Synchronized reception in mesh networks

Abstract

This application discloses synchronization reception in a mesh network. This document describes techniques and devices for synchronizing communications between devices in a wireless mesh network. Based on a terminal device's desire to sleep (e.g., not be in communication with the wireless mesh network) for a period of time, the terminal device indicates to a parent wireless mesh network device that the terminal device wants to configure operation in a synchronized reception mode, which causes the parent device to reply with a clock accuracy indication of the parent device. The terminal device uses the clock accuracy of the parent device to determine parameters for synchronized reception and communicates the parameters to the parent device. The terminal device activates its receiver to receive data from the parent device based on the parameters.

Description

[0001] Case Analysis

[0002] This application is a divisional application of Chinese invention patent application 201880093652.0, filed on August 27, 2018. Technical Field

[0003] This disclosure relates to synchronous reception in mesh networks. Background Technology

[0004] Using wireless mesh networking to connect devices to each other and to cloud-based services is becoming increasingly popular for sensing environmental conditions, controlling devices, and providing information and warnings to users. Many devices on wireless mesh networks are designed to operate for extended battery lifespans, which limits the available computing power, user interface, and radio resources within the devices.

[0005] Additionally, some wireless mesh network devices can periodically go into sleep mode to reduce power consumption and avoid continuous radio communication with the mesh network to receive data packets. A sleeping mesh network device can periodically wake up and poll its parent mesh network device to determine whether to queue data for delivery to the sleeping device. As the density of wireless mesh network devices in an area increases, increased polling traffic can lead to network congestion and increased communication latency.

[0006] For battery-powered, dormant mesh network devices, even without pending data for the dormant device, relying on polling to check for pending data requires limited battery power to transmit polling requests. When applications in dormant terminal devices require low communication latency, transmitting polling messages more frequently will consume battery power at a higher rate. Summary of the Invention

[0007] This invention provides a simplified concept of synchronous reception in mesh networks, typically relating to the synchronous reception of data from a parent device by a terminal device in a wireless mesh network. The simplified concept is further described in the detailed embodiments below. This invention is not intended to identify essential features of the claimed subject matter, nor is it intended to define the scope of the claimed subject matter.

[0008] In various aspects, methods, apparatuses, systems, and devices for synchronization reception in a mesh network are described, wherein a terminal device transmits a parent request message to a parent device, the parent request message instructing the terminal device to operate in an idle receiver-off mode. In response to the parent request message, the terminal device receives a parent response message, the parent response message including an indication of the clock precision of the parent device. The terminal device determines parameters for synchronization reception of communication from the parent device based in part on the received indication of the clock precision of the parent device. The terminal device transmits a sub-request message, the sub-request message including parameters for synchronization reception of communication from the parent device, which effectively enables the parent device to transmit communication to the terminal device based on the parameters.

[0009] Details of one or more embodiments are set forth in the accompanying drawings and the following description. Other features and advantages will become apparent from the specification, drawings, and claims. This summary is provided to introduce the subject matter further described in the detailed description and drawings. Therefore, this summary should not be considered as describing essential features, nor should it be used to limit the scope of the claimed subject matter.

[0010] A method is provided for synchronizing the reception of communications by a terminal device operating in an idle receiver-off mode in a wireless mesh network. The method includes transmitting a parent request message from the terminal device to a parent device. The method further includes receiving the parent response message from the parent device in response to the parent request message, the parent response message including an indication of the clock precision of the parent device. The method further includes determining parameters for synchronizing the reception of communications from the parent device, in part based on the received indication of the clock precision of the parent device. The method further includes transmitting a child request message from the terminal device, the child request message including parameters for synchronizing the reception of communications from the parent device, the transmission effectively enabling the parent device to transmit communications to the terminal device based on the parameters.

[0011] The method may further include periodically activating the receiver to receive communication from the parent device based on parameters used for synchronous reception.

[0012] Receiver activation can be based on the clock accuracy indication of the received parent device and the time since the previous synchronization.

[0013] The method may further include determining, based on the communication received from the parent device, that additional data of the terminal device is queued on the parent device, and sending a polling message to the parent device to effectively enable the parent device to transmit the additional data.

[0014] The method may further include determining, based on the communication received from the parent device, that additional data for the terminal device is queued on the parent device, and keeping the receiver on to receive the additional data.

[0015] The method may further include determining, at least in part, based on an indication of the clock precision of the received parent device, that the reception of communication from the parent device is no longer synchronized, and based on the determination that the reception of communication is no longer synchronized, transmitting a resynchronization message to the parent device to effectively resynchronize the reception of communication from the parent device.

[0016] The method may further include determining, at least in part, based on an indication of the clock precision of the received parent device, that the reception of communication from the parent device is no longer synchronized, and periodically sending polling messages to the parent device to receive data for the terminal device.

[0017] Applications in a terminal device may determine synchronous communication reception with the parent device based on one or more of the following: time of day, scheduling, occupancy status, status of the structure in the smart home system, status of the terminal device, alarm status, changes in sensor readings in the terminal device, sensor readings exceeding thresholds, environmental status, receiving input from the terminal device user, receiving interaction with the terminal device, determination of requiring higher throughput for receiving communication, determination of requiring higher network capacity, determination of queuing of data from the terminal device at the server or parent device, or determination of requiring lower communication latency.

[0018] Parameters for synchronous reception of communication from the parent device may include an indication of the channel for synchronous communication between the parent device and the terminal device, an indication of the maximum time the terminal device will remain synchronized with the parent device, or both.

[0019] The sub-request message can be a Mesh Link Establishment (MLE) sub-ID request message or an MLE sub-update request message.

[0020] A mesh network device configured as a terminal device is also provided. The mesh network device includes a mesh network interface configured for communication in a mesh network, and a memory and processor system for implementing a receiver manager application. The receiver manager application is configured to transmit a parent request message to a parent device using the mesh network interface, the parent request message instructing the terminal device to operate in an idle receiver-off mode. The receiver manager application is further configured to receive a parent response message in response to the parent request message, including an indication of the clock precision of the parent device. The receiver manager application is further configured to determine parameters for synchronous reception of communication from the parent device, in part based on the received indication of the clock precision of the parent device. The receiver manager application is further configured to transmit a sub-request message, the sub-request message including parameters for synchronous reception of communication from the parent device, the transmission effectively enabling the parent device to transmit communication to the terminal device based on these parameters.

[0021] The receiver manager application is further configured to periodically activate the receiver arrival time window of the mesh network interface based on parameters used for synchronous reception in order to receive communication from the parent device.

[0022] Receiver activation can be based on an indication of the clock accuracy of the received parent device and the time since the previous synchronization.

[0023] The receive manager application is further configured to determine, based on the received communication from the parent device, that additional data for the terminal device is queued on the parent device, and to send a polling message to the parent device that effectively enables the parent device to transmit the additional data.

