Landis+gyr Innovations, Inc.

Saurabh Jain

Shobhit Kumar Singh

Ankush Sabharwal

Vidya Prakash

Christopher Scott Hett

A system for optimizing routes for time-critical messages in a mesh network is provided. For example, a child node in a mesh network can communicate with the root node through any of its parent nodes. The child node is configured to transmit regular data to the root node through a primary route associated with its primary parent. When there is a time-critical message to be transmitted to the root node, the child node estimates a round trip time (RTT) for each route between the child node and the root node. The child node selects, among its parent nodes, a parent node whose associated route has the lowest RTT and transmits the time-critical message to the root node through the selected parent node. After the transmission of the time-critical message, the child node switches back to the primary route to transmit additional regular data to the root node.

Optimized route for time-critical traffic in mesh network

In some implementations, formation of loops between nodes in an RPL network may be avoided. A node that receives a neighbor-discovery message may determine, based on a parent-child status, whether the neighbor-discovery message was received from a parent of the node. If the neighbor-discovery message was received from the parent, the node may transmit an error code to the parent. In addition, the node may determine, based on a comparison of reliability rankings, whether the neighbor-discovery message was received from a node with relatively high reliability, such as a potential grandparent node. If the neighbor-discovery message was received from a high-reliability node, the node may transmit an error code to the high-reliability node. Furthermore, the node may reduce network traffic by withholding a neighbor-detection message from a child node. The node may transmit a response to neighbor-detection messages received from the child node.

Efficient message transmission and loop avoidance in an RPL network

This disclosure involves neighboring node discovery in a network. For instance, a neighboring node discovery method includes receiving, at a first node, a neighbor solicitation message. The neighbor solicitation message includes an indication that a second node is a low power device and a first scheduled response time. The method also includes transmitting at the scheduled response time, by the first node, a first neighbor advertisement message. The first neighbor advertisement message includes an indication of no availability in a neighbor cache of the first node and a second scheduled respond time. Further, the method includes removing one or more nodes from the neighbor cache, and receiving, at the first node at the second scheduled response time, a second neighbor solicitation message from the second node indicating availability in the neighbor cache. Additionally, the method includes linking the first node and the second node.

Systems and methods for neighboring node discovery in a network

A network using a routing protocol for low-power and lossy networks ('RPL') can provide timing information for a next destination oriented directed acyclic graph ('DODAG') information object (&#x201c;DIO&#x201d;) packet by including DIO timing information in an RPL packet or a beacon. When a low energy node receives the RPL packet, it may use the DIO timing information to determine a wake time which corresponds to the timing of the next DIO packet. The low energy node may enter a sleep state after determining the wake time and remain in the sleep state until the wake time when it enters an active state and listens for the next DIO packet. Alternatively, DIO slots in a DIO slot frame may be allocated for communicating DIO packets.

Communicating timing information for a next DIO transmission

Systems and methods are disclosed for prioritized associations between parent nodes operating on a time-slotted channel hopping (TSCH) network and child nodes installed in one or more home area networks. Upon initialization and bootup, a child node scans for one or more available parent nodes on the TSCH network. If there are less than a threshold number of available parent nodes within communication range of the child node, the child node transmits a prioritized association request to the parent node. The parent node supports prioritized association requests by reserving at least one connection slot for child nodes requesting prioritized association.

Prioritized association between child devices and parent devices operating on a time-slotted channel hopping network

Systems and methods are disclosed for synchronizing communications between a parent device operating on a time-slotted channel hopping (TSCH) protocol and a low-energy network device operating on a low-energy channel hopping protocol. The parent device sub-divides TSCH timeslots and communicates with adjacent TSCH devices during a primary portion of the timeslot and listens for communications from a connected low-energy device during the secondary portion of the timeslot. Upon receiving a synchronization request from a low-energy device, the TSCH device transmits a synchronization response comprising synchronization data. The synchronization data allows the low-energy device to synchronize communications with the TSCH network by synchronizing with the channel hopping pattern of the TSCH protocol.

Synchronization between low energy end point devices and parent devices in a time slotted channel hopping network

Disclosed are various embodiments for assigning a short address to a node in a network. A first node receives an association request that is a request from a second node to join the network. The first node transmits an association response to the second node, whereby the association response permits the second node to conditionally join the network and enter a low-power state. Data from the association request is transmitted to a coordinator node for the network on behalf of the second node. The first node receives a proxy response from the coordinator node in response to the data from the association request. When the second node is active, a notification is transmitted to the second node based on the response to the request. The notification includes an assignment of a short address when the response indicates the second node has joined the network.

Growing community of inventors

Ghaziabad, India

Saurabh Jain