Downlink routing solution for wireless communication networks

Abstract

The present invention relates to a routing system (300) for a wireless communication network (202). The routing system (300) includes one or more head devices (302) that participate in routing operations in the wireless communication network (202), each head device (302) having one or more member devices (304a-304n) and one or more destination devices (306a-306n). At least one head device (302) routes an uplink data packet (DP) generated by a destination device (306a) to the uplink data packet (DP). U ) from the member device 304a, the received uplink data packet (DP U ), stores link information indicating the link between the destination device (306a) and the member device (304a) in a routing table, and forwards a downlink data packet (DP) addressed to the destination device (306a). D ) in response to receiving the downlink data packet (DP D If link information related to the destination device (306a) that is the destination of the downlink data packet (DP) is stored in the routing table of the head device (302), the downlink data packet (DP) is forwarded to the destination device (306a) based on the routing table of the head device (302). D The downlink data packet (DP) is transmitted only to the member device (304a) to which the destination device (306a) is linked. D The present invention also relates to a routing method, a head device, a computer program product, and a computer-readable medium.

Description

[Technical Field]

[0001] The present invention relates generally to the technical field of wireless communication networks, and more particularly to data packet routing in wireless communication networks. [Background technology]

[0002] Some wireless communication network topologies, such as wireless sensor networks (WSNs) and wireless communication networks based on the DECT-2020 (Digital European Cordless Telecommunications) standard, support device densification and autonomous routing, providing the ability to rapidly adapt to changes in the device's environment and propagation conditions. In such networks, autonomous routing is based on route cost values, which provide devices with efficient routes in the uplink direction. Routing solutions based on comprehensive routing tables require new routing information to be propagated to each affected router device in the wireless communication network when a change occurs in the device's environment, or routes must be learned by each affected router device when a new packet is sent. This can result in excessive transmissions and potentially disrupt the wireless communication network.

[0003] Typically, devices used in the Internet of Things (IoT) are severely constrained in terms of processing power, energy consumption, and memory. Therefore, recording each device's route in a routing table on each routing device is not worthwhile in terms of network traffic overhead, power consumption, and memory requirements. In a wireless communication network using autonomous cost-based routing, when a device sends an uplink data packet in the uplink direction, it knows the next hop to reach the sink device via the most efficient route. The sink device acts as the wireless interface for a gateway device, which acts as a gateway between the wireless communication network and one or more external networks. However, in the downlink direction, it does not have information about the direct route to reach the device.

[0004] One solution is to use a flooding mechanism, which forwards downlink packets to all devices operating in routing mode until they reach the destination device. FIG. 1 schematically illustrates an example of flooding-based downlink routing of downlink data packets, where the downlink packets are transmitted from a sink device 102 to a destination device 106. The flooding-based routing in the example of FIG. 1 is member-only flooding, which is a special case of flooding. In the example of FIG. 1, the destination device 106 is a non-router device. Other non-router devices in the wireless communication network 100 are indicated by reference numeral 108. The topology of the wireless communication network 100 in the example of FIG. 1 is a cluster-tree topology. The downlink packets are forwarded, i.e., flooded, to all router devices 104, regardless of whether they reach the destination device 106. If the non-router devices (i.e., leaf nodes) 108 and the destination device 106 are router devices with router member devices, only the devices 104 subsequent to the destination device 106 that may be routers cannot participate in the flooding. Therefore, flooding mechanisms are inefficient and consume energy and spectrum resources for unnecessary transmissions and receptions. As the size of a wireless communication network increases, the performance of the wireless communication network degrades exponentially because more transmissions are forwarded to branches of the wireless communication network where no destination device exists. The branches in the topology of a wireless communication network increase exponentially as the size and number of hops in the wireless communication network increase, reducing the efficiency of flooding routing. In a non-limiting example, in a fully loaded wireless communication network with three hops, assume that each device within three hops is a routing device and that each routing device has five devices connected to it. This means that there are a total of 2,500 devices in the wireless communication network. Ideally, only four transmissions are required to send a packet to a destination device three hops away. However, when using a flooding mechanism, the wireless communication network generates a total of 1,875 transmissions (one for each routing device).

[0005] Some IoT applications, such as data-collection-focused WSNs, may require very little downlink traffic, so the inefficiency of flooding-based routing in the downlink direction is not a problem in all situations. However, there are many situations where downlink traffic requirements increase. For example, in situations where end-to-end reliability is required using end-to-end automatic repeat request (ARQ), downlink traffic can be generated every time a device transmits a packet in the uplink direction. Also, when delivering configuration packages to devices, for example, the configuration package is too large for a single radio link packet, requiring multiple downlink routings for each device. Therefore, it is important to minimize the number of transmissions to avoid overloading the wireless communication network. Summary of the Invention [Problem to be solved by the invention]

[0006] The following presents a simplified summary in order to provide a basic understanding of some aspects of various embodiments of the invention. This summary is not an exhaustive overview of the invention, and it is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of example embodiments of the invention.

[0007] The object of the present invention is to provide a routing system, a routing method, a head device, a computer program, and a computer-readable medium for a wireless communication network, which improve downlink data packet routing efficiency in a wireless communication network.

[0008] The object of the invention is achieved by a routing system, a routing method, a head device, a computer program and a computer-readable medium as defined by the respective independent claims. [Means for solving the problem]

[0009] According to a first aspect, there is provided a routing system for a wireless communication network including a plurality of communication devices, the routing system including one or more head devices participating in routing operations in the wireless communication network, each head device having one or more member devices, and one or more destination devices, the one or more head devices, the one or more member devices, and the one or more destination devices belonging to the plurality of communication devices, and in response to receiving, from a member device belonging to the one or more member devices, an uplink data packet generated by a destination device belonging to the one or more destination devices, at least one head device of the one or more head devices routes the received uplink data packet to a destination device belonging to the one or more member devices. forwarding the downlink data packet in an uplink direction, and storing link information representing a link between the destination device and the member device in a routing table; in response to receiving a downlink data packet addressed to a destination device belonging to the one or more destination devices, if link information related to the destination device that is the destination of the downlink data packet is stored in the routing table of the head device, forwarding the downlink data packet only to the member device to which the destination device that is the destination of the downlink data packet is linked, based on the routing table of the head device; updating the routing table, wherein updating the routing table includes prioritizing the storage of the link information based on a Quality of service (QoS) value included in the link information and / or downlink response information included in the link information.

[0010] Furthermore, if the link information related to the destination device that is the destination of the downlink data packet is not stored in the routing table of the head device, the head device may be configured to forward the received downlink data packet to all router member devices, or to broadcast the received downlink data packet to all communication devices within a wireless range including the router member device.

[0011] The link information may include at least information linking the address of the destination device and the address of the member device.

[0012] At least one head device may be a router device that operates in the role of a router in the wireless communication network, or a sink device configured to operate as a wireless interface of a gateway device that operates as a gateway between the wireless communication network and one or more external networks.

[0013] The head device, which is the sink device, may be configured to store the routing table in a memory unit of a management entity of the one or more external networks, or to transmit the routing table to be stored in a memory unit of a management entity of the one or more external networks.

[0014] Alternatively or additionally, updating the routing table may include deleting the stored link information from the routing table based on the time elapsed since the link information was stored, updating previously stored link information with new link information in response to receiving new link information, deleting the oldest link information from the routing table when the routing table reaches a maximum size, and / or learning when new link information should be stored based on a routing header in a packet header of the received uplink data packet.