[0024] The receiver manager application is further configured to determine, based on the reception of communication from the parent device, that additional data from the terminal device is queued on the parent device and to keep the receiver on to receive that additional data.

[0025] The receive manager application is further configured to determine, at least in part, that the reception of communication from the parent device is out of sync based on an indication of the clock precision of the received parent device, and based on the determination that the reception of communication is out of sync, to send a resynchronization message to the parent device to effectively resynchronize the communication received from the parent device.

[0026] The receive manager application is further configured to determine, at least in part, based on an indication of the clock precision of the received parent device, that the reception of communication from the parent device is out of sync, and to periodically send polling messages to the parent device to receive data from the parent device.

[0027] The parameters for synchronous reception of communication from the parent device include an indication of the channel for synchronous communication between the parent device and the terminal device, an indication of the maximum time the terminal device will remain synchronized with the parent device, or both.

[0028] A mesh network system is also provided. The mesh network system includes parent devices and terminal devices. Terminal devices are configured to transmit a parent request message to the parent device, which instructs the terminal device to operate in an idle receiver-off mode. The terminal device is further configured to receive a parent response message, including an indication of the parent device's clock precision, in response to the parent request message. The terminal device is further configured to determine parameters for synchronous reception of communication from the parent device, in part, based on the received indication of the parent device's clock precision. The terminal device is further configured to transmit a child request message, which includes parameters for synchronous reception of communication from the parent device, effectively enabling the parent device to transmit communication to the terminal device based on these parameters. Attached Figure Description

[0029] The following figures illustrate various aspects of synchronization reception in a mesh network. The same numbers are used throughout the figures to refer to similar features and components:

[0030] Figure 1 The diagram illustrates a mesh network system in which various aspects of synchronous reception in a mesh network can be achieved.

[0031] Figure 2 The illustration shows an example environment in which various aspects of synchronous reception in a mesh network can be implemented.

[0032] Figure 3A The illustration shows an example of transmitter and receiver synchronization based on aspects of the technology described herein.

[0033] Figure 3B The illustration shows another example of transmitter and receiver synchronization based on aspects of the technology described herein.

[0034] Figure 4 The illustration shows an example of data and control transactions between a parent device and a terminal device, based on aspects of the technology described herein.

[0035] Figure 5 The illustration shows an example method of synchronous reception in a mesh network, which is typically associated with establishing synchronous reception between a parent device and a terminal device in a mesh network, based on aspects of the technology described herein.

[0036] Figure 6 The illustration shows an example environment in which a mesh network can be implemented based on various aspects of the technology described in this article.

[0037] Figure 7 The illustration shows an example mesh network device that can be implemented in a mesh network environment according to one or more aspects of the technology described herein.

[0038] Figure 8 The illustration shows an example system with example devices that can achieve synchronous reception in a mesh network. Detailed Implementation

[0039] This document describes the techniques and apparatus used for communication between devices in a synchronized wireless mesh network. Based on a terminal device's request to hibernate (e.g., disconnected from the wireless mesh network) for a period of time, the terminal device indicates to its parent wireless mesh network device that it wishes to configure operation in synchronized receive mode, which causes the parent device to respond with its own clock precision. The terminal device uses the parent device's clock precision to determine the parameters used for synchronized receive and transmits these parameters to the parent device. Based on these parameters, the terminal device activates its receiver to receive data from the parent device.

[0040] A wireless mesh network is a communication network with wireless nodes connected in a mesh topology, which provides reliable and redundant communication paths for data services within the mesh network. Wireless mesh networks use multiple radio links or hops to forward data services between devices within the mesh network. This provides coverage over a larger area than the area covered by a single radio link.

[0041] Wireless mesh networks can be based on proprietary or standards-based technologies. For example, a wireless mesh network can be based on the IEEE 802.15.4 standard, which defines physical (PHY) and media access control (MAC) layer features and services for use by applications at higher layers of the mesh network stack. Upper-layer applications rely on these standard-defined services to support the addressing and routing of packet data, enabling application-level communication across the mesh network and between the mesh network and external networks. Similarly, other wireless mesh network technologies, such as... Bluetooth Low Energy (BLE), Bluetooth Smart, and Bluetooth Mesh have similar layered network stacks.

[0042] Applications in cloud-based services send and receive packets to and from mesh network devices. These packets traverse numerous networks using constantly evolving technologies. To facilitate low-power operation, mesh networks employ low-power radio technology, which can conserve energy using low data rates. Furthermore, network connections from mesh networks to cloud-based services can include cellular wireless systems with bandwidth and cost constraints for data transmission.

[0043] Many devices used in mesh networks (such as sensors) are designed for low-power battery operation over long periods of time, such as months or years. To achieve this long lifespan, battery-powered mesh devices may shut down or hibernate many device functions, such as radio and network interfaces, for periods of time. During hibernation, the mesh device is unavailable on the mesh network to receive packets addressed to it. These hibernating mesh devices are connected to a parent device, which is able to respond on behalf of the hibernating mesh device while it is not awakened and inactive on the mesh network. The parent device buffers packets destined for the child device and responds on behalf of the child device.

[0044] In various aspects, cloud-based services and various mesh networking devices can participate in distributed applications or use cases. The requirements of each use case may necessitate different levels of latency or availability in communication between the mesh network or cloud-based services and mesh networking devices. For example, cloud-based services and / or mesh networking devices can determine patterns or states of smart home or building automation applications associated with the structure in which the mesh networking devices are installed. Example patterns or states may include the occupancy status of the structure, alarm status within the structure, user interactions or mesh networking devices within the structure, environmental conditions at the structure, and schedules associated with the structure.

[0045] In response to conditions in the terminal device, such as sensor readings exceeding thresholds or interactions with the terminal device, or during certain states or modes, the terminal device may determine to operate in a synchronous reception mode with the parent device to reduce communication latency, reduce power consumption, and / or improve network utilization. The terminal device may determine to operate in synchronous reception mode for a period of time or while a certain state or mode exists and then return polling data (e.g., indirect transmission) after that period expires.

[0046] Although the features and concepts of the described devices, systems, and methods for synchronous reception in mesh networks can be implemented in any number of different environments, systems, devices, and / or various configurations, aspects of synchronous reception in mesh networks are described in the context of the following example devices, systems, and configurations.

[0047] Figure 1 The diagram illustrates an example system of mesh network 100, which implements various aspects of synchronous reception within the mesh network. Mesh network 100 is a wireless mesh network that includes router 102, router-eligible terminal devices 104 and 106. Router 102, router-eligible terminal devices 104 and 106 all include mesh network interfaces for communication over the mesh network. Router 102 receives and transmits packet data through its respective mesh network interface. Router 102 also routes traffic across mesh network 100.

