Path selection in wireless networks
In a wireless network, a lowest cost path from a source node to a target node is selected from a plurality of potential paths. The source node sums costs for the links of each potential path. For each link, these costs include a cost of interference, dependent on a number of nodes affected by a signal sent via the respective link. The link costs can also include a cost of transmission, dependent upon a data rate for the respective link, and a cost of coordination for transmissions with other nodes of the network.
1. A method of selecting a communication path, in a wireless network comprising a plurality of nodes and wireless communication links between the nodes, from a plurality of potential communication paths comprising different combinations of said links from a source node to a target node, comprising the steps of, in the source node:
determining for each link in the potential communication paths a cost of interference dependent upon a number of nodes affected by a signal sent via the respective link;
determining a total cost for each potential communication path, the total cost being dependent upon combined costs of interference for the links of the respective potential communication path; and
selecting as a communication path from the source node to the target node a potential communication path having a lowest total cost.
2. A method as claimed in claim 1 and including the step of, in the source node, determining for each link in the potential communication paths a cost of transmission dependent upon a data rate for a signal sent via the respective link, wherein the total cost determined for each potential communication path is also dependent upon combined costs of transmission for the links of the respective potential communication path.
3. A method as claimed in claim 2 and including the step of, in the source node, determining for each link in the potential communication paths a cost of coordination of transmissions on the link with transmissions from other nodes of the network, wherein the total cost determined for each potential communication path is also dependent upon combined costs of coordination for the links of the respective potential communication path.
4. A method as claimed in claim 2 wherein the source node determines the total cost for each potential communications path as a sum of the combined costs for the links of the respective potential communication path.
5. A method as claimed in claim 2 wherein the cost of interference for each link in the potential communication paths determined by the source node is also dependent upon a time interval required for a signal sent via the respective link.
6. A node for a wireless network, the node providing wireless communication links for wireless communications with other nodes of the network and being operable in accordance with the method of claim 2 .
7. A wireless network comprising a plurality of nodes each as claimed in claim 6 .
8. A method as claimed in claim 1 and including the step of, in the source node, determining for each link in the potential communication paths a cost of coordination of transmissions on the link with transmissions from other nodes of the network, wherein the total cost determined for each potential communication path is also dependent upon combined costs of coordination for the links of the respective potential communication path.
9. A method as claimed in claim 8 wherein the source node determines the total cost for each potential communications path as a sum of the combined costs for the links of the respective potential communication path.
10. A method as claimed in claim 8 wherein the cost of interference for each link in the potential communication paths determined by the source node is also dependent upon a time interval required for a signal sent via the respective link.
11. A method as claimed in claim 8 wherein the cost of coordination for each link in the potential communication paths determined by the source node is also dependent upon a time interval required for coordinating activities.
12. A node for a wireless network, the node providing wireless communication links for wireless communications with other nodes of the network and being operable in accordance with the method of claim 8 .
13. A wireless network comprising a plurality of nodes each as claimed in claim 12 .
14. A method as claimed in claim 1 wherein the source node determines the total cost for each potential communications path as a sum of the combined costs for the links of the respective potential communication path.
15. A node for a wireless network, the node providing wireless communication links for wireless communications with other nodes of the network and being operable in accordance with the method of claim 14 .
16. A wireless network comprising a plurality of nodes each as claimed in claim 15 .
17. A method as claimed in claim 1 wherein the cost of interference for each link in the potential communication paths determined by the source node is also dependent upon a time interval required for a signal sent via the respective link.
18. A node for a wireless network, the node providing wireless communication links for wireless communications with other nodes of the network and being operable in accordance with the method of claim 17 .
19. A node for a wireless network, the node providing wireless communication links for wireless communications with other nodes of the network and being operable in accordance with the method of claim 1 .
20. A wireless network comprising a plurality of nodes each as claimed in claim 19 .