[0015] The downlink response information may indicate whether a downlink response is required.

[0016] The downlink response information may include a higher layer protocol indication that a downlink response is expected.

[0017] The higher layer protocol indication may include an indication that the uplink data packet is an uplink automatic repeat request (ARQ) polling packet.

[0018] Alternatively or additionally, the uplink data packet may include a hop count field containing a hop count value, the hop count value being incremented by all router devices of the wireless communication network that forward the uplink data packet.

[0019] Further, the downlink data packet may include a downlink hop limit field containing a hop limit value, and the hop limit value may be initially set to correspond to the cumulative hop count value contained in the hop count field of the uplink data packet.

[0020] Furthermore, the hop limit value may be decremented by all router devices of the wireless communication system that forward the downlink data packet, and when a router device of the wireless communication system receives a downlink data packet with the hop count value of zero, the router device may not forward the downlink data packet unless the downlink data packet is addressed to a member device of the router device.

[0021] The destination device may be configured to generate the uplink data packet in response to receiving a downlink indication packet.

[0022] The downlink instruction packet may be delivered to the destination device by flooding, and after receiving the uplink data packet generated by the destination device in response to receiving the downlink instruction packet, the head device may be configured to forward one or more subsequent downlink data packets destined for the destination device based on the link information stored in the routing table of the head device.

[0023] According to a second aspect, there is provided a wireless communication network, said wireless communication network including the routing system described above.

[0024] According to a third aspect, there is provided a routing method for a wireless communication network, the method including the following steps: presenting one or more head devices participating in a routing operation in the wireless communication network, each head device having one or more member devices and one or more destination devices, the one or more head devices, the one or more member devices, and the one or more destination devices belonging to a plurality of communication devices of the wireless communication network; in response to receiving, by at least one head device, from a member device belonging to the one or more member devices, an uplink data packet generated by a destination device belonging to one or more destination devices, forwarding, by the at least one router device, the received uplink data packet in an uplink direction, and establishing a link between the destination device and the member device; storing link information representing a link in a routing table; in response to receiving, by at least one head device, a downlink data packet destined for a destination device belonging to the one or more destination devices, if link information related to the destination device that is the destination of the downlink data packet is stored in the routing table of the head device, forwarding, by the at least one head device, the downlink data packet only to a member device to which the destination device that is the destination of the downlink packet is linked based on the routing table of the head device; updating, by the at least one head device, the updating of the routing table including prioritizing storing of the link information based on a Quality of service (QoS) value included in the link information and / or downlink response information included in the link information.

[0025] According to a fourth aspect, there is provided a head device for a wireless communication network, the head device being configured to participate in a routing operation in the wireless communication network, the head device including a controller and a wireless radio for operating as a wireless node device, wherein the head device, in response to receiving, by the wireless radio, an uplink data packet generated by a destination device from a member device belonging to one or more member devices of the head device, forwards, by the wireless radio, the received uplink data packet in an uplink direction, and stores, by the controller, link information representing a link between the destination device and the member device in a routing table; in response to receiving, by the wireless radio, a downlink data packet destined for a destination device, if link information related to the destination device that is a destination of the downlink data packet is stored in the routing table of the head device, forwards, by the wireless radio, the downlink data packet only to a member device to which the destination device that is a destination of the downlink data packet is linked, based on the routing table of the head device; updating, by the controller, the routing table, and updating the routing table includes: updating, by the controller, a Quality of Service (QoS) included in the link information; The method may further include prioritizing storage of the link information based on a downlink service value and / or downlink response information included in the link information.

[0026] According to a fifth aspect, there is provided a routing method for a head device as described above, the method comprising: in response to receiving, by a wireless communication device of the head device, an uplink data packet generated by a destination device from a member device belonging to one or more member devices, the wireless communication device of the head device forwards the received uplink data packet in an uplink direction; and, by the controller of the head device, storing link information representing a link between the destination device and the member device in a routing table; in response to receiving, by the wireless communication device of the head device, a downlink data packet destined for the destination device, if link information related to the destination device that is the destination of the downlink data packet is stored in the routing table of the head device, forwarding, by the wireless communication device of the head device, the downlink data packet only to a member device to which the destination device that is the destination of the downlink data packet is linked, based on the routing table of the head device; updating, by the controller of the head device, the routing table, The method includes steps including prioritizing the storage of the link information based on a downlink service value and / or downlink response information included in the link information.

[0027] According to a sixth aspect, there is provided a computer program comprising instructions that, when the computer program is executed by a computer, cause the computer to perform at least each step of the method set out above.

[0028] According to a seventh aspect, there is provided a tangible, non-volatile computer readable medium, said computer readable medium comprising the computer program described above.

[0029] Various exemplary and non-limiting embodiments of the present invention, both as to structure and method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplary and non-limiting embodiments when read in connection with the accompanying drawings.

[0030] The verbs "to comprise" and "to include" are used in this document in an open-ended manner, neither excluding nor requiring the presence of unrecited features. Features recited in dependent claims may be freely combined with each other, unless expressly stated otherwise. Furthermore, it is to be understood that the use of "a" or "an", i.e., the singular, throughout this document does not exclude the plural.

[0031] Embodiments of the present invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. [Brief explanation of the drawings]

[0032] [Figure 1] 1 illustrates a schematic diagram of an example of flooding-based downlink routing of downlink data packets; [Figure 2] 1 illustrates an example of a wireless communication environment in which a routing system may operate. [Figure 3A] 1 illustrates a schematic diagram of an example routing system operating in a wireless communication network; [Figure 3B] 2 illustrates a schematic example of uplink routing of uplink data packets by a routing system in an uplink direction of a wireless communication network; [Figure 3C] 2 illustrates a schematic example of downlink routing of downlink data packets by a routing system in the downlink direction of a wireless communication network; [Figure 3D] 2 illustrates schematically another example of downlink routing of downlink data packets by a routing system in the downlink direction of a wireless communication network; [Figure 3E] 10 illustrates schematically yet another example of downlink routing of downlink data packets by a routing system in the downlink direction of a wireless communication network; [Figure 3F] 10 illustrates schematically yet another example of downlink routing of downlink data packets by a routing system in the downlink direction of a wireless communication network; [Figure 4] 1 illustrates a schematic diagram of an example of a routing method for routing data packets in a wireless communication network by a routing system. [Figure 5] 10 shows a schematic diagram of an example of simulated performance of a routing method. [Figure 6] 1 illustrates a schematic diagram of an example of the working parts of a wireless radio communication device; DETAILED DESCRIPTION OF THE INVENTION

[0033] 2 illustrates an example of a wireless communication environment in which routing system 300 may operate. The environment includes a wireless wireless communication network (system) 202 that includes multiple wireless wireless communication devices (nodes) 204a, 204b, and 204c. The devices 204a, 204b, and 204c operate in the same geographic region, such as the illustrated environment, and over the same spectrum, which may include one or more frequency bands. Each of the one or more frequency bands may include one or more frequency channels. The use of the same spectrum enables bidirectional wireless communication between the devices 204a, 204b, and 204c in network 202, such that wireless transmissions transmitted by one device 204a, 204b, and 204c can be received by another device 204a, 204b, and 204c, and vice versa.