[0048] Router-qualified terminal device 104 refers to terminal devices that meet router criteria, are located at leaf nodes in the mesh network topology, and do not actively route traffic to other nodes in the mesh network 100. Router-qualified device 104 can act as router 102 when connected to additional mesh network devices. Terminal device 106 is a device that can communicate using the mesh network 100, but lacks the ability to route traffic within the mesh network 100 beyond simply forwarding packets to its parent router 102. For example, a battery-powered sensor is one type of terminal device 106.

[0049] Some terminal devices 106 may power off (i.e., hibernate) certain operations or hardware during a portion of their operational time. For example, terminal device 106 may power off its radio or network interface to conserve power between operations that require connection to mesh network 100. For instance, a battery-powered temperature sensor may wake up only periodically to transmit temperature reports, and then hibernate until the next temperature sensor report. When terminal device 106 is hibernating, it does not actively connect to mesh network 100 to respond to address queries or receive packets through mesh network 100.

[0050] Figure 2 The illustration shows an example environment 200, in which various aspects and techniques for synchronous reception in a mesh network can be implemented. Environment 200 includes a mesh network 100, in which some routers 102 perform specific roles.

[0051] Border router 202 (also known as a gateway and / or edge router) is one of routers 102. Border router 202 includes a mesh network interface and a second interface for communicating with an external network outside the mesh network 100. Border router 202 is connected to access point 204 via the external network. For example, access point 204 can be an Ethernet router, a Wi-Fi access point, a cellular base station, or any other suitable device for bridging different types of networks. Although for clarity... Figure 2 The diagram shows a single border router 202. The mesh network 100 can have any number of border routers 202, which can connect to any number of external networks. In another embodiment, the terminal device 106 can operate as a border router 202. In this case, the terminal device operating as a border router 202 routes traffic between the mesh network 100 and external networks, but does not route traffic between other mesh network devices.

[0052] Access point 204 connects to a communication network 206, such as the Internet. Cloud service 208, connected via communication network 206, provides services related to and / or use of devices within mesh network 100. By way of example and not limitation, cloud service 208 provides applications including connecting end-user devices (such as smartphones, tablets, etc.) to devices in mesh network 100, processing and presenting data acquired in mesh network 100 to end users, linking one or more devices in mesh network 100 to a user account in cloud service 208, provisioning and updating devices in mesh network 100, and so on. Alternatively or optionally, the services described with respect to cloud service 208 may be distributed, wholly or partially, between cloud service 208 and hub devices (e.g., border router 202, security hub, etc.) installed at the structure where mesh network devices are installed. The storage location of the characteristics, resources, and interfaces of mesh network devices, or structure-related information, may be dynamically distributed between cloud service 208 and hub devices in any suitable manner.

[0053] One of the routers 102 performs the role of leader 210 for the mesh network 100. Leader 210 manages router identifier assignment, acts as the central arbiter of network configuration information, and propagates network data including network configuration information for the mesh network 100.

[0054] Synchronous reception

[0055] As discussed in detail below, the terminal device decides or is configured to operate in a synchronous reception mode, which can be established when the terminal device is attached to the parent device or at a later time. Figure 3A The illustration shows an example of transmitter and receiver synchronization 300 between parent device 302 (e.g., router 102 or router-compliant terminal device 104) and terminal device 304 (e.g., terminal device 106). See below for reference. Figure 4 In detail, terminal device 304 uses, for example, IEEE 802.15.4 Coordinated Sample Listening (CSL) to establish a schedule for synchronous reception of data transmitted to parent device 302. Terminal device 304 periodically activates its receiver to receive window 322 at time intervals 320, as shown in 310, 312, 314, 316, and 318.

[0056] When parent device 302 has data to transmit to terminal device 304, the parent device transmits the data as shown in 324 and 326. Terminal device 304 activates its receiver to reach a receive window 322, which is selected to be longer than the expected or maximum data packet length transmission time 328 in the wireless mesh network 100. As illustrated at 330, by activating the receiver of terminal device 304 to reach a window longer than the expected transmission time 328, the clocks of both parent device 302 and terminal device 304 may drift, and communication will be successful despite the clock drift.

[0057] Figure 3B This illustration shows another example of transmitter and receiver synchronization 350, typically associated with clock drift over time, for wireless communication between parent device 302 and terminal device 304. After initial synchronization is established between parent device 302 and terminal device 304, as shown at 352, a transmission from parent device 302 is centered within receive window 322. After a period of time, the clocks of parent device 302 and terminal device 304 may drift separately. As shown at 354, a transmission from parent device 302 is no longer centered within receive window 322. At 354, a transmission from parent device 302 is illustrated as occurring earlier in receive window 322, such as when the parent device's clock is faster relative to the terminal device 304's clock (higher frequency drift). Alternatively, when the parent device's clock is slower relative to the terminal device 304's clock (lower frequency drift), a transmission from parent device 302 may occur later in receive window 322.

[0058] At position 356, the clocks in the parent device 302 and the terminal device 304 may drift apart sufficiently, causing some or all of the transmissions from the parent device 302 to fall outside the receiving window 322. In this case, the terminal device 304 can no longer receive transmissions from the parent device in synchronous receive mode. To continue using synchronous receive, the parent device 302 and the terminal device 304 need to resynchronize, or the terminal device 304 can revert to indirect transmission by polling the queued data stored by the parent device 302.

[0059] Figure 4The illustration depicts example data and control transactions between parent device 302 and terminal device 304, participating in communication based on synchronous reception in a mesh network. At 405, terminal device 304 uses multicast addressing to transmit a Mesh Link Establishment (MLE) parent request message to devices in the mesh network 100, including parent device 302. The MLE parent request message includes an indication that terminal device 304 is configured to operate in idle receiver off (e.g., idle rx off) mode and / or synchronous reception mode. This indication may be a bit in the mode type-length-value (TLV) value set to indicate radio wake-up operation, or a bit in the mode type-length-value (TLV) value set to indicate that terminal device 304 operates in idle rx off mode, etc.

[0060] At 410, parent device 302 responds to the parent request message with an MLE parent response message that includes a CSL precision TLV. The CSL precision TLV includes an indication of the clock precision of parent device 302. For example, the CSL precision TLV includes a 16-bit CslAccuracy value in parts per million (ppm) of the clock used by parent device 302 for synchronous reception timing.

[0061] At 415, terminal device 304 uses the received CslAccuracy value to determine parameters for communicating with parent device 302 using synchronized reception. These parameters include the CSL synchronization timeout value. For example, terminal device 304 uses the CslAccuracy value and other information (such as the clock precision of terminal device 304, the maximum length of Media Access (MAC) layer Protocol Data Units (PDUs), etc.) to determine the CSL synchronization timeout value, which indicates when the parent device 302 transmitter and the terminal device 304 receiver will be considered out of sync. The CSL synchronization timeout value can be a 32-bit unsigned integer value in seconds.

