further improved.

Push-to-talk messages are sent via a wireless multicast channel to multiple push-to-talk groups of devices regardless of group membership. Thus, all of the devices using the multicast channel receive all of the push-to-talk messages. To separate messages bound for one push-to-talk group from those bound for another, a push-to-talk group specific orthogonal code is applied to each message. The devices in a specific group use the group specific orthogonal code to decode the received multicast messages. If a device decodes the multicast message with the correct group specific orthogonal code, then the message is decoded and the device can play the message. If a device decodes the multicast message with a different group specific code (i.e., because it is not a member of the group the message was intended for), the message is will not be properly decoded and thus will be unplayable or scrambled.

The present invention relates to a method and arrangement for optimizing data rates in communicating multicast data, the method comprising the steps of: obtaining available data rates corresponding to a user station; computing optimal data rate within each access network cell; and controlling the data rate for each data packet at each access network cell.

The invention relates to a wireless multicast transmission and rate adaptation method during train-ground communication and a system thereof. The communication method comprises the following steps that: a. an access point and a mobile node work in a multicast mechanism state and the multicast mechanism is correspondingly arranged corresponding to a frame control domain; b. the access point initially sends a multicast data flow to the mobile node as a fixed rate and receives an ACK data frame of the mobile node in a multicast group; c. after receiving the ACK data frame corresponding to the mobile node, the access point analyzes and compares link communication quality between the mobile node corresponding to the ACK data frame and the access point and selects a link with the poor communication quality between the access point and the mobile node as a reference link, and a signal to noise ratio of the reference link is selected as the reference signal to noise ratio; d. the access point selects to send the multicast data flow as the optimum transmission rate corresponding to the reference link according to a range of the reference signal to noise ratio. In the invention, the multicast rate adaptation can be realized; fluency and reliability of data transmission in a train-ground communication system can be increased.