[0034] The routing system 300 may be applied to any wireless radio communication network 202 that uses packet transmission for communication, i.e., data exchange. Preferably, the routing system 300 may be applied to any wireless radio communication network that may be used for multi-hop communication between devices 204, i.e., packets may be delivered via at least two consecutive radio links. The routing system 300 may be applied to a radio communication network 202 that complies with the Digital European Cordless Telecommunications (DECT-2020NR) standard. Some non-limiting examples to which the routing system 300 may be applied may include, but are not limited to, a wireless multi-hop network, a wireless mesh network, such as a wireless sensor network (WSN), a Bluetooth® Low Energy (BLE) mesh network, a Zigbee® network, a Thread network, a public land mobile network (PLMN), a wireless local area network (WLAN), a low power wide area network (LPWAN), a cellular-based local area network, a cellular network, and / or any other wireless network. An example of a WSN is described in Patent Publication US 8,064,363 B2.

[0035] The DECT-2020NR standard is a radio access technology developed by ETSI. DECT-2020NR supports Massive Machine Type Communications (mMTC) and Ultra-Reliable Low Latency Communications (URLLC). At the physical (PHY) layer, the key technology components of DECT-2020NR are Orthogonal Frequency Division Multiplexing (OFDM), Adaptive Modulation and Coding (MCS), advanced channel coding schemes (Turbo, LDPC, and convolutional coding), Hybrid Automatic Repeat Request (HARQ) for both scheduled and contention-based transmission, and support for multi-antenna transmission with different Multiple Input Multiple Output (MIMO) streams. At the media access (MAC) layer and on the system side, the key technology components of DECT-2020NR are support for a large number of Internet of Things (IoT) sensors, actuators, and other industrial applications; support for mesh network topologies; support for very low latency URLLC communications (a typical application might be wireless microphones); operation in unlicensed frequencies; and support for multiple overlapping uncooperative networks with cognitive radio capabilities to share spectrum resources between multiple networks.

[0036] As explained above, each device 204a, 204b, 204c can communicate wirelessly with at least one other device 204a, 204b, 204c via its radio 636. This means that if each device 204a, 204b, 204c can send at least one message to, and receive at least one message from, another device 204a, 204b, 204c in network 202, then each device 204a, 204b, 204c can operate as a transmitter, a receiver, or a transmitter-receiver.

[0037] The network 202 may also include at least one gateway device 205, e.g., one, two, three, four, or more gateway devices. Each gateway device 205 acts as a gateway between the network 202 and other external networks 206 (e.g., the Internet) and distributes data within and from the network 202. Each gateway device 205 communicates with at least one sink device (node) 204a, e.g., one, two, three, four, or more sink devices, and each sink device 204a acts as a wireless interface for the gateway device 205 within the network 202. The at least one sink device 204a belongs to multiple devices 204a, 204b, and 204c of the network 202. Each sink device 204a may be located in physical connection with the gateway device 205 or may be located separately in a different part of the network 202. If the gateway 205 includes multiple sink devices 204 a , one may be located connected to the gateway device 205 and others may be located separately in different parts of the network 202 .

[0038] The sink device 204a typically has a specific role of routing data packets from the network 202 to the gateway device 204 and / or to the network 202. The sink role does not need to be fixed, but for example, if the connection to the gateway device 205 is lost or if the gateway device 205 cannot provide service (e.g., if the gateway device 205 loses its connection to the Internet), the sink device 204a can change its role to that of a router. The other node devices 204b and 204c can operate in different fixed or non-fixed roles in the network 202. The other devices 204b and 204c in the network 202 are router devices (routers) 204b, i.e., devices operating in the role of a router, and non-router devices (non-routers) 204d, i.e., devices operating in the role of a non-router, depending on whether the devices need to participate in data packet forwarding. One method for selecting the role of a router or a non-router can follow, for example, the method described in U.S. Patent Publication No. 10,499,264. The sink device 204a and the router device 204b of the network 202 can participate in routing operations, ie, routing of data packets.

[0039] Each router device 204b maintains connectivity for the network 202 and routes (forwards) data (e.g., data packets) for the other devices 204a, 204b, and 204c as needed. Like the sink 204a and router device 204b, each non-router device 204c can transmit its own data (e.g., data packets) and receive data (e.g., data packets) directed to it, but the non-router device 204c does not route data (e.g., data packets) for the other devices 204a, 204b, and 204c. Each device in the network 202 can operate as at least a router 204b or a non-router device 204c. Alternatively, at least some of the devices in the network can operate as router devices 204b or non-router devices 204c, and one or more of the devices in the network 202 can operate only as router devices 204b or only as non-router devices 204c.

[0040] Network 202 includes devices 204b, 204c where it is not possible or preferred for all devices 204b, 204c to communicate directly with sink device 204a due to radio conditions, such as long distances between devices 204a, 204b, 204c, interference or signal attenuation between devices 204a, 204b, 204c, or limited radio range, in which case it is necessary or preferred by devices 204a, 204b, 204c to use multi-link (multi-hop) communication between each device 204b, 204c and sink device 204a.

[0041] Uplink data packets generated by one or more of the plurality of communication devices of the wireless communication network 202 are routed in an uplink direction within the wireless communication network 202, i.e., outward from the wireless communication network 202, for example, to one or more external networks 206. Downlink data packets generated for one or more of the plurality of communication devices of the wireless communication network 202 are routed in a downlink direction within the wireless communication network 202, i.e., for example, from one or more external networks 206 into the wireless communication network 202.

[0042] FIG. 3A schematically illustrates an example of a routing system 300 operating in a wireless communication network 202. The routing system 300 is used to route uplink and downlink data packets in the wireless communication network 102. The number of hops in the routing system 300 is not limited; that is, the routing system 300 may have any number of hops, for example, two, three, four, or more hops. In the example of FIG. 3A, the wireless communication network 202 is implemented in a cluster-tree topology. However, the present invention is not so limited, and the wireless communication network 202 may be implemented in other topologies, such as a star topology or a mesh topology other than a cluster tree. The routing system 300 includes one or more head devices 302 that participate in routing operations, and each head device 302 in the system 300 has one or more member devices 304a-304n. One or more member devices 304a-304n are associated with a respective head device 302 and can operate as member devices of the head device 302. After association, the head device 302 recognizes, i.e., knows, the addresses of one or more member devices 304a-304n of the head device 302. The routing system 300 further includes one or more destination devices 306a-306n. In other words, the routing system includes one or more head devices 302, one or more member devices 304a-304n of the one or more head devices 302, and one or more destination devices 306a-306n. The one or more head devices 302, the one or more member devices 304a-304n, and the one or more destination devices 306a-306n belong to multiple communication devices 204a, 204b, and 204c of the wireless communication network 202. In a cluster tree topology implementation of the network 202, each destination device 306a-306n of the system 300 is on the same branch of the network 202 as one member device 304a-304n of the system 300.For example, in the example of FIG. 3A , destination devices 306a and 306b are on the same branch of network 202 as member device 304a, destination device 306c is on the same branch of network 202 as member device 304b, and destination device 306n is on the same branch of network 202 as member device 304n. In the example of FIG. 3A , destination devices 306a-306n are non-router devices 204c. However, one or more of destination devices 306a-306n of routing system 300 may include router device 204b and / or non-router device 204c. In the example of FIG. 3A , member devices 304a-304n are router device 204b. However, one or more of member devices 304a-304n of routing system 300 may include router device 204b, i.e., router member device, and / or non-router device 204c, i.e., non-router member device. 3A, the head device 302 is the sink device 204a. However, one or more head devices 302 of the routing system 300 may include the sink device 204a and / or the router device 204b. Hereinafter, the present application will mainly use one head device 302 and one destination device 306a that belong to the routing system 300, operate within the network 202, and have one or more member devices 304a-304n that form device groups 302, 304a-304n, and 306a. However, these devices 302, 304a-304n, and 306a correspond to devices 204a, 204b, and 204c. The routing system 300 may also include multiple other devices 204a, 204b, 204c, 306b-306d that participate in forming the group, in which case the group includes devices 204, 204b, 204c, 302, 304a-304n, 306a, 306b-306d. The head device 302 can be a router device 204b or a sink device 204a.