[0062] At 420, terminal device 304 sends an MLE sub-ID request to parent device 302. This MLE sub-ID request includes parameters for establishing a parent-child relationship with parent device 302. The MLE sub-ID request may include CSL channel TLV and / or CSL synchronization timeout TLV indicating one or more channels used for CSL communication to establish synchronized reception at 425. Alternatively, if including the CSL channel TLV and / or CSL synchronization timeout TLV causes the MLE sub-ID request to exceed the maximum size of the MAC PDU (MPDU), terminal device 304 includes the CSL channel TLV and / or CSL synchronization timeout TLV in its MLE sub-update request message to parent device 302 to establish synchronized reception.

[0063] Alternatively, while establishing synchronous reception, terminal device 304 may still use indirect transmission (polling parent device 302). When receiving a data packet from parent device 302 indicating that additional data packets for terminal device 304 are queued on parent device 302, terminal device 304 may use indirect transmission to retrieve the queued data packets. Alternatively, terminal device 304 may instruct parent device 302 that it will enable its receiver when queued data exists, allowing parent device 302 to continue transmitting the queued data after terminal device 304 has successfully received the data packet.

[0064] Alternatively, terminal device 304 can establish a parent-child relationship without configuring synchronized reception with parent device 302. Later, terminal device 304 sends an MLE child update request to parent device 302, the request including a CSL channel TLV indicating the channel used for CSL communication and / or a CSL synchronization timeout TLV, to establish synchronized reception at 425.

[0065] Parent device 302 and terminal device 304 can communicate using synchronous reception, such as Figures 3A-3B As described above, after synchronization is established, and until the CSL synchronization timeout expires (indicating a synchronization error higher than the threshold for successful synchronization reception or an unknown synchronization error), the parent device 302 and the terminal device 304 determine whether the CSL timeout has expired at points 430 and 435, respectively. When the parent device 302 determines that the CSL timeout has expired, at point 440, the parent device 302 suspends the CSL transmission.

[0066] When terminal device 304 determines that the CSL timeout has expired, terminal device 304 determines at 445 whether to resume indirect transmission (polling parent device 302 for queued data packets addressed to terminal device 304) to receive data at 450 or to resynchronize with parent device 302. For example, as discussed, the application in terminal device 304 can determine whether synchronization reception should be re-established based on application status, sensor readings, etc.

[0067] To re-establish synchronized reception, terminal device 304 includes a CSL Information Element (IE) in its resynchronization message with parent device 302 at 455, which re-establishes synchronized reception at 460. For example, terminal device 304 includes the CSL IE in a mesh link re-establishment message or data packet to parent device 302 to resynchronize synchronized reception. Including the CSL IE in the message to parent device 302 resets the CSL timeout in both parent device 302 and terminal device 304. Although Figure 4The diagram illustrates resynchronization after the CSL timeout expires. However, terminal device 304 can send a CSL IE at any time when synchronization reception is established, which will resynchronize parent device 302 and terminal device 304 to continue operation using synchronization reception.

[0068] Example applications and use cases

[0069] In each aspect, one or more cloud-based services and various mesh network devices can participate in distributed applications or use cases. The requirements of each use case may require different levels of latency or availability for communication between mesh network devices or between cloud-based services and mesh network devices. The applications and use cases below are presented by way of example and not as limitation.

[0070] Cloud-based services and / or mesh network devices can determine patterns or states relevant to smart home or building automation applications on structures where mesh network devices are installed. For example, occupancy status for a structure can indicate whether the structure is occupied when an occupant leaves or is unoccupied. When a structure is occupied or transitions from unoccupied to occupied, it is desirable to use synchronous reception for various mesh network devices (such as thermostats and temperature sensors) to provide lower communication latency and faster response times for closed-loop HVAC control.

[0071] Mesh network devices can switch to synchronous reception based on alarm conditions. For example, a mesh network terminal device may receive an alarm condition indication from another mesh network device, receive an alarm condition indication forwarded by another mesh network device, or the mesh network terminal device itself may determine that an alarm condition exists, such as when sensor readings in the mesh network terminal device exceed a threshold. In response to an alarm condition, the terminal device can establish (or re-establish) synchronous reception to operate with lower communication latency, thus becoming more responsive when an alarm condition exists. When an alarm condition exists, the terminal device can establish (or re-establish) synchronous reception to suspend polling of data, which reduces potential interference and / or increases network availability and the capacity of other mesh network devices and services communicating in response to the alarm.

[0072] Mesh network devices can switch to synchronous reception to increase data reception throughput. For example, a mesh network endpoint device can establish (or re-establish) synchronous reception to increase network throughput for tasks greater than normal data downloads, such as receiving software updates. By using synchronous reception, throughput is increased while using less power than if the endpoint device used polling to retrieve software updates from the parent device. In yet another example, a mesh network endpoint device can periodically register queued data packets for cloud-based services. The mesh network endpoint device can establish (or re-establish) synchronous reception to increase network throughput for downloading queued data packets.

[0073] Mesh network devices can transition to synchronous reception based on scheduling. Scheduling can be used to indicate states or patterns associated with smart home or building automation applications on structures where mesh network devices are installed. Mesh network end devices can establish (or re-establish) synchronous reception based on scheduling of patterns or states. For example, the occupancy status of the structure (such as an office building) can be used to indicate occupancy periods (e.g., normal working hours). During occupancy periods, end devices can operate using synchronous reception to reduce communication latency, thereby becoming more responsive to input from users occupying offices.

[0074] Mesh network devices can use synchronized reception to increase mesh network capacity. Large numbers of mesh network devices can be deployed in commercial building automation systems, or homeowners can expand their smart home networks over time. As the mesh network grows in size, network traffic can increase interference and collisions, which can in turn affect the responsiveness experienced by users when interacting with mesh network devices and applications. For example, based on assessments of channel conditions, network statistics, the number of devices in the mesh network, configuration parameters, etc., end devices can establish (or re-establish) synchronized reception to reduce polling and response transmissions on the mesh network's operating channels, thereby increasing the overall capacity and availability of the mesh network.

[0075] Mesh network devices can have different communication latency requirements based on environmental conditions. For example, a solar-powered device, such as a solar-powered umbrella, can establish (or re-establish) synchronized reception to provide low-latency operation during sunny or hot weather conditions when the umbrella can draw energy from solar energy. When environmental conditions change (such as at night), and when there is no need for a fast response to user interaction, the umbrella can use indirect transmission operation with longer communication latency.

[0076] Mesh network devices can transition to synchronous reception based on interactions with other mesh network devices or one other mesh network device. For example, a mesh network device can receive interactions such as a user pressing a button, detecting motion or proximity, sensing contact closure, etc. In response to an interaction, the mesh network device can establish (or re-establish) synchronous reception to improve response time to commands that can be received in response to the interaction. In another example, another device, such as a camera, can capture images or video of the interaction, and based on the captured image, video, or subsequent facial or image recognition applied to the captured image or video, the mesh network device can establish (or re-establish) synchronous reception to improve responsiveness to the interaction or commands resulting from subsequent interactions or commands.

