Abstract: Techniques for computing electrical phase of electrical metering devices are described. In an example, data indicating zero-crossing times at first and second metering devices is obtained. A time-difference between the zero-crossing times may be determined. In a first example, the time-difference may be based at least in part on calculations involving a first value of a first free-run timer on a first metering device, a second value of a second free-run timer on a second metering device, and a time of a transmission between the metering devices. In a second example, the time-difference may be based at least in part on calculations involving a start or end time of a time-slot of a spread spectrum radio frequency transmission scheme. A phase difference between the first zero-crossing and the second zero-crossing may be determined, based at least in part on the determined time-difference.

Abstract: Techniques are directed to opportunistically communicating using a modulation scheme that is other than the preferred modulation scheme, to update communication metric data for the second modulation scheme, such as a modulation scheme that has not been used as much as the first modulation scheme. The second modulation scheme may be associated with a higher data rate than the preferred modulation scheme. If communication using the second modulation scheme is successful, subsequent communication may be carried out exclusively using the second modulation scheme, and the communication metrics may develop such that the second modulation scheme becomes the preferred modulation scheme.

Abstract: Techniques directed to servicing communications based on when communication sessions are initialized for nodes are described. For example, a routing device may prioritize packets in a buffer according to when nodes have initiated communication sessions with a service provider or another node. The routing device may give priority to nodes that have first initiated communication sessions. This may avoid communication sessions ending prematurely due to time-out periods and/or avoid delays in completing communication sessions.

Abstract: A wireless mesh network includes a plurality of nodes coupled together in parent-child relationships. A child node is configured to cascade listening rate changes upstream to a parent node to perform low-latency communications. The child node transmits an authentication message to the parent node indicating the listening rate change. The child node sets a timer and waits for an acknowledgement from the parent node. If the child node receives the acknowledgement, then the child node and the parent node change listening rate to permit low-latency communications. In addition, if the parent node loses network access, the parent node sets a timer and then waits to abandon the child node until after the timer elapses.

Abstract: A wireless mesh network includes a child node coupled to a parent node. The parent node transmits time sync beacons that indicate a time slot number and a start time for a current time slot. The child node receives the time sync beacons and determines a delta between the current time slot number of the child node and the current time slot number of the parent node. The child node also computes an offset between a start time of the current slot of the child node and the start time of the current slot of the parent node. The child node reports the delta and the offset to the parent node. Based on the delta and the offset, the parent node determines when, and on what channel, the child node is predicted to be receiving transmissions, and then schedules transmissions to the child node accordingly.

Abstract: Disclosed are techniques to minimize the electricity consumption of battery powered devices during network discovery and other phases of network operation. Example techniques include efficiently listening for other mains powered and battery powered devices within communication range of the battery powered device by, for example, shortening its listening window depending on how close the time reference maintained by the battery powered device is estimated to be to the time reference used by the other mains powered and battery powered devices within communication range. Other techniques include slowing the rate of listening by the battery powered device when the battery powered device is unlikely to be able to receive discovery messages or is already connected to the network. Other techniques include using knowledge of the network to listen for discovery messages on a channel or channels on which other devices are likely to be transmitting.

Abstract: Techniques for employing a Mains Powered Device as a proxy for communicating on behalf of a Battery Powered Device are described herein. In some examples, the Mains Powered Device may be a parent node to the Battery Powered Device in a network which operates using a Routing Protocol for Low-Power and Lossy Networks (RPL). The Mains Powered Device may detect and/or forward a Destination Advertisement Object (DAO) transmitted from the Battery Powered Device to a DODAG root of the network, and begin to perform subsequent transmission of DAOs on behalf of the Battery Powered Device. In this way, the Mains Powered Device updates a routing table of the DODAG root periodically to include an indication of the Battery Powered Device as existing in the network, while extending the battery life of the Battery Powered Device by transmitting DAOs on behalf of the Battery Powered Device.

Abstract: Techniques for providing additional timing information in periodic beacons in a network to enable battery powered devices to determine more appropriate listening windows for receiving the periodic beacons are described herein. In some examples, the battery powered devices use the additional information to determine more accurate listening windows based on a drift time of their internal clocks, and a jitter time of the network and/or a Coordinated Universal Time (UTC). Additionally, techniques for modifying when mains powered devices update their internal clocks based on transmission of beacons to downstream devices are described herein. For instance, the mains powered devices may refrain from updating their internal clocks to an updated network reference time until transmission of downstream beacons have occurred. In this way, timing synchronization of devices in a network may be improved, and battery life of battery powered devices in the network may be extended.

Abstract: A wireless network includes a plurality of nodes configured to implement an improved discovery process to efficiently and reliably pair with one another with low power consumption. A given node divides time into slots and then performs discovery operations during designated discovery windows. The discovery windows occur periodically but at different times of day. During a given discovery window, nodes attempt discovery using a reduced set of channels that varies from one window to the next, thereby increasing the likelihood that nodes operate on the same channel. Nodes also implement a pairing protocol to coordinate pairing, potentially avoiding situations where all nodes attempt to pair simultaneously. The discovery process may be completed expeditiously, thereby conserving power and extending the operational lifetime of nodes which rely on battery power.

Abstract: A wireless network includes a plurality of nodes configured to implement an improved discovery process to efficiently and reliably pair with one another with low power consumption. A given node divides time into slots and then performs discovery operations during designated discovery windows. The discovery windows occur periodically but at different times of day. During a given discovery window, nodes attempt discovery using a reduced set of channels that varies from one window to the next, thereby increasing the likelihood that nodes operate on the same channel. Nodes also implement a pairing protocol to coordinate pairing, potentially avoiding situations where all nodes attempt to pair simultaneously. The discovery process may be completed expeditiously, thereby conserving power and extending the operational lifetime of nodes which rely on battery power.