[0043] 4 is a schematic diagram illustrating an example of a routing method for routing data packets within the wireless communication network 202 using the routing system 300 described above. The routing method is illustrated as a flowchart. The routing method will be described primarily using the routing system 300 including one head device 302 having one or more member devices 304a-304n and one destination device 306a. The routing system 300 may further include at least one other head device 302, e.g., one, two, three, four, or more other head devices 302, each of which has one or more member devices 304a-304n, e.g., one, two, three, four, or more member devices 304a-304n, and / or at least one destination device 306a-306n, e.g., one, two, three, four, or more destination devices 306a-306n. Although the routing method will be described using a routing system 300 including one head device 302 having one or more member devices 304a-304n and one destination device 306a, each head device 302 of the routing system 300 may be independently configured to perform one or more method steps (i.e., features) of the routing method associated with the head device 302 as described for the one head device 302. Similarly, each member device 304a-304c of the routing system 300 may be independently configured to perform one or more method steps (i.e., features) of the routing method associated with one or more member devices 304a-304c as described for the one or more member devices 304a-304c. Similarly, each destination device 306a-306n of the routing system 300 may be independently configured to perform one or more method steps (i.e., functions) of the routing method associated with the destination device 304a-304n as described for the destination device 306a. As will be described, features of the routing method associated with the head device 302 may be applied (ie, implemented) by at least one router device 204 b of the network 202 .Alternatively or additionally, features of the routing method associated with head device 302 as will now be described may be applied by at least one sink device 204 a of network 202 .

[0044] In step 410, the head device 302 receives an uplink data packet DP generated by a destination device 306a belonging to one or more destination devices 306a to 306n of the system 300 from a member device 304a belonging to one or more of the member devices 304a to 304n. U Receives uplink data packet DP U The uplink data packet DP may include, for example, but is not limited to, sensor measurement data and / or control data. The sensor measurement data may be reported periodically and / or upon a predetermined event, such as when a temperature exceeds a threshold. The control data may include, for example, an acknowledgment in response to receiving a downlink packet in an ARQ. FIG. 3B illustrates the routing of an uplink data packet DP by the routing system 300. U 3B illustrates an example of routing in the uplink direction of a destination device 306a receiving an uplink data packet DP. The example routing system 300 of FIG. 3B corresponds to the example routing system 300 of FIG. 3A. In the example of FIG. 3B, a destination device 306a receives an uplink data packet DP. U and generates the generated uplink data packet DP U in the uplink direction to the member device 304a, which is the next router device 204b in the same branch as the destination device 306a of the network 202. The member device 304a then forwards the uplink data packet DP U In response to receiving the uplink data packet DP U The member device 304a transfers the uplink data packet DP UAlternatively, there may be at least one other router device 204b of the network 202 between the destination device 306a and the member device 304a in the same branch of the network 202. In that case, the uplink data packet DP U is routed from the destination device 306a through the at least one other router device 204b in the network 202 to the member device 304a.

[0045] In step 420, the uplink data packet DP generated by the destination device 306a in step 410 is U In response to receiving the received uplink data packet DP from the member device 304a, the head device 302 U In the uplink direction, the destination device 306a transfers the uplink data packet DP to the member device 304a, and stores link information indicating the link between the destination device 306a and the member device 304a in the routing table. U , and from there the head device 302 receives the uplink data packet DP generated by the destination device 306a. U The link information may include any information linking the address of the destination device 306a to the address of the member device 304a receiving the uplink data packet DP. The link information may include, for example, at least information linking the address of the destination device 306a to the address of the member device 304a. According to one example, the address of the destination device 306a and the address of the member device 304a are media access control (MAC) addresses. The link information may include any information linking the address of the destination device 306a to the address of the member device 304a receiving the uplink data packet DP. U For example, the further link information may include a hop count value, a Quality of Service (QoS) value, and / or downlink response information indicating whether a downlink response is required. The downlink response information may be, for example, an uplink data packet DP UThe ARQ poll packet includes an upper layer protocol indication that a downlink response is expected, such as an indication that the ARQ poll packet is an uplink ARQ poll packet. When one device, e.g., a first device, sends an ARQ poll packet (either uplink or downlink) to another device, e.g., a second device, the first device expects the second device to send a response to the ARQ poll packet. An uplink ARQ poll packet may be sent in the uplink direction, e.g., to obtain a reception status of the transmitted uplink data and / or to establish or refresh a route for an expected upcoming response in the downlink direction. A downlink ARQ poll packet may be sent in the downlink direction, e.g., to prompt the device to send an uplink response that establishes or refreshes a route for potentially transmitting one or more further downlink packets, as described later in this application. This further link information may be used, at least in part, in updating a routing table, e.g., as described later in this application. The head device 302 may store the routing table in a memory unit of the head device 302. Alternatively, if the head device 302 is a sink device 204a, the head device 302 may store the routing table in a memory unit, such as a database, of a management entity (i.e., backend) of one or more external networks 206, or may transmit the routing table to be stored in a memory unit of the management entity of one or more external networks 206. The management entity may be any computing entity, such as a cloud server. The link information stored in the routing table may be distributed to the management entity via the gateway device 205. The term "routing table" is used throughout this application to refer to a general information structure used to temporarily store link information in the memory of a communication device. In other words, the routing table may be permanently stored, and the link information may be temporarily stored in the routing table. The example of FIG. 3B illustrates a received uplink data packet DP by the head device 302. UIn the case where the head device 302 is the router device 204b, the head device 302 forwards the received uplink data packet DP U to the next router device 204b in the same branch in the network 202 as the head device 302 in the uplink direction, or to the sink device 204a if the next device in the same branch in the network 202 as the head device 302 in the uplink direction is the sink device 204a. If the head device 302 is the sink device 204a, the head device 302 forwards the received uplink data packet DP U to the gateway device 205, which then forwards the uplink data packet DP U outside the network 202 to one or more external networks 206, for example to a management entity of the one or more external networks 206.

