ROUTE DISCOVERY IN ZIGBEE NETWORKS WITH COMBO NODES

Abstract

The invention relates to the field of Zigbee wireless mesh communication networks and in particular to methods, systems and nodes (A,B,C,D) for use is such systems for establishing routes in mesh networks, wherein Zigbee router nodes (A,B,C) comprise a controller and radio transceiver and are arranged to include addresses of Zigbee End Device, ZED, child nodes (D) of the Zigbee router (C), in many-to-one route requests that the Zigbee router (C) transmits and/or include the addresses of the ZED child nodes (D) of the Zigbee router (C) in AODV route replies that the Zigbee router (C) transmits.

Claims

1. A Zigbee router for use in a Zigbee wireless mesh network the Zigbee router comprising: a controller and a radio transceiver arranged to communicate using the Zigbee wireless network protocol, wherein the controller is arranged to include addresses of Zigbee End Device, ZED, child nodes of the Zigbee router, in many-to-one route requests (MTORRs) that the Zigbee router transmits, and the Zigbee router is arranged to upon receipt of an MTORR from a concentrator that comprises a list of ZED addresses in the MTORR, add or update an entry in the route table for the concentrator and add or replace entries for all of the ZED children of that concentrator to the routing table.

2. The Zigbee router of claim 1, wherein: the controller is arranged to include the addresses of the ZED child nodes of the Zigbee router in AODV route replies that the Zigbee router transmits.

3. A Zigbee router for use in a Zigbee wireless mesh network, the Zigbee router comprising: a controller and a radio transceiver arranged to communicate using the Zigbee wireless network protocol, wherein the controller is arranged to include addresses of ZED child nodes of the Zigbee router in AODV route replies that the Zigbee router transmits and the Zigbee router is arranged to upon receipt of an AODV route reply that comprises a list of ZED addresses from a further Zigbee router and nwkSymLink=true, add or update a route entry for the further router and route entries for all of the ZED children of the further router to the routing table.

4. The Zigbee router of claim 3, wherein: the controller is arranged to include the addresses of the ZED child nodes of the Zigbee router, in many-to-one route requests (MTORRs) that the Zigbee router transmits.

5. (canceled)

6. The Zigbee router according to claim 1, wherein the Zigbee router is a router in a lighting network, and is comprised in one of a presence sensor, a light sensor, a lighting switch, a retrofit lamp, a luminaire, or a wireless network controller.

7. The Zigbee router according to claim 1, wherein the radio transceiver is arranged to receive a configuration package via the wireless mesh network, wherein the configuration package provides instructions for the Zigbee router, and wherein the configuration package is passed on to the controller and wherein the controller is configured to: switch the Zigbee router, when operating in a first mode wherein it deploys Zigbee router functionality, from the first mode to a second mode, wherein the Zigbee router deploys ZED node functionality when the configuration package so indicates.

8. The Zigbee router according to claim 6, wherein the radio transceiver is arranged to receive a further configuration package via the wireless network wherein the configuration package provides instructions for the Zigbee router, and wherein the controller is configured to switch the Zigbee router when operating in the second mode from the second mode to the first mode when the configuration package so indicates.

9. A method for execution by a Zigbee router for use in a Zigbee wireless mesh network, the method comprising: including, by a Zigbee router node, addresses of Zigbee End Device (ZED) child nodes of the Zigbee router, in many-to-one route requests (MTORRs) that the Zigbee router transmits and upon receipt of an MTORR from a concentrator that comprises a list of ZED addresses in the MTORR, adding or updating, by the Zigbee router node, an entry in the route table for the concentrator and add or replace entries for all of the ZED children of that concentrator to the routing table.

10. The method of claim 9, comprising: including, by the Zigbee route node, the addresses of ZED child nodes of the Zigbee router in AODV route replies that the Zigbee router transmits.

11. A method for execution by a Zigbee router for use in a Zigbee wireless mesh network, the method comprising: including, by a Zigbee router, the addresses of ZED child nodes of the Zigbee router in AODV route replies that the Zigbee router transmits and upon receipt of an AODV route reply that comprises a list of ZED addresses from a further Zigbee router and nwkSymLink=true, adding or updating, by the Zigbee router node, a route entry for the further router and route entries for all of the ZED children of the further router to the routing table.

12. The method of claim 11, comprising: including, by the Zigbee router node, addresses of Zigbee End Device, ZED, child nodes of the Zigbee router, in many-to-one route requests that the Zigbee router transmits.

13. A Zigbee wireless network comprising a plurality of Zigbee wireless routers according to claim 1.

14. The network of claim 13, wherein there are a plurality of Zigbee router nodes according to claim 6.

15. A method of configuring a network according to claim 13, the method comprising: configuring by assigning the second mode to a number of Zigbee routers operating in the first mode by means of a configuration message.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In the drawings, like reference characters generally refer to the same parts throughout the different figures. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.

