Patent application number | Description | Published |
20090290511 | SYSTEM AND METHOD FOR MERGING CLUSTERS OF WIRELESS NODES IN A WIRELESS NETWORK - A system includes a first cluster having multiple first wireless nodes. One first node is configured to act as a first cluster master, and other first nodes are configured to receive time synchronization information provided by the first cluster master. The system also includes a second cluster having one or more second wireless nodes. One second node is configured to act as a second cluster master, and any other second nodes configured to receive time synchronization information provided by the second cluster master. The system further includes a manager configured to merge the clusters into a combined cluster. One of the nodes is configured to act as a single cluster master for the combined cluster, and the other nodes are configured to receive time synchronization information provided by the single cluster master. | 11-26-2009 |
20090290572 | SYSTEM AND METHOD FOR TIME SYNCHRONIZATION IN A WIRELESS NETWORK - A system includes multiple wireless nodes forming a cluster in a wireless network, where each wireless node is configured to communicate and exchange data wirelessly based on a clock. One of the wireless nodes is configured to operate as a cluster master. Each of the other wireless nodes is configured to (i) receive time synchronization information from a parent node, (ii) adjust its clock based on the received time synchronization information, and (iii) broadcast time synchronization information based on the time synchronization information received by that wireless node. The time synchronization information received by each of the other wireless nodes is based on time synchronization information provided by the cluster master so that the other wireless nodes substantially synchronize their clocks with the clock of the cluster master. | 11-26-2009 |
20100014492 | APPARATUS AND METHOD FOR DETERMINISTIC LATENCY-CONTROLLED COMMUNICATIONS IN PROCESS CONTROL SYSTEMS - A method includes obtaining a data message having data associated with a process system and mapping the data message to one of multiple classifications. The method also includes wirelessly transmitting the data message, where a Quality of Service (QoS) associated with the transmission is based on the mapping. Mapping the data message could include identifying a type associated with the data message and mapping the data message based on the identified type. The type may include a publish message type, an alert message type, or a management message type. The publish message type could be mapped to an Unsolicited Grant Service (UGS) class, the alert message type could be mapped to a real-time Polling Service (rtPS) class, and the management message type could be mapped to a Best Effort (BE) or non-real-time Polling Service (nrtPS) class. A WiMAX standard could be used to transmit the message, and a WiMAX or WiFi standard could be used to obtain the message. | 01-21-2010 |
20100029317 | APPARATUS AND METHOD FOR TRANSMIT POWER CONTROL IN A WIRELESS NETWORK - A method includes repeatedly transmitting messages from a first wireless node at a transmit power. The method also includes receiving feedback from a second wireless node, where the feedback is based on a quality of reception of at least some of the messages at the second wireless node. The method further includes adjusting the transmit power of the first wireless node based on the feedback to maintain the quality of reception proximate to a setpoint. The feedback could be received from multiple second wireless nodes. The feedback could include quantized values. The quality of reception could include a bit error rate, a packet error rate, and/or a receive signal strength. The quality of reception can be determined for a sliding window associated with a subset of the transmitted messages. | 02-04-2010 |
20100075611 | APPARATUS AND METHOD FOR IMPROVED WIRELESS COMMUNICATION RELIABILITY AND PERFORMANCE IN PROCESS CONTROL SYSTEMS - An apparatus includes a transceiver configured to transmit wireless signals to and receive wireless signals from wireless nodes associated with an industrial process. The apparatus also includes a controller configured to initiate transmission of the wireless signals and to process data contained in the received wireless signals. The transceiver includes a diversity receiver configured to process the wireless signals from the wireless nodes. The transceiver may be further configured to perform beam-shaping in order to transmit a directional beam to at least one of the wireless nodes. Also, the controller may be configured to perform spatial routing by identifying a target of a wireless transmission and to initiate transmission of the directional beam towards a known or estimated location associated with the identified target. | 03-25-2010 |
20100254345 | METHODS FOR SUPPORTING MOBILE NODES IN INDUSTRIAL CONTROL AND AUTOMATION SYSTEMS AND OTHER SYSTEMS AND RELATED APPARATUS - A method includes providing wireless service to a mobile leaf node using at least one first infrastructure node in an industrial control or monitoring system. The method also includes detecting movement of the mobile leaf node away from the at least one first infrastructure node. The method further includes handing off the mobile leaf node to at least one second infrastructure node in the industrial control or monitoring system so that the at least one second infrastructure node provides the wireless service to the mobile leaf node. The wireless service provided to the mobile leaf node remains deterministic. Various techniques can be used to detect the movement of the mobile leaf node. Also, the first and second infrastructure nodes could be in different clusters of nodes, and various techniques can be used to support handoffs between infrastructure nodes in different clusters. | 10-07-2010 |
20100269005 | APPARATUS AND METHOD FOR IMPROVED RELIABILITY OF WIRELESS COMMUNICATIONS USING PACKET COMBINATION-BASED ERROR CORRECTION - Various techniques are disclosed for improved reliability of wireless communications using packet combination-based error correction. For example, a method includes receiving a first message transmitted wirelessly, where the first message contains a first copy of a data packet and has at least one error. The method also includes receiving a second message transmitted wirelessly, where the second message contains a second copy of the data packet and has at least one error. The method further includes identifying a set of bit positions based on where the first and second copies of the data packet differ and modifying the set of bit positions to produce a modified set of bit positions. In addition, the method includes modifying one or more bit values in the modified set of bit positions to produce at least one modified copy of the data packet and determining if the at least one modified copy of the data packet is error-free. | 10-21-2010 |
20100296552 | APPARATUS AND METHOD FOR HYBRID DIVERSITY COMBINING AND ADAPTIVE BEAM FORMING IN INDUSTRIAL CONTROL AND AUTOMATION SYSTEMS - An apparatus includes a plurality of antennas, where each antenna is configured to receive wireless signals transmitted using adaptive beam forming. The apparatus also includes a plurality of wireless radios, where each wireless radio is configured to output signals representing the wireless signals received by one of the antennas. The apparatus further includes a plurality of first diversity combiner units, where each first diversity combiner unit is configured to perform spread spectrum diversity combining using the signals output by one of the wireless radios. In addition, the apparatus includes a second diversity combiner unit configured to perform antenna diversity combining using signals output by the first diversity combiner units, where the second diversity combiner unit is configured to output recovered wireless signals. | 11-25-2010 |