Assigning slots in a mesh network
View Patent ↗Assigning slots to nodes in a mesh network. Slot numbers are assigned to nodes in a wireless mesh network using a depth-first search combined with information on 2-hop neighborhoods for each node. Assigning slots using 2-hop neighborhood information allows slots to be safely reused. The slot assignment process may take process in parallel using different wireless channels for different subtrees rooted to a controller. Slot assignment may be repeated when the mesh topology changes. Reporting using the slot numbers allows for information from child nodes to be aggregated or filtered at parent nodes.
1. A method of operating a wireless mesh network having a root node connected to a controller and a plurality of mesh nodes, each mesh node having a node id, the mesh nodes communicating in a tree topology with the root node, each mesh node having a parent node and zero or more child nodes, the method comprising:
each mesh node calculating its 2-hop neighborhood; and
initiating a depth-first search of the tree for a node starting with the root node and an empty token comprising:
while all child nodes are not visited:
send the token to a child node not visited
wait until the token returns
remember the slot allocation of each child node,
when all nodes in a subtree rooted at the node have been visited, assign a slot number s to the node with the following constraints:
s>maximum slot number allocated to any child nodes of the node, and
s≠slot number already allocated to a node in its 2-hop neighborhood,
append the node id and the slot number chosen to the token, and
return the token to a parent node of the node.
2. The method of claim 1 further comprising:
issuing a request from the controller causing the mesh nodes to report status in slot number order.
3. The method of claim 2 where a parent node aggregates status information reported by its child nodes.
4. The method of claim 2 where the parent node filters status information reported by its child nodes.