[0046] According to one example, the head device 302 may update the routing table. Updating the routing table may include deleting stored link information from the routing table based on the time elapsed since the link information was stored. Alternatively or additionally, updating the routing table may include updating previously stored link information with each new link information in response to receiving the new link information. Alternatively or additionally, updating the routing table may include deleting the oldest link information from the routing table when the routing table reaches a maximum size. Alternatively or additionally, updating the routing table may include deleting the oldest link information from the routing table in response to receiving uplink data packets DP UThe routing header may include learning when new link information should be stored in the routing table based on the routing header in the packet header of the destination device 306a. The routing header may, for example, include maximum retention time information indicating the time for which link information is considered valid and maintained by the head device 302. The destination device 306a may add this maximum retention time information based on its mobility history, i.e., how often it has changed next-hop head devices, knowledge of application activity, i.e., how often it sends uplink data packets, or QoS values. Alternatively or additionally, the routing header may include, for example, current packet travel time information. The head device 302 may subtract the current packet travel time indicated in the routing header from the maximum retention time indicated in the routing header to obtain the same maximum retention time information that the destination device 306a added to the routing header. By way of a non-limiting example, when the destination device 306a receives an uplink data packet DP U and in the routing header indicates that the link information is considered valid for 1 second, i.e., the maximum storage time information is 1 second, and the current packet travel time is 100 microseconds, then the uplink data packet DP UThe head device 302 receiving the packet may define a maximum storage time of currently 900 microseconds. Alternatively or additionally, updating the routing table may include prioritizing storage of link information based on a QoS value if the link information includes a QoS value, and / or prioritizing storage of link information based on downlink response information if the link information includes downlink response information. For example, link information including a higher QoS value may be assigned a higher priority than link information including a lower QoS value. According to another example, link information including downlink response information indicating that a downlink response is required may be assigned a higher priority than link information including downlink response information indicating that a downlink response is not required. For example, link information associated with an ARQ polling packet may be prioritized over link information associated with other data packets. When storing link information, link information with a higher priority may be stored first. In other words, link information with a lower priority may be overwritten or deleted first if the routing table reaches a maximum size due to, for example, memory capacity limitations. The destination device 306a may change the route to the head device 302 over time. Routing table updates allow you to keep your routing tables up to date.

[0047] Alternatively or additionally, according to one example, the head device 302 may, in step 420, receive an uplink data packet DP generated by the destination device 306. UThe link information may be stored in the routing table only if a response to the routing table, e.g., a downlink data packet, is expected soon (immediately). This is particularly beneficial when the head device 302 is a router device 204b in the network 202, because the router device 204b may have a limited memory capacity, which may limit the amount of link information that the router device 204b can store in the routing table. Typically, when the head device 302 is a sink device 204a, the memory capacity is not as limited as when the head device 302 is a router device 204b, especially when the sink device 204a stores the routing table in a memory unit of a management entity of one or more external networks 206, or transmits the routing table to be stored in a memory unit of a management entity of one or more external networks 206. An immediate response may be required, for example, when a response to the uplink data packet DP is expected soon (immediately). U The indication of an immediate response may be an implicit indication or an explicit indication. By way of non-limiting example, the implicit indication of an immediate response may be included in, for example, a higher protocol layer. By way of non-limiting example, in a wireless communication network 202 conforming to the DECT-2020NR standard, the higher protocol layer may be, for example, a convergence (CVG) layer. In step 420, the head device 302 may transmit the received uplink data packet DP U Before storing the link information in the routing table, the upper protocol layer is checked to see if a response is required. U According to another non-limiting example, an explicit indication of a response may be provided by, for example, the application layer sending an uplink data packet DP U The head equipment 302 may include a flag in the data link control (DLC) layer routing header to indicate that a response to the received uplink data packet DP is required. UBefore storing the link information in the routing table, the DLC layer is checked to see if a response is required. U It may store link information in the routing table only when a response is required.

[0048] In step 430, the head device 302 receives a downlink data packet DP destined for a destination device 306a belonging to one or more destination devices 306a-306b of the routing system 300. D Receives the downlink data packet DP D The downlink data packet DP may include, for example, but is not limited to, configuration data, control data, software updates, requests for changes in sensor measurement data reporting (e.g., changes to threshold levels for reporting sensor measurement data as described above), and / or retransmission requests (e.g., in ARQs). Generally, sink device 204a of network 202 may generate downlink data packets, i.e., sink device 204a may be the source device of the downlink data packets. However, depending on the network 202, other devices 204b, 204c of network 202 may also generate one or more downlink data packets. If head device 302 is router device 204b, head device 302 may receive downlink data packets DP from the previous router device 204b in the same branch of network 202 as head device 302 in the downlink direction, or from sink device 204a if the previous device in the same branch of network 202 as head device 302 in the downlink direction is sink device 204a. D If the head device 302 is a sink device 204a, the head device 302 may receive downlink data packets DP from one or more external networks 206 via the gateway device 205, for example, from a management entity of one or more external networks 206. D Receives the downlink data packet DP D to the destination device 306a, for example, Dmay include an address of the destination device 306a. By way of a non-limiting example, in a wireless communication network 202 conforming to the DECT-2020NR standard, the downlink data packet DP D The routing header of the downlink packet DP D The address of the device that first generated the downlink packet DP D According to another non-limiting example, in a wireless communication network 202 conforming to the DECT-2020NR standard, the downlink data packet DP D The MAC header of the downlink data packet DP contains the one-hop sender address and the one-hop receiver address, i.e., D the address of the device where the downlink data packet DP is received (the previous device in the same branch) D The address of the device receiving the message may be defined.

[0049] In step 440, the downlink data packet DP destined for the destination device 306a in step 430 is D After receiving the downlink packet DP, the head equipment 302 D In other words, the head device 302 stores the link information related to the destination device 306a of the received downlink packet DP in the routing table. D It is checked whether or not link information relating to the destination device 306a, which is the destination of the request, is included.

[0050] In step 450, a downlink data packet DP destined for destination device 306a is D In response to receiving the downlink data packet DP D If the link information related to the destination device 306a, which is the destination of the downlink packet DP , is stored in the routing table of the head device 302, the downlink packet DP DThe downlink data packet DP is transmitted only to the member device 304a to which the destination device 306a is linked. D In other words, if the head device 302 defines in step 440 that the link information related to the destination device 306a is stored in the routing table of the head device 302, then in step 450, the head device 302 forwards the downlink data packet DP only to the member devices 304a of the head device 302 to which the destination device 306a is linked, based on the routing table of the head device 302. D The head device 302 transfers the downlink data packet DP D to the destination device 306a. D 3C shows the routing system 300 forwarding the downlink data packet DP D 10 shows an example of downlink direction routing of a downlink data packet DP D 3B. The link information related to the destination device 306a of the received data packet is stored in the routing table of the head device 302. The example routing system 300 of FIG. 3C corresponds to the example routing system 300 of FIG. 3B, but in the example of FIG. 3C, the received data packet is routed in the downlink direction as a downlink data packet DP D In the example of Figure 3C, the member device 304a is the previous router device 204b in the same branch of the network 202 as the destination device 306a in the downlink direction. Therefore, in the example of Figure 3C, the downlink data packet DP D After receiving the downlink data packet DP D Alternatively, the destination device 306a may be on the same branch as the member device 304a, but at least one other router device 204b of the network 202 may be on that branch of the network 202 between the member device 304a and the destination device 306a. In this case, the downlink data packet DP Dis routed from the member device 304a to the destination device 306a via at least one other router device 204b in the network 202. FIG. 3D illustrates the routing of the downlink data packet DP D 10 shows another example of downlink direction routing of a downlink data packet DP D 3D, the destination device 306a is on the same branch as the member device 304a, but there is another router device 204b in the network 202 between the member device 304a and the destination device 306a, and the downlink data packet DP D is routed from the member device 304a through the other one of the router devices 204b in the network 202 to the destination device 306a.

