EP-3854039-B1 - A METHOD FOR ADDING REDUNDANT RELAY NODES DURING PATH DISCOVERY PROCEDURE OF A MESH NETWORK

Inventors

• ZHANG, JINGCHENG
• RIMHAGEN, THOMAS
• DI MARCO, Piergiuseppe

Dates

Publication Date

20260506

Application Date

20190920

Claims (10)

1. A method, being performed by a sender of an extended path reply message, EPREP message (SE), for setting up a path with one or more selected relaying nodes (SR) and one or more redundant relaying nodes (RR) from a path originator (PO) to a path destination (PD), where the path originator (PO), the one or more selected relaying nodes (SR), the one or more redundant relaying nodes (RR) and path destination (PD) participates in a mesh network, wherein the sender is any of the path destination (PD) and the one or more selected relaying nodes (SR), the method comprising; assign a selected relay node for the path (131, 151) ; assign one or more redundant relay nodes for the path (132, 152); generate an EPREP message containing an address for each of the assigned one or more redundant relay nodes and an address of the assigned selected relay node; and send the EPREP message (133, 153) as a broadcast message.
2. The method according to claim 1, where assigning the redundant relay is based on determining that the redundant relay node (RR) must have links to both the sender of the EPREP Message (SE) and the selected relay node (SR).
3. The method according to claim 2, where the determining is based on obtaining neighbour table information from either the selected relay node (SR), the redundant relay node (RR) or both.
4. The method according to claim 1, further comprising; starting a notification timer (154) for each redundant relay node.
5. A device (NODE, SE), for setting up a path with one or more selected relaying nodes (SR) and one or more redundant relaying nodes (RR) from a path originator (PO) to a path destination (PD), where the path originator (PO), the one or more selected relaying nodes (SR), the one or more redundant relaying nodes (RR) and path destination (PD) are configured to participate in a mesh network, wherein the device (NODE, SE) is any of the one or more selected relaying nodes (SR) and the path destination (PD), the device comprising; an assigning unit (U104) being configured to assign a selected relay node for the path (131, 151), and assign one or more redundant relay nodes for the path (132, 152); a controller unit (U100) being configured to generate an extended path reply message, EPREP message, containing an address for each of the assigned one or more redundant relay nodes and an address of the assigned selected relay node; and a transceiver unit (U110) being configured to send the EPREP message (133, 153) as a broadcast message.
6. The device (NODE, SE) according to claim wherein the assigning unit is further configured to assign one or more redundant relay nodes based on a determining unit (U102) being configured to determine that the redundant relay node (RR) must have links to both the sender of the EPREP Message (SE) and the selected relay node (SR).
7. The device (NODE, SE) according to claim where the determining unit (U102) is further configured to obtaining neighbour table information from either the selected relay node (SR), the redundant relay node (RR) or both.
8. The device (NODE, SE) according to claim further comprising; the controller unit (U100) starting a notification timer (154) for each redundant relay node.
9. A computer program (2020) comprising instructions, which, when executed on a device (NODE,SE), causes the device (NODE,SE) to execute any of the methods in claims 1 to 4.
10. A computer program product (2010) comprising a computer program (2020) according to claim 9, and a computer readable storage medium (2030) on which the computer program is stored.

Description

TECHNICAL FIELD Embodiments presented herein relate to a device, a method therein, a computer program, and a computer program product. Specifically, they relate to improving the success rate of transmitting messages on paths/routes created and maintained by routing algorithms in a mesh network, by assigning redundant relay nodes. BACKGROUND Mesh networking is a key architecture for Internet of Things (IoT). In this network topology all nodes/devices can communicate with each other; either through direct message exchange or via intermediate nodes that help forward the message from source to destination. This is often more cost effective and easier to implement than having to use additional gateway devices or access points which often need additional equipment and more extensive planning. Below follows an introduction on some terminology that is commonly used in this and related fields. An ad hoc network is put together for a specific purpose and is often, but not always, of a temporary nature. (Ad hoc is Latin and means "for this purpose".) Ad hoc network sometimes refers to any set of networks where the nodes/devices have equal status in the network and are free to associate and/or communicate with any other node/device. Sometimes these nodes/devices are referred to as ad hoc nodes/devices. A wireless ad hoc network is a decentralized type of wireless network were the nodes/devices communicates wirelessly. Sometimes these nodes/devices are referred to as wireless nodes/devices or wireless ad hoc nodes/devices. The network is referred to as ad hoc because it does not rely on a preexisting infrastructure, such as base stations, access points or routers, which are normally present in managed (comprising infrastructure) wireless networks like mobile telephony networks. Instead, each node/device participates in routing by forwarding/relaying data for other nodes/devices. The determination of which nodes/devices should forward data to which other nodes/devices is made dynamically based on network connectivity. A MANET (mobile ad hoc network) is a self-configuring infrastructure-less network of nodes/devices that are mobile and wirelessly connected. Sometimes these nodes/devices are referred to as mobile nodes/devices, wireless nodes/devices or mobile ad hoc nodes/devices. A MANET is a kind of wireless ad hoc network, but a MANET also specifically has to deal with the problems introduced by the mobility of the nodes/devices. Each node/device in a MANET is free to move independently in any direction and will therefore change its links to other devices frequently. Each device must forward traffic unrelated to its own use, and therefore act as a router. The primary challenge in building a MANET is equipping each device to continuously maintain the information required to properly route traffic. Such networks may operate by themselves or may be connected to the larger Internet. A mesh network is a network topology in which all nodes/devices cooperate in the distribution of data, typically by each node/device forwarding/relaying data for the network. The nodes/devices in a mesh network are sometimes referred to as mesh nodes/devices. A mesh network whose nodes/devices are all connected directly to each other is usually referred to as a fully connected mesh network. In this topology it is not necessary to use forwarding/relaying, unless for purposes like redundancy and/or load traffic load distribution. In a partially connected mesh network, one or more nodes/devices are not connected directly to all other nodes/devices. In a partially connected mesh network forwarding/relaying of messages is necessary in order to allow all nodes/devices to reach all other nodes/devices. This is a very common network topology when the nodes/devices are wirelessly connected. Ad hoc networks, wireless ad hoc networks and MANETs often use a mesh network topology. The nodes/devices in a mesh network does not necessarily have to be neither mobile nor wirelessly connected. Although the mesh network topology is mostly used in wireless situations, the concept is also applicable to wired networks and software interaction. The network types, and topology, mentioned above can be designed using a routing technique or a flooding technique. Any of those techniques can incorporate multipath routing. Multipath routing is the routing technique of using multiple alternative paths through a network, which can yield a variety of benefits such as fault tolerance, increased bandwidth, or improved security. Multipath routing can also be referred to as path redundancy and path diversity. When using a routing technique, a packet/message is propagated along a path, by hopping from node/device to node/device until the destination is reached. This is done by the having the intermediate nodes relaying/forwarding the packet/message. To ensure all its paths' availability, a mesh network must allow for continuous connections and reconfiguration around broken or blocke