[0026] FIG. 1 depicts an example illustrating the concept of the present invention;

[0027] FIG. 2 depicts a block diagram of a Zigbee wireless router;

[0028] FIG. 3A depicts a flow-chart of a first variant of a method of transmission;

[0029] FIG. 3B depicts a flow-chart of a second variant of a method of transmission and

[0030] FIG. 4 depicts a flow-chart of a method of configuring router nodes.

DETAILED DESCRIPTION OF EMBODIMENTS

[0031] In accordance with the invention, Zigbee router/coordinator includes the addresses of its ZED children in its many-to-one route requests and/or in the regular (AODV) route replies. This provides a node that receives this route message (MTORR or AODV route reply) with the route to the end devices that are included in this message.

[0032] Before a router/coordinator sends out a many-to-one route request, an AODV route request (in case of nwkSymLink=true) or AODV route reply (in case of nwkSymLink=false), it first reads out its child table or that portion of its neighbour table, which includes the NWK addresses of the end devices that are bound to it. This information is used to add a new parameter: list of ZED children in the payload of the many-to-one route request and the AODV route reply, by including the NWK address of each end device.

[0033] Many-to-one route request (extension to the Zigbee-standardized Route Request Command is the “Variable” field in the below table):

TABLE-US-00001 Octets: 1 1 2 1 0/8 Variable Command Route Destination Path Destination List of NWK options request address cost IEEE addresses of identifier address end devices NWK command payload
AODV route reply (extension to the Zigbee-standardized Route Reply Command is the “Variable” field in the below table):

TABLE-US-00002 Octets: 1 1 2 2 1 0/8 0/8 Variable Command Route Originator Responder Path Originator Responder List of options request address address cost IEEE IEEE NWK identifier address address addresses of end devices NWK command payload

[0034] In case an MTORR is received that contains a list of NWK addresses, each Zigbee router node will add not only the route for the concentrator to its routing table, but at the same time creates entries for all the ZED children of that concentrator. Same applies to received AODV route requests in case of nwkSymLink=true, because then routes are assumed to be comprised of symmetric links and the forward and backward route are created in a single route discovery.

[0035] The above refers to the case where the routing table does not have an entry for a certain destination. In case an entry already exists, the entry may be replaced/updated with the newly obtained information.

[0036] As a result, parent routers should be able to process MTORR errors on behalf of their ZED children.

[0037] See the FIG. 1 for further explanation. The lines in this figure symbolize the existence of links between nodes, i.e. node B has a direct link to node A and C. Node A, B, C are router nodes, node D is a ZED (and has no routing table).

[0038] The figure explains the example where node C sends its MTORR, including its ZED child D. Nodes B and A receive the MTORR and add the routes to nodes C and D to their routing table.

[0039] In case an AODV route reply is received that contains a list of NWK addresses, the originator will add next to the route for the destination, also the routes for the children of the destination to its routing table.

[0040] The new parameter can be appended at the end of the command as an additional parameter; its presence could be indicated using one of the reserved fields of the Command Options field of the RREQ command frame.

Route Request Command Options Field

[0041]

TABLE-US-00003 Bit: 0 to 2 Bit 3 and 4 Bit 5 Bit 6 7 Reserved Many-to-one Destination Multicast Reserved IEEE address

[0042] Alternatively, it can also be appended as a self-describing Type Length Value (TLV) field. Zigbee Revision 23 will allow the addition of TLVs to many Zigbee commands. Preferably, the many-to-one route request and/or AODV route reply include the list of NWK addresses by means of such a TLV.

[0043] In extension, the parent can trigger the route discovery (MTORR or AODV in case of nwkSymLink=true), e.g. upon a local change at the parent, e.g. new ZED child joining or re-joining at the parent, upon resolving an address conflict for the child node—or upon a remote change, e.g. when the parent detects that a new node has joined (e.g. on reception of Device-annce).

[0044] In a simplest embodiment, the list of ZED children can be included in every affected routing command sent by the router. In another embodiment, to limit the length of the respective routing frame, the ZED children list can only be included in selected affected routing messages, e.g. every Nth message, or depending on the polling frequency of the child (in every routing message if the child is fast polling or in a frequency matching the child's polling frequency) or the state the network is in: in the joining phase, when many devices are joining, it could be added in every affected routing message, and as the joining frequency gets lower—or the commissioning mode gets disabled on the network—the list be included less often.

[0045] As a further optimisation, the relation between the child and the parent could be preserved in the receiving remote nodes. Thus, when a change of the route to the parent or any of its children would be detected (e.g. a new route would be established or a route error reported), the routes to the parent and/or (other) children could be updated automatically, without the parent including the (complete) list of ZED children; the relationship could be preserved e.g. until the ZED child rejoins, the parent leaves the network or until another indication of parent change is received.

[0046] In case of RREP, the responding parent node could always include the list of ZED children—or only if triggered by the RREQ, e.g. by inclusion of another “ZED query” TLV— or by inclusion of the ZED list by the RREQ originator.