[0051] In step 460, the downlink data packet DP D If the link information associated with the destination device to which the downlink data packet DP is addressed is not stored in the routing table of the head device 302, the head device 302 will D may be forwarded to all its router member devices 304a to 304n, i.e., all member devices 304a to 304n of the head device 302 that are acting in the role of a router, i.e., that can participate in the routing operation. D In other words, if the head device 302 determines in step 440 that the link information associated with the destination device 306a is not stored in the routing table of the head device 302, the head device 302 determines in step 460 that the received downlink data packet DP D The address of one or more of the member devices 304a-304n of the head device 302 is known by the head device 302, so the head device 302 may forward the downlink data packet DPD , the head device 302 can infer that the destination device 306a, which is the destination of the received downlink data packet DP D The downlink data packet DP is not required to be forwarded to the non-router member devices. D In member-only flooding, the downlink data packet DP D reaches all (connected) devices in the network 202. FIG. 3E illustrates the routing of the downlink data packet DP D 1 is a diagram showing an example of downlink direction routing of a downlink data packet DP D 3F, the link information related to the destination device 306a, which is the destination of the downlink data packet DP D When the link information related to the destination device 306a to which the downlink data packet DP is addressed is not stored in the routing table of the head device 302, D 3E is a schematic diagram illustrating an example of member-only flooding in the head device 302. In the example of FIG. 3E, all member devices 304a to 304n of the head device 302 are routing member devices, and the head device 302 receives a downlink data packet DP D to the router member devices 304a to 304n of the head device 302. If the head device 302 alternatively or additionally includes one or more non-router member devices, the head device 302 forwards the received downlink data packet DP D to non-router member devices of the head device 302. In member-only flooding, similar to flooding, the downlink packet DP Dis forwarded to all router member devices 304a-304n. If the non-router device 204c and the destination device 306a are router devices with router member devices, only the device 204b subsequent to the destination device 306a, which may be a router, may not participate in member-only flooding, as in flooding.

[0052] Alternatively, in step 470, the downlink data packet DP D If the link information associated with the destination device to which the downlink data packet DP is addressed is not stored in the routing table of the head device 302, the head device 302 will D may be broadcast to all communication devices within its radio range 308, i.e., downlink data packet DP D may be flooded to all communication devices within the radio range 308 of the head device 302. In other words, if the head device 302 determines in step 440 that the link information associated with the destination device 306a is not stored in the routing table of the head device 302, the head device 302 may, in step 470, flood the received downlink data packet DP D may be broadcast to all communication devices within its wireless range 308, i.e., its neighbors, including its router member devices 304a-304n. D One method for broadcasting the downlink data packet DP may be, for example, but not limited to, the method described in Patent Publication US2019 / 208512A1. Step 470 may be applied, for example, only in limited circumstances. An example of such a limited situation is when the received downlink data packet DP D Another example of such a limited situation is when the destination device 306a, which is the destination of the downlink data packet DP, was recently a member device 304a-304n of the head device 302, but is no longer a member device. DFor example, the situation may be one in which the presence of a destination device 306a, which is the destination of the downlink data packet DP 1 , within the radio range of the head device 302 is indicated by one or more neighboring communication devices of the head device 302. This can be considered based on the following assumption: D 3F illustrates the routing of a downlink data packet DP by the routing system 300. The recent membership of destination device 306a, which is the destination of the downlink data packet DP, indicates that destination device 306a has likely changed its route, but perhaps not far away; for example, destination device 306a may now be associated with a branch nearby head device 302. D 10 shows another example of downlink direction routing of a downlink data packet DP D 3F, the link information related to the destination device 306a, which is the destination of the downlink data packet DP D If the link information related to the destination device 306a to which the downlink data packet DP is to be sent is not stored in the routing table of the head device 302, the routing system 300 sends the downlink data packet DP D In the example of FIG. 3F, the head device 302 floods the received downlink data packet DP D to all communication devices 304a-304n, 306a-306n, 310 within its radio range 308. In the example of FIG. 3F, the head device 203 broadcasts the received downlink data packet DP D to its member devices 304a to 304n and to neighboring communication devices 310 that are not on the same branch as the head device 302 but are within the radio range 308 of the head device 302. The neighboring communication devices 310 broadcast the received downlink data packet DP D In this example, the received downlink data packet DP D3F, the neighboring communication device 310 is a router device 204b, but the neighboring communication device 310 may alternatively be a sink device 204a. Alternatively or additionally, there may be multiple neighboring communication devices 310 within wireless range 308 of the head device 302, and the multiple neighboring communication devices 310 may be router devices 204b, sink devices 204a, and / or non-router devices 204c.

[0053] The term "neighboring communication device" throughout this application means a communication device whose transmission can be correctly received by a receiving communication device. An expanded meaning of the term "neighboring communication device" takes into account the neighborhood of a neighborhood of a communication device, i.e., multi-hop neighborhood such as a two-hop neighborhood, a three-hop neighborhood, a four-hop neighborhood, etc. The term "neighbor of a communication device" throughout this application means one or more communication devices whose transmission can be correctly received by a receiving communication device. An expanded meaning of the term "neighbor of a communication device" takes into account the neighborhood of a neighborhood of a communication device, i.e., multi-hop neighborhood such as a two-hop neighborhood, a three-hop neighborhood, a four-hop neighborhood, etc.

[0054] According to one example, the uplink data packet DP generated by the destination device 306a U The uplink data packet DP may include a hop count field containing a hop count value. U is routed in the uplink direction in the network 202, the uplink data packet DP U may be incremented by all router devices 204b in the network 202 that forward the

[0055] According to another example, a downlink data packet DP addressed to destination device 306a D The uplink data packet DP generated by destination device 306a may include a downlink hop limit field that includes a hop limit value. UIf the hop count field is included in the uplink data packet, the hop limit value may be initialized to correspond to the cumulative hop count value included in the hop count field of the uplink data packet. D The hop count value may be decremented by all router devices 204b in the network that forwards the downlink data packet DP . D When receiving the downlink data packet DP D Unless the downlink data packet DP is addressed to a member device of the router device 204b, D Do not transfer.

[0056] Alternatively or additionally, according to yet another example, in response to receiving the downlink indication packet, the destination device 306a may forward the uplink data packet DP received by the head device 302 in step 410. U The downlink indication packet may be generated, for example, by at least one sink device 204a of the network 202. According to an example, the at least one sink device 204a of the network 202 may generate the downlink indication packet in response to receiving a request from a management entity of one or more external networks 206 via the gateway device 205. The downlink indication packet may be delivered to the destination device 306a using, for example, a flooding mechanism, i.e., the downlink indication packet may be delivered to the destination device 306a by forwarding the downlink indication packet to all router devices 204a, 204b of the network 202. The uplink data packet DP generated by the destination device 306a in response to receiving the flooded downlink indication packet may be UAfter receiving the downlink data packet DP , the head device 302 routes one or more subsequent downlink data packets (downlink data packets DP ) destined for the destination device 306a based on the link information stored in the routing table of the head device 302, as described above with reference to steps 410-450. D , including downlink control packets). According to one example, the downlink indication packet may be any downlink packet that triggers an uplink packet transmission response. According to another example, the downlink indication packet may be a dedicated downlink polling packet (e.g., a downlink ARQ polling packet), or an ARQ poll message may be piggybacked on any downlink packet. According to yet another example, the downlink indication packet may be a downlink packet (e.g., a downlink data packet, a downlink control packet, or another downlink packet) that includes an indicator (e.g., a flag, a bit field, or other indicator) that indicates that more data (e.g., one or more downlink data packets) is coming to the destination device 306a. The indicator may be included, for example, in the header of the downlink indication packet. The use of a downlink indication packet is particularly beneficial when the downlink indication packet is part of a burst of downlink data packets (e.g., a downlink data packet DP addressed to the destination device 306a). Dis segmented into multiple downlink data packets forming a burst of downlink data packets. For example, in the case of a burst of downlink data packets, the downlink indication packet may include an indicator that the downlink indication packet is a fragment (e.g., the first or middle fragment) of a burst of downlink data packets. The use of downlink indication packets improves the performance of the wireless network 202 by improving downlink data packet routing efficiency. Because, by using a flooding mechanism, only downlink indication packets indicating that there is more data coming for the destination device 306a need to be delivered to the destination device 306a, and downlink data packets DP destined for the destination device 306a can be routed to the destination device 306a by forwarding the downlink data packets only to the associated router device 204b based on the link information stored in the routing table of the head device 302, as described above with reference to steps 410-450. D , and possibly one or more subsequent downlink data packets destined for destination device 306a, can also be delivered to destination device 306a. According to yet another example, destination device 306a receives uplink data packet DP U The periodicity of the normal uplink data packet generation may be defined based on the maximum storage time information displayed above, for example.