[0077] Example Method

[0078] refer to Figure 5 Example method 500 is described based on one or more aspects of synchronous reception in a mesh network. Generally, any component, module, method, and operation described herein can be implemented using software, firmware, hardware (e.g., fixed logic circuitry), manual processing, or any combination thereof. Some operations of the example method can be described in the general context of executable instructions stored on computer-readable storage memory local and / or remote on a computer processing system, and implementations may include software applications, programs, functions, etc. Alternatively or additionally, any functionality described herein may be implemented at least in part by one or more hardware logic components, such as, but not limited to, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip (SoCs), complex programmable logic devices (CPLDs), etc.

[0079] Figure 5 The illustration shows an example method 500 for synchronous reception in a mesh network, typically related to establishing synchronous reception between a parent device and a terminal device in a mesh network. The order in which the method boxes are described is not intended to be construed as limiting, and any number of the described method boxes can be combined or skipped in any order to implement the method or alternative methods.

[0080] At box 502, the terminal device (e.g., terminal device 304) transmits a parent request message (e.g., an MLE parent request message) to the parent device (e.g., parent device 302).

[0081] At box 504, in response to the parent request message, the terminal device receives a parent response (e.g., an MLE parent response message) from the parent device, which includes an indication of the parent device's clock precision (e.g., CSL precision TLV).

[0082] At box 506, the terminal device determines the parameters for synchronous reception of communication from the parent device based in part on an indication of the clock precision received from the parent device.

[0083] At box 508, the terminal device transmits a sub-request message (e.g., an MLE sub-ID request message or an MLE sub-update request message) that includes parameters for synchronous reception of communication from the parent device (e.g., CSL channel TLV and / or CSL synchronization timeout TLV), which causes the parent device to transmit communication to the terminal device based on the parameters.

[0084] At box 510, the terminal device determines whether the timer indicates that the CSL synchronization timeout has expired. If the CSL synchronization timeout has expired, the terminal device determines at box 512 whether to resynchronize the reception of communication with the parent device. If the terminal device determines to resynchronize the reception of communication with the parent device, the terminal device sends a resynchronization message to the parent device at box 514; otherwise, the terminal device reverts to indirect transmission at box 516 to receive queued data packets from the parent device.

[0085] Example environment and equipment

[0086] Figure 6 The illustrated example environment 600 can implement a mesh network 100 (see reference). Figure 1 (As described) and aspects of synchronous reception in the mesh network. Typically, environment 600 includes mesh network 100 implemented as part of a smart home or other type of structure having any number of mesh network devices configured to communicate in the mesh network. For example, mesh network devices may include thermostat 602, hazard detector 604 (e.g., for smoke and / or carbon monoxide), camera 606 (e.g., indoor and outdoor), lighting unit 608 (e.g., indoor and outdoor), and any other type of mesh network device 610 implemented inside and / or outside structure 612 (e.g., in a smart home environment). In this example, mesh network devices may also include any previously described devices, such as border router 202, and any devices implemented as router device 102 and / or terminal device 106.

[0087] In Environment 600, any number of mesh network devices can be implemented for wireless interconnection to communicate and interact with each other. Mesh network devices are modular, intelligent, multi-sensing, network-connected devices that can be seamlessly integrated with each other and / or with a central server or cloud computing system to provide a variety of useful smart home goals and implementation methods. Reference Figure 7 Examples of mesh network devices that can be implemented as any of the devices described herein are shown and described.

[0088] In an implementation, the thermostat 602 may include A learning thermostat detects ambient climate characteristics (e.g., temperature and / or humidity) and controls the HVAC system 614 in a smart home environment. The learning thermostat 602 and other smart devices "learn" by capturing settings set by the occupant of the device. For example, the thermostat learns preferred temperature setpoints in the morning and evening, when the occupant of the structure is asleep or awake, and when the occupant is typically away from home or at home.

[0089] Hazard detector 604 can be implemented to detect the presence of hazardous substances or substances that indicate hazardous substances (e.g., smoke, fire, or carbon monoxide). In a wirelessly interconnected example, hazard detector 604 can detect the presence of smoke, indicating a fire in the structure. In this case, the hazard detector that first detects the smoke can broadcast a low-power wake-up signal to all connected mesh network devices. Then, other hazard detectors 604 can receive the broadcast wake-up signal and initiate a high-power state for hazard detection and wireless communication to receive warning messages. Furthermore, lighting unit 608 can receive the broadcast wake-up signal and activate in the detected hazard area to illuminate and identify the problem area. In another example, lighting unit 608 can be activated with one lighting color to indicate a problem area or region in the structure, such as a detected fire or intrusion, and activated with different lighting colors to indicate safe areas and / or escape routes outside the structure.

[0090] In various configurations, the mesh network device 610 may include an entry interface device 616 that works in conjunction with a network-connected door lock system 618 and detects and responds to the approach or departure of a person from a location, such as the exterior door of structure 612. The entry interface device 616 may interact with other mesh network devices based on whether someone has approached or entered the smart home environment. The entry interface device 616 may control doorbell functionality, announce the approach or departure of a person via audio or visual means, and control settings on security systems, such as activating or deactivating the security system when an occupant enters or exits. The mesh network device 610 may also include other sensors and detectors, such as those for detecting ambient lighting conditions, detecting room occupancy (e.g., using occupancy sensor 620), and controlling the power and / or dimming status of one or more lights. In some cases, the sensors and / or detectors may also control the power status or speed of fans (such as ceiling fan 622). Furthermore, the sensors and / or detectors may detect occupancy in a room or perimeter and control the supply of power to a power outlet or device 624, such as if the room or structure is not occupied.

[0091] Mesh network device 610 may also include connected appliances and / or controlled systems 626, such as refrigerators, stoves and ovens, washing machines, dryers, air conditioners, pool heaters 628, irrigation systems 630, security systems 632, etc., as well as other electronic and computing devices, such as televisions, entertainment systems, computers, intercom systems, garage door openers 634, ceiling fans 622, control panels 636, etc. When plugged in, appliances, devices, or systems can advertise themselves to the mesh network as described above and can automatically integrate with the controls and devices of the mesh network, such as in a smart home. It should be noted that mesh network device 610 may include devices physically located outside the structure but within wireless communication range, such as devices controlling pool heaters 628 or irrigation systems 630.

