# US 9,882,804 B2 · Co-existence of a distributed routing protocol and centralized path computation for deterministic wireless networks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,882,804 B2 - Document ID: US9882804B2 - Status: Granted - Kind: B2 - Application number: 14/038,253 - Filed: 2013-09-26 - Published: 2015-03-26 - Granted: 2018-01-30 - Earliest claimed: 2013-09-26 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Pascal Thubert; Eric Levy-Abegnoli; Patrick Wetterwald; Jean-Philippe Vasseur - Web page: https://patentgrep.com/patent/US9882804B2 ## CPC - H04W 40/26: for hybrid routing by combining proactive and reactive routing - H04L 45/12: Shortest path evaluation - H04L 45/42: Centralised routing - H04L 45/44: Distributed routing - H04W 40/30: for proactive routing - H04L 45/48: Routing tree calculation - Y02D 30/70: in wireless communication networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract In one embodiment, a device both communicates with a network operating a distributed proactive routing protocol, and participates in a centralized path computation protocol. The device communicates routing characteristics of the distributed proactive routing protocol for the network from the network to the centralized path computation protocol, and also communicates one or more computed paths from the centralized path computation protocol to the network, where the computed paths from the centralized path computation protocol are based on the routing characteristics of the distributed proactive routing protocol for the network. ## Claims ### Claim 1 A method, comprising: communicating, by a device, with a network operating a distributed proactive routing protocol, wherein the distributed proactive routing protocol is a routing protocol for low-Power and lossy networks (RPL); participating, by the device, in a centralized path computation protocol; and configuring, the device, to both communicate with the network operating the distributed proactive routing protocol and participate in a centralized computation protocol by: communicating, by the device, routing characteristics of the distributed proactive routing protocol for the network from the network to the centralized path computation protocol, and communicating, by the device, one or more computed paths from the centralized path computation protocol to the network, wherein the computed paths from the centralized path computation protocol are based on the routing characteristics of the distributed proactive routing protocol for the network. ### Claim 2 (depends on 1) The method as in claim 1, further comprising: receiving node rank as a routing characteristic communicated to the centralized path computation protocol; and favoring routes by the centralized path computation protocol that are orthogonal to routes that increase or decrease in rank. ### Claim 3 (depends on 1) The method as in claim 1, further comprising: receiving node rank as a routing characteristic communicated to the centralized path computation protocol; and favoring routes by the centralized path computation protocol that avoid closeness to a root node based on the node rank. ### Claim 4 (depends on 1) The method as in claim 1, further comprising: receiving reserved timeslots as a routing characteristic communicated to the centralized path computation protocol; and avoiding use of the reserved timeslots by the centralized path computation protocol. ### Claim 5 (depends on 1) The method as in claim 1, further comprising: receiving a degree of routing changes as a routing characteristic communicated to the centralized path computation protocol; and computing paths by the centralized path computation protocol that increase stability of the distributed proactive routing protocol based on the degree of routing changes. ### Claim 6 (depends on 1) The method as in claim 1, further comprising: receiving a timeslot usage density as a routing characteristic communicated to the centralized path computation protocol; and computing paths by the centralized path computation protocol that use the timeslot usage density as a path cost characteristic. ### Claim 7 (depends on 1) The method as in claim 1, further comprising: determining that a portion of a route used in the distributed proactive routing protocol uses a same link in opposite directions; and requesting a corresponding route to avoid using the same link in opposite directions from the centralized path computation protocol. ### Claim 8 (depends on 1) The method as in claim 1, further comprising: determining, by the distributed proactive routing protocol, timeslot usage of the centralized path computation protocol for particular nodes in the network; and reducing attractiveness of the particular nodes for selection as parent nodes within the distributed proactive routing protocol based on increased timeslot usage. ### Claim 9 (depends on 1) The method as in claim 1, wherein the method is performed by a node in the network. ### Claim 10 (depends on 1) The method as in claim 1, wherein the method is performed by a path computation element (PCE). ### Claim 11 An apparatus, comprising: one or more network interfaces to communicate with a network; a processor coupled to the network interfaces and adapted to execute one or more processes; and a memory configured to store a process executable by the processor, the process when executed operable to: communicate with a network operating a distributed proactive routing protocol, wherein the distributed proactive routing protocol is a routing protocol for low-Power and lossy networks (RPL); participate in a centralized path computation protocol; and configure, the apparatus, to both communicate with the network operating the distributed proactive routing protocol and participate in a centralized computation protocol by: communicate routing characteristics of the distributed proactive routing protocol for the network from the network to the centralized path computation protocol, and communicate one or more computed paths from the centralized path computation protocol to the network, wherein the computed paths from the centralized path computation protocol are based on the routing characteristics of the distributed proactive routing protocol for the network. ### Claim 12 (depends on 11) The apparatus as in claim 11, wherein the process when executed is further operable to: receive node rank as a routing characteristic communicated to the centralized path computation protocol; and favor routes by the centralized path computation protocol that are orthogonal to routes that increase or decrease in rank. ### Claim 13 (depends on 11) The apparatus as in claim 11, wherein the process when executed is further operable to: receive node rank as a routing characteristic communicated to the centralized path computation protocol; and favor routes by the centralized path computation protocol that avoid closeness to a root node based on the node rank. ### Claim 14 (depends on 11) The apparatus as in claim 11, wherein the process when executed is further operable to: receive reserved timeslots as a routing characteristic communicated to the centralized path computation protocol; and avoid use of the reserved timeslots by the centralized path computation protocol. ### Claim 15 (depends on 11) The apparatus as in claim 11, wherein the process when executed is further operable to: receive a degree of routing changes as a routing characteristic communicated to the centralized path computation protocol; and compute paths by the centralized path computation protocol that increase stability of the distributed proactive routing protocol based on the degree of routing changes. ### Claim 16 (depends on 11) The apparatus as in claim 11, wherein the process when executed is further operable to: receive a timeslot usage density as a routing characteristic communicated to the centralized path computation protocol; and compute paths by the centralized path computation protocol that use the timeslot usage density as a path cost characteristic. ### Claim 17 (depends on 11) The apparatus as in claim 11, wherein the process when executed is further operable to: determine that a portion of a route used in the distributed proactive routing protocol uses a same link in opposite directions; and request a corresponding route to avoid using the same link in opposite directions from the centralized path computation protocol. ### Claim 18 (depends on 11) The apparatus as in claim 11, wherein the process when executed is further operable to: determine, by the distributed proactive routing protocol, timeslot usage of the centralized path computation protocol for particular nodes in the network; and reduce attractiveness of the particular nodes for selection as parent nodes within the distributed proactive routing protocol based on increased timeslot usage. ### Claim 19 (depends on 11) The apparatus as in claim 11, wherein the apparatus is a node in the network. ### Claim 20 (depends on 11) The apparatus as in claim 11, wherein the apparatus is a path computation element (PCE). ### Claim 21 A tangible, non-transitory, computer-readable media having software encoded thereon, the software when executed by a processor operable to: communicate, from a device, with a network operating a distributed proactive routing protocol, wherein the distributed proactive routing protocol is a routing protocol for low-Power and lossy networks (RPL); participate, by the device, in a centralized path computation protocol; and configure, the device, to both communicate with the network operating the distributed proactive routing protocol and participate in a centralized computation protocol by: communicating routing characteristics of the distributed proactive routing protocol for the network from the network to the centralized path computation protocol, and communicating one or more computed paths from the centralized path computation protocol to the network, wherein the computed paths from the centralized path computation protocol are based on the routing characteristics of the distributed proactive routing protocol for the network.