[0057] Thus, the routing system 300 and routing method have been described to improve the routing efficiency of downlink data packets in the wireless communication network 202. The greatest improvement in the routing efficiency of downlink data packets in the network 202 may be achieved by applying the features of the routing method associated with the head device 302 by all sink devices 204a and all router devices 204b of the network 202, particularly in a network 202 in which the mobility of devices 204a, 204b, and 204c is substantially low. On the other hand, if the features of the routing method associated with the head device 302 are applied by only one device in the network 202, preferably, the features of the routing method associated with the head device 302 are applied by the sink device 204a of the network 202 to achieve the greatest possible improvement in the routing efficiency of downlink data packets in the network 202.

[0058] The improved performance, i.e., improved downlink data packet routing efficiency, of the above-described routing method compared to the member-only flooding-based routing method is demonstrated by an exemplary simulation using an exemplary single sink device network 202 including 500 communication devices 204a, 204b, and 204c. In the member-only flooding-based routing method, each downlink data packet is forwarded, i.e., flooded, to all router devices 204a and 204b in the network 202. In this simulation example, the routing method features associated with the head device 302, as described above, are applied only by the sink device 204a in the exemplary network 202. FIG. 5 schematically illustrates the simulation performance between the above-described routing method and the member-only flooding-based routing method as a cumulative distribution function (CDF). The performance metric in the example of FIG. 5 is the percentage of avoided transmissions using the above-described routing method and the member-only flooding-based routing method. The percentage of avoided transmissions is defined by the following equation: Avoided Transmissions (%) = (N F -N R ) / N R In the formula, N F is the number of transmissions in the member-only flooding-based routing method, and N R is the number of transmissions in the above-described routing method. Figure 5 shows that applying the features of the routing method associated with the head device 302 by the sink device 204a can save 80% of the transmissions and 50% of the time. If the features of the routing method associated with the head device 302 are further applied by one or more routing devices 204b in the network 202, the performance index may be further improved.

[0059] 6 schematically illustrates communication devices 302, 304a-304n, and 306a-306n that communicate in network 202 and that can perform the associated functions (steps) of the routing method described above. In other words, we have described devices that can operate as head device 302 and perform the features of the routing method associated with head device 302 as described above, devices that can operate as member devices 304a-304n and perform the features of the routing method associated with member devices 304a-304n as described above, and / or devices that can operate as destination devices 306a-306n and perform the features of the routing method associated with destination devices 306a-306n as described above.

[0060] The devices 302, 304a to 304n, and 306a to 306n each include a controller (control unit) 630 that controls the operation of each of the units 632, 634, 636, 638, and 640 so that the devices 302, 304a to 304n, and 306a to 306n operate as described above.

[0061] The controller 630 includes a processor 632 that executes operator-initiated instructions and / or computer program-initiated instructions and processes data to run applications. The processor 632 may include at least one processor, for example, one, two, three, four, or more processors.

[0062] The controller 630 also includes a memory 634 for storing and retaining data, which may be instructions, computer programs, and data files. The memory 634 may include at least one memory, such as one, two, three, four, or more memories.

[0063] Devices 302, 304a-304n, 306a-306n also include a radio (wireless communication unit, data transfer unit) 636 and an antenna (antenna unit) 638 that controller 630 uses to transmit commands, requests, messages, and data (e.g., data packets) to at least one of the devices in routing system 300 and / or network 202 via antenna 638. Radio 636 also receives commands, requests, and data (e.g., data packets) from at least one of the devices in routing system 300 and / or network 202 via antenna 638. Communications between radios 636 of devices 302, 304a-304n, 306a-306n and other devices in routing system 300 and / or network 202 are provided wirelessly via antenna 638.

[0064] The devices 302, 304a to 304n, and 306a to 306n may further include a power supply (power supply unit) 640. The power supply 640 includes components for supplying power to the devices 302, 304a to 304n, and 306a to 306n, such as a battery and a regulator.

[0065] The memory 634 stores at least a wireless communication application 642 for operating (controlling) the wireless communication device 636 and a power supply application 644 for operating the power supply 640.

[0066] The memory 634 also stores a computer program (computer software, computer application) 646 which, when executed (implemented) by the controller 630 in a computer, such as devices 302, 304a-304n, 306a-306n, uses at least one of the functional units 636, 638, 640 to perform at least one operation of devices 302, 304a-304n, 306a-306n described above in the context of the previous figures.

[0067] The computer program 646 may be stored on a tangible, non-volatile computer readable storage medium, such as a compact disc (CD) or universal serial bus (USB) type storage device.

[0068] The specific examples provided in the above description should not be construed as limiting the scope and / or interpretation of the appended claims. Any list or group of examples provided in the above description is not exhaustive, unless expressly stated otherwise.

Claims

1. A routing system (300) for a wireless communication network (202) including a plurality of communication devices (204a, 204b, 204c), the routing system (300) comprising: one or more head devices (302) participating in routing operations in the wireless communication network (202), each having one or more member devices (304a-304n); one or more destination devices (306a-306n); Equipped with the one or more head devices (302), the one or more member devices (304a to 304n), and the one or more destination devices (306a to 306n) belong to the plurality of communication devices (204a, 204b, 204c); At least one head device (302) of the one or more head devices (302) From the member device (304a) belonging to the one or more member devices (304a-304n), an uplink data packet (DP) generated by a destination device (306a) belonging to one or more destination devices (306a-306n) is transmitted. Ｕ ) in response to receiving the received uplink data packet (DP Ｕ ) in the uplink direction, and stores link information representing the link between the destination device (306a) and the member device (304a) in a routing table; A downlink data packet (DP) destined for a destination device (306a) belonging to the one or more destination devices (306a-306n) Ｄ ) in response to receiving the downlink data packet (DP Ｄ ) is stored in the routing table of the head device (302), the downlink data packet (DP Ｄ ) is transmitted to only the member device (304a) to which the destination device (306a) is linked. Ｄ ) and transfer updating the routing table, where updating the routing table includes prioritizing storage of the link information based on a Quality of Service (QoS) value included in the link information and / or downlink response information included in the link information; It is configured as follows: A routing system (300).

2. The downlink data packet (DP Ｄ If the link information related to the destination device (306a) that is the destination of the packet is not stored in the routing table of the head device (302), the head device (302) The received downlink data packet (DP Ｄ ) to all router member devices (304a to 304n), or The received downlink data packet (DP Ｄ ) to all communication devices (304a to 304n, 306a to 306n) within the wireless range including the router member devices (304a to 304n). It is configured as follows: The routing system (300) of claim 1.