[0092] As described above, mesh network 100 includes a border router 202 for communicating with external networks outside mesh network 100. Border router 202 is connected to access point 204, which is connected to a communication network 206, such as the Internet. Cloud service 208, connected via communication network 206, provides services related to and / or use of devices within mesh network 100. By way of example, cloud service 208 may include applications for connecting end-user devices 638, such as smartphones, tablets, etc., to devices in the mesh network; processing data acquired in mesh network 100 and presenting it to end users; linking one or more devices in mesh network 100 to user accounts in cloud service 208; provisioning and updating devices in mesh network 100; and so on. For example, a user can use a network-connected computer or portable device (such as a mobile phone or tablet) to control thermostat 602 and other mesh network devices in a smart home environment. Furthermore, mesh network devices can transmit information to any central server or cloud computing system via border router 202 and access point 204. Data communication can be performed using a variety of custom or standard wireless protocols (e.g., Wi-Fi, low-power ZigBee, 6LoWPAN, Thread, etc.) and / or any of a variety of custom or standard wired protocols (CAT6 Ethernet, HomePlug, etc.).

[0093] Any mesh networking device in mesh network 100 can be used as a low-power communication node to create mesh network 100 in a smart home environment. Individual low-power nodes in the network can periodically emit messages about what they are sensing, and other low-power nodes in the environment—in addition to emitting their own messages—can repeat these messages, thus transmitting messages from node to node (e.g., from device to device) throughout the mesh network. Mesh networking devices can be implemented to save power, particularly when battery powered, utilize low-power communication protocols to receive messages, convert messages to other communication protocols, and send the converted messages to other nodes and / or a central server or cloud computing system. For example, occupancy and / or ambient light sensors can detect occupants in a room and measure ambient light, activating the light source when ambient light sensor 640 detects darkness in the room and when occupancy sensor 620 detects someone in the room. Furthermore, sensors can include low-power wireless communication chips (e.g., ZigBee chips) that periodically emit messages about room occupancy and the amount of light in the room, including immediate messages consistent with the occupancy sensor detecting the presence of a person in the room. As mentioned above, these messages can be wirelessly transmitted from node to node (i.e., from smart device to smart device) in a smart home environment using a mesh network, as well as transmitted over the Internet to a central server or cloud computing system.

[0094] In other configurations, a variety of mesh network devices can be used as "tripwires" for alarm systems in smart home environments. For example, an alarm can still be triggered by receiving occupancy, movement, heat, sound, or other messages from one or more low-power mesh nodes in the mesh network, even if a criminal evades detection through alarm sensors located at windows, doors, and other entry points in the structure or environment. In other implementations, the mesh network can be used to automatically turn lighting unit 608 on and off as a person moves from one room to another within the structure. For example, mesh network devices can detect movement of people through the structure and transmit corresponding messages via the nodes of the mesh network. Using a message indicating which room is occupied, other mesh network devices receiving the message can be activated and / or deactivated accordingly. As cited above, in emergency situations, the mesh network can also be used to provide exit lighting, such as by activating appropriate lighting unit 608 leading to a safe exit. Lighting unit 608 can also be activated to indicate the direction along the exit route a person should take to safely leave the structure.

[0095] Various mesh network devices can also be implemented to integrate with and communicate with the wearable computing device 642, such as being used to identify and locate occupants of the structure and adjust temperature, lighting, sound systems, etc. accordingly. In other implementations, RFID sensing (e.g., a person with an RFID bracelet, necklace, or keychain), synthetic vision technology (e.g., a camera and facial recognition processor), audio technology (e.g., sound, sound pattern, vibration pattern recognition), ultrasonic sensing / imaging technology, and infrared or near-field communication (NFC) technology (e.g., a person wearing an infrared or NFC-enabled smartphone), along with rule-based inference engines or artificial intelligence technology, can derive useful conclusions about the location of an occupant in the structure or environment from the sensed information.

[0096] In other implementations, the performance of personal comfort zone networks, personal health zone networks, personal safety zone networks, and / or other human-oriented functionalities of service robots can be enhanced through logical integration with other mesh network devices and sensors in the environment, based on rule-based inference techniques or artificial intelligence techniques. In an example related to personal health zones, the system could detect, along with rule-based inference and artificial intelligence techniques, whether a household pet is moving toward the occupant's current location (e.g., using any mesh network devices and sensors). Similarly, based on the inference that any small increase in ambient smoke levels is most likely due to cooking activity rather than a genuine hazardous condition, a hazard detector service robot can be notified that the temperature and humidity in the kitchen are rising, and a hazard detection threshold, such as a smoke detection threshold, can be temporarily raised. Any service robot configured for any type of monitoring, detection, and / or service can be implemented as a mesh node device on a mesh network, conforming to wireless interconnection protocols used for communication on a mesh network.

[0097] The mesh network device 610 may also include a smart alarm clock 644 for each individual occupant in a smart home environment. For example, an occupant can customize and set an alarm device for their wake-up time (such as the next day or week). When an alarm sounds, artificial intelligence can be used to consider the occupant's response to the alarm and infer preferred sleep patterns over time. Individual occupants can then be tracked in the mesh network based on a person's unique signature, determined based on data obtained from sensors located in the mesh network device, such as sensors including ultrasonic sensors, passive IR sensors, etc. The occupant's unique signature can be based on a combination of patterns such as movement, voice, height, size, etc., and can also utilize facial recognition technology.

[0098] In a wirelessly interconnected example, an individual's wake-up time can be correlated with thermostat 602 to effectively control the HVAC system, preheating or cooling the structure to the desired sleep and wake-up temperature settings. Preferred settings can be learned over time, such as by capturing the temperature set in the thermostat before a person falls asleep and upon waking. The collected data may also include biometric indicators of the person, such as breathing patterns, heart rate, movement, etc., which can be inferred based on this data combined with data indicating when the person actually wakes up. Other mesh network devices can use this data to provide other smart home objectives, such as adjusting thermostat 602 to preheat or cool the environment to a desired setting, and turning lights 608 on or off.

[0099] In implementations, mesh network devices can also be used for sound, vibration, and / or motion sensing, such as detecting tap water and determining inferences about water use in a smart home environment using algorithms and mappings based on water use and consumption. This can be used to determine a signature or fingerprint of each water source in the home, also known as “audio fingerprint water use.” Similarly, mesh network devices can be used to detect subtle sounds, vibrations, and / or movements of unwanted pests such as mice and other rodents, as well as termites, cockroaches, and other insects. The system can then notify occupants of suspected pests in the environment, such as through warning messages, to help facilitate early detection and prevention.

[0100] Environment 600 may include one or more mesh network devices 102 used as hubs 646. Hub 646 may be a general-purpose home automation hub or a specialized hub, such as a security hub, energy management hub, HVAC hub, etc. The functionality of hub 646 can also be integrated into any mesh network device 102, such as a smart thermostat device or border router 202. The managed functionality on hub 646 in structure 612 can improve reliability when a user's internet connection is unreliable, can reduce the latency of operations typically associated with connecting to cloud service 208, and can meet system and regulatory constraints regarding local access between mesh network devices 102.

[0101] Additionally, example environment 600 includes a smart speaker 648. The smart speaker 648 provides a voice assistant service, including voice control of smart home devices. The functionality of hub 646 can be hosted within the smart speaker 648. The smart speaker 648 can be configured to communicate via mesh networking, Wi-Fi, or both.

