Alternating scheduling method for use in a mesh network
View Patent ↗An alternating scheduling algorithm is useful in a mesh network. Transmissions are scheduled along a branch in a tree structure such that simultaneous transmissions occur only in non-adjacent layers along the branch. In a disclosed example, every other layer is grouped into a set of layers such that the sets are mutually exclusive and the sets only include non-adjacent layers. One example includes designating one set of layers as the even layers and another set as odd layers. A scheduler schedules transmissions on the layers such that simultaneous transmissions along a branch occur only on layers within one of the sets while transmissions on the other set along the same branch are prevented. The sets of layers selected for transmission are alternated each subsequent scheduling window or frame.
1. A method of communicating in a mesh network including a tree having at least one first branch between a root node and a first child node with at least one link at each of a plurality of layers between the nodes, each link facilitating communications between a node and at least one next node along the branch, the network including at least a second branch from the root node to a second child node, the method comprising
scheduling transmissions between selected nodes such that simultaneous transmissions occur only on non-adjacent layers along each of the first and second branches, respectively and such that simultaneous transmissions occur on layers of the first branch that are different than the layers on which transmissions occur along the second branch during a single scheduling window.
2. The method of claim 1 , comprising scheduling the transmissions such that the simultaneous transmissions occur only on every other layer along the each of the first and second branches, respectively.
3. The method of claim 1 , comprising
designating at least one of the layers an even layer;
designating at least one layer adjacent the at least one even layer an odd layer;
scheduling the transmissions such that at least one transmission on any even layer of the first branch occurs within a scheduling window; and
preventing any transmissions on any odd layer of the first branch during the scheduling window.
4. The method of claim 3 , comprising
scheduling the transmissions such that at least one transmission on any odd layer of the first branch occurs within a next scheduling window; and
preventing any transmissions on any even layer of the first branch during the next scheduling window.
5. The method of claim 4 , comprising
scheduling the transmissions such that at least one other transmission occurs within a next subsequent scheduling window on any layer of the first branch that did not include any transmissions during a previous scheduling window; and
preventing any other transmissions within the next subsequent scheduling window on any of the layers of the first branch that included a transmission during the previous scheduling window.
6. The method of claim 5 , comprising
repeatedly performing the scheduling and preventing of the other transmissions during any following next subsequent scheduling window until a selected number of transmissions along the first branch are completed.
7. The method of claim 1 , comprising
designating at least one of the layers an even layer;
designating at least one layer adjacent the at least one even layer an odd layer;
scheduling the transmissions such that at least one transmission on at least one of the even layers of the first branch occurs within a scheduling window;
preventing any transmissions on any of the odd layers of the first branch during the scheduling window
scheduling the transmissions such that at least one transmission on at least one of the odd layers of the second branch occurs within the scheduling window; and
preventing any transmissions on any of the even layers of the second branch during the scheduling window.
8. The method of claim 7 , comprising
scheduling the transmissions such that at least one transmission on at least one of the odd layers of the first branch occurs within a next scheduling window;
preventing any transmissions on any of the even layers of the first branch during the next scheduling window;
scheduling the transmissions such that at least one transmission on at least one of the even layers of the second branch occurs within a next scheduling window; and
preventing any transmissions on any of the odd layers of the second branch during the next scheduling window.
9. The method of claim 8 , comprising
scheduling the transmissions such that at least one other transmission occurs during a next subsequent scheduling window on any of the layers that did not include a transmission during a previous scheduling window;
preventing any other transmissions within the next subsequent scheduling window on any layers that included a transmission during the previous scheduling window.
10. The method of claim 9 , comprising
repeatedly performing the scheduling and preventing of the other transmissions during any following next subsequent scheduling window until a selected number of transmissions along at least one of the branches are completed.
11. The method of claim 1 , comprising
scheduling any downlink transmissions in a direction from the root node to any one of the child nodes before scheduling any uplink transmissions in an opposite direction.
12. A mesh network assembly, comprising
a tree having at least one first branch between a root node and a first child node and at least one second branch between the root node and a second child node with at least one link at each of a plurality of layers between the nodes, each link facilitating communications between a node and at least one next node along the corresponding branch; and
a scheduler configured to schedule transmissions between selected one of the nodes such that simultaneous transmissions occur only on non-adjacent layers along each of the branches, respectively, the scheduler configured to schedule transmissions such that simultaneous transmissions occur only on non-adjacent layers of the second branch that are different than the layers on which transmissions occur along the first branch during a selected scheduling window.
13. The assembly of claim 12 , wherein the scheduler is configured to schedule the transmissions such that the simultaneous transmissions on at least one of the branches occur only on every other layer along the at least one of the branches.
14. The assembly of claim 12 , wherein the scheduler is configured to
designate at least one of the layers an even layer;
designate at least one layer adjacent the at least one even layer an odd layer;
schedule the transmissions such that at least one transmission on any even layer of the first branch occurs within the selected scheduling window;
prevent any transmissions on any of the odd layers of the first branch during the scheduling window;
schedule the transmissions such that at least one transmission on any odd layer of the first branch occurs within a next scheduling window; and
preventing any transmissions on any of the even layers of the first branch during the next scheduling window.
15. The assembly of claim 14 , wherein the scheduler is configured to
schedule the transmissions such that at least one other transmission occurs within a next subsequent scheduling window on a layer of the first branch that did not include any transmissions during a previous scheduling window; and
prevent any other transmissions during the next subsequent scheduling window on any of the layers of the first branch that included any transmission during the previous scheduling window.
16. The assembly of claim 15 , wherein the scheduler is configured to
repeat the scheduling and preventing of the other transmissions during any following next subsequent scheduling window until a selected number of transmissions along the first branch are completed.
17. The assembly of claim 12 , wherein the scheduler is configured to
designate at least one of the layers an even layer;
designate at least one layer adjacent the at least one even layer an odd layer;
schedule the transmissions such that at least one transmission on at least one of the even layers of the first branch occurs within the selected scheduling window;
prevent any transmissions on any of the odd layers of the first branch during the scheduling window
schedule the transmissions such that at least one transmission on at least one of the odd layers of the second branch occurs within the scheduling window; and
prevent any transmissions on any of the even layers of the second branch during the scheduling window.
18. The assembly of claim 17 , wherein the scheduler is configured to
schedule the transmissions such that at least one other transmission occurs within a next subsequent scheduling window on a layer of each of the branches that did not include any transmissions during a previous scheduling window;
prevent any other transmissions during the next subsequent scheduling window on any of the layers of each of the branches that included any transmission during the previous scheduling window; and
repeat the scheduling and preventing of the other transmissions during any following next subsequent scheduling window until a selected number of transmissions along the branch are completed.