Adaptive control of transmission power and data rates of transmission links between access nodes of a mesh network
View Patent ↗A method of optimizing link transmission parameters between access nodes within a mesh network is disclosed. The method includes each access node within the mesh transmitting packets at N different combinations of data rates and power levels. Each receiving node that receives the data packets at one or more of the N combinations, selects a most desirable one of the received combinations. The receiving nodes indicate to the transmitting nodes the selected most desired combination for transmitting to the receiving node.
1. A method of optimizing link transmission parameters between access nodes within a mesh network, comprising:
each access node within the mesh transmitting packets at N different combinations of data rates and power levels;
each receiving node that receives data packets at one or more of the N combinations, selecting a most desirable one of the received combinations; wherein selecting a most desirable one of the received combinations comprises selecting the combinations that provide a link with a greatest expected throughput from transmitting node to receiving node, and from the greatest expected throughput combinations, selecting the one combination that causes a least amount of interference to other nodes in the mesh network; and
each receiving node indicating to corresponding transmitting nodes the selected most desired combination for transmitting to the receiving node.
2. The method of claim 1 , wherein each transmitting node uses the selected most desired combination to transmit to corresponding receiving nodes.
3. The method of claim 1 wherein expected throughput is determined by measuring a packet success rate of a transmission link between the receiving node and the transmitting node.
4. The method of claim 1 , wherein an estimate of the interference includes magnitudes of received power levels at other nodes within the mesh network relative to a threshold required for reception.
5. The method of claim 4 , wherein the estimate of the interference comprises determining a number of interfered nodes.
6. The method of claim 5 , wherein the estimate of the interference further factors an airtime required per transmitted bit.
7. The method of claim 4 , wherein the estimate of the interference comprises determining a fraction of time that the threshold is exceeded over a time interval, for each interfered node.
8. The method of claim 1 , wherein the estimate of interference consists of summing over all interfered nodes a product of (i) a fraction of time that a threshold is exceeded on each of interfered nodes and (ii) an airtime required for the transmitting node to transmit a bit to the receiving node.
9. The method of claim 1 , wherein selecting a most desirable one of the received combinations of data rate and power level comprises:
determining a level of use of clients connected to the mesh network;
if the level of use is below a predetermined threshold, then selecting the one of the N combinations that provides the greatest expected throughput;
if the level of use is above the predetermined threshold, then selecting the one of the N combinations that provides a predetermined level of expected throughput, and a minimal amount of interference to other nodes in the mesh network.
10. The method of claim 1 , further comprising each access node periodically re-selecting a most desirable one of the received rate and power level combinations for transmission over each link.
11. The method of claim 10 , wherein reselecting data rate and power levels occurs once every set period of time for each link and in each link direction.
12. The method of claim 10 , wherein reselecting occurs adaptively based on changes in an interference metric.
13. The method of claim 1 , wherein data rate and power combinations includes those defined by 802.11 standards.
14. The method of claim 1 , further comprising:
selecting routing paths through the access nodes of the mesh network conditioned upon the selected combinations of data rate and power level for each link between each transmitting/receiving pair of access nodes within the mesh network.
15. The method of claim 14 , wherein routing beacons are originated at gateways of the mesh network and transmitted at all relevant data rates and power levels.
16. The method of claim 15 , wherein relevant data rates and power levels are defined by a transmission protocol being used.
17. The method of claim 15 , wherein relevant data rates and power are a subset of available data rates and power levels, and the subset is determined by preset configuration parameters of the transmitting nodes.
18. The method of claim 15 , wherein relevant data rates and power are a subset of available data rates and power levels, and the subset is determined by a density of nodes within the mesh network.
19. The method of claims 15 , wherein the beacons are transmitted at a predetermined rate.
20. The method of claim 15 , wherein each access node that receives the routing beacons selects a routing path to a gateway based upon a quality parameter of the received routing beacons.
21. The method of claim 20 , wherein only the routing beacons at the selected most desired combination of data rate a power lever are used for selecting the routing path.
22. The method of claim 21 , further comprising both uplink and downlink qualities being used in selecting routing paths, wherein the uplink and down link data rate and power level combinations correspond with the selected most desired combinations.
23. A method of optimizing link transmission parameters between access nodes within a mesh network, comprising:
each access node within the mesh transmitting packets at N different combinations of data rates and power levels;
each receiving node that receives data packets at one or more of the N combinations, selecting a most desirable one of the received combinations, wherein selecting a most desirable one of the received combinations comprises; selecting the combinations that allow a link to cause a least interference to other nodes in the mesh network; and from the least interference combinations, selecting the one combination that provides a greatest expected throughput from the transmitting node to the receiving node:
each receiving node indicating to corresponding transmitting nodes the selected most desired combination for transmitting to the receiving node.
24. The method of claim 23 , wherein expected throughput is determined by measuring a packet success rate of a transmission link between the neighboring access node and the transmitting access node.
25. The method of claim 23 , wherein an estimate of the interference includes magnitudes of received power levels at other nodes within the mesh network relative to a threshold required for reception.
26. The method of claim 23 , wherein the estimate of the interference comprises determining a number of interfered nodes.
27. The method of claim 23 , wherein the estimate of the interference comprises determining a fraction of time that the threshold is exceeded over a time interval, for each interfered node.
28. The method of claim 27 , wherein the estimate of the interference further comprises an airtime required per transmitted bit.
29. The method of claim 23 , wherein the estimate of the interference consists of summing over all interfered nodes a product of(i) a fraction of time that a threshold is exceeded on each of interfered nodes and (ii) an airtime required for the transmitting node to transmit a bit to the receiving node.
30. A method of a selecting transmission parameters of an access node within a mesh network, comprising:
the access node receiving data packets from neighboring access nodes through transmission signals having N combinations of data rate and power level;
the access node selecting a most desired combination of data rate and power level for each link between the access node and each neighboring access node, comprising selecting the combinations that provide the link with a greatest expected throughput, and from the greatest expected throughput combinations, selecting the one combination that creates a least amount of interference;
the access node communicating the selected combination back to each corresponding neighboring access node; and
the access node receiving data packets from the neighboring nodes transmitted at the selected combinations of data rates and power levels.
31. The method of claim 30 , wherein selecting a most desired combination of data rate and power level comprises:
determining a level of use of clients connected to the mesh network;
if the level of use is below a predetermined threshold, then selecting the one of the N combinations that provides the greatest expected throughput;
if the level of us is above the predetermined threshold, then selecting the one of the N combinations that select that combination that provides a predetermined level of expected throughput, and a minimal amount of interference.