[0102] Figure 7This is a block diagram illustrating an example mesh network device 700, which can be implemented as any mesh network device in a mesh network for synchronous reception of one or more aspects according to the mesh network described herein. Device 700 can be integrated with electronic circuitry, microprocessors, memory, input / output (I / O) logic control, communication interfaces and components, and other hardware, firmware, and / or software to implement a device in a mesh network. Furthermore, mesh network device 700 can be implemented with various components, such as any number and combination of different components, as shown in the references... Figure 8 The example device shown is further described.

[0103] In this example, the mesh network device 700 includes a low-power microprocessor 702 and a high-power microprocessor 704 (e.g., a microcontroller or digital signal processor) that process executable instructions. The device also includes input-output (I / O) logic control 706 (e.g., including electronic circuitry). The microprocessor can include components of integrated circuits, programmable logic devices, logic devices formed using one or more semiconductors, and other implementations in silicon and / or hardware, such as processors and memory systems implemented as a system-on-a-chip (SoC). Alternatively or additionally, the device can be implemented using any or a combination of software, hardware, firmware, or fixed logic circuitry that can be implemented by processing and control circuitry. The low-power microprocessor 702 and the high-power microprocessor 704 can also support one or more different device functionalities. For example, the high-power microprocessor 704 can perform computationally intensive operations, while the low-power microprocessor 702 can manage less complex processes, such as detecting hazards or temperature from one or more sensors 708. The low-power processor 702 can also wake up or initialize the high-power processor 704 for computationally intensive processing.

[0104] One or more sensors 708 can be implemented to detect various characteristics, such as acceleration, temperature, humidity, water, supplied power, proximity, external motion, device motion, sound signals, ultrasonic signals, light signals, fire, smoke, carbon monoxide, satellite global positioning (GPS) signals, radio frequency (RF) signals, or other electromagnetic signals or fields. Thus, sensor 708 can include any one or a combination of the following: temperature sensors, humidity sensors, hazard-related sensors, other environmental sensors, accelerometers, microphones, and optical sensors up to and including cameras (e.g., electrically coupled devices or cameras), active or passive radiation sensors, GPS receivers, and RFID detectors. In embodiments, mesh network device 700 can include one or more primary sensors and one or more secondary sensors, such as primary sensors that sense data from the core operating center of the device (e.g., sensing temperature in a thermostat or smoke in a smoke detector), while secondary sensors can sense other types of data (e.g., motion, light, or sound), which can be used for energy-saving or smart operation goals.

[0105] Mesh network device 700 includes a memory device controller 710 and a memory device 712, such as any type of non-volatile memory and / or other suitable electronic data storage devices. Mesh network device 700 can also include various firmware and / or software, such as an operating system 714, which is stored in memory as computer-executable instructions and executed by a microprocessor. The device software may also include a receiver manager application 716 that implements various aspects of synchronous reception in the mesh network. Mesh network device 700 also includes a device interface 718 for interfacing with another device or peripheral component and includes an integrated data bus 720 that couples various components of the mesh network device for data communication between components. The data bus in the mesh network device can also be implemented as any or a combination of different bus structures and / or bus architectures.

[0106] Device interface 718 can receive input from and / or provide information to a user (e.g., as a user interface), and the received input can be used to determine settings. Device interface 718 may also include mechanical or virtual components responsive to user input. For example, a user can mechanically move a sliding or rotatable component, or can detect movement along a touchpad, and such movement can correspond to adjustments in device settings. Physical and virtual movable user interface components can allow a user to make settings along a portion of an apparent continuum. Device interface 718 can also receive input from any number of peripheral devices such as buttons, keyboards, switches, microphones, and imaging devices (e.g., camera devices).

[0107] The mesh network device 700 may include: a network interface 722, such as a mesh network interface for communicating with other mesh network devices in the mesh network; and an external network interface for network communication such as via the Internet. The mesh network device 700 also includes a wireless radio system 724 for wirelessly communicating with other mesh network devices via the mesh network interface and for use with multiple different wireless communication systems. The wireless radio system 724 may include Wi-Fi, Bluetooth, etc. TM Mobile broadband, BLE, and / or point-to-point IEEE 802.15.4. Each of the different radio systems can include radio equipment, antennas, and chipsets implemented for a specific wireless communication technology. The mesh network device 700 also includes a power source 726, such as a battery, and / or a means of connecting the device to a line voltage. AC power can also be used to charge the device's battery.

[0108] Figure 8 The illustration includes an example system 800 with example device 802, which can be implemented as described above. Figures 1 to 7 Any mesh network device that synchronously receives information in the described mesh network. Example device 802 can be any type of computing device, client device, mobile phone, tablet, communication, entertainment, gaming, media playback, and / or other type of device. Furthermore, example device 802 can be implemented as any other type of mesh network device configured for communication on a mesh network, such as a thermostat, hazard detector, camera, lighting unit, debugging device, router, border router, connection router, connection device, terminal device, boot segment, access point, hub, and / or other mesh network device.

[0109] Device 802 includes a communication device 804 that enables wired and / or wireless communication of device data 806, such as data communicated between devices in a mesh network, data being received, data scheduled for broadcast, data packets, data synchronized between devices, etc. Device data can include any type of communication data, as well as audio, video, and / or image data generated by applications running on the device. Communication device 804 may also include transceivers for cellular telephone communication and / or for network data communication.

[0110] Device 802 also includes an input / output (I / O) interface 808, such as a data network interface that provides connections and / or communication links between the device, data networks (e.g., mesh networks, external networks, etc.), and other devices. The I / O interface can be used to couple the device to any type of component, peripheral device, and / or accessory device. The I / O interface also includes a data input port through which any type of data, media content, and / or input can be received, such as user input to the device and any type of communication data, as well as audio, video, and / or image data received from any content and / or data source.

[0111] Device 802 includes a processing system 810, which can be implemented at least partially in hardware, such as utilizing any type of microprocessor or controller that processes executable instructions. The processing system can include components of integrated circuits, programmable logic devices, logic devices formed using one or more semiconductors, and other implementations in silicon and / or hardware (such as processors and memory systems implemented as system-on-a-chip (SoC)). Alternatively or additionally, the device can be implemented using any or a combination of software, hardware, firmware, or fixed logic circuitry that can be implemented using processing and control circuitry. Device 802 may further include any type of system bus or other data and command transmission system coupling various components within the device. The system bus can include any or a combination of different bus structures and architectures, as well as control and data lines.