[0047] Furthermore, in very dense systems, where a router may serve multiple ZED children, the children list may be too long for a single routing command. Then it may need to be delivered in chunks, split over several messages. Alternatively, it only includes a selected subset of its ZED children, such that the children list fits a single routing command.

[0048] In some situations, e.g. when the parent detects that a new router node has joined (e.g. on reception of Device_annce with device type flag of the Capability information field set to FFD), it may be beneficial to not only include the short address of the ZED nodes of the router, but also their IEEE addresses; this will not only save the independent route discoveries for the children, but also the multiple unicast IEEE_addr_req.

[0049] Furthermore, the parent may only include the ZED children on a need to know basis, e.g. if it is aware of any bindings on or to a ZED child, or if RREQs have been generated on behalf of or received for the child, within a defined time period, or since its joining.

[0050] Equally, nodes receiving an MTORR with a child list could be selective as to routes to which children to store locally; e.g. using information about bindings and RREQs. They may need to overwrite a previously established route to the ZED child with the information received in the parent's routing frame. This may also lead to changing the routing table entry type, e.g. from AODV route (which needs to be repaired via a broadcast RREQ) to an MTORR route (which can be repaired by sending unicast route error message to the route destination, using the fact that any router neighbour should have a working route to a concentrator).

[0051] FIG. 2 provides block diagram of a Zigbee wireless router 10, comprising a controller 20 and a radio transceiver 30 arranged to communicate using the Zigbee wireless network protocol as used by various embodiments of the present invention. Optionally, the Zigbee wireless router comprises a routing table 40 for storing route information. Alternatively, the route information may be stored as a data structure in another storage means, such as a memory of the controller, known in the art.

[0052] FIG. 3A provides a flow-chart of a first variant of a method for execution by a Zigbee router node for use in a Zigbee wireless mesh network, wherein the router node is arranged to include 310 the addresses of its ZED children in its many-to-one route requests and optionally, the Zigbee router node is further arranged to include 320 the addresses of its ZED children in its (AODV) route replies.

[0053] FIG. 3B provides a flow-chart of a second variant of a method for execution by a Zigbee router node for use in a Zigbee wireless mesh network, wherein the router node is arranged to include 320 the addresses of its ZED children in its (AODV) route replies and optionally, the router node is further arranged to include 310 the addresses of its ZED children in its many-to-one route requests.

[0054] FIG. 4 provides a flow-chart of a further method, for configuring a Zigbee wireless mesh network, which method involves configuring (400) by assigning ZED status to a number of Zigbee wireless nodes having router functionality; and having a select number of Zigbee wireless routers in the Zigbee wireless network to warrant proper connectivity and redundancy to maintain requirements such as a minimum network connectivity to improve fault-tolerance (e.g. at least two paths (or another pre-determined number of paths) to every node).

[0055] The methods according to the invention may be implemented on a computer as a computer implemented method, or in dedicated hardware, or in a combination of both.

[0056] Executable code for a method according to the invention may be stored on computer/machine readable storage means. Examples of computer/machine readable storage means include non-volatile memory devices, optical storage medium/devices, solid-state media, integrated circuits, servers, etc. Preferably, the computer program product comprises non-transitory program code means stored on a computer readable medium for performing a method according to the invention when said program product is executed on a computer or a processing means comprised in a node or a network or a commissioning device as disclosed in the above-described embodiments.

[0057] Methods, systems and computer-readable media (transitory and non-transitory) may also be provided to implement selected aspects of the above-described embodiments.

[0058] The term “controller” is used herein generally to describe various apparatus relating to, among other functions, the operation of one or more network devices or coordinators. A controller can be implemented in numerous ways (e.g., such as with dedicated hardware) to perform various functions discussed herein. A “processor” is one example of a controller which employs one or more microprocessors that may be programmed using software (e.g., microcode) to perform various functions discussed herein. A controller may be implemented with or without employing a processor, and also may be implemented as a combination of dedicated hardware to perform some functions and a processor (e.g., one or more programmed microprocessors and associated circuitry) to perform other functions. Examples of controller components that may be employed in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs).

[0059] In various implementations, a processor or controller may be associated with one or more storage media (generically referred to herein as “memory,” e.g., volatile and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM, compact disks, optical disks, etc.). In some implementations, the storage media may be encoded with one or more programs that, when executed on one or more processors and/or controllers, perform at least some of the functions discussed herein. Various storage media may be fixed within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor or controller so as to implement various aspects of the present invention discussed herein. The terms “program” or “computer program” are used herein in a generic sense to refer to any type of computer code (e.g., software or microcode) that can be employed to program one or more processors or controllers.

[0060] The term “network” as used herein refers to any interconnection of two or more devices (including controllers or processors) that facilitates the transport of information (e.g. for device control, data storage, data exchange, etc.) between any two or more devices and/or among multiple devices coupled to the network.

[0061] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items.