3. 3. The routing system (300) of claim 1 or 2, wherein the link information includes at least information linking an address of the destination device (306a) with an address of the member device (304a).

4. The routing system (300) of any one of claims 1 to 3, wherein the at least one head device (302) is a router device (204b) that operates in the role of a router in the wireless communication network (202), or a sink device (204a) configured to operate as a wireless interface of a gateway device (205) that operates as a gateway between the wireless communication network (202) and one or more external networks (206).

5. 5. The routing system of claim 4, wherein the head device of the sink device is configured to store the routing table in a memory unit of a management entity of the one or more external networks, or to transmit the routing table to be stored in a memory unit of a management entity of the one or more external networks.

6. Updating the routing table includes: deleting the stored link information from the routing table based on the time elapsed since the link information was stored; responsive to receiving the new link information, updating the previously stored link information with the new link information; removing the oldest link information from the routing table when the routing table reaches a maximum size; and / or The received uplink data packet (DP Ｕ ) based on the routing header in the packet header, learning when new link information should be stored. further comprising: A routing system (300) according to any one of claims 1 to 5.

7. The routing system (300) of any one of claims 1 to 6, wherein the downlink response information indicates whether a downlink response is required.

8. 8. The routing system (300) of claim 7, wherein the downlink response information comprises an upper layer protocol indication that a downlink response is expected.

9. The higher layer protocol indication is Ｕ 9. The routing system (300) of claim 8, wherein the packet includes an indication that the packet is an uplink automatic repeat request (ARQ) polling packet.

10. The uplink data packet (DP Ｕ ) includes a hop count field containing a hop count value, said hop count value being Ｕ 10. The routing system (300) of claim 1, wherein the packet size is incremented by all router devices (204b) of the wireless communication network (202) that forward the packet size.

11. The downlink data packet (DP Ｄ ) includes a downlink hop limit field containing a hop limit value, and the hop limit value is Ｕ 11. The routing system (300) of claim 10, wherein the hop count field of the routing table is initialized to correspond to a cumulative hop count value contained in the hop count field of the routing table.

12. The hop limit value is the value of the downlink data packet (DP Ｄ ) is decremented by all router devices (204b) of the wireless communication system (202) that forward the downlink data packet (DP), and when a router device (204b) of the wireless communication system (202) receives a downlink data packet with the hop count value of zero, the router device (204b) decrements the downlink data packet (DP Ｄ ) is addressed to a member device of the router device (204b), Ｄ 12. The routing system (300) of claim 11, wherein the routing system (300) does not forward any of the following:

13. The destination device (306a) transmits the uplink data packet (DP) in response to receiving the downlink indication packet. Ｕ 13. The routing system (300) of any one of claims 1 to 12, configured to generate a route map.

14. The downlink instruction packet is distributed to the destination device (306a) by flooding, and the uplink data packet (DP) generated by the destination device (306a) in response to receiving the downlink instruction packet is Ｕ 14. The routing system (300) of claim 13, wherein after receiving the link information stored in the routing table of the head device (302), the head device (302) is configured to forward one or more subsequent downlink data packets destined for the destination device (306 a) based on the link information stored in the routing table of the head device (302).

15. A wireless communication network (202) comprising a routing system (300) according to any one of claims 1 to 14.

16. A routing method for a wireless communication network (202), comprising: presenting one or more head devices (302) participating in routing operations in the wireless communication network (202), each head device (302) having one or more member devices (304a-304n) and one or more destination devices (306a-306n), the one or more head devices (302), the one or more member devices (304a-304n), and the one or more destination devices (306a-306n) belonging to a plurality of communication devices (204a, 204b, 204c) of the wireless communication network (202); At least one head device (302) transmits an uplink data packet (DP) generated by a destination device (306a) belonging to one or more destination devices (306a-306n) from a member device (304a) belonging to one or more of the member devices (304-304n). Ｕ ) by the at least one router device (302) in response to receiving (410) the received uplink data packet (DP Ｕ ) in an uplink direction (420), and storing link information representing the link between the destination device (306a) and the member device (304a) in a routing table; The at least one head device (302) receives a downlink data packet (DP) destined for a destination device (306a) belonging to the one or more destination devices (306a-306n). Ｄ ) in response to receiving (430) the downlink data packet (DP Ｄ ) is stored in the routing table of the head device (302), the at least one head device (302) routes the downlink data packet (DP) based on the routing table of the head device (302). Ｄ ) is transmitted to only the member device (304a) to which the destination device (306a) is linked. Ｄ ) and transferring (450) the updating the routing table by the at least one head device (302), wherein updating the routing table includes prioritizing storage of the link information based on a Quality of Service (QoS) value included in the link information and / or downlink response information included in the link information; A routing method, including:

17. a head device (302) for a wireless communication network (202), the head device (302) configured to participate in routing operations in the wireless communication network (202); a controller (630); a wireless communication device (636) for operating as a wireless node device; Including, The wireless communication device (636) receives an uplink data packet (DP) generated by a destination device (306a) from a member device (304a) belonging to the one or more member devices (304a-304n). Ｕ ) by said radio (636) in response to receiving said received uplink data packet (DP Ｕ ) in the uplink direction, and the controller (630) stores link information representing the link between the destination device (306a) and the member device (304a) in a routing table; The radio (636) transmits a downlink data packet (DP) destined for the destination device (306a). Ｄ ) in response to receiving the downlink data packet (DP Ｄ If link information related to the destination device (306a) that is the destination of the downlink data packet (DP) is stored in the routing table of the head device (302), the wireless communication device (636) routes the downlink data packet (DP) to the destination device (306a) based on the routing table of the head device (302). Ｄ ) is transmitted to only the member device (304a) to which the destination device (306a) is linked. Ｄ ) and transfer The controller (630) updates the routing table, and updating the routing table includes prioritizing storage of the link information based on a Quality of Service (QoS) value included in the link information and / or downlink response information included in the link information. The head device (302) is configured to:

18. 20. A head device (302) routing method according to claim 17, comprising: The radio (636) of the head device (302) transmits an uplink data packet (DP) generated by a destination device (306a) from a member device (304a) belonging to the one or more member devices (304a-304n). Ｕ ) by the radio (636) of the head device (302) in response to receiving (410) the received uplink data packet (DP Ｕ ) in an uplink direction, and storing link information representing a link between the destination device (306a) and the member device (304a) in a routing table by the controller (630) of the head device (302); The radio (636) of the head device (302) transmits a downlink data packet (DP) destined for the destination device (306a). Ｄ ) in response to receiving (430) the downlink data packet (DP Ｄ ) is stored in the routing table of the head device (302), the radio (636) of the head device (302) routes the downlink data packet (DP) to the destination device (306a) based on the routing table of the head device (302). Ｄ ) is transmitted to only the member device (304a) to which the destination device (306a) is linked. Ｄ ) and updating the routing table by the controller (630) of the head device (302), wherein updating the routing table includes prioritizing storage of the link information based on a Quality of Service (QoS) value included in the link information and / or downlink response information included in the link information; A routing method, including:

19. 20. A computer program (646) comprising instructions that, when executed by a computer, cause the computer to perform at least each step of the method of claim 18.

20. 20. A tangible, non-volatile computer readable medium containing the computer program (646) of claim 19.

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