[0112] Device 802 also includes computer-readable storage memory 812, such as a data storage device capable of being accessed by a computing device and providing persistent storage for data and executable instructions (e.g., software applications, modules, programs, functions, etc.). The computer-readable storage memory described herein does not include propagating signals. Examples of computer-readable storage memory include volatile and non-volatile memory, fixed media devices and removable media devices, and any suitable storage device or electronic data storage device that holds data for access by a computing device. Computer-readable storage memory can include various implementations of random access memory (RAM), read-only memory (ROM), flash memory, and other types of storage memory in various storage device configurations.

[0113] Computer-readable storage memory 812 provides storage for device data 806 and various device applications 814, such as an operating system stored in computer-readable storage memory as a software application and executed by processing system 810. Device applications may also include device managers, such as any form of control application, software application, signal processing and control modules, device-specific code, and device-specific hardware abstraction layers. In this example, the device applications also include a receiver manager application 816 that implements various aspects of synchronous reception in a mesh network, such as when example device 802 is implemented as any mesh network device described herein.

[0114] Device 802 also includes an audio and / or video system 818 that generates audio data for audio device 820 and / or display data for display device 822. The audio and / or display devices include any devices that process, display, and / or otherwise render audio, video, display, and / or image data, such as image content from digital photographs. In this embodiment, the audio and / or display devices are integrated components of example device 802. Alternatively, the audio and / or display devices may be external, peripheral components of the example device. In various aspects, at least a portion of the techniques described for synchronous reception in a mesh network can be implemented in a distributed system, such as on a “cloud” 824 on platform 826. Cloud 824 includes and / or represents platform 826 for services 828 and / or resources 830.

[0115] Platform 826 abstracts the underlying functionality of hardware such as server devices (e.g., included in service 828) and / or software resources (e.g., included as resource 830), and connects example device 802 to other devices, servers, etc. Resource 830 may also include applications and / or data that can be utilized while performing computer processing on a server remote from example device 802. Additionally, service 828 and / or resource 830 can facilitate subscriber network services, such as via the Internet, cellular networks, or Wi-Fi networks. Platform 826 can also be used to abstract and scale resources to serve the demand for resource 830 implemented via the platform, such as in interconnected devices with functionality distributed throughout system 800. For example, this functionality may be partially implemented at example device 802 and via platform 826, which abstracts the functionality of cloud 824.

[0116] Although aspects of synchronization reception in a mesh network have been described in feature- and / or method-specific language, the subject matter of the appended claims is not necessarily limited to the specific features or methods described. Rather, specific features and methods are disclosed as exemplary embodiments of synchronization reception in a mesh network, and other equivalent features and methods are intended to be within the scope of the appended claims. Furthermore, various different aspects have been described, and it should be understood that each described aspect can be implemented independently or in combination with one or more other described aspects.

Claims

1. A method for receiving synchronous communication by a parent device using a terminal device operating in an idle receiver-off mode in a wireless mesh network, the method comprising: The parent device receives the parent request message from the terminal device; In response to receiving the parent request message, a parent response message is transmitted including a clock precision indication of the parent device, the indication effectively enabling the terminal device to determine parameters for synchronous reception of communication from the parent device, wherein the parameters for synchronous reception include a synchronization timeout value calculated by the terminal device; The parent device receives a sub-request message, the sub-request message including the parameters for synchronous reception of communication from the parent device; In response to receiving the sub-request message, communication is transmitted to the terminal device based on the parameters; and Based on the expiration of the timer for the synchronization timeout value, it is determined to suspend the transmission of the communication to the terminal device.

2. The method according to claim 1, further comprising: The terminal device receives a resynchronization message, which effectively resynchronizes the reception of communications from the parent device. as well as In response to receiving the resynchronization message, synchronization communication is transmitted to the terminal device.

3. The method according to claim 2, further comprising: In response to receiving the resynchronization message, the timer for the synchronization timeout value is reset.

4. The method according to claim 1, further comprising: The terminal device periodically receives polling messages that cause the parent device to transmit data to the terminal device.

5. The method according to claim 1, wherein, The transmission of communication to the terminal device occurs during the time window in which the terminal device activates its receiver to receive the communication.

6. The method of claim 1, further comprising: The data packets include an indication of queuing additional data packets for the terminal device at the parent device; as well as The data packets are transmitted to the terminal device, and the transmission effectively keeps the terminal device's receiver active to receive the additional data packets.

7. The method of claim 6, further comprising: The additional data packets are transmitted to the terminal device.

8. The method according to claim 1, wherein, The parameters for synchronous reception of communication from the parent device include: an indication of the channel for synchronous communication between the parent device and the terminal device, an indication of the longest time the terminal device will remain synchronized with the parent device, or both.

9. The method according to claim 1, wherein, The parent request message is the Mesh Link Establishment (MLE) parent request message.

10. A mesh network device configured as a parent device, the mesh network device comprising: A mesh network interface configured for communication within a mesh network; as well as A memory and processor system, wherein the memory and processor system are configured to implement a receiver manager application, the receiver manager application being configured to: Receive the parent request message from the terminal device; In response to receiving the parent request message, a parent response message is transmitted including a clock precision indication of the parent device, the indication effectively enabling the terminal device to determine parameters for synchronous reception of communication from the parent device, wherein the parameters for synchronous reception include a synchronization timeout value calculated by the terminal device. Receive a sub-request message, the sub-request message including the parameters for synchronous reception of communication from the parent device; In response to receiving the sub-request message, communication is transmitted to the terminal device based on the parameters; and Based on the expiration of the timer for the synchronization timeout value, it is determined to suspend the transmission of the communication to the terminal device.

11. The mesh network device according to claim 10, wherein, The receiver manager application is further configured to: Receive a resynchronization message from the terminal device, the resynchronization message effectively resynchronizing the reception of communication from the parent device; and In response to receiving the resynchronization message, synchronization communication is transmitted to the terminal device.

12. The mesh network device according to claim 11, wherein, The receiver manager application is further configured to: In response to receiving the resynchronization message, the timer for the synchronization timeout value is reset.

13. The mesh network device according to claim 10, wherein, The receiver manager application is further configured to: The terminal device periodically receives polling messages that cause the parent device to transmit data to the terminal device.

14. The mesh network device according to claim 10, wherein, The transmission of the communication to the terminal device occurs during the time window in which the terminal device activates its receiver to receive the communication.

15. The mesh network device according to claim 10, wherein, The receiver manager application is further configured to: The data packet includes an indication of queuing additional data packets for the terminal device at the parent device; and The data packets are transmitted to the terminal device, and the transmission effectively keeps the terminal device's receiver active to receive the additional data packets.

16. The mesh network device according to claim 15, wherein, The receiver manager application is further configured to: The additional data packets are transmitted to the terminal device.

17. The mesh network device according to claim 10, wherein, The parameters for synchronous reception of communication from the parent device include: an indication of the channel for synchronous communication between the parent device and the terminal device, an indication of the longest time the terminal device will remain synchronized with the parent device, or both.

18. The mesh network device according to claim 10, wherein, The parent request message is the Mesh Link Establishment (MLE) parent request message.

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