Abstract: Methods and devices for providing routing path and transit delay time data to a device running traceroute on an IP network comprising routing tunnels are described herein. In examples, a tunnel entrance device may copy a hop limit value associated with a traceroute probe into a hop limit field of a tunneled IP header. In other examples, the tunnel entrance device may perform address spoofing to generate an error message with a source address corresponding to an intermediate device disposed within a routing tunnel. In this way, a device executing traceroute may be able to receive network addresses corresponding to intermediate devices in a routing tunnel in order to perform network diagnostics, construct routing tables, determine more efficient routing paths, and so on.

Abstract: A wireless mesh network includes a plurality of nodes coupled together in parent-child relationships. A child node is configured to cascade listening rate changes upstream to a parent node to perform low-latency communications. The child node transmits an authentication message to the parent node indicating the listening rate change. The child node sets a timer and waits for an acknowledgement from the parent node. If the child node receives the acknowledgement, then the child node and the parent node change listening rate to permit low-latency communications. In addition, if the parent node loses network access, the parent node sets a timer and then waits to abandon the child node until after the timer elapses.

Abstract: A wireless mesh network includes a child node coupled to a parent node. The parent node transmits time sync beacons that indicate a time slot number and a start time for a current time slot. The child node receives the time sync beacons and determines a delta between the current time slot number of the child node and the current time slot number of the parent node. The child node also computes an offset between a start time of the current slot of the child node and the start time of the current slot of the parent node. The child node reports the delta and the offset to the parent node. Based on the delta and the offset, the parent node determines when, and on what channel, the child node is predicted to be receiving transmissions, and then schedules transmissions to the child node accordingly.

Abstract: Techniques for discovering a device in a wireless network are described herein. For example, a first device may send a network discovery solicitation message to a second device to solicit a communication relationship (e.g., request connection to a parent). The network discovery solicitation may include one or more information elements that indicate a channel function associated with the first device and a listening window during which the first device will be listening for communications. The second device may use the channel function to frequency hop and send a network discovery message to the first device during the listening window. The network discovery message may include one or more information elements to establish a sampled schedule for the first device moving forward.

Abstract: Techniques for broadcasting data in a multi-channel network having a control channel and multiple data channels are described. A node wishing to broadcast data may determine a particular data channel from among the multiple data channels, a modulation technique, and a data rate to be utilized to broadcast the data. The broadcasting node may transmit a message over the control channel indicating that the data will be broadcast on the particular data channel using the modulation technique and at the determined data rate. The broadcasting node and a node wishing to receive the data may switch to the particular data channel. The broadcasting node may broadcast the data over the particular data channel, while the receiving node may receive the data. After broadcasting the data or a predetermined time period has expired, the broadcasting node and receiving node may switch to the control channel.

Abstract: Techniques for discovering a device in a wireless network are described herein. For example, a first device may send a network discovery solicitation message to a second device to solicit a communication relationship (e.g., request connection to a parent). The network discovery solicitation may include one or more information elements that indicate a channel function associated with the first device and a listening window during which the first device will be listening for communications. The second device may use the channel function to frequency hop and send a network discovery message to the first device during the listening window. The network discovery message may include one or more information elements to establish a sampled schedule for the first device moving forward.

Abstract: Techniques for providing additional timing information in periodic beacons in a network to enable battery powered devices to determine more appropriate listening windows for receiving the periodic beacons are described herein. In some examples, the battery powered devices use the additional information to determine more accurate listening windows based on a drift time of their internal clocks, and a jitter time of the network and/or a Coordinated Universal Time (UTC). Additionally, techniques for modifying when mains powered devices update their internal clocks based on transmission of beacons to downstream devices are described herein. For instance, the mains powered devices may refrain from updating their internal clocks to an updated network reference time until transmission of downstream beacons have occurred. In this way, timing synchronization of devices in a network may be improved, and battery life of battery powered devices in the network may be extended.

Abstract: Techniques for employing a Mains Powered Device as a proxy for communicating on behalf of a Battery Powered Device are described herein. In some examples, the Mains Powered Device may be a parent node to the Battery Powered Device in a network which operates using a Routing Protocol for Low-Power and Lossy Networks (RPL). The Mains Powered Device may detect and/or forward a Destination Advertisement Object (DAO) transmitted from the Battery Powered Device to a DODAG root of the network, and begin to perform subsequent transmission of DAOs on behalf of the Battery Powered Device. In this way, the Mains Powered Device updates a routing table of the DODAG root periodically to include an indication of the Battery Powered Device as existing in the network, while extending the battery life of the Battery Powered Device by transmitting DAOs on behalf of the Battery Powered Device.

Abstract: Techniques directed to servicing communications based on when communication sessions are initialized for nodes are described. For example, a routing device may prioritize packets in a buffer according to when nodes have initiated communication sessions with a service provider or another node. The routing device may give priority to nodes that have first initiated communication sessions. This may avoid communication sessions ending prematurely due to time-out periods and/or avoid delays in completing communication sessions.

Abstract: Techniques for discovering a device in a wireless network are described herein. For example, a first device may send a network discovery solicitation message to a second device to solicit a communication relationship (e.g., request connection to a parent). The network discovery solicitation may include one or more information elements that indicate a channel function associated with the first device and a listening window during which the first device will be listening for communications. The second device may use the channel function to frequency hop and send a network discovery message to the first device during the listening window. The network discovery message may include one or more information elements to establish a sampled schedule for the first device moving forward.